United States Office of Research and EPA/600/R-94/038b
Environmental Protection Development April 1994
Agency Washington, DC 20460
&EPA Quality Assurance
Handbook for
Air Pollution
Measurement
Systems
Volume II: Ambient Air
Specific Methods
(Interim Edition)
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EPA-600/R-94/0385
QUALITY ASSURANCE HANDBOOK
FOR
AIR POLLUTION MEASUREMENT SYSTEMS
Volume II ~ Ambient Air Specific Methods
(Interim Edition)
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH and DEVELOPMENT
ATMOSPHERIC RESEARCH and ENVIRONMENTAL ASSESSMENT LABORATORY
RESEARCH TRIANGLE PARK, NORTH CAROLINA 27711
•;X A'.' Printed on Recycled Paper
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OVERVIEW OF THE INTERIM EDITION OF VOLUME II
The Quality Assurance (QA) Handbook is comprised of five
volumes: Volume I (Principles), Volume II (Ambient Air Methods),
Volume III (Stationary Source Methods), Volume IV (Meteorological
Measurement's), and Volume V (Precipitation Measurement Systems) .
Much of the material in Volumes II, III and V are out-of-date and
some portions of these volumes have long been out-of-print.
EPA is now preparing an updated version of the QA Handbook
series which will be available in September 1995. To meet the
needs of the user community until the updated version is
available, EPA has published Interim Editions of Volumes I', II,
III, IV and V. Each volume of the Interim Editions, is being
issued as a complete unit with out-of-date sections either
deleted or modified using addendum sheets and handwritten
notations in the text.
This volume and the-other four volumes of the Interim
Edition of the QA Handbook are available at no charge from-
USEPA/ORD
Center for Environmental Research Information
26 West Martin Luther King Drive
Cincinnati, Ohio .45268
For the reasons given below the following six sections
published in the original edition of Volume II were excluded from
this'edition of the handbook. . • " .
Section 2.0.7 (Protocol 2 Gases) was combined'with Section
3.0.4 of Volume III (Protocol 1 Gases) and published as a
separate document entitled "EPA Traceability Protocol for Assay
and Certification of Gaseous Calibration Standards (Revised
September 1993)," EPA 600/R93/224). This document provides
guidance to those who prepare and sell gaseous pollutant
standards traceable to the National Institute of Standards' and
Technology (NIST).
Section 2.0.8 (Calculating Precision and Accuracy for SLAM
and PSD Analyzers) was deleted because it has been supplanted by
guidance available in Part 58 of Title 40 of the Code of Federal
Regulations (40 CFR 58, Appendix A). Section 2,1.(SO2 by ' -
Pararosaniline) and Section 2.4 (NO2 by Sodium Arsenite) were
deleted because these methods are no longer used in the United
States (U.S.). Section 2.5 (SO2 by Flame Photometry) and
Section 2.7 (O3 by chemiluminescence) were deleted because they
are used by less than 1 percent of the U.S. organizations
measuring air pollution.
These six deleted sections can be obtained by writing to-
QA Handbook Coordinator
US EPA/ORD/AREAL/MD 77B
Research Triangle Park, NC 27711
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Many of the EPA contacts and organizational units identified
in Volume II are no longer correct and some of the reference
materials and procedures cited have been discontinued or
replaced. This type of put-of-date information is widely
dispersed throughout Volume II. Rather than change every
affected section, for clarity and neatness sake, we have provided
below a listing of the original information and the corresponding
updated information.
1) NBS is now the National Institute of Standards and
Technology (NIST)1
2) EMSL is ,now the Atmospheric Research and Exposure
Assessment Laboratory (AREAL). •
3) QAD is now the Quality Assurance and Technical Support
Division (QATSD/AREAL).
4) CRM is now NIST Traceable Reference Material (NTRM).
5) SAROAD is now the Aerometrie Information Retrieval
System (AIRS).
6). The National Aerometrie Data Bank (NADP) and the SLAMS
Precision and Accuracy Reporting System (PARS) are now included
in AIRS.
7) The TSP (total suspended particulate matter) standard
has now been replaced with a standard based on particle size (PM-
10) .
8) Correspondingly the TSP sample (hi vol) has been
replaced with size selective (PM-10) particle samplers.
9) The address to obtain the most .recent "List of EPA
Designated Reference and Equivalent Methods" is now:
US EPA/ORD/AREAL/MRDD/MD-77
Research Triangle Park, NC 27711
10) Due to the current widespread use of data loggers
references made to chart recorders should also be considered to
include data loggers.
In the updated version of Volume II, which wil-1 be available
in September 1995, these changes will be included in the text.
Sections on QA for organic compound measurement systems, for O3
by UV and for automated PM-10 samplers will be added and a new
page numbering system will be used.
• Finally, the user of the' QA Handbook is cautioned to bear in
mind that the information provided in the handbook is"for
guidance purposes only. EPA regulations are published in the
Code of Federal Regulations (CFR). When information in the CFR
conflicts with information in the QA Handbook, the CFR shall be
considered the authoritative and legally bonding document.
William J. Mitchell
Chief
Quality Assurance Support Branch
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Volume II
(Interim Edition)
Table of Contents
Overview of the Interim Edition of Volume II
2.0 General Aspects of Quality Assurance for
Ambient Air Monitoring Systems
2.0.1 Sampling Network Design and Site Selection
2.0.2 Sampling Considerations
2.0.3 Data Handling and Reporting
2.0.4 Reference and Equivalent Methods
2.0.5 Recommended Quality Assurance Program
for Ambient Air Measurements
2.0.6 Chain-of-Custody Procedures for Ambient
Air Samples
2.0.7—Traccability Protocol for Establishing True
. Concentrations of Gases
Uocd for Calibration and Auditn of Air
Pollution Analyzers (Protocol No. 2)
2.0.8—Calculationo to Aosooo Monitoring Data for
Prccioion ond Accuracy for SLAMS ond PSD
Automated Analyzers and Monuol Mcthoda
2.0.9 Specific Guidance for a Quality Control
Program for SLAMS and PSD Automated
Analyzers and Manual Methods
2.0.10 USEPA National Performance Audit Program
2.0.11 System Audit Criteria and Procedures for
Ambient Air Monitoring Programs
2.0.12 Audit Procedures for Use by State and Local
Air Monitoring Agencies
Reference! Method for the Determination of
Sulfur Dioxide in the Atmoophcrc
(Pororosonilinc Method)
2.2 Reference Method for the Determination of
Suspended Particulates in the Atmosphere
(High-Volume Method)
2.2.1 Procurement of Equipment and Supplies
2.2.2 Calibration of Equipment
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2.2.3 Filter Selection and Preparation
2.2.4 Sampling Procedure
2.2.5 Analysis of Samples
2.2.6 Calculations and Data Reporting
2.2.7 Maintenance
2.2.8 Auditing Procedure
2.2.9 Assessment of Monitoring Data for Precision
and Accuracy
2.2.10 Recommended Standards for Establishing
Traceability
2.2.11 Reference Method
• 2.2.12 Rcfcrcncca
2.3.13 Data forma
2.3 Reference Method for the Determination of
Nitrogen Dioxide in the Atmosphere
(Chemiluminescence)
2.3.1 Procurement of Apparatus and Supplies
2.3.2 Calibration of Equipment
2.3.3 Operation and Procedure
2.3.4 Data Reduction, Validation and Reporting
2.3.5 Maintenance
2.3.6 Auditing Procedure
2.3.7 Assessment of Monitoring Data for Precision
and Accuracy
2.3.8 Recommended Standards for Establishing
Traceability
2.3.0—Reference Method
2.3.10 References
2.3.11 Data forma
3r4 Equivalent Method for the Determination of
Nitrogen Dioxide in the Atmosphere
(Sodium Arocnitc)
Equivalent Method for the Determination of
Sulfur Dioxide in the Atmosphere (Flame
Photometric Detector)
2.6 Reference Method for the Determination of
Carbon Monoxide in the Atmosphere
(Non-Dispersive Infrared Spectrometry)
2.6.1 Procurement of Equipment and Supplies
2.6.2 Calibration of Equipment
2.6.3 Operation and Procedure
2.6.4 Data Reduction, Validation and Reporting
2.6.5 Maintenance
2.6.6 Auditing Procedure
2.6.7 Assessment of Monitoring Data for Precision
and Accuracy
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2.6.8 Recommended Standards for Establishing
Traceability
2r7 Reference Method for the Determination of
Ozone in the Atmosphere (Chcmilumincoccncc)
2.8 Reference Method for the Determination of
Lead in Suspended Particulate Matter
Collected from Ambient Air (Atomic
Absorption Spectrometry)
2.8.1 Procurement of Equipment and Supplies
2.8.2 Calibration of Equipment
2.8.3 Filter Selection'and Procedure
2.8.4 Sampling Procedure
2.8.5 Analysis of Samples
2.8.6 Calculations and Data Reporting
2.8.7 Maintenance
2.8.8 Auditing Procedure
2.8.9 Assessment of Monitoring Data for Precision
and Accuracy
2.8.10 Recommended Standards for Establishing
Traceability
2.9 Reference Method for the Determination of
Sulfur Dioxide in the Atmosphere'
(Fluorescence)
2.9.1 Procurement of Apparatus and Supplies
2.9.2 Calibration of Equipment
2.9.3 Operation and Procedure
2.9.4 Data Reduction. Validation and Reporting
2.9.5 Maintenance
2.9.6 Auditing Procedure
2.9.7 Assessment of Monitoring Data for Precision
and Accuracy
2.9.8 Recommended Standards for Establishing
Traceability
2.10 Reference Method for the Determination of Particulate
Matter as PM10 in the Atmosphere (Dichotomous
Sampler Method)
2.10.1 Procurement of Equipment and Supplies
2.10.2 Calibration Procedures
2.10.3 Field Operations
2.10.4 Filter Preparation and Analysis
2.10.5 Calculations, Validations, and Reporting of PM10 Data
2.10.6 Maintenance
2.10.7 Auditing Procedures
2.10.8 Assessment of Monitoring Data for Precision and Accuracy
2.10.9 Recommended Standards for Establishing Traceability
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2.11 Reference Method for the Determination of Particulate
Matter as PM10 in the Atmosphere ( High-Volume PM10
Method)
2.11.1 Procurement of Equipment and Supplies
2.11.2 Calibration Procedures
2.11.3 Field Operations
2.11.4 Filter Preparation and Analysis
2.11.5 Calculations, Validations, and Reporting of PM10 Data
2.11.6 Maintenance
2.11.7 Auditing Procedures
2.11.8 Assessment of Monitoring Data for Precision and Accuracy
2.11.9 Recommended Standards for Establishing Traceability
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Addendum to Section 2.0.1
Sampling Network Design and Site Selection
The following information should be added to Table 1.2.
Pollutant Spatial Scale Characteristics
PM
10
Micro
Middle
Areas such as downtown street
canyons and traffic corridors;
generally not extending more
than 15 meters from the roadway
but could continue the length of
the roadway.
Used to evaluate possible short-
term public health effects of
particulate matter pollution;
includes areas such as shopping
center parking lots and feeder
streets. .
Pb
Neighborhood
Micro
Middle
Homogeneous urban subregion;
dimensions of a few kilometers.
Areas such as downtown street
canyons and traffic corridors, and
areas extending up to
approximately 100 meters that
are impacted by plumes of
stationary sources.
Areas up to several city blocks
with dimensions on the order of
100 to 500 meters; areas may
include schools and playgrounds
in center city areas that are close
to major roadways.
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Pollutant Spatial Scale Characteristics
Neighborhood Homogeneous land use areas
where children live and play;
dimensions of 0.5 to 4
kilometers.
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Section No. 2.0.1
Revision No. 1
Date July 1, 1979
Page 1 of 23
1.0 SAMPLING NETWORK DESIGN AND SITE SELECTION
Air quality samples are generally collected for one or more
of the following purposes: . '
. 1. To judge compliance -with and/or progress made toward
meeting ambient air quality standards.
2. To activate emergency control procedures that prevent
or alleviate air pollution episodes.
3. To observe pollution trends throughout a region,
including nonurban areas.
4. To provide a -data base for research evaluation of
effects; urban, land-use, and transportation planning; develop-
ment and evaluation of abatement strategies; and development
and validation of diffusion models.
With the end use of the air quality samples as a prime con-
sideration, determination of one or more of the following must be
basic objective(s) of the monitoring network:
1. The highest concentrations expected in the area covered
by the network.
2. The representative concentrations in areas of high
population density.
3. The impact of significant sources or source categories
on ambient pollution levels.
4. The general background concentration levels.
These four objectives indicate the nature of the samples that
the monitoring network will collect and that must be representa-
tive of the spatial area being studied.
1-1 Monitoring Objectives and Spatial Scales
The goal in siting monitors is to match the spatial scale
represented by the sample of monitored air with the spatial scale
most appropriate for the stations monitoring objective .(see
Tables 1.1 and 1.2). The representative measurement scales 'of
most interest for the previously stated monitoring objectives are
defined as follows:
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Section No. 2.0.1
Revision No. 1
Date July 1, 1979
Page 2 of 23
Table 1.1 RELATIONSHIPS AMONG MONITORING OBJECTIVES
AND SCALES OF REPRESENTATIVENESS
Monitoring objective
Highest concentration
Population
Source
General/background
Appropriate siting scales
Middle, neighborhood (sometimes
urban) } M
Neighborhood j
Middle, neighborhood fi/cfLo
Neighborhood, regional
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Section No^ 2.0.1
Revision No. 1
Date July 1, 1979
Page 3 of 23
Table 1.2
CHARACTERISITICS OF SPATIAL SCALES RELATED
TO EACH POLLUTANT
Pollutant
Spatial scale
Characteristics
P1-.C
Middle
Neighborhood
Regional
Dimensions of a few hundred
meters; e.g., parking lots
shopping centers, stadiums,
office buildings
Homogeneous urban subregion;
dimensions of a few kilom-
eters; e.g., industrial,
commercial, and residential
areas
Dimensions of hundreds of
kilometers; sparsely populated
areas with uniform surface
dust entrainment
SO,
Middle
Neighborhood
Regional
Effects of control strategies
to reduce urban concentrations
and monitoring air pollution
episodes assessed
Suburban areas surrounding
urban center or large sections
of small cities and towns;
may be associated with base-
line concentrations in areas
of projected growth
Information on background
air quality and interregional
pollutant transport
CO
Middle
Dimensions of tens of meters
to hundreds of meters; e.g.,,
freeway corridor or block of
street development or indirect'
sources (shopping centers,
stadiums, and office build-
ings.)
(continued)
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Section No. 2.0.1
Revision No. 1
Date July 1, 1979
Page 4 of 23
Table 1.2 (continued)
Pollutant
°3 '
NO,
Spatial scale
Neighborhood
Neighborhood
Urban
Regional
Middle
Neighborhood
Urban
Characteristics
Homogeneous urban subregion;
dimensions of a few kilometers
Information on health effect;
information on developing, •
testing and revising concepts
and models that describe
urban/regional concentration
patterns
Large portions of an urban
area; dimensions of several
kilometers to >_50; used to
determine trends
Large portions of metropol-
itan area; dimensions as much
•as hundreds of kilometers;
used to assess transport into
urban area
Dimensions of hundreds of
meters to 0.5 km; character-
izes public exposure.in popu-
lated areas
Same as for O3
Same as for O0
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Section No. 2.0.1
Revision No. 1
Date July 1, 1979
Page 5 of 23
1. Microscale - concentrations in air volumes with dimen-
sions ranging from a few meters to about '100 m.
2. Middle scale - concentrations typical of areas up to
several city blocks with dimensions ranging from about 100 m to
0.5 km.
3. Neighborhood scale - concentrations within an extended
area of the city- that has relatively uniform land uses with
dimensions ranging from 0.5 to 4 km.
4. Urban scale - overall citywide concentrations with
dimensions of about 4 to 50 km; this scale usually requires more
than one site for definition. - •-
5. Regional scale - usually 'concentrations measured in a
rural area of reasonably homogeneous geography that extends from
10's to 100's of km.
6. National and global s.cales - concentrations character-
izing the Nation and/or the globe as a whole.
1 - 2 Representative' Sampling '. '
Assuring the collection of a representative air quality
sample depends on the following factors:
1. Locating the sampling site, and determining that the
network size is consistent with the monitoring objectives.
2. Determining the restraints on the sampling site that
are imposed by meteorology. .' .
3. Determining the restraints on the sampling site that
are imposed by local topography, emission sources, and the
physical constraints.
4. Planning sampling schedules that are consistent with
the monitoring objectives. ' •
1-2-1 Site Location - In designing an air quality monitoring
program, four criteria should be considered either singly or in
combination for -site location, depending on the sampling objec-
tive. Orient the monitoring sites to measure:
1. The impacts of known pollutant emission categories on
air quality.
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Section No. 2.0.1
Revision No. 1
Date July 1, 1979
Page 6 of 23
2. The population density relative to receptor-dose levels,
both short and long term.
3. The impacts of known pollutant emission sources (area
and point) on air quality.
4. The. representative area-wide air quality.
To select locations according to these criteria, i£ is-necessary
to have detailed information on the location of sources of
emissions, the geographical variability of ambient pollutant
concentrations, the meteorological conditions, and the population
density. Therefore, the selection of the number, locations, and
types of sampling stations is a complex process that defies a
purely objective solution. Furthermore, the variability of
sources and their intensities, terrains, meteorological condi-
tions, and demographic features requires that each network be
developed individually. Thus, selection of the network will be
the result of subjective judgments, based on available evidence
and on the experience of the decision1team.
The sampling site selection process involves considerations
of economic, logistic, atmospheric, and- pollutant reaction
factors in addition to the motivation for and the objective of
the sampling program. None of the factors stand alone. Each is
dependent in part on the others. However, the objective -of
the sampling program must be clearly defined before the selec-
tion process can be initiated, and the initial definition of
priorities may have to be reevaluated after considerations of the
remaining factors and before the final .locations are chosen.
Economic considerations - The economic considerations are
rather clearly defined. The amount of money required for data
gathering (instrumentation, installation, maintenance, data re-
trieval), data analysis, quality assurance, and data interpreta-
tion must be balanced against the available monies (current and
projected) and the cost-benefits of additional or relocated
sampling sites.
Logistical problems - The logistical problems involve the
means of obtaining, analyzing, and interpreting the data. Can
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Section No. 2.0..I
Revision No. 1
Date July 1, 1979
Page 7 of 23
the current staff manage the proposed system, or are more or
fewer persons needed to accomplish the tasks? Is the derived in-
formation necessary on a real-time basis, or can several weeks
pass before it is available?
Atmospheric problems - The atmospheric problems pertain to
definitions of the spatial and temporal variabilities of the
pollutants and their transport. Effects of buildings, terrain,
and heat sources or sinks on the air trajectories" can produce
local anomalies of excessive pollutant concentrations. Wind
velocity, wind shear, . and atmospheric stability can greatly
influence the dispersal of pollutants.
Pollutant considerations - A sampling site or an array of
sites for one pollutant may be inappropriate for another pol-
lutant species because of the configuration of sources, the local
meteorology, or the terrain. Pollutants undergo changes in their
compositions between their emission and their detection; there-
fore, fhe impact of that change on the measuring system should be.
considered. Atmospheric chemical reactions such as the produc-
tion of O_ .in the presence of NOv and HC, -and the time -delay
*5 X
between the emission of NO and HC and detection of peak O_
X • O
values may require either a sampling network for the precursors
of O3 and/or a different network for the actual O_ measurement.
Summary - While the interactions of the' factors identified
above are complex, the site selection problems can be- resolved.
Experience in the operation of air quality measurement systems;
estimates of air • quality; field and theoretical studies of
atmospheric .diffusion; and considerations of atmospheric
chemistry and air pollution effects are the requirements that
combine to make up the expertise needed to select the optimum
sampling site for obtaining data representative of the monitoring
objectives.
1-2.2 Meteorological Restraints - Meteorology must be considered
in determining not only the geographical location of a monitoring
site but also such factors as height, direction, and extension
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Section No. 2.0.1
Revision No. 1
Date July 1, 1979
Page 8 of 23
of sampling probes. Meteorological parameters having the
greatest influence on the dispersion of pollutants are the
direction, speed, and variation of the wind as well as the at-
mospheric stability and lapse rate.
Wind direction indicates the general movement of pollutants
in the atmosphere. Review of available data can indicate mean
wind direction in the vicinity of the major sources of emissions.
The windspeed affects (1) the travel time from the source
to receptor and (2) the dilution of polluted air in the downwind
direction. That is, the concentrations of air pollutants are in-
versely proportional to the windspeed. Turner gives an example:
If a continuous source is emitting a certain pollutant at
a rate of 10 g/s, and the windspeed is 1 m/s, then in a
downwind length of the plume of 1 m will be contained 10 q
of the pollutant, since 1 m of air moves past the sourcl
each second. Next, . consider that the conditions of emis-
sions are the same, but the windspeed is 5 m/s. In this
.
SJ?h nf1^ !• mi °f 'fir m°Ves past the source each second,
each meter of plume length contains 2 g of pollutant.
Wind variability refers to random motions in both the
horizontal and vertical velocity components of the wind. These
random motions can be considered atmospheric turbulence, which
is either mechanical (caused by structures and changes in ter-
rain) or thermal (caused by heating and cooling of land masses
or bodies of water). if the scale of a turbulent motion is
larger -than the size of the pollutant plume, the turbulence will
move the entire plume and cause looping or fanning. If the
scale of turbulent motion is smaller than the size of the pol-
lutant plume, the turbulence will cause the plume to diffuse or
spread out. If these meteorological phenomena impact with some
frequency on a sampling site, the measured data must be evaluated
in light of possible fumigation or other unusual atmospheric
conditions .
A useful way of displaying wind data is a wind rose diagram
constructed to show the distribution of windspeeds and direc-
tions. Data from which wind rose diagrams can be constructed
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Section No. 2.0.1
Revision No. 1
Date July 1, 1979
Page 9 of 23
are available in tabulated form through the National Climatic
Center of the National Oceanographic and Atmospheric Admini-
stration in Asheville, North Carolina. The wind rose diagram
shown in Figure 1.1 represents conditions as they converge on
the center (or site under consideration) from each direction of
the compass. More complete explanations of the construction and
use of wind roses are available.- This brief discussion and
figure indicate a few meteorological effects to be considered in'
the siting of network surveillance equipment. More detailed
guidance for meteorological considerations is available.1'4
Relevant weather .information such as stability-wind roses are
usually available from local National Weather Service stations.
In cases of complex meteorological and terrain situations,
diffusion meteorologists should be consulted.
1-2.3 Topographical Restraints - Both the transport and-the dif-
fusion of air pollutants are complicated by topographical
features. Minor- topographical features may exert small in-
fluences; major features,, such as deep river valleys or mountain
ranges, may affect large areas. Before, final site selection, re-
view the topography of the area to ensure that the purpose of
monitoring at that site will not be adversely affected.
Table 1.3 summarizes important topographical features, their
effects on air flow, and some examples of influences on monitor-.
ing site selection..
Land use and topographical characteristics of specific areas.
can be determined from U.S. Geological Survey (USGS) maps as well
as from land-use maps.
Final placement of the monitor at a selected site depends
on physical. obstructions and activities in the immediate area;
accessibility, availability of utilities and other support facil-
ities; and correlations with the defined purpose of the specific
monitor and the monitor design. Because obstructions such as
trees and fences can significantly alter the air flow-, monitors
should be placed away from such obstructions. It is important
for air flow around the monitor to be representative of the
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Section No.' 2.0.1
Revision No. 1
Date July 1, 1979
Page 10 of 23
0-3_ 4-7 8-12 13-18 19-24
Speed Classes (mph)
0 12 3 A 5 67 8910
Scale; %
a,,.
Bias removed and calms distributed.
Figure 1.1 Wind rose pattern.
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Section No. 2.0.1
Revision No. 1
Date July 1, 1979
Page 11 of 23
Table 1.3 RELATIONSHIPS OF TOPOGRAPHY, AIR FLOW, AND
MONITORING SITE SELECTION
Topographical
feature
Influence- on air flow
Influence on monitoring
site selection
Slope/Valley
Downward air currents at night
and on cold days; upslope winds
on clear days when valley
heating occurs
Slope winds and valley
channelled winds; tendency
toward down-slope and down-
valley winds; tendency
toward inversions
Slopes and valleys as special
sites for air monitors
because pollutants generally
well dispersed; concentration
levels not representative of
other geographic areas; pos-
sible placement of monitor to '
determine concentration levels
in a population or industrial
center in a valley
Water
Sea or lake breezes inland
or parallel to shoreline
during the day or in cold
weather;, land breezes at
night . , '
Monitors on shorelines gener-
ally useful for background
readings or for obtaining
pollution data on water
traffic
Hill'
Sharp ridges causing tur-
bulence; air flow around
obstructions during stable
conditions, but over obstruc-
tions during unstable condi-
tions
Depends on source orientation;
upwind source emissions gener-
ally mixed down the slope,
and siting at foot of hill not
generally advantageous; down-
wind source emissions generally
downwashed near the source;
monitoring close to a source
generally desirable if popula-
tion centers adjacent or if
monitoring protects workers
Natural or
manmade
obstruction
Eddy effects
Placement near obstructions
not generally representative
in readings
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Section No. 2.0.1
Revision No. 1
Date July 1, 1979
Page 12 of 23
general air flow in the area to prevent sampling bias. Detailed
information on urban-physiography (e.g., buildings, street dimen-
sions) can be determined through visual observations, aerial
phst-ography, and surveys. Such information can be important in
determining the exact locations of pollutant sources in and
around the prospective monitoring site areas.
Network designers should avoid sampling locations that are
unduly influenced by downwash or by ground dust (e.g., a rooftop
"air inlet near a stack or a ground-level inlet near an unpaved
road); in these cases, either elevate the sampler intake above
the level of the maximum ground turbulence effect or pl-ace it
reasonably far from the source of ground dust.
Depending on the defined objective—that is, to determine
the background levels, or to determine the maximum concentrations
and so forth—the monitors .(for sampling at a particular site)
would be placed according to exposure to pollution, including
exposure to motor vehicle emissions. Therefore in " most every
instance, a practical consideration must be made of unavoidable
physical restraints on the optimum representativeness of sample
collection. This consideration should include categorization of
sites relative to their local placements. Suggested, categories
relating to sampling site placement for measuring a corresponding
pollutant impact are as follows:
Category A (ground level station) - Heavy, pollutant concen-
trations—high potential for pollutant buildup. A site that is
3 to 5 m>(10-16 ft) from major traffic artery and that has local
terrain features restricting ventilation. A sampler probe that
is 3 to 6 m (10-20 ft) above ground.
Category B (ground level station) - Heavy pollutant concen-
trations—minimal potential for a pollutant buildup. A site 3 to
15 m (15-50 ft) from a major traffic artery with good natural
ventilation. A sampler probe that is 3 to 6 m (10-20 ft) above
ground.
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Section No. 2.0.1
Revision No. 1
Date July 1, 1979
Page 13 of 23
Category C (ground level station) - Moderate pollutant con-
centrations. A site that is 15 to 60 to (50-200 ft) from a major
traffic artery. A sampler probe that is 3 to 6 m (10-20 ft)
above ground.
Category D (ground level station) - Low pollutant concen-
trations. A site that is >_60 m (>200 ft) from a traffic artery.
A sampler probe that is 3 to 6 m (10-20 ft) above ground.
Category E (air mass station) - Sampler probe that is be-
tween 6 and 45 m (20 and 150 ft) above ground. Two subclasses:
(1) good exposure from all sides (e.g., on top of building) or
(2) directionally biased exposure (probe extended from window).
Category F (source-oriented station) - A sampler that is
adjacent to a point source. • Monitoring that yields data
directly .relatable to emission source.
1-2-4 Sampling Schedules -r Current Federal regulations' specify
the frequency of sampling for. criteria pollutants to meet minimum
SIP (State Implementation Plan) surveillance requirements .' Con-
^MU°/^ /Lamp}^n1-^s sPecified except for 24-h ' measurements of
,"' « tOj rb OL.MD Tor%
total tfLionondod fm-t-i ml -it- nr (Tgp) -.1-.^ a/|-h integrated valuoc of.
SO^ and NO^ . n-n^ K-J »~-\ nri^ ^nc impingar maacurcmcntc arc ro
quirod at — leact — once — every 6 dayc - -an • equivalent of about 61-
random oamploo/yE. The 24-h samples should be taken from mid-
night (local standard time) to midnight and thus shou-ld represent
calendar days to permit the direct use of the sampling data in
standard daily meteorological summaries. The following are rec-
ommended frequencies for noncontinuous hi-vol and impinger sam-
plings to adequately define TSP, SO2 , and NO2 levels:
1. The most polluted . sites in an -urban area should be.
sampled at frequencies greater than the minimum requirements."
2. Sites where the highest 24-h and annual averages are
expected should' yield the most frequent
3. Areas of maximum SO2 and N02 concentrations should be
sampled using continuous monitors in place of SO2/NO2 impingers
if possible.
-------
Section No. 2.0.1
Revision No. 1
Date July 1, 1979
Page 14 of 23
4. Noncritical sites (i.e., sites other than maximum con-
centration sites) can be sampled intermittently. Intermittent
sampling calls for adopting a systematic sampling schedule that
considers statistical relationships for characterizing an air
pollutant for a given time period and area. ' Actually any
schedule which gives 61 samples/yr and 5/quarter (in accordance
with item 6 below) is satisfactory, but not as convenient -as the
systematic schedule of every 6th day, for example.
5. Downwind sites monitoring for SO_, NO2/ and *S3»Afrom
isolated point sources should use continuous instruments for the
gaseous pollutants, and should sample at least once every 6 days
for •£§£-. /vj-AT/cuL/f-rs: M/hTT££.
6. The minimum numbers of samples required for the appro-
priate summary statistics should be taken. At least 75% of the
total possible observations must be present before summary sta-
tistics are calculated. The exact requirements follow:7
Time interval Minimum number of observations/averages
3-h running average 3 consecutive hourly observations
8-h running average 6 hourly observations
24 h 18 hourly observations
Monthly . 21 daily averages
Quarterly 3 consecutive monthly .averages
Yearly • 9 monthly averages with at least
2 monthly averages/quarter
For intermittent sampling data, there must be at least five ob-
servations/quarter; if one month has no observations, the re-
maining two months must have at least two.
7. If validation procedures indicate that the criteria in
item 6 are not fulfilled (the minimum numbers must be valid ob-
servations), the sampling frequency should be increased during
the period in which corrective measures are being pursued.
-------
Section No. 2.0.1
Revision No. 1
Date July 1, 1979
Page 15 of 23
More extensive treatments of sampling frequencies, as
related to data analysis,'are in References 6, 7, and 8.
Table 1.4 lists approximate numbers of stations for each
NAMS area, as determined by population and concentration catego-
P/M-/O 9
ries, for SO2 and ¥Si> as specified in Appendix D, 40 CFR 58.
1.3 Sampling Site and Equipment Requirements
Sampling site and equipment requirements are generally
divided into three categories, consistent with the desired
averaging- times:
1. Continuous—Pollutant concentrations determined with
automated methods, and recorded or displayed .continuously.
2. Integrated—Pollutant concentrations determined with
manual or automated methods from integrated hourly or daily
samples on a fixed schedule.
3. • Static—Pollutant estimates or effects determined
from long-term (weekly or monthly) exposure of qualitative
-m—
measurement devices or materials.
Air quality monitoring sites that use automated equipment
to continually sample and analyze pollutant levels may be
classified as primary. Primary monitoring stations are generally
located in areas where pollutant concentrations are expected
to be among the highest and in areas with the highest population
densities; thus, they are often used in health effects research
networks; in addition, these stations are designed as a part of
the air pollution episode warning system.
1.4 Quality Assurance
The .quality assurance plan* should include specific docu-
mentation of site characteristics for each monitoring station.
*Minimum suggested content for such a plan is discussed in the
Quality Assurance Handbook for Air Pollution Measurement
Systems, Vol. I, Section 1.4.23, entitled "Quality Assurance
Plans for Projects and Programs."
-------
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-------
Section No. 2.0.1
Revision No. I
Date July 1, 1979
Page 17 of 23
This information will assist in providing objective inputs into
the evaluation of data generated at that site. Typically, the
2
site identification record should include:
1. Data acquisition objective: air quality standards
monitoring.
2. Station type (stationary, mobile, etc.);
3. Instrumentation checklist ("manufacturer's model num-
ber, pollutant measurement technique, etc.).
4. Sampling system (probe type, height, flow, etc.).
5. Spatial scale of the station (site category—i.e.,
urban/industrial, suburban/commercial, etc.; physical location-.-
i.e., address, AQCR, UTM coordinates, etc.).
6. Influential pollutant sources (point and area sources,
proximity, pollutant density, etc.).
7. Topography (hills, valleys, bodies of water, trees';
type and size, proximity, orientation, etc.; picture of a 360°
view from the probe of the monitoring site).
8. Atmospheric exposure (unrestricted, interferences,
etc.).
9. Site diagram (sample flowsheet, service lines, equip-
ment configuration, etc.).
1.5 Network Designs Examples
As previously noted, networks are designed for at least one
of four major purposes (Subsection 1.0). The following tabula-
tion presents examples of currently implemented networks applica-
ble to each of these four.
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Section No. 2.0.1
Revision No. 1
Date July 1, 1979
Page 18 of 23
Monitoring
objective Network Comment
Compliance SIP (State Imple- To demonstrate attainment
mentation Plan) or maintenance of AQS
Emergency SIP/local, agency To activate immediate,
episode emergency control short-term emission
program' controls for episode
prevention
Trend . NASN (National To fulfill mandate of
Air Sampling Federal legislation
Networks)
Research , CHAMP (Community To determine long-term
Health Air Monitor- pollutant trend in
ing Program) selected areas with
health effects
1•5•1 Compliance Monitoring - The information required for
selecting the number of samplers and the sampler location is
essentially the same—that is, isopleth maps, the population
density maps, and the source locations. Following are the sug-
gested guidelines:
1. The priority area is the zone of highest pollutant
concentration within the region; one or more stations are to
be located in this area.
•2. Close attention should be given to densely populated
areas within the region, especially when they are in the vicinity
of heavy pollution.
3. The quality, of air entering the region is to be as-
sessed by stations situated on the periphery of the region;
meteorological factors (e.g., frequencies of wind directions) are
of primary importance in locating these stations.
4. Sampling should be undertaken in areas of projected
growth to determine the effects of future development on the
environment.
5. A major objective of surveillance is evaluation of
progress made in attaining the desired air quality; for this
purpose, sampling stations should be strategically situated to
facilitate evaluation of the implemented control tactics.
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Section No. 2.0.1
Revision No. 1
Date July 1, 1979
Page 19 of 23
6. Some information of air quality should be available to
represent all portions of the regions.
Some stations will be capable of fulfilling more than one of the
functions indicated; for example, a station located in a densely
populated area can indicate population exposures and'also docu-
ment the changes in pollutant concentrations resulting from
control strategies used in the area.
1-5.2 Emergency Episode Monitoring - For episode avoidance pur-
poses, data are needed quickly--in no less than a few hours after
the sensor is contacted by the pollutant. While it is possible
to obtain . data rapidly by on-site manual data reduction and
by telephone reporting, there is a trend toward using automated
monitoring networks. The severity of the problem, the size of
the receptor area, and the .availability of resources all influ-
ence both the scope and sophistication of the monitoring system.
It is necessary to use continuous air samplers because an
episode lasts only a few days and because the control actions
taken must be based on real-time measurements that .are correlated
with the decision criteria. Based on alert criteria now in use,
1-h averaging times are adequate for surveillance of episode con-
ditions. Shorter averaging times provide information on data-
collecting excursions, but they increase the need for automation
because of the bulk of the data obtained. Longer averaging times
(>6 h) are not desirable because of the delay in response that
these impose. After an alert is announced, data are needed
quickly so that requests for information on the event can be
responded to. ,
Collection and analysis must be accomplished rapidly if the
data are to be useful immediately. There is no time to check out
the methods, to run blanks, to. calibrate and so forth, after the
onset of episode conditions. For the instrument to be maintained
in peak operating condition, either personnel must be stationed
at the sites during the episode or automated equipment must be
operated that can provide automatic data- transmission to a
central location.
-------
Section No. 2.0.1
Revision No. 1
Date July 1, 1979
Page 20 of 23
The instruments employed for measuring the pollutant- param-
eter use either wet chemical techniques or physical methods.
Chemical analysis always involves the • use of consumable sup-
plies. The chemicals must be replaced on a schedule that is con-
sistent with their stability and with the rate at which samples
are taken. Currently used instruments require adequate supplies
of chemicals for operation. for 3 mo so that the supplier can
comply > with delivery schedules. In some cases, analytical
reagents for specific air contaminants deteriorate rapidly and
should have. protective storage. Physical methods are performed
with relatively complex equipment that must be installed cor-
rectly and" cared for by trained personnel; the accuracy of the
equipment is affected by mechanical shock, ambient temperature
extremes, voltage supply stability, dirty or dusty atmospheres,
and corrosive chemicals.
Episode conditions threaten human health and welfare. Moni-
toring sites should be located in areas where human health and
welfare are most threatened:
1. In densely populated areas.
2. Near large stationary sources of pollutants.
3. Near hospitals'.
4. Near high-density traffic interchanges.
5. Near homes for the aged.
A network of sites is useful in determining the 'range of
pollutant concentrations within an area. Although the most de-
sirable monitoring sites are not necessarily the most convenient,
consideration should be given for reasons of access, security,
and existing communications 'to the use of public buildings:
schools, firehouses, police stations, hospitals, and water or
sewage plants.
1-5.3 Trend monitoring - As typified by the National Air
Surveillance Network (NASN), trend monitoring is characterized
by locating a minimal number of monitoring sites across as large
an area as possible. The program objective is not only to
-------
Section No. 2.0.1
Revision No. 1
Date July 1, 1979
Page 21 of 23
determine, in a broad sense the extent and nature of air pollu-
tion but also to determine the variations in the measured levels
of atmospheric contaminants in respect to geographical, socio-
economic, climatological, and other factors. The.data acquired
are useful in planning epidemiological investigations and in pro-
viding the background, against which more intensive community and
'statewide studies of air pollution can be-conducted.
Urban sampling stations are usually located in the most
densely populated areas of a region. In most regions, there are
several urban sites.
Nonurban station locations include various topographical
categories such " as farmland, desert, forest, mountain, and
coast. Nonurban stations are not specifically selected to be
"clean air" control sites for urban areas, but they do provide.
a' relative comparison between some urban and nearby nonurban
areas.
in interpreting trend data, one must- consider the limita-
tions" imposed by the network design. Even though precautions are
taken, to ensure that each sampling site is as representative as
possible of the designated area, it is impossible to be totally
certain that the measurements obtained at a specific site are
not sometimes unduly influenced by -local factors. Such factors
might include topography, structures, and sources of pollution in
the immediate vicinity of the site, and other variables—the
effects of which cannot always be accurately anticipated, but
should be considered in network design. It must be kept in mind
that comparisons among pollution' levels for various areas are
valid only if the sites are comparable.
1.-5.4 Research Monitoring - An example of a research-oriented
air quality monitoring effort is EPA's Community Health Air
Monitoring Program (CHAMP), which has provided data to develop
criteria for both short- and long-term air quality standards.
Air monitoring networks related to health effects are composed
-------
Section No. 2.0.1
Revision No. 1
Date July 1, 1979
Page 22 of 23
of integrating samplers both for determining pollutant concen-
trations for >24 h and for developing long-term (>_24 h) ambient
air quality standards. This research requires that monitoring
points be located so that the resulting data will represent the
population group under study; thus the monitoring stations, are
established in the centers of small well-defined residential
areas within a community. Data correlations are made between
observed health effects and observed air quality exposures. •
Requirements for aerometric monitoring in support of health
studies are:
1. Station must be located in or near the population under
study.
2. Pollutant sampling averaging times must be sufficiently
short to allow for use in acute health effects studies that form
the scientific basis for short-term standards.
. 3. Sampling frequency, usually daily, should be sufficient
to characterize air quality as a function of time.
4. System should be flexible and responsive to emergency
conditions with data available on short notice.
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Section No. 2.0.1
Revision No. 1
Date July 1, 1979
Page 23 of 23
1.6 References
1. Guidelines of Air Quality Monitoring Network Design and
Instrument Siting. U.S. Environmental Protection
Agency, Office of Air Quality Planning and Standards.
OAQPS No. 1.2-012. Revised. September 1975. Draft.
2. Air Quality Monitoring Site Description Guideline,
Environmental Protection Agency, Research Triangle
.-Park, N.C. OAQPS No. 1.2-019, 1974. Draft.
3. Code of Federal Regulations 40. Protection of the
Environment. Parts 50 to 69. Revised July 1, 1975.
4. Turner, D. B. Workbook of Atmospheric Dispersion.
Estimates-. Environmental Protection Agency. 7th
printing, January 1974.
5. Ludwig, F. L. and J. H. S. Kealoha. Selecting Sites
for Carbon Monoxide Monitoring. EPA-450/3-75-077.
September 1975.
6,.. Hunt, W. F. The Precision Associated with the Sampling
.Frequency of Log Normally Distributed Air Pollutant
Measurements. JAPCA 22. September 1972.
7. Guidelines for the Evaluation of Air Quality Data.
Environmental Protection Agency, Office of Air Quality
Planning and Standards. OAQPS No. 1.2-015. January
1974. p. 21.
8. Akland, G. Design of Sampling Schedule. JAPCA 22.
April 1972. . —
9. 40 CFR 58, Appendices C - E.
Guideline for Lead Monitoring in the Vicinity of Point Sources EPA-
45 0/4-81-00 6.
.Optimum Sampling Site Exposure Criteria for Lead. EPA 450/4-84-
012. February 1984.
Network Design and Optimum Site Exposure Criteria for Particulate
Matter. EPA 450/4-87-009. May 1987.
-------
-------
Addendum to Section 2.0.2
•• Sampling Considerations
The following information should be added to table 2-2:
Pollutant
Pb
*
r.
i
• '
Scale
Micro
Middle,
neighbor-
urban,
and
regional
Height above
ground,
meters
2-7
2-15
Distance from supporting structure,
meters
Vertical
-
-
Horizontal"
>2
>2
=======
Other spacing criteria
1. Should be >20 meters from
trees.
2. Distance from sampler to
obstacle, such as a building, most
be at least twice the height that the
obstacle protrudes above the
sampler.
3. Must have unrestricted airflow
270° around the sampler.
4. No furnace or incineration fhies
should be nearby. b
1. Should be >20 meters from
trees.
2. Distance from sampler to
obstacle, such as a building, must
be at least twice the height that the
obstacle protrudes above the
sampler.
3. Must have unrestricted airflow
270° around 'the sampler.
4. No furnace or incineration flues
should be nearby."
5. Spacing from roads varies with
traffic (see Table 4 of Appendix
-------
Pollutant
PM!0
t
.
PMW
Scale
Micro
Middle,
neighbor-
hood.
urban,
and
regional
scale.
Height above
ground,
meters
2-7
2-15
Distance from supporting structure,
meters
Vertical
.
.
Horizontal*
>2
>2
I
Other spacing criteria
1. Should be >20 meters from the
dripline and must be 10 meters
from the dripline when the tree(s)
acts as an obstruction.
2. Distance from sampler to
obstacle, such as buildings, must
be at least twice the height the
obstacle protrudes above the
sampler except for street canyon
sites'*.
3. Must have unrestricted airflow
270° around the sampler except for
street canyon sites.
4. No furnace or incineration flues
should be nearby.
5. Spacing from roads varies with
traffic (see Figure 2 of Appendix
E°) except for street canyon sites
which must be from 2 to 10 meters
from the edge of the nearest traffic
lane.
— — .
1. Should be >20 meters from the
. dripline and must be 10 meters
from the dripline when the tree(s)
act as an obstruction.
2. Distance from sampler to ;
obstacle, such as buildings, must
be at least twice the height the
obstacle protrudes above the
sampler1".
3. Must have unrestricted airflow
270° around the sampler.
4. No furnace or incineration flues
should be nearfayb.
5. Spacing from roads varies with
traffic (see Figure 2 of Appendix
E"). ' 1
-------
Pollutant
Scale
Height above
ground,
meters
Distance from supporting structure,
meters
Vertical
Horizontal*
Other spacing criteria
VOC
PAMS
3-15
>1
>1
1. Should be' >20 meters from the
dripline and must be 10 meters
from the dripline when the tree(s)
act as an obstruction.
2. Distance from probe inlet to
obstacle must be at least twice the
height the obstacle protrudes above
the inlet probe.
3. Must have unrestricted air flow
in an arc of at least 270° around
the probe inlet and the predominant
wind direction for the period of
greatest pollutant concentration (as
described for each site in section
4.2 of appendix D*) must be
included in the 270° arc. If probe
located on the side of a building
unrestricted air flow must be 180°.
4. Spacing from roadways varies
with traffic (see Table 5 of
Appendix E*).
When a probe is located on a rooftop, this separation is in reference to walls, parapets or
penthouses located on the roof.
Distance is dependent on the height of the furnace or the incineration flue, the type of fuel
or waste burned, and the quality of the fuel (sulfur, ash or lead content). This is to avoid
undue influences from minor pollutant sources
40CFR58.
Sites not meeting this criterion would be classified as middle scale.
-------
-------
Section No. 2.0.2
Revision No. 1
Date July 1, 1979
Page 1 of 9
2.0 SAMPLING CONSIDERATIONS
2.1 Environment Control
A proper sampling environment demands control of all physi-
cal parameters external to the samples that might affect Sample
stability, chemical reactions within the sampler, or the function
of sampler components. The important parameters to be controlled
are summarized in Table 2.1.
Table 2.1 ENVIRONMENT CONTROL PARAMETERS
Parameter
Source of
specification
Method of
control
Instrument vibration
Manufacturer's
specifications
Design of instru-
ment housings,
benches, etc. ,
per mfr. spec.
Light
Method description
or manufacturer's
• specifications
Shield chemicals
or instruments
that can be
affected by nat-
ural or artifi-
cial light
Electrical voltage
Method description
or manufacturer's
specifications
Constant voltage
transformers or
regulators; sep'a-•
rate power lines;
isolated high cur-
rent drain eguip-
ment such as hi-
vols, heating
baths, pumps from
regulated circuits
Temperature
Method description
or analyzer
specifications
Regulated air con-
ditioning system;
24-hour temperature
recorder; use
electric heating
and cooling only
(see note on next
page)
Humidity
Method description
or analyzer
specifications.
Regulated air con-
ditioning system;
24-hour recorder
-------
Section No. 2.0.2
Revision No. 1
Date July 1, 1979
Page 2 of 9
Note; With respect to environmental temperature for designated
analyzers, most such analyzers have been tested and qualified
over a temperature range of 20°C (68°F) to 30°C (86°F). (A few
analyzers are qualified over a wider range.) This temperature
range specifies both the range of acceptable operating tempera-
tures and the range of temperature change which the analyzer can
accommodate without excessive drift. It is the latter—the range
of temperature change that may occur between zero and span ad-
justments—that is, by far, the most important. To accommodate
current energy conservation regulations or guidelines specifying
lower thermostat settings, designated analyzers located in faci-
lities subject to these restrictions may be operated at tempera-
tures down to 18°C (64°F), provided the analyzer temperature does
no.t fluctuate by more than 10°C (e.g., 18° to 28°C) between zero
and span adjustments. However,' operators should be alert to
situations -where environmental temperatures might fall below
18°C (64°F), such as during night hours or weekends. Use of a
thermograph at the analyzer site may be necessary to detect such
situations. Temperatures below 18°C may necessitate supplemental
temperature control equipment or rejection of the area as an
analyzer installation site.
2-2 Sampling Probes and Manifolds
2-2-1 Design of Probes and Manifolds1 - Some important variables
affecting the sampling manifold design are the diameter', length,
flow rate, pressure drop, and materials of construction. Con-
siderations for these parameters are discussed below for both a
.vertical laminar flow and a conventional manifold design.
Vertical laminar flow design - By the proper selection of a
large diameter vertical inlet probe and by maintaining a laminar
flow throughout, the sample air is not permitted to react with
the walls of the probe. Numerous materials such as glass, PVC
plastic, galvanized steel, and stainless steel, can be used
for constructing the probe. Removable sample lines constructed
of Teflon or glass can be used to provide each device with sample
-------
Section No. 2.0.2
Revision No. 1
Date July 1, 1979
Page 3 of 9
air. A flow rate of 5 3,/min (0.18 ft3/min) in 1.5-cm (0.6 in.)
diameter tubing (commonly used in monitoring stations) is not
satisfactory for this application because of almost complete dif-
fusion losses.
Diameters from 1.5 to 2.5 cm (0.6 to 1.0 in.) with 50 to
150. £/min (1.8 to 5.4 ft /min) are unacceptable because of high
pressure drops. Therefore, inlet line diameters of 15 cm (6 in.)
with a flow rate of 150 £/min (5.4 ft3/min) are necessary if
diffusion losses and pressure drops are to be minimized. The
sampling rate should be maintained to insure laminar flow con-
ditions. • . : •
Figure 2.1 is an example of a vertical laminar flow mani-
fold. This configuration has the following advantages: ' '
1- A 15-cm (6 in.) pipe can be cleaned easily by pulling
a cloth through it with a string.
. 2". Sampling ports can be cut into- the pipe at any loca-
tion and, . if unused, can be plugged with .stoppers of similar
compositions.
3. Metal poses no breakage hazard.
4. The pipe does not have to be clean to provide a repre-
sentative sample, as in the case with smaller tubes.
Conventional manifold design - In practice, it may be diffi-
cult to achieve .vertical laminar flow because of the- elbows
within the intake manifold system. Therefore, a conventional
manifold system should be constructed of inert materials such as
Pyrex glass and/or Teflon, and in modular sections to enable
frequent cleaning. The system (Figure 2.2) consists of a verti-
cal "candy cane" protruding through the roof of the shelter with
a horizontal sampling manifold connected by a tee to the vertical
section. Connected to the other vertical outlet of the tee is a
bottle for collecting heavy particles and moisture before they
enter the horizontal section. A small blower, 1700 £/min
(60 ft /min) at 0 cm of water at static pressure, is at the
exhaust end of the system to provide a flow through the system
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Section No. 2.0.2
Revision No. 1
Date July 1, 1979
Page 4 of 9
1 - 2 m
(3-6 ft)
15 cm
(6 In.)
ROOF
SAMPLE PROBES
INCLINED MANOMETER
ORIFICE METER
BLOWER - 150 fc/min FOR FLOW MEASUREMENT
Figure 2.1 Vertical laminar flow manifold.
-------
Section No. 2.0.2
Revision No. 1
Date July 1, 1979
Page 5 of 9
BLOWER-^
MODULAR SECTION
MOISTURE TRAP ->
Figure 2.2 Conventional manifold system.
of approximately 85 to 1401/min (3 to 5ft3/min). Particu-
late monitoring instruments, such 'as nephelometers, should
each have - separate, intake probes that are as short and as
straight as possible to avoid particulate losses due to impaction
on the walls of the probe.
A recent investigation2 has shown that there are no signifi-
cant losses of reactive gas (O3) concentrations in. conventional
13 mm (0.5 in.) inside diameter sampling lines of glass or
Teflon, if the sample residence time is 10 s or less. This is
true even in sample lines up to 38 m (125 ft) in length, which
collect substantial amounts of visible contamination due to
ambient aerosols. However, when the sample residence time ex-
ceeds 20 s, loss is detectable, and at 60 s the loss is nearly
-------
Section No. 2.0.2
Revision No. 1
Date July 1, 1979
Page 6 of 9
complete. Conversely, when the sample lines are free of contami-
nation, there is no detectable loss at sample residence times up
to 120 s.
2.2.2 Placement of Probes and Manifolds - Probes and manifolds
must be placed to avoid introducing bias to the sample. Impor-
tant considerations are probe height above the ground, probe
length (for horizontal probes), and physical influences near the
probe. Some general guidelines for probe and manifold placement
are:
1. Probes should not be placed next to air outlets such as.
exhaust fan openings " •
2. Horizontal probes must extend beyond building over-
hangs .
3. Probes should not be near physical obstructions such
as chimneys which can affect the air flow in the vicinity of the
probe.
4. Height of the probe above the ground depends on the,
pollutant being measured. •
Table 2.2 summarizes'probe siting criteria specified in Ap-
pendix E, 40'CFR 58 for NAMS and SLAMS.5
3
2.3 Maintenance
After an adequately designed sampling probe and/or manifold
has been selected and installed, the following steps will help
in maintaining constant sampling conditions:
1. Conduct a leak test - For the conventional manifold,
seal all ports and pump down to approximately 1.25 cm (0.5 in.)
water gauge vacuum, as indicated by a vacuum gauge or manometer
connected to one port. Isolate the system. The vacuum measure-
ment should show no change at the end of a 15-min period.
2. Establish cleaning techniques and a schedule - a large
diameter manifold may be cleaned by pulling a cloth on a string
through it. Otherwise the manifold must be disassembled period-
ically and cleaned with soap and water. Visible dirt should not
be allowed to accumulate.
-------
Section No. 2.0.2
Revision No. 1
Date July 1, 1979
Page 1 of 9
ITERIA
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-------
Section No. 2.0.2
Revision No. 1
Date July 1, 1979
Page 8 of 9
3. Plug the ports on the manifold when sampling lines are
detached.
4. Maintain . a flow rate in the manifold that is either 2
to 5 times the total sampling requirements or at a rate equal zo
the total sampling requirement plus 140 £/min (5 ft: /mir-}.
Either rate will help to reduce the sample residence time in the
manifold and ensure adequate gas flow to the monitoring instru-
ments.
5. Maintain the vacuum in the manifold £0.64 cm (O-25 in.)
water gauge. Keeping the vacuum low will help to prevent the
development of leaks.
2.4 Support Services
Most of the support services necessary for the successful
operation. of ambient air monitoring networks can be provided by
the laboratory. The major support services are the generation of
reagent water and the preparation of standard atmospheres for
calibration of equipment. Table 2.3 summarizes guidelines for
quality control of these two support services.
In addition to the information presented above, the
following should be considered when designing a sampling manifold:
• suspending strips of paper in front of the blower's
exhaust to permit a visual check of blower operation,
• positioning air conditioner vents away from the manifold
to reduce condensation of water vapor in the manifold,
• positioning sample ports of the manifold toward the
ceiling to • reduce the potential for accumulation of
moisture in analyzer sampling lines, and
• using borosilicate glass, stainless steel, or their
equivalent for VOC sampling manifolds at PAMS sites is to
avoid adsorption and desorption reactions of VOC' s on FEP
Teflon.
Also, probe-siting criteria for Pb and PM10 NAMS and SLAMS for PAMS
have been added to 40 CFR 58 since the publication of this section
in 1979.
-------
Section No. 2.0.2
Revision No. 1
Date July 1, 1979
Page 9 of 9
Table 2.3 TECHNIQUES FOR QUALITY CONTROL OF SUPPORT SERVICES*
Support
service
Parameters
affecting quality
Control
techniques
Laboratory
and cali-
bration
gases
Purity specifications -
vary among manufacturers
Variation between lots
Atmospheric interferences
Composition
Develop purchasing
guides
Overlap use of old
and new cylinders
Adopt filtering .and
drying procedures
Ensure traceability-to
primary standard
Reagents
and
water
Commercial source
variation
Purity requirements
Atmospheric interferences
Generation and storage
equipment
Develop purchasing
guides. Batch test
for conductivity
Redistillation, heat-
ing, deionization
with ion exchange
' columns.
Filtration of ex-
change air
Maintenance schedules'
from manufacturer's
recommendations and
from method require-
ments
2.5 References
4.
5.
Guidelines of Technical Services of a State Air Pollu-
tion Control Agency. Environmental Protection Agency.
Contract No. 68-02-0211. 1972.
Unpublished research,. California Air Resource Board.
January 1977.
Field Operations Guide for Automatic Air Monitoring
Equipment. Environmental Protection Agency. APTD-0736
October 1972.
40 CFR 58, Appendices C, D, and E, May 10, 1979.
Quality Control Practice in Processing Air Pollution
Samples. Environmental Protection Agency. APTD-1132
March 1973.
-------
V
-------
Addendum to Section 2.0.3
Data Handling and Reporting
In addition to data validation information presented in this section, an excellent
document concerning this topic, Validation of Air Monitoring Data (EPA 600/4-
80-030), has been published by EPA. It is available as document number PB 81
112534 from the National Technical Information Service, 5285 Port Royal
Road, Springfield, Virginia 22161.
-------
-------
Section No. 2.0.3
Revision No. 1
Date July 1, 1979
Page 1 of 13
3.0 DATA HANDLING AND REPORTING
3 .-1. Data Recording
This section presents standard forms generally used to
record data .gathered by ambient air monitoring systems, and it
identifies problems common to data reporting.
3.*1-1 Standard Forms for Reporting1 - All data forms should in-
clude station identification adequate for tracing to the original
site description.. The site description should include all infor-
•mation identified on the SAROAD, form, Figure 3.1; the same codes
should be assigned to the SAROAD daily and hourly data forms,
Figures 3.2 and 3.3, respectively. These standard EPA data forms
are designed to aid in transmitting data from the State and local
agencies to the EPA data bank in accordance with 40 CFR 51,
Part 51.7. The detailed procedures to be followed in completing
these forms are . given on Reference 2. These 'forms will be up-
dated • periodically and • the user should maintain current forms.
If computer techniques 'are used for recording results, the
computer system must be designed to maintain compatibility be-
tween the SAROAD station codes and the codes used by the computer
program. Whenever station parameters change or when a station
is moved, an updated site identification form (.Figure 3.1) should
be submitted to the data bank.
Identification errors can be avoided by preprinting all
forms, checklists, calibration forms, and so forth, with the
station identification. 'If this technique is adopted, control
must be employed to be certain that unused forms are discarded
and-new ones printed when the station identification changes.
Preprinting the pollutant I.D. and the proper decimal points for
that pollutant on the reporting forms can eliminate the problem
of misplaced decimals.
Acceptability limits for start-stop times, flow rate, and
other routine system checks performed by the operator should
-------
Section No. 2.0.3
Revision No. 1
Date July 1, 1979
Page 2 of 13
ENVIRONMENTAL PROTECTION AGENCY
National Aerometric Data Bank
Research Triangle Park. N. C. 27711
SAROAO Site Identification Form
6/6/77
D
TO 8E COMPLETE1" BY THE
i A\ C^ Q. \ i
• UO4< 3 characters)
Bj ^
ernc»v-di»oo
•"•»'• County Name (15
City Population (right justified)
|OlO|0|3!2|5l5ll
JJ 43
1 0 0 1 W
(U fl tl
UTM Zone
•1 1 1
(O| 'M^l' IWI
characters)
54 IS i« 4/ 58 49
Longitude Latitude
Deg. Mm. Sec. Oeg. Mm. Sec.
I ll7(4l3lZk
ft fi S4 «b 6; 63
Easting Coord., meters
1
D N|3l4|/lolo|Sl
69 ."'• /I ;: ;3 M »5 18
Northing Coord., meters
1 1 1 1 1 1 1
• ^\ • f"3
rKiiou riiv* HcSot
Supporting Agency
j^^,- Rr-rtir^
(61 characters)
Supporting Agency, continued
"':' Optional, Comments that will help identify
the sampling site (132 characters)
irn
IF)
DO NOT WRITE
State Area
A
1 7 a < 4 6
Agency Project
a
HERE
Site
1 1
r a 9 10
II 12 13
Region Action
a a
') 80
State Area
8 i
Site
|
1 .' 3 » S G 7 8 9 JO
Agency Proiect SMSA Actio
L 1 1 U !_'
i — i i — i i i i
11 1*13 1415
State Area
c 1
1 7 3 4 S 6
Agency Project
n ED
11 1? 13
State Area
0 |
1 .-3*56
Agency Project
n ED
! i 17 13
State Area
E
n n
i ..i 1 1 — i
16 i; in
Site
F
7 a s ..
Action
n
ao
Site
1
/ 8 9 10
Action
n
30
Site
1
Abbreviated Site Address (25 characters)
OMB No. 1S8-R0012
Approval expires 6/30/76
3 « 5 6 ' 89
Agency Project Action
D ED D
(over)
Figure 3.1 SAROAD site identification (front).
-------
Section No. 2.0.3
Revision No. 1
Date July 1, 1979
Page 3 of 13
SAROAD Site Identification Form (continued)
TO BE COMPLETED BY THE REPORTING AGENCY
DO NOT WRITE HERE
(R IO5O San
Sampling Site Address (41 characters)
Check the ONE
major category that
best describes the
location of the
sampling site.
1.CH CENTER CITY
Address, continued
Next, check the subcategory
that best describes the domi-
nating influence on the sampler
within approximately a 1-mile
radius of the sampling site.
2.12SI SUBURBAN
X
RURAL
1. Industrial
2. Residential
3. Commercial
4. Mobile
1. Industrial
2. Residential
3. Commercial
4. Mobile
1. Near urban
2. Agricultural
3. Commercial
4. Industrial
5. None of the above
4.f~l REMOTE
Specify
units
20-Pi-
Elevation of sampler above ground
Specify
units
Elevation of sampler above mean sea level
Circle pertinent time zone: EASTERN CENTRAL
MOUNTAIN PACIFIC YUKON ALASKA BERING
HAWAII
State
Area
Site
1 234561
Agency
n
Project
an
Station Type
County Code
AOCR Number
61 63 63
AQCR Population
69 70 71
Elevation/Gr
J3 73 74
Elevation/MSL
Time
Zone Action
75 76 77 78
Figure 3.1 (continued)
SAROAD site identification form (back).
-------
Section No. 2.0.3
Revision No. 1
Date July 1,.1979
Page 4 of 13
ENVIRONMENTAL PROTECTION AGENCY
National Aerometric Dad Bank
Research Triangle Park. N. C. 27711
SAROAD Daily Data Form
24-hour or .greater sampling interval
OMB No. 158-R0012
Approval empires 6/30/76
2
Cali-rorKii'CL Air Re5oufa?^ Boovei
' l4i«UI
Units
lo
1
31' 31
34 3i 36
n
I
— —I
'
1
1
'
i
O
^J"
-f -
j
DP
o]
32
Time Interval
Name
PARAMETER
Code
Me
3t 39 4-J Jl
hod . Units DP
nnnn
a] 44 4^ 4€
....
• Ag
[
Slate Area Site •
0|Sl©|4-|4.k
Dlolokvl
; j 4 •. 6 ; i u in
ency Project Tirre Year
II 1. 13 14 IS 16
Name
PARAMETER
Code
C
Me
J)
1
hod
D
iS
6'
-"
Units
| i
S? 91 t-J
.
DP
n
6U
Month
lolel
U II
Name
PARAMETER
Code
Met
c
66 6/68 (9
hod .Units DP
nmn
7t 77 ;j /4
'') '6 •' IB
.....
1)10
4371
Figure 3.2 SAROAD daily data form.
-------
Section No. 2.0.3
Revision No. 1
Date July 1, 1979
Page 5 of 13
SSS
•steU
J£
fQ
•Q-
CD
fe
i-s 5
£.„. ty
= d_l
C.3
II
a
o
e C
H
~3
-eg
- u
I,C
5 S
O
"*c
i3
< a
? 'C
1/1 C
i
OCi-s
nccc
= 3
0^
C-
OCC
CCQ
CC
GO
CC
00
u
CC
•r
—;~M
-HH
i
,-.-L
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i
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-1-U l.
i n^r
THTT
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trur
itn
-f
~tt!
-------
Section No. 2.0.3
Revision No. 1
Date July 1, 1979
Page 6 of 13
appear on the data recording form as a reminder to the operator.
If a value outside these limits of acceptability is recorded,
the operator should flag the value for the attention of individ-
uals performing data validation functions.
3.1.2 Data Errors in Intermittent Sampling - The most common
errors in recording data in the field are transposition of digits
and incorrect placements of decimal points. These errors are
almost impossible to detect. The decimal error can be avoided to
some extent by providing an operator with the following guide-
lines for accuracy:
• Number of Example cone:,
Pollutant ' decimal places pg/m3
Suspended particulate matter 0 87
Benzene soluble organic"matter 1' 6.1
Sulfates 1 10.1
Nitrates 1 2.3
Ammonium . . 1 . 0.7
Sulfur dioxide 0 98
Nitrogen dioxide 0 40
Nitric oxide 08
Carbon monoxide 1 4.5
Total oxidants 0 100
Total hydrocarbons 1 2.7
Ozone • 0 72
Methane ' 1 ]_ _ 5
3.1.3 Data Errors, in Continuous Sampling - Data error's in con-
tinuous sampling primarily include errors in recording device
functioning, and errors in strip chart reading for manual techni-
ques or in data transmission for. automated techniques of data
recording. See Sections 1.4.10 and 1.4.17 of Volume I of this
Handbook for additional information concerning data reduction and
data validation. In particular, for errors in automated tech-
niques of data transmission and recording, see Section 1.4;10.
-------
Section No. 2.0.3
Revision No. 1
Date July 1, 1979
Page 7 of 13
Strip chart errors - Errors in mechanical functions of strip
charts can occur. General guidelines to avoid errors or loss of
data caused by mechanical problems follow:
1. Perform a daily check to assure an adequate supply of
strip chart paper. Check the ink-level in the recorder pen to
verify that the .level is adequate for the next sampling period
and that the pen tip is not blocked.
2. 'Perform a daily check to verify that the pen on the
recorder aligns with the baseline of the strip chart during the
instrument zero check.
3. Verify the timing of the strip. chart drive against a
standard timepiece immediately after installation of the recorder
and at intervals dictated by experience with the recorder.
4. Replace recorder pens, and soak in cleaning solution
occasionally.
5. Examine the strip chart for apparent evidence of chart
drag of malfunction, and mark suspected intervals.
When reviewing a strip chart, typical signs of system mal-
function are:
1. A straight trace for several hours (other than minimum
detectable).
2. Excessive noise as indicated by a wide solid trace, or
erratic behavior such as spikes.that are sharper than is possible
with .the normal instrument response time. Noisy- outputs usually
result when analyzers are exposed to vibrations.
.3. A long steady increase or decrease in deflection.'
4. A cyclic pattern of the trace with a definite time
period indicating a "sensitivity to changes in temperature or
parameters other than the pollutant concentration.
5. Periods where the trace drops below the zero baseline.
This may result from a larger-than-normal drop in the ambient
room temperature or power line voltage.
Void any data for any time interval for which malfunction of
the sampling system is detected.
-------
Section No. 2.0.3
Revision No. 1
Date July 1, 1979
Page 8 of 13
Suggestions for minimizing errors in reading strip charts
are as follows: '
1. Chart readers should be trained with a standard strip
of chart, whose readings have been determined by one or more
experienced readers. When the new reader can perform adequately
on the standard strip, then permit him/her to read new sample
charts. A suggested procedure for reading a strip chart is given
in the following subsection.
2. An individual should spend only a portion of a day
reading strip charts since productivity and reliability are
expected to decrease after a few hours.
3. A senior technician should check at least 5% to 10% of
the strip' chart values reduced. The percentage of checking is
arbitrary, and depends on both the depth of training of the junior
technicians and the time available for checking their work. If
minimum performance criteria established for a particular network
are not being met, additional training is indicated.
4. Use a chart re-ader to reduce technician fatigue and to.
improve accuracy in data reduction.
Data reduction from strip chart - To obtain hourly average
concentrations from a strip chart record, the following" proce-
dures are used:
1. Be sure the strip chart record for the sampling period
has span and zero traces at the beginning and at the end of the
sampling period.
2. Fill in the identification data called for at the top
of an hourly averages form, Figure 3.4.
3. Using a straight edge, draw a line from the zero base-
line at the start of the sampling period to the zero 'baseline at
the end of the sampling period. This line represents the zero
baseline to be used for the sampling period.
4. Read the zero baseline in percent of chart at the mid-
point of each hour interval, and record the value on Figure 3.4.
5. Determine the hourly averages by using a transparent
straight edge at least 25 mm (1 in.) long. Place the straight
-------
Section No. 2.0.3
Revision No. 1
Date July 1, 1979
Page 9 of 13
CITY.
SITE
^
Cc
LOCATI ON IOSO Sar\
RA
SITE N0._
POLLUTANT.
OPERATOR
V
DATE
*j£
HOUR
00
""
READING ! ZERO BASELINE 1 DIFFERENCF 1 ADD + 5 1 PPm
ORIGINAL
:.JL
CHECK
ORIGINAL
S~
CHECK
ORIGINAL
¥
.
CHECK
ORIGINAL
p
CHECK
ORIGINAL
0. 0&0
CHECK d
_
—
The check columns are for use by an independent audit.
performed on approximately 7 percent -of the data.
The check is
Figure 3.4 Sample form for recording hourly averages.
-------
Section No. 2.0.3
Revision No. 1
Date July 1, 1979
Page 10 of 13
edge parallel to the horizontal chart division lines. For the
interval of interest between two vertical hour lines, adjust the
straight edge between the lowest and highest points of the trace
in thac interval, keeping the straight edge parallel to the chart
division lines until the total area above the straight edge
bounded by the trace and the hour lines is estimated to equal the
total area below the straight edge bounded, by the trace and hour
lines. Read and record-the percentage of chart deflection on the
hourly average form. Repeat the procedure for all the hour
intervals sampled which have not been marked invalid. Record
all values in the column headed "Reading - Original" (Figure 3.4).
6. Subtract the zero baseline value from the reading
value, and record the difference (Figure 3.4).
7. Add .the percentage of zero offset, +5, to the differ-
ence.
8. Convert the percentage chart values to concentration
(ppm) ' using the most recent calibration curve. Record the ppm
NO2 values in the last column (Figure 3.4).
Data validation - The purpose of data validation is- to
detect and then verify any data values that may not represent
actual air quality conditions at the sampling station. Effective
data validation procedures usually are handled completely inde-
pendently from the procedures of initial data collection. More-
over, it is advisable that the individuals responsible for data
validation not be directly involved with data collection.
Both manual and computer-oriented systems require individual
reviews of all data tabulations. As an individual scans tabula-
tions, there is no way to determine that all values are valid.
The purpose of manual inspection is to spot unusually high (or
low) values that, might indicate a gross error in the data col-
lecton system. Obviously, to recognize that the reported con-
centration of a given pollutant is extreme, the individual must
have basic knowledge of the major pollutants and of air quality
conditions prevalent at the- reporting station. Data values
-------
Section No. 2.0.3
Revision No. 1
Date July 1, 1979
Page 11 of 13
considered questionable are referred to the data collection group
for verification. This scanning for high/low values is sensitive
tc spurious extreme values but not to intermediate values that
could be grossly in error.
Manual review of data tabulations also allows detection of
uncorrected drift in the zero baseline of a continuous -sensor.
Zero drift may be indicated when the daily minimum concentration
tends to increase or decrease from the norm over a period of
several days. For example, at most sampling stations the early
morning (3:00 a.m. to 4:00 a.m.) concentrations of carbon
monoxide tend to reach a minimum of 2 to 4 ppm. If the minimum
concentration differs significantly from this, a zero drift can
be suspected. Zero drift could be confirmed by review of the
original strip chart.
In an automated data processing system, procedures for data
validation can easily be incorporated into the basic software.
The computer can . be programmed to. scan each data value before
preparing an output tabulation. Questionable data values are
then flagged on the data tabulation to indicate a possible error.
A computer can easily handle inspection for extreme values.
Tables of high and low values for each pollutant at each sampling
station can be built into the program. The check for extreme
values can be further refined to account for time of day, time of
week, and other cyclic conditions.
Because the computer can perform computations and make
comparisons extremely rapidly, it can also make some determina-
tion concerning the validity of data values that are not neces-
sarily high or low. Data validation procedures should be recom-
mended as standard operating procedures.-"2 One way to do this is
to test the difference between successive data values, since one
would not normally expect very rapid changes in concentrations of
a pollutant during a 5-min or 1-h reporting period. When the
difference between two successive values exceeds a predeter-
mined value, the tabulation can be flagged, with an- appropriate
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• Section No. 2.0.3
Revision No. 1
Date July 1, 1979
Page 12 of 13
symbol. For example, if two values for hourly sulfur dioxide
3
concentrations differ by >0.05 ppm (100 pg/m ), the data
wlidd'cion stall may wish to recheck the original records from
which the data were obtained.
i. 1 Systematic Data Management
An orderly process of data management based on analysis of
all the data-handling procedures and their interrelationships is
sometimes called a "systems" approach. This kind of systematic
overview of the total data function is accomplished in three
phases:
1. Surveying current and future reporting requirements.
2. Outlining the present routine flow of data within and
outside the agency.
3. Redesigning the current system to allow maximum func-
tional overlap of filing and retrieval routines.
A survey of current reporting requirements involves summa-
rizing and categorizing the reports .currently required and their
important data elements. The purpose of this analysis is to
identify report elements that require similar input, to allow
optimum scheduling, and to differentiate between required 'reports
and those provided as a service. Future reporting requirements
will be based on projected legal requirements, projected develop-
ments of systems for communicating with various data banks, and
projected growth of the air quality surveillance network.
Outlining present data flow requires a review of the origin
of each data form, the- editing procedures applied, the calcula-
tions performed, the application of quality control procedures,.
and the reports for which each form is used. The. purpose of
outlining the data flow is to "identify data elements that are
subjected to similar checks and to similar calculating procedures
and to classify them "according to their points of origin. Once
again, this procedure provides a means of preventing unnecessary
duplication.
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Section No. 2.0.3
Revision No. 1
Date July 1, 1979
Page 13 of 13
As a final step in systematic data management, the data
system should be continually updated. The following items are
suggested for review:
1. What operations are duplicated in the system?
2. Blow can the system be changed to eliminate needless
duplications? .
3. How do the . manual systems and computerized systems
augment each other?
4. Are the data formats, identification codes, and other
elements compatible throughout the system?
5. Can reporting schedules be changed to minimize the
filing and retrieval of each data record?
6. Can special techniques, such as the use of multipart
forms/ be applied to minimize data transposition?
7. Are filing and retrieval systems sufficiently flexible
to allow expansion or upgrading at minimum cost?
3.3 Evaluation of Air Quality Data • . •
Minimum requirements and procedures for .evaluation of" air
quality data are given in References 2, 3, and 4. However, the
analyst should also use Reference 4 for specific statistical
methodology for analysis of air quality trends. A bacic did
CUEn-inn nf 1-hn r-t-i-M r-h-i r--n rr^-t-fr^r; -j n contained in th~ appendices
to Volume I of thic Handbook.
3.4 References
1. Quality Control Practice in Processing Air Pollution
Samples. Environmental Protection Agency. APTD-1132.
March 1973.
2. AEROS Manual Series Volume II: AEROS USER'S Manual
EPA-450/2-76-029, OAQPS No. 1.2-.039. December 1976.
3. Guidelines for the Evaluation of Air Quality Trends.
Environmental Protection Agency, Research Triangle
Park, N.C. OAQPS No. 1.2-014. December 1974.
4. Guidelines for the Evaluation of Air Quality Data.
Environmental Protection Agency, Research Triangle
Park, N.C. OAQPS No. 1.2-015. January 1975.
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Section No. 2.0.4
Revision No. 1
Date July 1, 1979
Page 1 of 6
4.0 REFERENCE AND EQUIVALENT METHODS
For monitoring in a SLAMS or NAMS network, either
reference or equivalent methods are generally required.3 This
requirement is specified in-40 CFR Part 58, Appendix C (Federal
Register, Vol 44, May 10, 1979, page 27584). • In addition,
reference or equivalent methods may be required for certain
other monitoring applications—for example, monitoring
associated with prevention of significant deterioration (PSD).
Requiring the uses of .reference or equivalent methods =helps to
assure that air quality measurements ' are made with methods
which have been shown to have adequate accuracy and reliability.
The definitions and specifications of reference and
equivalent methods are given in 40 CFR Part 53. However, for
most jnonitoring applications the distinction between reference
and equivalent methods is unimportant;, either, may be used
interchangeably..
Reference and equivalent methods may be either manual or
automated (analyzers). For S02, particulates, and Pb, the
reference method for each is a unique manual method that is
completely specified in an Appendix to .40 CFR Part 50; all
other methods for S02 and Pb qualify as equivalent methods.
(As yet, there is no provision in the regulations for
designating equivalent methods for particulates.) • For CO, NO2/
and O3/. Part 50 gives only a measurement principle' and
calibration procedure applicable to reference methods for those
pollutants. Automated methods (analyzers) for these pollutants
may be designated either as reference methods or equivalent
methods, depending on whether or not the methods utilize the
same measurement principle and calibration procedure specified
in Part 50 for reference methods. ' since any analyzer which
a
Certain exceptions, to' this general requirement are provided
in Appendix C of 40 CFR Part 58.
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Section No: 2.0.4
Revision No. 1
Date July 1, 1979
Page 2 of 6
meets the requirements of the specified measurement principle
and calibration procedure may be designated as a reference
method, there are numerous reference methods for CO, NO-, and
Og. Further information on this subject is in the preamble to
40 CFR Part 53, published in the Federal Register, February 18,
1975 (40 FR 7045-7046),..
Except for the (unique) reference methods for S02/
particulates, and Pb specified in Part 50, all reference and
equivalent methods must be officially designated as such by EPA
under the provisions of 40 CFR Part 53. Notice of each
designated method is published in the Federal Register at the
time of designation. In addition, a current list of all
designated reference and equivalent methods is maintained and
updated by EPA whenever a new method is designated. This list
may be obtained from the Quality Assurance Coordinator at any
EPA regional office or from the Environmental Monitoring
Systems Laboratory, Department E, MD-77, -Research Triangle
Park, North Carolina 27711. Moreover, any analyzer offered
for sale as a reference or equivalent method after April 16,
1976, must bear a label or sticker indicating that the analyzer
has been designated as a reference or equivalent method by EPA.
For automated methods, a designation applies only to an
analyzer which is identical to the analyzer described in the
designation. Since in the past manufacturers may have changed
or modified analyzers without changing the model number, the
model number alone does not necessarily indicate that an
analyzer is covered under a - designation. In many cases,
analyzers manufactured prior to the designation may be' upgraded
(e.g., by minor modification or by substitution of a new
operation or instruction manual) to make them identical to the
designated method and thus to achieve the designated status at
modest cost. The manufacturer should be consulted to determine
whether an analyzer is covered under a designation or whether,
it is feasibile to upgrade it to the designated status.
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Section No. 2.0.4
Revision No. 1
Date July 1, 1979
Page 3 of 6
Furthermore, any modification to a reference or equivalent
method made by a user must be approved by EPA if the designated
status is to be maintained (see Section 2.8 of 40 CFR Part 58,
Appendix C).
Sellers of designated automated methods must comply with
the conditions summarized below:
. 1. A copy of the approved operation or instruction manual
must accompany the analyzer when it is delivered to the
ultimate purchaser.
2. The analyzer must not generate any unreasonable hazard
to operators or to the environment.
3. The analyzer must function . within the limits of the
performance specifications in Table 4.1 for at least 1 yr after
delivery when maintained and operated in accordance with the
operation manual.
4: ' Any analyzer offered for sale as a reference or
equivalent method must bear a label or sticker indicating 'that
it has been designated as a reference or equivalent method in
accordance with Part 53.
5. If such an analyzer has one or more selectable ranges,
the label or sticker must be placed in close proximity to the
range selector and must indicate which range or ranges, have
been designated as reference or equivalent methods.
6. An applicant who offers analyzers for sale as
reference or equivalent methods is required to maintain a list
of ultimate purchasers of such analyzers and to notify them
within 30 days if a reference or equivalent method designation
applicable to the analyzers has been cancelled or if adjustment
of the analyzers is necessary under 40 CFR 53.11(b) to avoid a
cancellation.
7. An applicant who modifies an analyzer previously
designated as a reference or equivalent method is neither
permitted to sell the modified analyzer as a reference or
equivalent method (although an applicant may choose to sell it
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Section No. 2.0.4
Revision No. 1
Date July 1, 1979
Page 5 of 6
without such representataion) nor permitted to attach a label
or sticker to the analyzer (as modified) under the provisions
described above, until the applicant has received notice under
40 CFR 53.14(c) that either the original designation or a new
designation applies to the method as modified or until the
applicant has applied for and received notice of - a new
reference or equivalent method determination for the analyzer
as modified. .
Aside from occasional breakdowns or malfunctions,
consistent or repeated noncompliance with any of these
conditions should be reported to EPA at the address given
previously.
In selecting designated methods, keep in mind that
designation of a method indicates only that it meets certain
minimum -standards. Competitive differences still exist among
designated analyzers. Some analyzers or methods may have
performance, operations, economic,' or .other advantages over
other analyzers or methods. Thus the need for a careful
selection process based on the individual air monitoring
application and circumstances is still very important.
However, some of the performance tests and other criteria used
to qualify a method for designation as a reference or equiv-
alent method are intended only as pass/fail tests to determine
compliance with the minimum standards. Therefore, test data
from such tests may not. be usable to quantitatively compare one
method with another method. Furthermore, designation as a
reference or equivalent method provides no guarantee that a
particular analyzer will operate properly, since' any ,analyzer
can malfunction. So an on-going quality assurance progaram is
necessary and required for designated methods under Appendix A
for SLAMS and Appendix B for PSD of 40 CFR Part 58.
Appendices- A and B require the monitoring organization to
establish an internal quality control program. Specific
guidance for a minimum quality control program is described in
Section 2.0.9 of this Handbook..
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Section No. 2.0.4
Revision No. 1
Date July 1, 1979
Page 6 of 6
Many organizations have elected to specify 'or select
designated reference or equivalent methods even for monitoring
applications other than those required by Part 58. This
practice may offer significant advantages, such as: (1) ease
of specification, (2) guarantee of minimum performance,.
(3) better instruction manuals, (4) flexibility of application,
and (5) increased credibility of measurements.
4.1 References
1. Code of Federal Regulations 40. Protection of the
Environment. Parts 50 to 69. As ammended, May 10, 1979.
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Section No. 2.0.5
Revision No. 0
Date May 1, 1978
Page 1 of 5
5.0 RECOMMENDED QUALITY ASSURANCE PROGRAM FOR AMBIENT AIR
MEASUREMENTS
In order for air monitoring data to be useful, they must be
of acceptable quality. The dissemination and use of data of poor
or unknown quality can lead to incorrect decisions with regard to
environmental standards and regulatory actions. The gathering of
air monitoring data under the umbrella of a quality assurance
program does' much to avoid regulatory mistakes; thus all control
agencies should vigorously pursue the implementation of such
measures. '
The major elements of a satisfactory quality assurance
program are (-1) the availability of an evaluated measurement
methodology which is adequate for ' its intended purpose,
(2) satisfactory performance by organizations collecting the air
pollution monitoring data, (3) documentation of. quality assurance
practices, and (4) the .availability o.f competent technical as-
sistance for organizations needing to improve their performance.
It is imperative that the management of the monitoring program be
committed to a quality assurance program and that adequate re-
sources be available to carry on the activities involved in its
major elements. • '
To be s.ure, the implementation of a formal quality assurance
program does have its price, but the cost of collecting good air
monitoring data is far less than the cost of making incorrect
regulatory decisions because of poor data. Experience has shown
that an agency should be prepared to spend between 10% and 25%
of its monitoring budget for its quality assurance program.
5.1 Development and Implementation of Air Pollution Measurement
Quality Assurance Programs
Federal, State, and local agencies all have important roles
to play in developing and implementing a satisfactory quality
a
Recommendations of EPA's Standing Air monitoring Work Group
.(SAMWG) v
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Section No. 2.0.5
Revision No. 0
Date May 1, 1978
Page 2 of 5
assurance program. EPA's responsibility is to develop the tools
needed to carry on a quality assurance program, and it is up to
the State and"local agencies to implement their programs.
5.1.1 Role of EPA Headquarters - EPA headquarters has the fol-
lowing responsibilities:
1. To be certain that the methods and procedures used in
making air pollution measurements are well evaluated and that
their limits of precision and accuracy are well understood.
2. To determine the performance of laboratories making air
pollution measurements of importance to the regulatory process.
3. To implement satisfactory quality assurance programs
over EPA's air pollution monitoring which have the potential for
generating data used for setting, standards.
4. To be certain that air monitoring data of importance to
the regulatory process are of satisfactory quality.
5. To share with EPA regional offices - the rendering of
technical assistance to .the air pollution monitoring community.
5.1.2 Role of the EPA Regional Offices - The major responsibil-
ity of EPA's regional offices is the coordination . of quality
assurance matters between the various elements of EPA and the
State and local agencies. This role requires that the regional
offices make available to the State and local agencies the tech-
nical information 'and quality assurance programs which EPA head-
quarters has developed and make known to EPA headquarters the
unmet quality assurance needs of the State and local agencies.
Another very important function of the regional office is the
evaluation of the capabilities of State and local agency
laboratories to measure air pollutants of regulatory concern. To
be effective in these'roles, the regional offices should maintain
and strengthen their technical capabilities with respect to air
pollution monitoring.
5'1-3 Role of State and Local Agencies - The major responsibil-
ity of State and local agencies is the implementation of satis-
factory quality assurance programs over the monitoring which
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Section No. 2.0.5
Revision No. 0
Date May 1, 1978
Page 3 of 5
yields the air quality data needed for the regulatory process.
It is the responsibility of State and local agencies to implement
these programs in their own laboratories and in any consulting
and contractor laboratories which they may use to obtain data of
importance to the regulatory process.
5.2 Minimum Quality Assurance. Programs
Comprehensive quality assurance programs in air monitoring
are relatively new, and many agencies responsible for air moni-
toring have not formalized their quality assurance activities
into an identifiable program. As an aid to agencies who are
developing quality assurance programs and to agencies who wish
to review existing programs, we present here those activities
considered to be essential in an air pollution monitoring quality
assurance program. These essential activities and other aspects
of a complete quality assurance program are described in detail
in "Quality Assurance Handbook for Air Pollution Measurement
Systems-- Volume I, Principles" (EPA-600/9-76-005), thus this
document should be consulted in establishing or evaluating a
quality assurance program.
A suggested sequence for the development of a quality as-
surance program is given below. About 12 mo is required for
complete implementation.
5.2.1 Develop Immediately -
1. Agency quality assurance policy and objective - Each
agency should develop a written. quality assurance policy, and
this policy should be made known to all agency personnel. As a
minimum, this policy should create an awareness of quality assur-
ance activities, provide specific procedures for implementing a
quality control program, provide for corrective action when
required, state the quality assurance objectives for each major
monitoring project operated by the agency, and explicitly dele-
gate authority to implement quality assurance systems planned by
management officials.
2. Organization and responsibilities - An organization
chart showing the key agency personnel and their areas of quality
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Section No. 2.0.5
Revision No. 0
Date May 1, 1978
Page 4 of 5
assurance responsibilities should be prepared. A quality assur-
ance coordinator should be designated for the agency. This
designee should be responsible for the coordination of quality
assurance activities within the agency and with other agencies.
5.2.2 Develop Within Six Months -
1. ' Measurement method review and application - All exist-
ing methods (sampling and analysis) used for routine measurements
should be reviewed and revised if necessary; written procedures
should be prepared where none exists. A document control system
should be developed for these methods to keep agency personnel
abreast of changes in methodology. Any ambient air monitoring
for criteria pollutants conducted under State Implementation
Plans must use EPA's reference methods or EPA-approved equivalent
methods.
2. Calibration procedure review - Calibration procedures
used for all measurement methods should be reviewed, revised if
necessary, documented, and included in the method writeup just
mentioned. Document control should also be established for these
calibration procedures to inform agency personnel of any changes.
As an agency policy, traceability of the accuracy of working
calibration standards should be established by comparing these
standards to standards of higher accuracy whenever standards of
higher accuracy are available.
3. Internal quality control procedures - The procedures
used during sampling and analysis to detect, correct, and record
out-of-control conditions should be defined and documented. Use
of control charts is encouraged.
4. Audit .performance - Procedures should be selected and
implemented that will permit comparison of the performance of the •
measurement system (sampling and analysis) under routine opera-
tion versus an independent technique. Commonly, this independent
technique is either a performance audit' or the use of a dual
measurement system. Results from these audit procedures are
useful in detecting bias in the routine measurement system.
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Section No. 2.0.5
Revision No. 0
Date May 1, 1978
Page 5 of 5
5. Interlaboratory testing - Each agency and its contrac-
tors conducting monitoring activities should participate in the
EPA quality assurance performance surveys. Requests for partici-
pation should be made at the EPA regional office.
5.2.3 Develop Within Twelve Months -
1. Data validation procedures - The criteria used to
validate air monitoring data should be documented, and the
routine tests or checks on the raw data should be defined.
2. Preventive maintenance - A schedule for preventive
maintenance should be prepared that identifies the required main-
tenance tasks and frequencies.•. A procedure for performing the
maintenance tasks should be prepared if none is available.
3. Review of training needs - Proper training of staff
members is essential for the performance of their assigned job
responsibilities. During the first 12 mo, the training and
experience of all staff members should be reviewed, and plans
should be made to obtain needed training.
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Section 2.0.6 Chain-of-Custody Procedures for Ambient Air Samples
This section is up-to-date except that data logger printouts have now replaced
most strip chart recording systems for ambient air monitoring. Also, the
manual, wet chemical methods for SO2 and NO2 that use bubbler solutions, as
mentioned in Figures 6.1 and 6.2, are now rarely used because automated SO2
and NO2 air monitoring instruments are available.
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Section No. 2.0.6
Revision No. 0
Date July 1, 1979
Page 1 of 11
6.0 CHAIN-OF-CUSTODY PROCEDURES FOR AMBIENT AIR SAMPLES
A quality assurance program associated with the collection
of ambient air monitoring data must include an effective proce-
dure for preserving the integrity of the data. Ambient air test
results and, in certain types of tests, the sample itself may be
essential elements in proving the compliance status of a facil-
ity; that is, it may be necessary to introduce the sample or the
test results as evidence in an enforcement proceeding. These
will not be admitted as evidence unless it can be shown that they
are representative of the conditions that existed at the time
that the test was conducted. Showing this requires that each
step in the testing and analysis procedure be carefully monitored
and documented.
There are basically four elements in the evidentiary phase
of an overall quality.assurance program: •
1. Data collection - includes testing, preparation and
identification of the sample, strip charts, or -other data.
2. Sample handling - includes protection from contamina-
tion and tampering during transfer between individuals and from
the sampling site to the evidence locker.
3. Analysis - includes storage of samples prior to and
after analysis as well as data interpretation.
4. Preparation and filing of test report - includes evi-
dentiary requirements and retention of records."
Failure to include any one' of these elements in the'collection
and analysis of ambient air monitoring data may render the re-
sults of the program inadmissible as evidence, or may seriously
undermine the credibility of any report based on these data.
6.1 Sample Collection
Ambient air sampling is primarily concerned' with the atmo-
spheric concentrations of such pollutants as particulates, SO
NO , CO, and photochemical oxidants.
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Section No. 2.0.6
Revision No. 0
Date July 1, 1979
Page 2 of 11
To establish the basic validity of such ambient air monitor-
ing data, it must be shown that (1) the proper methods were used,
(2) the equipment was accurately calibrated, and (3) the operat-
ing technician and data analysts were qualified and competent.
The data analyst generally has the primary responsibility
for determining that the proposed sampling method complies with
the appropriate testing regulations and that the equipment is
accurately sited. The technician is responsible for calibration
and operation of the monitors. Each should be able to support
and justify the test methods and calibration procedures used,
especially in instances where it is necessary to deviate from
accepted practices. For example, if the only reasonable, test
site has a less than ideal location, the network analyst must be
competent to make a judgment based upon training and experience
as to whether a -representative sample can .be. obtained at the
site. This .determination, should be recorded and included
in the program's protocol. An after-the-fact site.analysis' may
suffice in many instances, but good quality assurance techniques
dictate that this analysis be made prior to spending the many
man-hours required to collect the, data. Similarly, the techni-
cian must be able to confidently assert that the equipment was
accurately calibrated using correct and established calibration
methods.
6.1.1 Preparation - Prior to the implementation of a sampling
and analysis program, a variety of sampling and analysis equip-
ment must be calibrated. All data and calculations involved in
these calibration activities should be recorded in a calibration
log book. It is suggested that this log be arranged so that" a
separate section is designated for each apparatus and sampler
used in the program.
In some cases, reagents are prepared prior to sampling.
Some of these reagents will be used to calibrate the equipment,
while others will become an integral part of the sample itself.
In any case, their integrity must be carefully maintained from
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Section No. 2.0.6
Revision No. 0
Date July 1, 1979
Page 3 of 11
preparation through analysis. If there are any doubts about the
method .by which the reagents for a particular test were prepared
or about the competence of the laboratory technician preparing
these items, the credibility of the ambient air samples and the
test results will be diminished. It is essential that a careful
record be kept listing the dates the reagents were prepared, by
whom, and their locations at all times" from preparation until
actual use. Prior to the test, one individual should be given
the responsibility of -monitoring the handling and the use of the
reagents. Each use of the reagents should be recorded in a field
.notebook. . . ,
Similarly, filters must be selected and prepared prior to
sampling. These should be inspected to assure that there are no
pinholes, tears, creases, or other flaws which may affect the
collection efficiency of the filter. Each step in the filter
equilibration, weighing, and handling procedures should be care-
fully recorded by the/technician.to assure that the ambient air
sample obtained with each filter' adequately represents existing
conditions.
6-l-2 Identification - Care must be taken to properly mark all
samples and monitoring device readings to ensure positive identi-
fication throughout the test and analysis procedures. The rules
of evidence used, in legal proceedings require that procedures for
identification of samples used in analyses form the. basis for'
future evidence. An.admission by the laboratory analyst that he/
she cannot be positive whether he/she analyzed sample No. 6 or
sample No. 9, for example, could destroy the validity of the
entire test report.. •
Positive identification also, must be provided for any fil-
ters used in the program. If ink is used for marking, it must be
indelible and unaffected by the gases and temperatures to which
it will be subjected. Other methods of identification can be
used, if they provide a positive means of identification and do
not impair the capacity of the filter to function.
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Section No. 2.0.6
Revision No. 0
Date July 1, 1979
Page 4 of 11
Strip charts from automated analyzers must also be clearly
and unambiguously identified. The information must be placed
upon each strip chart so as not to interfere with any of the data
on the chart. If the strip chart is very long, the information
should be pla'ced at periodic intervals on the chart. The
markings should be indelible and permanently affixed to each
strip chart.
Finally, each container should have a unique identification
to preclude the possibility of interchange. Grease pencils may
be used for this purpose; a better method, however, is to affix
an adhesive-backed . label to the container. The number' of the
container should be subsequently recorded on the analysis data
form. Figure 6.1 shows a' standardized identification sticker
which may be used. Additional information may be added as re-
quired, depending on the particular monitoring program.'
6.2 Sample Handling
If actual • samples are cpllected, they must be properly
handled to ensure that there is no contamination and that the
sample analyzed, is actually the sample taken under the conditions
reported. For this reason, samples should be kept in a secure
place between the time they, are collected and the time they are
analyzed. It is highly recommended that all samples be secured
until discarded. These security measures should be documented by
a written record, signed by the handlers of the sample.
6-2.1 Contamination and Tampering - To reduce the possibility of
invalidating the results, all collected samples must be care-
fully, removed from the monitoring device and -placed in
sealed, nonreactive containers. The best method of sealing
depends on. the container; in general, the best way is to simply
use a piece of tape to preclude accidental opening of the con-.
tainer and to act as a sufficient safeguard where all other
aspects of the chain-of-custody procedure are observed. However,
when there is any possibility of temporary access to'the samples
by unauthorized personnel, the sample jars, containers, or
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.Section ,No. 2.0.6
Revision No. 0
Date July 1, 1979
Page 5 of 11
Site name rjc/WZ ^fT
Site address --#"33 18
<*T — &O/& • &/J- J3S~0
Date collected ^^_-7^ J~r>?/eT
Signature £krh-— • s&l-o-*—
U
Figure 6.1 Label for sample identification showing typical
entries for SO2 bubbler solution.
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Section No. 2.0.6
Revision No. 0
Date July 1, 1979
Page 6 of 11
envelopes should be sealed with a self-adhesive sticker which has
been signed and numbered by the operating technician. This
sticker must adhere firmly to ensure that it cannot be removed
without destruction. The samples should then be delivered to the
laboratory for analysis. It is recommended that this be done on
the same -day that the sample is taken from the monitor. If this
is impractical, all the samples should be placed in a carrying
case (preferably locked) uin which • they are protected from
breakage, contamination, and loss.
In transporting samples and other monitoring data, it is
important that precautions be taken to .eliminate the possibility
of tampering, accidental destruction, and/or physical and chemi-
cal action on the sample. These practical considerations must
be dealt with on-a case-by-case basis.
The person who has custody of the samples, .strip charts, or
Other data must be able to testify that no tampering occurred.
Security must be continuous. If the samples are put • in a
truck—lock it. After delivery to the laboratory, the samples
must be kept in a secured place.
To ensure that none of the sample is lost in transport, mark
all liquid levels on the side of the container with a grease
pencil. Thus, any major losses which occur will be readily
ascertainable.
6-2-2 Chain of Custody - If the results of a sampling program
are to be used as evidence, a written record must be available
listing the location of the data at all times.' This chain-of-
custody record is necessary to make a prima facie showing of the
representativeness of the sampling data. Without it, one cannot
be sure that the sampling data analyzed was the same as the data
proported to have been taken at a particular time. The data
should be handled only by persons associated in some way with the
test program. A good general rule to follow is "the fewer hands
the better," even though a properly sealed sample,
for example, may pass through a number of hands without affecting
its integrity.
-------
"Section No. 2.0.6
Revision No. 0
Date July 1, 1979
Page 7 of 11
Each person handling the samples or strip charts must be
able to state from whom the item was received and to whom
delivered. Recommended practice is to have each recipient sign
a chain-of-custody form for the sampling data. Figure 6.2 is a
form which may be used to establish the chain of custody. This
form must- accompany the samples or strip charts at all times from
the field to ~ the laboratory. All persons who handle the data
must sign the form.
When using the U.S. Postal Service to transport sampling
data, only certified or registered mail should be used, and a
return receipt .should be requested. The return receipt should be
marked to indicate that the package is to be delivered to the
addressee only. The addressee should be the specific person who
is authorized to receive the data.
When using the United Parcel Service, commercial bus lines,
or similar, means of shipment, information describing the enclosed
sampling data should be placed .on the Bill of Lading. The
package should be marked "Deliver to Addressee Only," and it
should be addressed to the specific person authorized to receive
the data.
6.3 Analysis of the Sample
For ambient air- samples to provide useful information . or
evidence, laboratory analyses must meet the following four basic
requirements:
.1. Equipment must be frequently and properly calibrated
and maintained.
2. Personnel must be qualified to make the analysis.
3- Analytical -procedures must be in accordance with ac-
cepted practice.
4- Complete and accurate records must be kept.
The first three requirements are similar to those previously
discussed, and need no further elaboration. Proper records may
consist of a laboratory notebook 'or summary sheets which contain
hourly average concentrations from strip chart readings. Where
-------
Section No. 2.0.6
Revision No. 0
Date July 1, 1979
Page 8 of 11
Plant
Sample
number
5!<6f5- ,
-23;??
J381
Number
of
container
1
1
1
Description
of samples
A;-\Jol •£•;/•{-££ ?W 2)/'io*J C-A#£r
SO*. 6a2>£j£/Z ' So/*T/etO /9/i/a/ d#-r# S/)££T
rf
3.3 J-9
Relinquished
by
~Jchn ~Do£
"70s"' 3~o*J€s
-rZ*i TtfK/rs
"7^/n .'TrfVfS
Received
by
'Tom 3~od£S
2)&M;e dfat
frs* C/ae.;?
37/»i C//w.£
Time
He 30
tftso
/ a a O
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Date
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Ar/rt/vj/'s of S0*
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Figure 6.2 Ambient air sample integrity form showing
typical entries.
-------
Section No. 2.0.6
Revision No. 0
• Date July 1, 1979
Page 9 of 11
practical, standard preprinted forms should be used. .Do not
discard these records since it is possible that they will be
required to substantiate the final report in the future.
It is important to realize that chain-of-custody procedures
discussed earlier in this report do not stop with delivery of the
sampling data for analysis. Monitoring data which are not
immediately analyzed should be stored in a •secure location to
which only authorized persons have access. The analyst must be
prepared to testify that at all times the sampling data were
either in his/her possession and view or in a secure place. Once
the data are analyzed, they should be returned to the secured
storage location and retained at least until the report has been
finally accepted.
6.4 Field Notes
Manual recording of data is sometimes required for ambient
air tests. Standardized forms should be utilized to ensure that
all necessary information is obtained.. These forms should be
'designed to clearly identify the .process tested, the date and
time, location of test station, and operating personnel. These
data may determine the' credibility of the data and should no.t be
erased or altered. Any errors should be crossed out with a
single line, and the correct value recorded above the crossed-out
number.
Do not discard the original field records even if. they
become soiled. Copies are not normally admissible as evidence.
For neatness, the field data may be transcribed or copied for
'incorporation in.a final report, but the originals should be kept
on file. Since these records may be subpoenaed, it is important
that all field notes be legible.
6.5 The Report as Evidence
In addition to samples and field records, the report of the
analysis itself may serve as material evidence. Just as the
procedures and data leading up to the final report are subject to
the rules of evidence, so is the report itself. Written docu-
-------
Section No. 2.0.6
Revision No. 0
Date July 1, 1979
Page 10 of 11
ments, generally speaking, are considered as hearsay, and are not
admissible as evidence without a proper foundation. A proper
foundation consists of introducing testimony from all persons
having anything to do with the major portions of the test and
analysis. Thus the field operator, all persons having custody of
the samples, and the analyst would be required to lay the founda-
tion for the introduction of the test report as evidence.
Legal rules recognize that a record of events is the result
of input from many per sons*'"who have no reason to lie and that
production of all these persons as witnesses is onerous. These
rules recognize the complexity and mobility of our society and
are relatively liberal. Indeed in many cases the trial 'judge
will require the parties to stipulate as to the authenticity of
ambient air test reports during the pretrial proceedings.
However, the party against whom the report is offered still has
the right to cross-examine the sampling program participants if
the party has reasonable cause. In this area, the trial judge
may exercise discretion.
The relaxed attitude toward reports of experiments made by
persons in the regular course of activity greatly simplifies the
introduction of the report in evidence. Only the' custodian of
the report need testify in most cases.
To ensure compliance with legal rules, all test reports
should be filed 'in a safe place by a custodian having this re-
sponsibility. Although the field notes and calculations are not
generally included in the summary report, these materials may be
required at a future date to bolster the acceptability and credi-
bility .'of the report as evidence in an enforcement proceeding.
Therefore, the full report including all original' notes and
calculation sheets should be kept in the file. Signed receipts
for all samples, strip charts, or other 'data, should also be
filed.
The original of a document is the best evidence; and a copy
is not normally admissible as evidence. Microfilm, snap-out
-------
Section No. 2.0.6
Revision No. 0
Date July 1, 1979
Page 11 of 11
carbon copies, and similar contemporary business methods of
producing copies are acceptable in many jurisdictions if unavail-
ablility of the original is adequately explained and if the copy
was made in the ordinary course of business.
In summary, although all original calculations and test data
need not be included in the final report, they should.be kept in
the agency's files. It is a good rule to file all reports
together in a secure place. Keeping these documents under lock
and key will ensure that the author can testify at future court
hearings that the report has not been altered.
-------
-------
March 1985
Section Z.O.9
9.0 QUALITY ASSURANCE IN THE OPERATION OF AUTOMATED AND MANUAL
MONITORING METHODS IN SLAMS AND PSD NETWORKS
On May 10, 1979, the U.S. Environ-
mental Protection Agency, in re-
sponse to Section 319 of the Clean
Air Act amendments of 1977, pro-
mulgated regulations set forth in 40
CFR Part 581 specifying ambient
monitoring requirements for State
Implementation Plans (SIP's). These
regulations establish a national mon-
itoring network and provide uniform
monitoring requirements for all State
monitoring networks.
An Important part of these specific
requirements is the establishment by
monitoring organizations of quality
assurance programs covering all as-
pects of their ambient monitoring.
Appendix A2 of Part 58 describes the
quality assurance requirements for
organizations responsible for State
and'local air monitoring stations
(SLAMS). Appendix B3 of Part 58 de-
scribes the quality assurance require-
ments for organizations responsible
for prevention of significant deterio-
ration (PSD) air monitoring. Specifi-
cally, Section 2 of Appendices A and
B requires that the affected monitor-
ing organizations develop and imple-
ment quality assurance programs
consisting of policies, procedures,
specifications, standards, and docu-
mentation necessary to: (1) provide
data of adequate quality to meet
monitoring objectives and (2) mini-
mize loss of air quality data due to
malfunctions or out-of-control condi-
tions.
The purpose of the following is to
provide guidance, recommendations,
and suggestions for the development
and implementation of suitable qual-
ity assurance programs, as required
by Appendices A and B, related to
the operation of continuous auto-
mated analyzers and manual meth-
ods used in SLAMS and PSD moni-
toring networks. The guidance
provided here is directed mainly to-
ward establishing a minimum level
of quality assurance for SLAMS and
PSD monitoring. Additional, more ex-
tensive quality assurance is encour-
aged. Reference 4 and the measure-
ment methods sections of this
Handbook (Volume II) provide addi-
tional quidance.
9.1 Quality Assurance for
Automated Analyzers
9.1.1 Analyzer Selection and Accep-
tance Tests—Except for the specific
exceptions described in Appendix C5
of Part 58, monitoring methods used
for SLAMS monitoring must be refer-
ence or equivalent methods desig-
nated as such by the USEPA.6 Moni-
toring methods selected for PSD
monitoring of gaseous criteria pollu-
tants are restricted to automated ref-
erence or equivalent methods.7 Ap-
proval of any Appendix C exceptions
for PSD monitoring must be obtained
from the permit-granting authority
before PSD monitoring is initiated.
Section 2.0.4 of this Handbook (Vol-
ume II) provides more information
on reference and equivalent analyz-
ers. A list of designated reference
and equivalent methods may be ob-
tained from the quality assurance co-
ordinator of any USEPA regional of-
fice or from the Environmental
Monitoring Systems Laboratory,
Quality Assurance Division (MD-77),
Research Triangle Park, North Caro-
lina 27711.
Among reference and equivalent
methods, a variety of analyzer de-
signs and features are available. For
some pollutants, analyzers employ-
ing different measurement principles
are available. And some analyzer
models provide a higher level of per-
formance than others that may only
meet the minimum performance
specifications. Accordingly, in select-
ing a designated method for a partic-
ular monitoring application, consider-'
ation should be given to such
aspects as the suitability of the mea-
surement principle, analyzer sensitiv-
ity and susceptability to interferences
that may be present at the monitor- '
ing site, requirements for support
gases or other equipment, reliability
and maintenance requirements, ini-
tial as well as operating costs, fea-
tures such as internal or fully auto-
matic zero and span checking or
adjustment capability, etc. Refer-
ence 8 and a series of four analyzer
reports (References 9-12) may be
helpful in evaluating and selecting
automated analyzers.
It is important that the purchase
order for a new reference or equiva-
lent analyzer specify designation by
EPA and .document the required per-
formance specifications, terms of the
warranty, time limits for delivery and
for acceptance testing, and what hap-
pens in the event that the analyzer
delivered fails short of the require-
ments.8 Upon receiving the new ana-
lyzer, the user should carefully read
the instruction or operating manual
provided by the manufacturer of the
analyzer. The manufacturer's manual
should contain information or in-
structions concerning:
1. unpacking and verifying that all
component parts were delivered;
2. checking for damage during
shipment;
3. checking for loose fittings and
electrical connections;
4. assembling the analyzer;
5. installing the analyzer;
6. calibrating the analyzer;
7. operating the analyzer;
8. preventive maintenance sched-
ule and procedures;
9. trouble shooting;-
10. list of expendable parts.
Following analyzer assembly, an
initial calibration should be per-
formed to determine if the analyzer
is operating properly. Analyzer per-
formance characteristics such as re-
sponse time, noise, short-term span
and zero drift, and precision should
be checked during the initial calibra-
tion or measured by using abbrevi-
ated forms of the test procedures
provided in 40 CFR Part 53.6 Accep-
tance of the analyzer should be
based on results from these perfor-
mance tests.8 Once accepted, refer-
ence and equivalent analyzers are •
warranted by the manufacturer to
operate 'within the required perfor-
mance limit for one year.6
9.1.2 Analyzer Calibration—Calibra-
tion of an analyzer establishes the
quantitative relationship between ac-
'tual pollutant, concentration input (in
ppm, ppb, (ig/m3, etc.) and the ana-
lyzer's response (chart recorder read-
ing, output volts, digital output, etc.).
This relationship is used to convert
subsequent analyzer response values
-------
Section 2.0.9
March 1985
to corresponding pollutant concen-
trations. Since the response of most
analyzers has a tendency to change
somewhat with time (drift), the cali-
bration must be updated (or the ana-
lyzer's response must be adjusted)
periodically to maintain a high de-
gree of accuracy.
Each analyzer should be calibrated
as directed by the analyzer's opera-
tion or instruction manual and in ac-
cordance with the general guidance
provided here. For reference meth-
ods for CO, NO2, and O3, detailed
calibration procedures may also be
found in the appropriate appendix to
40 CFR Part 50. Additional calibration
information is contained in Refer-
ences 13, 14, 15, and 16.
Calibrations should be carried out
at the field monitoring site by allow-
ing the analyzer to sample test
atmospheres containing known pol-
lutant concentrations. The analyzer to
be calibrated should be in operation
for at least several hours (preferably
overnight) prior to the calibration so
that it is fully warmed up and its op-
eration has stabilized. During the
calibration, the analyzer should be
operating in its normal sampling
mode, and it should sample the test
atmosphere through all filters, scrub-
bers, conditioners, and other compo-
nents used during normal ambient
sampling and through as much of
the ambient air inlet system as is
practicable.* All operational adjust-
ments to the analyzer should be
completed prior to the calibration
(see section 9.1.2 (g)). Analyzers that
will be used on more than one range
or that have autoranging capability
should be calibrated separately on
each applicable range.
Calibration documentation should
be maintained with each analyzer
and also in a central backup file. Doc-
umentation should be readily avail-
able for review and should include
calibration data, calibration equation
(and curve, if prepared), analyzer
identification, calibration date, ana-
lyzer location, calibration standards
used and their traceabilities, identifi-
cation of calibration equipment used,
and the person conducting the cali-
bration.
•Deviations from this general rule may be ac-
ceptable for some CO analyzers to reduce con-
sumption of calibration gas or to accommo-
date automatic calibration systems because
CO is more stable than other gaseous criteria
pollutants and the scale range is normally 100 '
limes higher. However, such deviations should
be used with caution to avoid possible calibra-
tion errors or bias.
(a) Calibration Standards—In gen-
eral, ambient monitoring instruments
should be calibrated by allowing the
instrument to sample and analyze
test atmospheres of known concen-
.trations of the appropriate pollutant
in air. All such (non-zero) test con-
centrations must be, or be derived
from, local or working standards
(e.g., cylinders of compressed gas or
permeation devices) that are certified
as traceable to an NBS primary
standard. "Traceable" is defined in
40 CFR Parts 50 and 58 as mean-
ing" ... that a local standard has been
compared and certified, either di-
rectly or via not more than one inter-
mediate standard, to a primary
standard such as a National Bureau
of Standards Standard Reference Ma-
terial (NBS SRM) or a USEPA/NBS-
approved Certified Reference Mate-
rial (CRM)." Normally, the working
standard should be certified directly
to the SRM or CRM, with an interme-
diate standard used only when nec-
essary. Direct use of a CRM as a
working standard is acceptable, but
direct use of an NBS SRM as a work-
ing standard is discouraged because
of the limited supply and expense of
SRM's. As a minimum, the certifica-
tion procedure for a working stand-
ard should (a) establish the concen-
tration of the working standard
relative to the primary standard,
(b) certify that the primary standard
(and hence the working standard) is
traceable to an NBS primary stand-
ard, (c) include a test of the stability
' of the working standard over several
days, and (d) specify a recertification
interval for the working'Standard.
Certification of the working standard
may be established by either the
supplier or the user of the standard.
A recommended protocol for certify-
ing'gaseous standards against an
SRM or CRM is given in Section 2.0.7
of this Handbook (Volume II). Also, a
list of CRM sources is available from
the Quality Assurance Division
(MD-77), Environmental Monitoring
Systems Laboratory, U.S. Environ-
mental Protection Agency, Research
' Triangle Park, North Carolina 27711.
Test concentrations of ozone must
be traceable to a primary standard
UV photometer as described in Ap-
pendix D of 40 CFR Part 50. Refer-
ence 17 describes procedures for cer-
tifying transfer standards for ozone
against UV primary standards.
Test concentrations at zero concen-
tration are considered valid stand-
ards. Although zero standards are
not required to be traceable to a pri-
mary standard, care should be exer-
cised to ensure that zero standards
are indeed adequately free of all sub-
stances likely to cause a detectable
response on the analyzer. Periodi-
cally, several different and indepen-
dent sources of zero standards
should be compared. The one that
yields the lowest response can usu-
ally (but not always!) be assumed to
be the best zero standard. If several
independent zero standards produce
exactly the same response, it is likely
. that all the standards are adequate.
The accuracy of flow measure-
ments is critically important in many
calibration procedures. Flow or vol-
ume measuring instruments should
be calibrated and certified at appro-
priate intervals (usually 3 to 6
months) against NBS or other au-
thoritative standards such as a trace-
able bubble flow meter or gas meter.
Calibration procedures for some
types of flow and volume meters
may be found in section 2.1.2.1
(Vol. II) and section 3.5.2 (Vol. Ill) of
this Handbook.
Documentation of all calibrations
of instruments and certification of
standards should be maintained,
showing calibration date, calibration
procedure used, calibration data or
curve, name of person conducting
the calibration, and the date for the
next calibration.
(b) Multi-point Calibrations—
Multi-point calibrations consist of
three or more test concentrations, in-
cluding zero concentration, a concen-
tration between 80% and 90% of the
full scale range of the analyzer under
calibration, and one or more
intermediate concentrations spaced
approximately equally over the scale •
range. Multi-point calibrations are
used to establish or verify the linear-
ity of analyzers upon initial installa- •
tion and after major repair. Most
modern analyzers have a linear or
very nearly linear response with con-
centration. If a non-linear analyzer is
being calibrated, additional calibra-
tion points should be included to ad-
equately define the calibration rela-
tionship, which should be a smooth
curve. Multi-point calibrations are
likely to be more accurate than two-
point calibrations because of the av-
eraging effect of the multiple points
and because an error in the genera-
tion of a test concentration (or in
recording the analyzer's response) is
more likely to be noticed as a point
that is inconsistent with the others.
For this reason, calibration points
should be plotted or evaluated statis-
-------
March 1985
Section 2.0.9
tically as they are obtained so that
any deviant points can be investi-
gated or repeated immediately.
Most analyzers have zero and span
adjustment controls, which should be
adjusted based on the zero and high-
est test concentrations, respectively,
to provide the desired scale range
within the analyzer's specifications
(see section 9.1.2.e). (Note—for ana-
lyzers in routine operation, unad-
justed ("as is") analyzer zero and
span response readings should be
obtained prior to making any zero or
span adjustments—see the discus-
sion of unadjusted readings under
"Level 1 zero and span calibration".)
NO/NO2/NOX analyzers may not have
•individual zero and span controls for
each channel; the analyzer's opera-
tion/instruction manual should be
consulted for the proper zero and
span adjustment procedure. Zero and
span controls often interact with
each other, so the adjustments may
have to be repeated several times to
obtain the desired final adjustments.
After the zero and span adjust-
ments have been completed and the
analyzer has.been allowed to stabi-
lize on the new zero and span set-
tings, all calibration test concentra-
. tions should.be introduced into the
analyzer for the final, calibration. The
• final, post-adjusted analyzer re-
sponse readings should be obtained
from the same device (chart
recorder, data acquisition system,
etc..) that will be used for subsequent
ambient measurements.
The analyzer readings are plotted
against the respective test concentra-
tions, and the best linear (or non-
linear if appropriate) .curve to fit the
points'is determined. Ideally, least
squares regression analysis (with an
appropriate transformation of the
data for non-linear analyzers) should
be used to determine the slope and
intercept for the best fit calibration
line of the form, y = mx + a, where y
represents the analyzer response, x
represents the pollutant concentra-
tion, m is the slope, and a is the
x-axis intercept of the best fit calibra-
tion line. When this calibration rela-
tionship is subsequently used to
compute concentration measure-
ments (x) from analyzer response
readings (y), the formula is trans-
posed to the form, x = (y - a)/m. If
the calibration points show very little
deviation from the regression line
(i.e., very little scatter), it may be ac-
' ceptable (i.e., the error will be negli-
gible) to do the regression "back-
• wards," letting x represent the ana-
lyzer response and y represent the
concentration. In this case, the cali-
bration relationship, y = mx + a, is
used directly, without transposition,
to calculate concentration measure-
ments (y) from analyzer response (x).
As a quality control check on cali-
brations, the standard error or corre-
lation coefficient can be calculated
along with the regression calcula-
tions. A control chart of the standard
error or correlation coefficient could
then be maintained to monitor the
degree of scatter in the calibration
points and, if desired, limits of ac-
ceptability could be established.
(e) Level 1 Zero and Span Calibra-
tion—A level 1 zero and span calibra-
tion is a simplified, two-point ana-
lyzer calibration used when analyzer
linearity does not need to be checked
or verified. (Sometimes when no ad-
justments are made to the analyzer,
the level 1 calibration may be called
a zero/span check, in which case it
must not be confused with a level 2
zero/span check (see (d)). Since most
analyzers have a reliably linear or
near-linear output response with con-
centration, they can be adequately
calibrated with only two concentra-
tion standards (two-point calibration).
Furthermore, one of the standards
may be zero concentration, which is
relatively easily obtained and need
not be certified. Hence, only one cer-
tifed concentration standard is
needed for the two-point (level 1)
zero and span calibration. Although
lacking the advantages of the multi-
point calibration, the two-point zero
and span calibration—because of its
simplicity—can be (and should be)
carried out much more frequently.
Also, two-point calibrations are easily
automated. Frequent checks or up-
dating of the calibration relationship
with a 2-point zero and span calibra-
tion improves the quality of the mon-
itoring data by helping to keep the
calibration relationship more closely
matched to any changes (drift) in the
analyzer response.
As with any calibration, the ana-
lyzer should be operating in its nor-
mal sampling mode, and generally
the test concentrations should pass
through as much of the inlet and
sample conditioning system as is
practicable. For NO2, SO2, and partic-
ularly for QZ, wet or dirty inlet lines
and paniculate filters can cause
changes in the pollutant concentra-
tion. Efforts should be made, at least
periodically, to introduce the span
calibration concentration into the
sampling system as close to the out-
door sample inlet point as possible.
The calibration response under these
conditions can then be compared to
the response when the span concen-
tration is introduced at the analyzer,
downstream of the sample inlet com-
ponents, as a check of the entire
sample inlet system.
Some CO analyzers may be tempo-
rarily operated at reduced vent or
purge flows, or the test atmosphere
may enter the analyzer at a point
other than the normal sample inlet,
provided that such a deviation from
the normal sample mode is permit-
ted by the analyzer's operation or in-
struction manual and the analyzer's
response is not likely to be altered by
the deviation. Any such operational
modifications should be used with
caution, and the lack of effect should
be verified by comparing test calibra-
' tions made before and after the mod-
ification.
The standards used' for a level 1
zero and span calibration must be
certified traceable, as described pre-
viously under "calibration stand-
ards." The span standard should be
a concentration between about 70%
and 90% of the analyzer's full scale
measurement range.
-Adjustments to the analyzer may
be made during the zero and span
calibration. However; it is strongly
recommended that unadjusted (i.e.,
"as is") analyzer response readings
be obtained before any adjustments
are made to the analyzer. As de-
scribed later, these unadjusted zero
and span readings provide valuable
information for (1) confirming the
validity of (or invalidating) the mea-
surements obtained immediately pre-
ceding the calibration, (2) monitoring
the analyzer's calibration drift and
(3) determining the frequency of re-
calibration. Accordingly, the follow-
ing procedure for a zero and span
calibration is recommended:
1. Disconnect the analyzer's inlet
from the ambient intake and con-
nect it to a calibration system.
Leave the analyzer in its normal
sampling mode, and make no
other ajustments to the analyzer
(except as mentioned previously
for some CO analyzers).
2. Sample and measure the span
test concentration and record the
unadjusted, stable ("as is") span
response reading (S'). NOTE: All
analyzer response readings should
be recorded in the analyzer's nor-
mal output units, e.g., millivolts,
percent of scale, etc. (the same
units used for the calibration
curve). If these units are concentra-
-------
Section 2.0.9
March 1985
tion units they should be identified
as "indicated" or "uncorrected" to
differentiate them from the
"actual" concentration units that
are used for reporting actual ambi-
.ent concentration measurements.
3. Sample and measure the zero
test concentration standard and
record the unadjusted, stable zero
reading (2').
4. Perform any needed analyzer
adjustments (flow, pressure, etc.)
or analyzer maintenance.
5. If adjustment of the zero is
needed (see subsections (e) and
(f)) or if any adjustments have
been made to the analyzer, adjust
the zero to the desired zero read-
ing. Offsetting the zero reading
(e.g., to 5% of scale) may help to
observe any negative zero drift that
may occur. Record the adjusted,
stable zero reading (Z). If no zero
adjustment is made, Z= Z.'
6. Sample and measure the span
test concentration. If span adjust-
ment is'needed (see subsections
(e) and {f}), adjust the span re-
sponse to the desired value, allow-
ing for any zero offset used in the
previous step. Record the final ad-
justed, stable span reading (S). If
no adjustment is made, S = S.
7. If any adjustments made to the
zero, span, or other parameters or
if analyzer maintenance was car-
ried but, allow the analyzer to
restafalize at the new settings, then
recheck the zero and span readings
and record new values for Z and S,
if necessary.
If the calibration is updated for
each zero/span calibration (see sec-
tion 9.1.3), the new calibration rela-
tionship should be plotted using the
Z and S readings, or the intercept
and slope should be determined as
follows:
intercept» Z
slope<
S-Z
span concentration
Id) Level 2 Zero and Span Check—A
level 2 zero and span check is an
"unofficial" check of an analyzer's re-
sponse. It may include dynamic
checks made with uncertified test
concentrations, artificial stimulation
of the analyzer's detector, electronic
or other types of checks of a portion
of the analyzer, etc.
Level 2 zero and span checks are
not to be used as a basis for analyzer
zero or span adjustments, calibration
updates, or adjustment of ambient
data. They are intended as quick,
convenient checks to be used be-
tween zero and span calibrations to
check for possible analyzer malfunc-
tion or calibration drift. Whenever a
level 2 zero and span check indicates
a possible calibration problem, a
level 1 zero and span (or multipoint)
calibration should be carded out be-
fore any corrective action is taken.
If a level 2 zero and span check is
to be used in the quality control pro-
gram, a" "reference response" for the
check should be obtained immedi-
ately following a zero and span (or
multipoint) calibration while the arfa-
lyzer's calibration is accurately
known. Subsequent level 2 check re-
sponses should then be compared to
the most recent reference response
to determine if a change in response
has occurred. For automatic level 2
zero and span checks, the first sched-
uled check following the calibration
should be used for the reference re-
sponse. It should be kept in mind
that any level 2 check that involves
only part of the analyzer's system
cannot provide information about the
portions of the system not checked
and therefore cannot be used as a
verification of the overall analyzer
calibration.
(e) Physical Zero and Span Adjust-
ments—Almost ail ambient monitor-
ing instruments have physical means
by which to make zero and span ad-
justments. These adjustments are
used to obtain the desired nominal
scale range (within the instruments'
specifications), to provide convenient
(nominal) scale units, and to periodi-
cally adjust the instruments' re-
sponse to correct for calibration drift.
Note: NO/N02/NOX analyzers may
not have individual zero and span
controls for each channel. If that is
the case, the zero and span controls
must be adjusted only under the con-
ditions specified in the' calibration
procedure provided in the analyzer's
operation/instruction manual.
Precise adjustment of the zero and
span controls may not be possible
because of (1) limited resolution of
the controls, (2) interaction between
the zero and span controls, and
(3) possible delayed reaction to ad-
justment or a substantial stabilization
period after adjustments are made.
Precise adjustments may not be nec-
essary, however, because calibration
of the analyzer following zero and
span adjustments will define the pre-
cise response characteristic (calibra-
tion curve). Accordingly, zero and
span adjustments must always be
followed by a calibration. Allow suffi-
cient time between the adjustments
and the calibration for the analyzer to
fully stabilize. This stabilization time
may be substantial for some analyz-
ers. Also, obtain unadjusted re-
sponse readings before Adjustments
are made, as described in the previ-
ous section on level 1 zero arid span
calibration.
Zero and span adjustments do not
necessarily need to be made at each
calibration. In fact, where only rela-
tively small adjustments would be
. made, it is probably more accurate
not to make the adjustments because
of the difficulty of making precise ad-
justments mentioned earlier. An ap-
propriate question, then, is how
much zero or span drift can be al-
lowed before a physical zero or span
adjustment should be made to an an-
alyzer?
Ideally, all ambient measurements
obtained from an analyzer should be
calculated or adjusted on the basis of
the most recent (zero and span or
. multipoint) calibration or on the
basis of both the previous and sub-
sequent calibrations (see section
9.1.3 on Data Processing). In this
case, considerable drift (i.e., devia-
tion from an original or nominal re-
sponse curve) can be allowed before
physical adjustments must be made
because the calibration curve used to
calculate the ambient measurements
is kept in close agreement with the
actual analyzer response. The chief
limitations are the amount of change
in the effective scale range of the an-
alyzer that can be tolerated and pos-
sible loss of linearity in the analyzer's
response due to excessive deviation
from the design range. Cumulative
drifts of up to 20% or 25% of full
scale from the original or nominal
zero and span values may not be
unreasonable, subject to the
limitations mentioned above. '
In situations where it is not possi-
ble to update the calibration curve
used to calculate the ambient read-
ings after each zero and span calibra-
tion, then the ambient readings must
be calculated from the most recent
multipoint calibration curve or from a
fixed nominal or "universal" calibra-
tion curve (section 9.1.3). In this case,
the zero and span calibrations serve
only to measure or monitor the devi-
ation (drift error) between the actual
analyzer response curve and the cali-
bration curve used to calculate the
ambient measurements. Since this
error must be kept small, physical
zero and span adjustments are much
more critical and should be made be-
-------
March 1986
Section 2.0.9
fore the error becomes large. More
information on drift limits and deter-
mining when physical zero and span
adjustments are needed is contained
in the next section on frequency of
calibration. See also'Figure 9-2.
(f) Frequency of Calibration and An-
alyzer Adjustment—As previously in-
dicated, a multipoint calibration
should be carried out on new analyz-
ers or after major repairs to establish
analyzer linearity. It is also appropri-
ate to carry out a multipoint calibra-
tion on each analyzer in routine oper-
ation at least twice per year to
reverify linearity, although an annual
multipoint audit may serve in lieu of
one of these. (Nonlinear analyzers
may, of course, require more fre-
quent multipoint calibration if they
cannot be calibrated adequately with
2-point calibrations.)
The calibrations referred to bglp_w
would normally be 2-point zero and
span (level 1) calibrations; however,
a multi-point calibration can always
substitute for a 2-point calibration.
bration.
An analyzer should be calibrated
(or recalibrated):
1. upon initial installation;
2. following physical relocation;
3. after any repairs or service that
might affect its calibration;
4. following an interruption in oper-
ation of more than a few days; and
5. upon any indication of analyzer
malfunction or change in calibra-
tion.
In addition, analyzers in routine oper-
ation should be recalibrated periodi-
cally to maintain close agreement be-
tween the calibration relationship
used to convert analyzer responses
to concentration measurements and
the actual response of the analyzer.
The frequency of this routine peri-
odic recalibration is a matter of judg-
ment and is a tradeoff among several
considerations, including: the inher-
ent stability of the analyzer under the
prevailing conditions of temperature,
pressure, line voltage, etc. at the
monitoring site; the cost and incon-
venience of carrying out the calibra-
tions; the quality of the ambient
measurements needed; the number
of ambient measurements lost dur-
ing the calibrations; and the risk of
collecting invalid data because of a
malfunction or response problem
with the analyzer that wouldn't be
discovered until a calibration is car-
ried out.
When a new monitoring instru-
ment is first installed, level 1 zero
and span calibrations should be very
frequent—rperhaps daily or 3 times
per week—because little or no infor-
mation is available on the drift per-
. formance of the analyzer. (Informa-
tion on another unit of the same
model analyzer may be useful; how-
ever, individual units of the same
model may perform quite different-
ly.) After enough information on the
drift performance of the analyzer has
been accumulated, the calibration
frequency can be adjusted to provide
a suitable compromise among the
various considerations mentioned
above. However, prudence suggests
that the calibration frequency should
not be less than every two weeks. If
a biweekly frequency is selected and
the level 1 zero/span calibration is
carried out on the same day as the
one-point precision check required in
Subsection 3 of Appendices A and B
of Part 58, the precision check must
be done first.
To facilitate the process of deter-
mining calibration frequency, it is
strongly recommended that control
charts be used to monitor the zero
and span drift performance of each
analyzer. Control charts can be con-
structed in different ways, but the
important points are to visually rep-
resent and statistically monitor zero
and span drift, and to be alerted if .
the drift becomes excessive so that
corrective action can be taken. Exam-
ples of simple zero and span control
charts are shown in Figure 9-1. Such
control charts make important use of
the unadjusted zero and span re-
sponse readings mentioned in sec-
tion 9.1.2(c).
In the zero drift chart of Figure 9-1,
cumulative zero drift is shown by
plotting the zero deviation in ppb for
each zero/span calibration relative to
a nominal calibration curve (inter-
cept = 0 scale percent, slope = 200
scale percent per ppm for a nominal
scale range of 0.5 ppm). This zero
deviation may be calculated as fol-
lows:
Z'-
m0
;x 1000 ppb/ppm
where
Dz = zero deviation from the refer-
ence calibration (e.g., nomi-
nal or original calibration),
ppb;
Z' = unadjusted zero reading, e.g.,
scale percent;
I0 = intercept of reference calibra-
tion, e.g., scale percent;
m0 = slope of reference calibration,
e.g., scale percent/ppm.
Similarly, cumulative span drift may
be shown by plotting the percent de-
viation in the slope of the calibration
curve relative to the reference cali-
bration. This percent deviation in the
span slope may be calculated as fol-
lows:
Ds
x 100 percent
where
Ds = span deviation from reference
calibration, percent;
m0 = slope of reference calibration,
e.g., scale percent/ppm;
mc = current analyzer calibration
S' — Z'
slope = — g — , e.g., scale
percent/ppm;
S' = unadjusted span reading, e.g.,
scale percent;
Z' = unadjusted zero reading, e.g.,
scale percent;
C = span concentration.
Where physical zero or span ad-
justments have been made to the an-
alyzer (marked by diamonds along
the horizontal axes in Figure 9-1),
both the unadjusted (Z'f- S') and the
adjusted readings (Z, S) are plotted
(substitute Z for Z' and S for S' in
the- formulas). The connecting line
stops at the unadjusted reading,
makes a vertical transition represen-
tative of the physical adjustment,
then continues from the adjusted
reading.
The charts in Figure 9-1 cover a pe-
riod of 150 days, with zero/span cali-
bration every 2 or 3 days (2.7 days
on the average). Practical adjustment
limits were set at ±15 ppb for zero
and ±7% for span, (shown as broken
lines in Figure 9-1), although most of
the span adjustments and all of the
zero adjustments were made before
•these limits were reached. These lim-
its could have been set wider be-
cause the calibration slope and inter-
cept used to calculate the ambient
readings were updated at each zero/
span calibration. Narrower limits
may be needed if the calibration
curve used to calculate the ambient
data is not updated at each zero/span
calibration.
The total net cumulative zero drift
over the entire 150 day period (ignor-
ing zero adjustments) was +.9 ppb,
indicating that the analyzer's zero
stability was good. Total net cumula-
tive span drift (ignoring span adjust-
ments) was +15.4%, indicating that
the analyzer should be watched
closely for continued positive span
drift. Most of the individual zero and
-------
Section 2.0.9
March 1985
Q
I
+30
+20
+ro
+0
•10
•20
-30
Tot. Nat Zero Drift, ppb +.9
Number of Drift Periods: 55
Ave Drift Period, days: 2.7
Ave[Drifty Period, ppb: 1.5
Std Dev. Zero Drift, ppb: 2.4
1 - 1 - 1 - 1
1 •
_1 1_
6
30
45
60 '
75
SO
JOS
Day of Year
120
135
150
165
180
Total Net Span Drift, %: +1S.4
Number of Drift Periods: 55
A ve Drift Period, days: 2.7
Ave [DriftyPeriod, %: 1.8
Std Dev. Span Drift. %: 2.3
105 120
Day of Year
135
150
165
180
Ftgurs 9-1. Examples of simple zero and span control charts.
span drifts {i.e., the net change from
'one zero/span calibration to the next)
were small. The average of the abso-
lute values of these individual zero
drifts (ignoring zero adjustments)
was 1.5 ppb, and the average of the
absolute values of the individual
span drifts (ignoring span adjust-
ments) was 1.8 percent. In view of
these relatively low values, the fre-
quency of zero/span calibrations
could be reduced, say to twice a
week or every 4 days, particularly if
level 2 zero/span checks were used
between the level 1 zero/span cali- .
brations. However, such reduced cali-
bration frequency would tend to in-
crease the average error between the
actual analyzer response and the cali-
bration curve used to calculate the
ambient measurements. Reduced cal-
ibration frequency would also in-
crease the risk of collecting invalid
data because of potentially increased
delay in discovering a malfunction or
serious response change. If either of
the average zero or average span
drift is large, more frequent zero/
span calibration should be consid-
ered.
A final pair of statistics that should
be calculated is the standard devia-
tions of the individual zero and span
drifts, respectively (again, ignoring
zero and span adjustments). These
values (2.4 ppb and 2.3%, respec-
tively, for the charts shown in Fig-
ure 9-1) provide a measure of-the
typical drift performance of the ana-
lyzer. A band equal to ±3 standard
deviations can be established to rep-
resent "normal" performance of the
analyzer. Such a band is represented
on the charts of Figure 9-1 by the
l-bands at the right edge of the
charts. Any excursion outside of
these bands is an indication of a pos-
sible performance problem that may
need corrective action or additional
scrutiny.
In continual monitoring, the total
cumulative drift, average of the abso-
lute values of the individual drifts,
and the standard deviation of the in-
dividual drifts should be calculated
on a running basis over the last 100
or so days. Figure 9-2 summarizes
some of the ranges and control chart
limits discussed previously. These
limits are suggested,'but they could
be modified somewhat at the discre-
tion of the monitoring agency. There
are also other ways.tqjonstruct con-
trol charts. Appendices J and H of
Volume I of this Handbook provide
additional information on the calcula-
tion of standard deviations and on
the construction and interpretation of
control charts.
(g) Automatic Self-Adjusting Ana-'
lyzer—Some air monitoring analyz-
ers are capable of periodically carry-
ing out automatic zero and span
calibrations and making their own
zero and span self adjustments to
predetermined readings. How should
such automatic zero/span calibrations
be treated? If the automatic zero/
span calibration meets all the re-
quirements discussed previously for
level 1 zero and span calibrations
(i.e., traceable standards that pass
through the sample inlet and sample
-------
March 1985
Section 2.O.9
Calibration updated at each zero/span
Zero
Drift
+20 to 30 ppb
(2 to 3 ppm CO)
+3 stddev
+1 stddev
0
-1 stddev
-3 std dev
-20 to -30 ppb
(-2 to -3 ppm CO)
and recalibrate
Analyzer adj
option
Normal analyzer
range
\
'ustment
aT
Analyzer adjustment
not recommended
Analyzer adj
ustment
optional
I
Adjust analyzer
and recalibrate
Span
Drift
+20% to 25%
+3 std dev
+J stddev
0
•1 stddev
•3 std dev
-20% to -25%
Fixed calibration used to calculate data
zero
Drift
+ 10 to 15 ppb
11 to 1.5 ppm CO)
+3 std dev
+ std dev
0 —
-/ stddev
-3 std dev
-JO to -15 ppb
(-1 to -1.5 ppm CO)
Invalidate data; adjust ,
and recalibrate analyzer
I
Adjust and
recalibrate analyzer
Normal analyzer J
1 range
Adjustment
optional
Analyzer adjustment
not recommended
Adjustment
optional
1
Adjust and
recalibrate analyzer
1
Invalidate data; adjust
and recalibrate analyzer
Span
Drift
+15%
+3 std dev
+1. std dev
— 0
-1 stddev
-3 std dev
•15%
Figure 9-2. Suggested zero and span drift limits when the calibration used to calculate
measurements is updated at each zero/span calibration (upper) and when a
fixed calibration is used to calculate measurements (lower).
conditioning system) and both the
adjusted and unadjusted zero and
span response readings can be ob-
tained from the data recording de-
vice, then the calibration may be
treated as a valid zero/span calibra-
tion as discussed in this section. If
the automatic calibrations do not
qualify as level 1 calibrations (be-
cause the final zero and span read-
ings cannot be read from the strip
chart for example), then the analyzer
must receive manual zero/span cali-
brations as if it had no automatic ca-
pabilities. In this case, the automatic
zero and span adjustments should be
ignored, except that manual calibra-
tions should be separated in time as
much as possible from the occur-
rence of the automatic calibrations
for maximal benefit. It may some-
times happen that automatic and
manual calibrations interact, produc-
ing a detrimental effect on the moni-
toring data. If so, the automatic cali-
brations should be discontinued or
adjusted to avoid continuation of the
conflict.
(h) Level 1 Zero and Span Calibra-
tion Documentation—All Level 1 zero
or span calibrations should be docu-"
mented in a chronological format.
Documentation should include ana-
lyzer identification, date, standard-
used and its traceability, equipment
used, the individual conducting the
calibration, the unadjusted zero and
span responses, and the adjusted
zero and span responses. Again,
quality control charts are an excellent
form of documentation to graphically
record and track calibration results.
Level 1 zero and span documentation
should be maintained both in a cen-
tral file and at the monitoring site.
HI Use of Computers for Control
Chart Plotting and Warning of Out-of-
Control Conditions—With .the wide
range of economical computers now
available, consideration should be
given to a computer system that can
process and output the information -
in a timely fashion. Such a computer
system should be able to:
1. Compute calibration equations
2. Compute measures of linearity of
calibrations (e.g., standard error or
correlation coefficient)
3. Plot calibration curves
4. Compute zero/span drift results
5. Plot zero/span drift data
6. Compute precision and accuracy
results
7. Compute control chart limits
8. Plot control charts
9. Automatically flag out-of-control
results
-------
Section 2.0.9
March 1985
10. Maintain and retrieve calibra-
tion and performance records.
9.1.3 Data Processing
M Calculation of Ambient Mea-
surements—As noted previously, an
analyzer's response calibration curve
relates the analyzer response to ac-
tual concentration units of measure,
and the response of most analvzers
tends to change (drift) unpredictably
with passing time. These two condi-
tions must be addressed in the
mechanism that is used to process
the raw analyzer readings into final
concentration measurements. Four
practical methods are described be-
low. They are listed in order of pref-
erence, with the first one being the
most likely to minimize errors caused
by differences between the actual an-
alyzer response and the response
curve used to calculate the measure-
ments. As would be expected, the
order also reflects decreasing com-
plexity and decreasing difficulty of
implementation. The first 3 methods
are best implemented with automatic
data processing systems because of
the number of calculations required.
Methods 3 and, 4 could be used on a
manual basis and are more labor in-
tensive because of the need for more
frequent and precise physical adjust-
ment of analyzer zero and span con-
trols.
1} Linear Interpolation—In this
method, the (linear) calibration curve
used to convert analyzer readings to
concentration values is defined by a
slope and intercept, which are up-
dated at each calibration. Both unad-
justed and adjusted response read-
ings are required for each calibration.
Each ambient concentration is calcu-
lated from individual slope and inter-
cept values determined by linear in-
terpolation between the adjusted
slope and intercept of the most re-
cent previous calibration and the un-
adjusted slope and intercept of the
first subsequent calibration.
Because of the need for subse-
quent (level 1) calibration informa-
tion, this method cannot be used for
real time calculation of concentration
readings. Also, some contingency ar-
rangement (such as method 2) must
be employed when a subsequent cal-
ibration is missing (e.g., following a
disabling malfunction). Physical zero
and span adjustments to the analyzer
are needed only to maintain an ap-
propriate scale range or to avoid
scale nonlinearity due to cumulative
drift in excess of design values.
Within these constraints, data invali-
dation limits should be based on net
change from one calibration to the
next, rather than on total cumulative
drift, because the calibration is con-
tinually updated.
A significant problem with this
method is acquiring the requisite cal-
ibration data and making sure it is
merged correctly with the.ambient
data to facilitate the required calcula-
tions. Some automated data acquisi-
tion systems support this application
by making special provisions to ac-
quire and process periodic zero and
span data. One way to ensure that
the zero/span data are correctly
merged with the ambient readings is
to code the zero and span values di-
rectly into the data set at the location
corresponding to the time of calibra-
tion, replacing the normal hourly
reading that is lost anyway because
of the calibration. This data can be
marked (such as with a negative
sign) to differentiate it from ambient
data and later deleted from the final
report printout.
When zero and span data is ac-
quired automatically by.a data acqui-
sition system for direct computer
processing, the system must be suffi-
ciently sophisticated to: ,
a. ensure that zero or span data
is never inadvertently reported as
ambient measurements;
b. ignore transient data during the
stabilization period before the ana-
lyzer has reached a stable zero or
span response (this period may
vary considerably from one ana-
lyzer to another);
c. average the stable zero and span
readings over some appropriate
time period so that the zero or
span reading obtained accurately
represents the analyzer's true zero
or span response;
d. ignore ambient readings for an
appropriate period of time immedi-
ately following a zero or span read-
ing until the analyzer response has
restabilized to the ambient-level
concentration.
2) Step-Change Update—This
method is similar to Method 1 above
except that the adjusted slope and
intercept of the most recent calibra-
tion are used to calculate all subse-
quent ambient readings until up-
dated by another calibration (i.e., no
interpolation). No unadjusted zero or
span readings are used, and ambient
measurements can be calculated in
real time if desired. The same com-
ments concerning physical zero and
span adjustments and data invalida-
tion limits given for Method 1 apply,
as well as the comments concerning
zero and span data acquired auto-
matically by a data acquisition sys-
tem.
3) Major Calibration Update—In
this method, the calibration slope
and intercept used to calculate ambi-
ent measurements are updated only
for "major" calibration—i.e., monthly
or quarterly multi-point calibrations.
All ambient measurements are calcu-
lated from the most recent major cal-
ibration. Between major calibrations,
periodic zero and span calibrations
are used to measure the difference
between the most recent major cali-
bration and the current instrument
response. Whenever this difference
exceeds the established zero/span
adjustment limits (see sections
9.1.2 e and 9.1.2 f), physical zero and/
or span adjustments are made to the
analyzer to restore a match between
the current analyzer response and
the most .recent major calibration.
Neither adjusted nor unadjusted zero
or span readings are used in the cal-
culation of the ambient concentra-
tions.
4) "Universal" Calibration—A fixed,
"universal" calibration is established
for the analyzer and used to calculate
all ambient readings. All calibrations
are used to measure the deviation of
the current analyzer response from
the universal calibration. Whenever
this deviation exceeds the estab-
lished zero and span adjustment lim-
its, physical zero and/or span adjust-
ments are made to the analyzer to
match the current analyzer response
to the universal calibration.
(b) Invalidation of Ambient Data—
When zero or span drift data valida-
•tion limits (see section 9.1.2 (f)) are '
exceeded, ambient measurements
must be invalidated back to the most
recent point in time where such mea-
surements are known to be valid.
Usually this point is the previous cal-
ibration (or accuracy audit), unless
some other point in time can be
identified and related to the probable
cause of the excessive drift (such as
a power failure or malfunction). Also,
data following an analyzer malfunc-
tion or period of non-operation
should be regarded as invalid until
the next subsequent (level 1) calibra-
tion unless unadjusted zero and span
readings at that calibration can
support its validity.
Data quality assessment measure-
ments (precision and accuracy
checks) are not intended to be used
-------
March 1985
Section 2.0.9
for data validation/invalidation. But if
the assessment results clearly indi-
cate a serious response problem with
the analyzer, the agency should re-
view all pertinent quality control in-
formation to determine whether any
ambient data, as well as any associ-
ated assessment data, should be in-
validated. However, this means
should not be used merely to im-
prove the data quality of specific an-
alyzers or of the reporting agency.
Procedures for screening data for
possible errors or anomalies should
also be implemented. Reference. 18
recommends several statistical
screening procedures for ambient air
quality data that should be applied to
identify gross data anomalies. Addi-
tional information on validation of air
monitoring data is contained in Ref-
erences 19 and 20.
(c) Data Reporting—Procedures for
coding, key punching, and data edit-
ing should be documented and im-
plemented. Recommended proce-
dures for these data processing
activities are described in various
sections of Reference 21: coding in-
structions in Sections 3.4.1 through
3.4.6; key punch instructions in Sec-
tions 4.4.1 through 4.4.6; and data
editing in Section 7.1.2. • ,
(d) Processing of Data Quality As-
sessment Information—It is of the ut-
most importance that all precision
and accuracy assessment readings
from an analyzer be processed ex-
actly as ambient readings recorded
at that time would be processed.
Many automatic data acquisition and
processing systems do not include •
provision for handling such extra
readings, and this capability is diffi-
cult to incorporate into such systems
unless it is done in the earliest plan-
ning stage. External or hand process-
ing of such readings should be dis-
couraged unless it is done with
extreme care and assurance that pro-
cessing is identical to the way ambi-
• en.t readings are processed by the
automatic system. Perhaps the best
way to handle such readings is to en-
ter them into the automatic process-
ing system in such a way that the
system thinks they are actual ambi-
ent readings and processes them ac-
cordingly; After processing, the read-
ings can be removed from the final
ambient data listing and used in the
data quality assessment calculations.
When precision or accuracy as-
sessment readings are obtained dur-
ing any period for which the ambient
readings immediately before or im- •
mediately after these readings are
determined by suitable reason to be
invalid, then the precision and accu-
racy readings should also be invali-
dated. Any data quality calculations
using the invalidated readings should
be redone. Also, the precision or ac-
curacy checks should be resched-
uled, preferably in the same calendar
quarter. The basis or justification for
all data invalidations should be per-
manently documented.
9.1.4 Non-Programmed Adjust-
ments to Ambient Data—Adjust-
ments to ambient data as described
in the previous section, made rou-
tinely according to a documented,
pre-established procedure (pro-
grammed adjustments), would be a
normal part of an overall scheme to
maintain high levels of data quality.
In contrast, after-the-fact adjustments
or "corrections" are occasionally pro-
posed to ambient data based on
unanticipated events or discoveries.
This latter type of adjustment should
be scrutinized completely before any
changes are made to ambient data.
In general, such adjustments are dis-
couraged as there is a substantial
risk that they may cause more harm
than good. There is also a risk that
such proposed adjustments might be
used or might appear to be used for
ulterior purposes. In many cases, this
type of correction may not be worth
the trouble of carrying it out.
If, after scrutiny, a special, unpro-
grammed adjustment is determined
to be appropriate and is made to a
block of ambient data, it is very im-
portant to ensure that the exact same
adjustment is also made to any pre-
cision and accuracy measurements
obtained during the affected time pe-
riod. Any data quality calculations af-
fected by the change should also be
recomputed. All such adjustments
should be completely documented,
including the rationale and justifica-
tion for the adjustment.
9.1.5 Written Operational Proce-
dures and Document Control—All
significant quality assurance proce-
dures should be described in writing'
in sufficient detail to assure that all
operators or analysts carry out the
procedures in the same way. Docu-
ment control should also be consid-
ered for these written operational
procedures. Section 1.4.1 of Refer-
ence 4 provides information on es-
tablishing a document control sys-
tem.
As'outlined in Appendices A and 8
of 40 CFR Part 58, written operational
procedures should be available for at
least the following monitoring activi-
ties:
1. selection of analyzers;
2. training of analyzer operators;
3. installation of analyzers and as-
sociated equipment;
4. selection, Control, and traceabil-
ity of calibration standards;
5. procedures for multipoint cali-
brations;
6. procedures for level 1 zero/span
calibrations and adjustments of an-
alyzers;
7. procedures for .establishing the
frequency of level 1 zero/span cali-
brations (and level 2 checks, if
used);
8. control limits for zero, span and
other control checks, and respec-
tive corrective actions when such
limits are surpassed;
9. calibration and zero/span checks
for multiple range analyzers, if ap-
plicable;
10. preventive and remedial
maintenance;
.11. quality control procedures for
air pollution episode monitoring;
12. data recording, processing, and
validating procedures and limits;
13. data quality assessment (preci-
sion and accuracy);
14. documentation of quality con-
trol information.
Guidance for many of these opera-
tional procedures is currently avail-
able in (a) analyzer operation or in-
struction manuals, (b) EPA reference
and equivalent methods, and (c) EPA
guideline documents, particularly
References 7, 13, 14, 16, 17, 18, 21,
and other sections of this volume of
the Handbook. However, it is the or-
ganization's responsibility to develop
its own unique written operational
procedures applicable to air quality
measurements made by the organi-
zation.
9.1.6 Special Guidance for Epi-
sodes—As defined here for the pur-
. pose of quality control, an air pollu-
tion episode is any concentration
equal to or greater than a pollutant
standard index (PSI) of 200. Pollutant
concentrations corresponding to PSI
of 200 are shown in Tables 1 and 2
of Reference 22.
In addition to the previous guid-
ance, the following procedures are
recommended for analyzers used to
monitor during air pollution
episodes.
1. A Level 1 zero and span calibra-
tion should be performed during the
episode and at least weekly if the
episode lasts longer than one week.
-------
Section 2.0,9
10
March 1985
2. During the episode season, but
not during an episode, analyzers
which are used to measure episode
concentrations should be subjected
to Level 1 zero and span calibrations
at least every two weeks on the mea-
surement range used for episode
monitoring. This Level 1 zero and
span calibration should be performed
at the same time the Level 1 zero
and span calibration is performed on
the analyzer's normal measurement
range.
3. During the episode season, but
not during an episode, analyzers
which have previously measured
episode concentrations should be
subjected to a performance audit of
the type described in Appendices A
and B.
4. As soon as possible after an ac-
tual episode the analyzer calibration
should be checked with a 3 or more
point performance audit, using
standards different from the routine
calibration standards.
9.2 Quality Assurance for
Manual Methods
An appropriate and effective qual-
ity control program for manual meth-
ods is as necessary as it is for auto-
mated analyzers, although the quality
control activities will be more
specific to the individual monitoring
method used. Suggestions and guid-
ance for method-specific quality con-
trol activities, such as equipment per-
formance and acceptance testing,
calibration, and data quality assess-
ment procedures, are generally con-
tained in the method description and
in the method-specific sections of
this Handbook (see sections 2.1, 2.2,
2.4, and 2.8).
9.2.1 Data Validation and Reporting
(or Manual Methods—Monitoring
data of poor quality may be worse
than no data at all. For manual meth-
ods, the first level of data validation
should be to accept or reject moni-
toring data based upon results from
operational checks selected to moni-
tor the critical parameters in all three
major and distinct phases of manual
methods—sampling, analysis, and
data reduction.
In addition to using operational
checks for data validation, the user
must observe all limitations, accep-
tance limits, and warnings described
in the reference and equivalent meth-
ods per se that may invalidate data.
It is further recommended that re-
sults from performance audits re-
quired in Appendices A and B not be
used directly for data validation be-
cause these checks (performance au-
dits) are intended only to assess the
quality of the data.
Procedures for coding, key punch-
ing, and data editing should be im-
plemented. Recommended proce-
dures for these data processing
activities are described in Reference
21: coding instructions in Sec-
tions 3.4.1 through 3.4.6; key punch
instructions in Sections 4.4.1 through
4.4.6; and data editing in Sec-
tion 7.1.2.
Procedures for screening data for
possible errors or anomalies should
also be implemented. References 18
and 19 recommend several screening
procedures for ambient air quality
data that should be applied to iden-
tify gross data anomalies.
9.2.2 Written Operational Proce-
dures and Document Control for
Manual Methods—To standardize
the approach used by different field
operators and different laboratory
analysts, certain operational proce-
dures (standard operating proce-
dures, or SOP's) must be written and
readily available to all organization
personnel. Document control should
also be considered for many of these
written operational procedures. Sec-
tion 1.4.1 of Reference 4 provides in-
formation on establishing a docu-
ment control system. '
Written operational procedures
must be available for at least the fol-
lowing TSP monitoring activities:
1. calibration of the hi-vol sampler,
2. important preventive mainte-
nance tasks and a schedule for
completion of these tasks,
3. calculation of monitoring con-
centration, including an example
calculation,
4. performance audits required in
Appendices A and B to assess ac-
curacy,
5. collocated sampling required in
Appendices A and B to assess pre-
cision,
6. data validation,
7. field handling of filters,
8. flow measurements, and
9. conditioning and weighing of fil-
ters.
Written operational procedures
must be available for at least the fol-
lowing SO2 and NO2 monitoring ac-
tivities:
1. calibration of the air flow control
devices,
2. calibration of the spectrophoto-
meter.
•
3. important preventive mainte-
nance tasks and a schedule for
completion of these tasks,
4. calculation of monitoring con-
centration, including an example
calculation,
5. performance audits required in
Appendix A to assess accuracy,
6. collocated sampling required in
Appendix A to assess precision,
7. data validation,
8. flow measurements, and
9. chemical analysis..
• Written operational procedures
must be available for at least the fol-
lowing lead monitoring activities:.
1. calibration of the hi-vol sampler,
2. calibration of the atomic absorp-
tion spectrophotometer,
3. important preventive mainte-
nance tasks and a schedule for
completion of these tasks,
4. calculation of monitoring con-
centration, including an example
calculation,
5. performance audits required in
Appendices A and B to assess ac-
curacy,
6. collocated sampling required in
Appendices A and B to assess pre-
cision,
7. data validation,
8. flow measurement, and
9. analysis.
Many of these operational proce-
dures are currently in (a) EPA refer-
ence and equivalent methods, and
(b) EPA guideline documents, partic-
ularly this Handbook. However, it is
the organization's responsibility to
develop its own unique written oper-
ational procedures applicable to air
quality measurements made by the
organization.
9.3 References
1. Code of Federal Regulations, Title
40, Chapter 1-, Part 58, "Ambient Air
Quality Surveillance."
2. Code of Federal Regulations, Title
40, Chapter 1, Part 58, Appendix A,
"Quality Assurance Requirements for
State and Local Air Monitoring Sta-
tions (SLAMS)."
3. Code of Federal Regulations, Title
40, Chapter 1, Part 58, Appendix B,
"Quality Assurance Requirements for
Prevention of Significant Deteriora-
tion (PSD) Air Monitoring."
4. "Quality Assurance Handbook for
Air Pollution Measurement Systems,
Volume l-Principles." EPA-600/9-75-'
005. March 1976. Available from U.S.
Environmental Protection Agency
ORD Publications 26 W. St. Clair St
Cincinnati, OH 45268.
-------
March 1988
11
Section 2.0.9
5. Code of Federal Regulations, Title
40, Chapter 1, Part .58, Appendix C,
"Ambient Air Quality Monitoring
Methodology."
6. Code of Federal Regulations, Title
40, Chapter 1, Part 53, "Ambient Air
Monitoring Reference and Equivalent
Methods."
7. U.S. Environmental Protection
Agency, "Ambient Monitoring Guide-
lines for Prevention of Significant De-
terioration (PSD)." EPA-450/2-78-019
(OAQPS 1.2-0.96). May 1978.
8. Kopecky, M.J. and B. Roger,
"Quality Assurance for Procurement
of Air Analyzers," 33rd Annual Tech-
nical Conference Transactions, Amer-
ican Society for Quality Control,
Houston, TX, May 1979.
9. Sexton, F.W., F.F. McEIroy, R.M.
Michie, Jr., V.L Thompson, and J.A.
Bowen.' Performance Test Results
and Comparative Data1 for Designated
Reference and Equivalent Methods
for Ozone. EPA-600/4-83-003, U.S. En-
vironmental Protection Agency, Re-
search Triangle Park, NC 27711. April
1983.
10. Michie, P.M., Jr., F.F. McEIroy,
J.A. Sokash, V.L. Thompson, D.P.
Dayton, and,C.R. Sutcliffe. Perfor-
mance Test Results and Comparative
Data for Designated Reference Meth-
ods for Carbon Monoxide. EPA-600/
4-83-013, U.S. Environmental Protec-
tion Agency, Research Triangle Park,
NC 2771 I.June 1983.
11. Michie, R.M., Jr., F.F. McEIroy,
J.A. Sokash, V.L Thompson and B.P.
Fritschel. Performance Test Results
and Comparative Data for Designated
Reference and Equivalent Methods
for Nitrogen Dioxide. EPA-600/4-83-
019, U.S. Environmental Protection
Agency, Research Triangle Park, NC
27711. June 1983.
12. Michie, R.M., Jr., F.F..McEIroy,
F.W. Sexton, and V.L. Thompson.
Performance Test Results and Com-
parative Data for Designated Equiva-
lent Methods for Sulfur Dioxide. EPA-
600/4-84-015, U.S. Environmental
Protection Agency, Research Triangle
Park, NC 27711. January, 1984.
13. Ellis, E.G., "Technical Assistance
Document for the Chemilumines-
cence Measurement of Nitrogen
Dioxide." EPA-600/4-75-003. U.S. En-
vironmental Protection Agency, Re-
search Triangle Park, NC 27711. De-
cember 1975.
14. Easton, W.C., "Use of the Flame
Photometric Detector Method for •
Measurement of Sulfur Dioxide in
Ambient Air: A Technical Assistance
Document." EPA-600/4-78-024. U.S.
Environmental Protection Agency,
Research Triangle Park, NC 27711.
May 1978.
15. Von Lehmden, D.J., "Suppres-
sion Effect of C02 on FPD Total Sul-
fur Air Analyzers and Recommended
Corrective.Action." Proceedings, 4th
Joint Conference on Sensing Soci-
ety, pp. 360-365, 1978.
16. Paur, RJ. and F.F. McEIroy.
Technical Assistance Document for
the Calibration of Ambient Ozone
Monitors. EPA-600/4-79-057. U.S. En-
vironmental Protection Agency, Re-
search Triangle Park, NC 27711. Sep-
tember 1979.
17. McEIroy, F.F. Transfer Standards
for the Calibration of Ambient Air
Monitoring Analyzers for Ozone.
EPA-600/4-79-056. U.S. Environmen-
tal Protection Agency, Research Tri-
angle Park, NC 27711. September
1979.
18. "Screening Procedures for Ambi-
ent Air Quality Data." EPA-450/2-78-
037 (OAQPS 1.2-092). July 1978.
19. "Validation of Air Monitoring
Data." EPA-600/4-80-030. U.S. Envi-
ronmental Protection Agency. June
1980.
20. Rhodes, R.C. "Guideline on the
Meaning and Use of Precision and
Accuracy Data Required by 40 CFR
Part 58, Appendices A and B." EPA-
600/4-83-023. U.S. Environmental
Protection Agency, Research Triangle
Park, NC 27711. June 1983.
21. "AEROS Manual Series, Volume
II: AEROS Users Manual." EPA-450/
2-76-029 (OAQPS 1.2-0.39). December
1976.
22. Code of Federal Regulations,
Title 40, Chapter 1, Part 58, Appendix
G. "Uniform Air Quality Index and
Daily Reporting."
-------
-------
Section 2.0.10 USEPA National Performance Audit Program
(February 1994)
The National Performance Audit Program is a cooperative effort between EPA's
Atmospheric Research and Exposure Assessment Laboratory (AREAL), the 10
EPA Regional Offices, and the 170 state and local agencies that 'operate
SLAMS/NAMS air pollution monitors. Also included in the NPAP are
organizations that operate air monitors at PSD sites. Participation in the NPAP
is required for agencies operating SLAMS/NAMS and PSD monitors as p«r
Section 2.4 of 40 CFR Part 58, Appendix A and Section 2.4 of 40 CFR Part 58
Appendix B. The NPAP is operated by the Quality Assurance Support Branch
of AREAL.
The goal of the NPAP is to provide audit materials and devices that will enable
o^AoaSSeSS the Proficiency of agencies who are operating monitors in the
SLAMS/NAMS and PSD networks. To accomplish this, the NPAP has
established acceptable limits or performance criteria, based on the
SLAMS/Nams and PSD requirements for each of the audit materials and devices
provided in the program. Any device or material not meeting the=e
'predetermined criteria is not used in the program. .
All audit devices and materials used in the NPAP are certified as to their true
value, and that certification is traceable to an NIST standard material or device
wherever poss.ble. The audit materials used in the NPAP are as representative
and comparable as possible to the calibration materials and actual air samples -
used and/or collected in the SLAMS/NAMS and PSD networks The audit
matenal/gas cylinder ranges used in the NPAP are those specified in the Federal
register.
The mailing address and many of the audit materials used in the National
Performance Audit Program (NPAP) have changed since the publication of this
section in 1979. The present address is:
Ambient Air Audit Coordinator
Quality Assurance and Technical Support Division
Atmospheric Research and Exposure Assessment Laboratorv
MD 77B
Research Triangle Park, NC 27711
-------
The following audit materials are now used in the program:
Hi-Vo»/PM-10 (SSI)
The reference flow device (ReF) consists of a modified orifice, a wind deflector,
a manometer, and five resistance plates. The ReF for the PM-10 (SSI) flow
audit is similar except a filter is used as the only resistance.
Ozone
Ozone was added to the NPAP in 1989, The audit device is self-contained with
its own zero air and ozone generation system.
Dfchotomous (PM-10) (flow)
The dichot audit device consists of an inclined manometer filled with red gauge
oil, an altimeter that measures BP in millimeters, a small dial thermometer that
reads in °F, and the LFE (laminar flow element) with air cleaner. The dichot
measures fine flow (1 5.00 Ipm) and total flow (16.7 Ipm).
Lead (analysis)
The samples are 1.9 cm wide and 20 cm long glass fiber filter strips that have
been spiked with an aqueous solution of lead nitrate and oven-dried. Two filter
strips comprise a sample.
Sulfur Dioxide/NO-NO2/Carbon Monoxide (aas dilution system)
Beginning in 1991 one gas dilution system was used for all 3 audits. It.is
comprised of an audit device, one zero air system, and 2 cylinders of gas (NO2
and a blend of SO2/ NO, and CO).
Newly designed audit systems that have gas phase titration capability are
presently being evaluated to determine their suitability for improving the stability
of NO2 audits. If acceptable, these devices will be phased in during the 1994
audit year.
Sulfate/Nitrate
The samples are 1.9 cm wide and 20 cm long glass fiber filter strips that have
been spiked with aqueous solutions of sodium sulfate and potassium nitrate and
oven-dried. Three filter strips comprise a set. This audit is voluntary since
sulfate/nitrate are not criteria pollutants.
-------
. April 1885
Section 2.0.11
11.0 Systems Audit Criteria and Procedures
for Ambient Air Monitoring Programs
11.1 Introduction
11.1.1 General - A systems audit is
an on-site review and inspection of a
state or local agency's ambient air
monitoring program to assess its
compliance with'established regula-
tions governing the collection, analy-
sis, validation, and reporting of ambi-
ent air quality data. A systems audit
of each state or autonomous agency
within an EPA Region is performed.
annually by a member of the Re-
gional Quality Assurance (QA) staff.
The purpose of the guidance in-
cluded here is to provide the regula-
tory background and appropriate
technical criteria which form the
basis'for the air program evaluation
by the Regional Audit Team. To pro-
mote national uniformity in the eval-
uation of state and local agency
monitoring programs and agencies'
performance, all EPA Regional Of-
fices are required to use at least the
short form questionnaire (Section
11.6), corrective action implementa-
tion request (CAIR) (Section 11.4.2),
and the systems audit reporting for-
mat (Section 11.4.4) each year. Use
of sections of the long form ques-
tionnaire is left to the discretion of
the Regional QA Coordinator, with
the concurrence of the State or local
agency. The short form questionnaire
is essentially the same as the moni-
toring audit questionnaire used in
FY-84. No substantive changes have
been made; however, the question-
naire has been reorganized to im-
prove the information received and
facilitate its completion. In addition,
requests for resubmission of data al-
ready possessed by EPA have been
deleted.
The scope of a' system-s audit is of
major concern to both EPA Regions
and the agency to be evaluated. A
systems audit as defined in the con-
text of this document is seen to in-
clude an appraisal of the following
program areas: network manage-
ment, field operations, laboratory op-
erations, data management, quality
assurance and reporting. The guid-
ance provided concerning topics for
discussion during an on-site inter-
view have been organized around
these key program areas (Section
11.5). The depth of coverage within
these areas may be increased or de-
creased by using one or more sec-
tions of the long-form questionnaire
(Section 11.7) in conjunction with the
short-form questionnaire (Section
11.6). Besides the on-site interviews,
the evaluation should include the re-
view of some representative ambient
air monitoring sites and the monitor-
ing data processing procedure from
field acquisition through reporting
into the Storage And Retrieval Of Air
^ataJSAROAD) computer system.
The systems audit results should
present a clear, complete and accu-
rate picture of the agency's acquisi-
tion of ambient air monitoring data.
11.1.2 Road Map to Using this Sec-
tion—This section contains guidance
and sufficient information for operat-
ing a systems audit of an agency re-
sponsible for operating ambient air
monitoring sites, as part of the State
and Local Air Monitoring Stations
(SLAMS) network, arid to report the
results in a uniform manner. The fol-
lowing topics are covered in the sub-
sections below:
• a brief sketch of the regulatory
requirements which dictate that
systems audits be performed, indi-
cating the regulatory uses to which
the audit results may be put (Sec-
tion 11.2);
• a discussion of
1) the requirements on the
agency operating the SLAMS net-
work;
2) program facets to be evalu-
ated by the audit; and
3) additional criteria to assist in
determining the required extent
of the forthcoming audit (Section
11.3);
• a recommended audit protocol
for use by the Regional Audit
Team, followed by a detailed dis-
cussion of audit results reporting
(Section 11.4);
• criteria for the evaluation of State
and local agency performance in-
cluding suggested topics for dis-
cussion during the on-site inter-
views (Section 11.5);
• a short-form questionnaire,
based on the National Air Monitor-
ing Audit Questionnaire prepared
by the STAPPA/ALAPCO Ad Hoc
Air Monitoring Audit Committee.
(10-20-83) (Section 11.6);
• a long-form questionnaire, orga-
nized around the six key program
areas to be evaluated (Section
11.7); and
• a bibliography of APA guideline
documents, which provides addi-
tional technical background .for the
different program areas under
audit (Section 11.8).
The guidance provided in this section
is addressed primarily to EPA Re-
gional QA Coordinators and mem-
bers of the Regional audit teams to
guide them in developing and imple-
menting an effective and nationally
uniform yearly audit program. How-
ever, the criteria presented can also
prove useful to agencies under audit
to provide them with descriptions of
the program areas to be evaluated.
Clarification of certain sections,
special agency circumstances,.and
regulation or guideline changes may
require additional discussion or infor-
mation. For these reasons, a list of
contact names and telephone num-
bers is given in Table 11-1.
11.2 Regulatory Authority to
Perform a Systems Audit
11.2.1 General Regulatory Author-
ity—The authority to perform sys-
tems audits is derived from the Code
of Federal Regulation (Title 40).
Specifically: 40 CFR Part 35, which
discusses agency grants and grant
conditions, and 40 CFR Part 58,
which deals specifically with the in-
stallation, operation and quality as-
surance of the SLAMS/NAMS net-
works.
The regulations contained in 40
CFR Part 35 mandate the perfor-
mance of yearly audits of agency air
monitoring programs by the Re-
gional Administrators or their de-
signees. Pertinent regulatory cita-
tions are summarized in Table 11-2.
All citations are quoted directly from
the regulations and are intended as
an indication of the context within
which systems audits are performed
and the impact that audit results may
have on a given agency. Even
though this is the regulatory author-
ity to conduct such audits, for the
SLAMS network, the specific author-
ity is derived from 40 CFR Part 58.
Three specific citations from 40 CFR
Part 58 are also, quoted in Table 11-2.
-------
Section 2.0.11
April 1986
Ttblo 11-1. List of Key Contacts and Telephone Numbers
Assistance Area
Office/Laboratory
Name
Telephone
Number
EPA Location
Laboratory William J. Mitchell (919) 541-2769 EMSL/QAD/PEB
Areas and NPAP FTS 629-2769
Monitoring
wnuam h, aarnora
WEIL FtfAWK.
Ctanlay 'C/om
{Witt 0*1 3UUb
(919) 541-5631
tlMiaUtatAUi'HtlU
O
OAQPS/MDAD/MRB
Objectives/Siting
Syetor,
1Q1QLKA1
enact /A,i/\rt/riDO
SAROAD
System/NADP
Jake Summers
(919) 541-5694 OAQPS/MDAD/NADB
NPAP = National Performance Audit Program
PARS » Precision and Accuracy Reporting System
NADB * National Aerometric Data Bank
In addition to the regulations pre-
sented in Table 11-2, a further re-
quirement is imposed on reporting
organizations submitting data sum-
mary reports to the National Aero-
metric Data Bank (NADB) through the
SAROAD computer system. SAROAD
acceptance criteria call for at least
75% data completeness, which has
been accepted as a data quality ob-
jective for state and local agencies'
monitoring operations. The Regional
QA Coordinator may wish to use this
requirement together with informa-
tion obtained by'accessing the
SAROAD NA285 or NA288 Computer
Programs, discussed in Section 11.3.
The percent data completeness may
be effectively used as an indicator of
Tabla 11-2. Summary of Regulatory Authority to Conduct System Audits
Section Number
and Description
Text
35.510-2
Grant Amount
35.510-3
Reduction in
Grant Amount
35.520
Criteria for (Grant)
Award
35.530
A. Highlights of 40 CFR 35
"In determining the amount of support for a control agency, the Regional Administrator will
consider
A. The functions, duties and obligations assigned to the agency by an applicable
implementation plan,
B. the feasibility of the program in view of the resources to be made available to achieve or
maintain EPA priorities and goafs,
C. the probable or estimated total cost of the program in relation to its expected accomplish-
ments,
D. the extent of the actual or potential pollution problems,
E. the population served within the agency's jurisdiction,
F. the financial need, and,
G. the evaluation of the agency's performance."
"If the Regional Administrator's annual performance evaluation reveals that the grantee will
fail or has failed to achieve the expected outputs described in his approved program, the
grant amount shall be reduced..." •
"No grant may be awarded to any interstate or intermunicipal air pollution control agency
unless the applicant provides assurance satisfactory to the Regional Administrator that the
agency provides for adequate representation of appropriate State, interstate, local and (when
appropriate) international interests in the air quality control region, and further that the
agency has the capability of developing and implementing a comprehensive air quality plan
for the air quality control region."
"No grant may be awarded unless the Regional Administrator had determined that (1) the
agency has the capability or will develop the capability, to achieve the objectives and outputs
described in its EPA-approved program, and (2) the agency has considered and incorporated
as appropriate the recommendations of the latest EPA performance evaluation in its pro-
gram."
In addition to any other requirements herein, each air pollution control grant shall be subject
to the following conditions:
-------
April 1985
Section Z.O.11
Table 11-2. Summary of Regulatory Authority to Conduct System Audits (Cont'd)
Section Number
and Description
Text
Grant Conditions
35.538-1
Agency
Evaluation
35.410
Evaluation of
Agency Perfor-
mance
A. Direct cost expenditures for the purchase of...
B. The sum of non-Federal recurrent expenditures ...
C. The grantee shall provide such information as the Regional Administrator may from time
to time require to carry out his functions. Such information may contain, but is not limited
to: Air quality data, emission inventory data, data describing progress toward compliance
with regulations by specific sources, data on variances granted, quality assurance informa-
tion related to data collection and analysis and similar regulatory motions, scfurce reduc-
tion plans and procedures, real time air quality and control activities, other data related to
air pollution emergency episode, and regulatory actions.
"Agency evaluation ... should be continuous throughout the budget period. It is EPA policy to
limit EPA evaluation to that which is necessary for responsible management of regional and
national efforts to control air pollution. The Regional Administrator shall conduct an agency
performance evaluation annually in accordance with 35.410."
"A performance evaluation shall be conducted at least annually by the Regional Administrator
and the grantee to provide a basis for measuring progress toward achievement of the ap-
proved objectives and outputs described in the work program. The evaluation shall be consis-
tent with the requirements of 35.538 for air pollution control agencies ..."
Air Quality
Surveillance
Plan Content
(SLAMS)
58.23
Monitoring
Network
Completion
58.34
NAMS Network
Completion
Appendix A
^Section 2.4
National Perfor-
mance and Sys-
tems Audit
B. Highlights of 40 CFR 58
"By January 1, 1980 the State shall adopt and submit to the Administrator a revision to the
plan which will: . . .
A. Provide for the ....
B. Provide for meeting the requirements of Appendices A, C, D, and E, to this part
C. Provide for the operation of...
D. Provide for the review of the air quality surveillance system on an annual basis to deter-
mine if the system meets the monitoring objectives defined in Appendix D to this part.
Such review must..."
"By January 1, 1983:
A. Each station in the SLAMS network must be in operation, be sited in accordance with the
criteria in Appendix E to this part, and be located as described on the station's SARD AD
site identification form, and
B. The quality assurance requirements of Appendix A to this part must be fully imple-
mented."
"By January 1, 1981:
A. Each NAMS must be in operation ...
B. The quality assurance requirements of Appendix A to this part must be fully implemented
for all NAMS."
"Agencies operating all or a portion of a SLAMS network are required to participate in EPA's
national performance audit program and to permit an annual EPA systems audit of their ambi-
ent air monitoring program ... for additional information about these programs. Agencies
should contact either the appropriate EPA Regional Quality Control Coordinator or the Quality
Assurance Branch, EMSL/'RTP, ... for instructions for participation."
-------
Section 2.0.11
April 1985
whether a rigorous systems audit,
using the long form questionnaire,
might be needed or not.
11.2.2 Specific Regulatory Guidance
—The specific regulatory require-
ments of an EPA-acceptable quality
assurance program are to be found
in Appendix A to 40 CFR Part 58.
Section 2.2 of Appendix A details the
operations for which an agency must
have written procedures. The exact
format and organization of such pro-
cedures is not indicated, however.
Thus, many approaches to appropri-
ate documentation have been sug-
gested by EPA, local agencies and
other groups.
One approach adopted by many
EPA Regional Offices is the organiza-
tion of the required material into the
framework recommended by the EPA
Quality Assurance Management Staff
in the document titled "Interim
Guidelines for the Preparation of
Quality Assurance Project Plans"
(QAMS 005/80, December 1980). The
sixteen (16) elements described in
the guideline document provide the
framework for organizing the re-
quired Air Program operational pro-
cedures, integrating quality assur-
ance activities and documenting
overall program operations. This ap-
proach is consistent with the re-
quired eleven items of 40 CFR
Part 58, Appendix A. Table 11-3 illus-
trates this consistency and demon-
strates how each required program
element will be evaluated in the con-
text of the program areas used in the
organization of the long-form ques-
tionnaire.
11.3 Guidelines for
Preliminary Assessment and
Systems Audit Planning
In performing a systems audit of a
given agency, the Regional QA Coor-
dinator is seeking a complete and ac-
curate picture of that agency's cur-
rent ambient air monitoring
operations. Past experience has
shown that four (4) person-days
should be allowed for an agency op-
erating 10-20 sites within close geo-
graphical proximity. The exact num-
ber of people and the time alloted to
conduct the audit are dependent on
the magnitude and complexity of the
agency and on the EPA Regional Of-
fice resources. During the alloted
time frame, the Regional QA Audit
Team should perform those inspec-
tions and interviews recommended
in Section 11.4. This includes on-site
interviews with key program person-
Table 11-3. Specific Regulatory Requirements to be Evaluated in a
Systems Audit
Requirement
(40 CFR 58, Appendix A)
Pertinent Section
of OAMS Document
005/80
Pertinent Section
of Questionnaire
(11.7)
(1) Selection of Methods and
Analyzers
(1) Selection of Methods,
Analyzers
Project
Description
Organization &
Responsibility
QA Objectives
Sampling Proce-
dures
(11) Documentation of Quality Sample Custody
Control Information
(2) Installation of Equipment
(3) Calibration
(7) Calibration and Zero/Span
Checks for Multiple Range
Analyzers
Only applicable if other
than automated analyzers
are used and analyses are
being performed on filters •
e.g., /VOJ or lead and TSP
(10) Recording and Validating
Data
(4) Zero/span checks and ad-
justments of automated
analyzers
(5) Control checks and their
frequency
(6) Control Limits for Zero/
Span
(7) Calibration and Zero/Span
for Multiple Range Ana-
lyzers
(9) Quality control checks for
air pollution episode
monitoring
Appendix A - Sections 2.0,
3.0 and 4.0
(8) Preventive and Remedial
Maintenance
Appendix A - Section 4.0
(10) Recording and Validating
Data
(4) Zero/Span checks_and ad-
justments of automated
analyzers
Calibration
Procedures and
Frequency
Analytical
Procedures
Data Reduction,
Validation and
Reporting
Internal Quality
Control Checks
Performance and
System Audits
Preventive
Maintenance
Specific Routine
Procedures used
to Assess Data
Precision,
Accuracy and
Completeness
Corrective
Action
Planning
Planning
Planning
Planning
Field Operations
~Field/Lab Operations
Field/Lab Operations
Lab Operations
Data Management
Field/Lab Operations
QA/QC
QA/QC
Field/Lab Operations
QA/QC
Data Management
Field/Lab Operations
-------
April 1985
'Section 2.0.11
Table 11-3. Specific Regulatory Requirements to be Evaluated in a
Systems Audit
Requirement
(40 CFR 58, Appendix A)
Pertinent Section
of OAMS Document
005/80
Pertinent Section
of Questionnaire
(11.7)
(6) Control Limits and Cor-
rective Actions
(11) Documentation of Quality
Control Information
(W) Data Recording and
Validation
Quality Assurance
Reports to
Management
Reporting
nel, evaluations of some ambient air
monitoring sites operated by the
agency, and scrutiny of data process-
ing procedures.
11.3.1 Frequency of Audits—The
EPA Regional Office retains the regu-
latory responsibility to evaluate
agency performance annually. Re-
gional Offices are urged to use the
short-form questionnaire (Section
11.6), the CAIR (Fig. 11-4), and the
audit reporting format (Section
11.4.4 ). Utilizing the above to
provide OAQPS with this audit infor-
mation will establish a uniform basis
for audit reporting throughout the
country. For many well-established
agencies, an extensive systems audit
and rigorous inspection may not be
necessary every year. The determina-
tion of the extent of the systems
audit and its rigor is left completely
to EPA Regional Office discretion.
Therefore, the option is provided
here that extensive inspections and
evaluations may be accomplished
using the short-form questionnaire
(Section 11.6), and appropriate sec-
tion^) -of the long-form questionnaire
(Section 11.7). It is suggested that a
complete systems audit using the
long-form questionnaire be per-
formed at'least once every three
years. Yearly reports must still, how-
ever, include the short form, CAIR,
and the report completed according
to Section 11.4.4.
The primary screening tools to aid
the EPA Regional QA Audit Team in
determining which type of audit to
conduct and its required extent are:
A. National Performance Audit
Program (NPAP) Data—which pro-
vide detailed information on the
ability of participants to certify
transfer standards and/or calibrate
monitoring instrumentation. Audit
Data summaries provide a relative
performance ranking for each par-
ticipating agency when compared
to the other participants for a par-
ticular pollutant. These data could
be used as a preliminary assess-
ment of laboratory operations at
the different local agencies.
. B. Precision and Accuracy Report-
ing System (PARS) Data—which
provide detailed information on
precision and accuracy checks for
each local agency and each pollu-
tant, on a quarterly basis. These
data summaries could be used to
identify out-of-control conditions at
different local agencies, for certain
pollutants.
C. National Aerometric Data Bank
(NADB) NA285 Data Summaries-7-
which provide a numerical count
of monitors meeting and those not
meeting specifications on monitor-
ing data completeness on a quar-
terly basis, together with an associ-
ated summary of precision and
accuracy probability limits. An ad-
ditional program, NA288, will pro-
vide data summaries indicating the
percent of data by site and/or by
state for each pollutant.
11.3.2 Selection of Monitoring Sites
for Evaluation—It is suggested that
approximately five percent (5%) of
the sites of each local agency in-
cluded in the reporting organization
be inspected during a systems audit.
Many reporting organizations contain
a large number of monitoring agen-
cies,'while in other cases, a monitor-
ing agency is its own reporting orga-
nization. For smaller local agencies,
no fewer than two (2) sites should be
inspected. To insure that the selected
sites represent a fair cross-section of
agency operations, one half of the
sites to be evaluated should be se-
lected by the agency itself, while the
other half should be selected by the
Regional QA Audit Team.
The audit team should use both
the Precision and Accuracy Reporting
System (PARS) and the SAROAD
computer databases in deciding on
specific sites to be evaluated. High
flexibility exists in the outputs
obtainable from the NADB NA 285
computer program; data
• completeness can be assessed by
pollutant, site, agency, time period
and season. These data summaries
would assist the Regional audit team
in spotting potentially persistent
operational problems in need of
more complete on-site evaluation. At
least one site showing poor data
completeness, as defined by
SAROAD, must be included in those
selected to be evaluated.
If the reporting organization under
audit operates many sites and/or its
structure is complicated and perhaps
inhomogeneous, then an additional
number of sites above the initial 5%
level should be inspected so that a
fair and accurate picture of the state
and local agency's ability to conduct
field monitoring activities can be ob-
tained. At the completion of the site
evaluations, the Regional audit team
- is expected to have established the
adequacy of the operating proce-
dures, the flow of data from the sites
and to be able to provide support to
conclusions about the homogeneity
of the reporting organization.
11.3.3 Data Audits—With the imple-
mentation by many agencies of auto-
mated data acquisition systems, the
data management function has, for
the most part, become increasingly
complex. Therefore, a complete sys-
tems audit must include a review of
the data processing and reporting
procedures starting at the acquisition
stage and terminating at the point of
data entry into the SAROAD com- •
puter system. The process of audit-
ing the data processing trail will be
dependent on size and organizational
characteristics of the repqrting orga-
nization, the volume of data pro-
cessed, and the data acquisition sys-
tem's characteristics. The details of
performing a data processing audit
are left, therefore/to Regional and
reporting organization personnel
working together to establish a data
processing audit trail appropriate for
a given agency.
Besides establishing and docu-
menting processing trails, data pro-
cessing audits procedure must in-
volve a certain amount of manual
recomputation of raw data. The pre-
liminary guidance provided here, for
the number of data to be manually
recalculated, should be considered a
minimum enabling only the detection
of gross data mishandling:
-------
Section 2.0.11
April 1985
(a) For continuous monitoring of
criteria pollutants, the Regional QA
Coordinator should choose two 24-
hour periods from the high and
low seasons for that particular pol-
lutant per local agency per year. (In
most cases the seasons of choice
will be winter and summer). The
pollutant and time interval choices
are left to the Regional auditor's
discretion.
(b) For manual monitoring, four
24-hour periods per local agency
per year should be recomputed.
The Regional QA Coordinator
should choose the periods for the
data processing audit while planning
the systems audit and ihspecting the
completeness records provided by
the NADB NA285 system. The recom-
mended acceptance limits for the dif-
ferences between the data input into
SAROAD and that recalculated dur-
ing the on-site phase of the systems
audit, are given in Table 11-4.
Systems audits conducted on large
reporting organizations (e.g. four
local agencies) require recomputa-
tion of eight 24-hour periods for each
of the criteria pollutants monitored
continuously. This results from two
24-hour periods being recomputed
for each local agency, for each pollu-
tant monitored, during a given year.
For manual methods, sixteen 24-hour
periods are recomputed, consisting
of four periods per local agency, per
year.
11.4 Guidelines for
Conducting Systems Audits of
State and Local Agencies
A systems audit should consist of
three separate phases :
• Pre-Audit Activities
• On-Site Audit Activities
* Post-Audit Activities
Summary activity flow diagrams
have been included as Figures 11-1,
Develop Audit Schedule
Contact Report
to Set Ter
Revise Schedu
ing Organizations
tative Dates
fe as Necessary
Contact Reporting Organization to
Discuss Audit Procedure
Firm Dates for On-Site Visits
Send Questionnaire and Request
Preliminary Support Material
Review Material Discuss with
Reporting Organization QA Officer
Develop Checklist of Points
for Discussion
Initiate Travel Plans
Finalize Travel Plans with Information
Provided by Reporting Organization
Contact Agency to Set Specific
Interview and Site Inspection Times
Travel On-Site
Figure 11-1. Pre-audit activities.
11-2 and 11-3, respectively. The
reader may find it useful to refer to
these diagrams while reading this
protocol.
11.4.1 Pre-Audit Activities - At the
beginning of each fiscal year, the Re-
Table 11-4. Acceptance Criteria for Data Audits
Dafa Acquisition
Mode
Automatic Data
Retrieval
Stripchart
Records
Vlanuat
Reduction
Pollutants
SO2, QS, NOZ,
CO
SO2, O& NO2,
CO
TSP
Pb
Measurement
Range (ppm)(a>
0-0.5, or 0-1.0
0-20, or 0-50
0-0.5, or 0-1.0
0-20, or 0-50
Tolerance
Limits
±3 ppb
±0.3 ppm
±20 ppb
±1 ppm
±0.1 n.g/m3
WApptoptitta scaling should be used for higher measurement ranges.
tolSpecittad at 760 mm Hg and 25'C.
gional QA Coordinator or a desig-
nated member of the Regional QA
Audit Team, should establish a tenta-
tive schedule for on-site systems au-
dits of the agencies within their re-
gion.
Six (6) weeks prior to the audit, the
Regional QA Coordinator should con-
tact the Quality Assurance Officer
(QAO) of the reporting organization
to be audited to coordinate specific
dates and schedules for the on-site
audit visit. During this initial contact,
the Regional QA Coordinator should
arrange a tentative schedule for
meetings with key personnel as well
as for inspection of selected ambient
air quality monitoring and measure-
ment operations. At the same time, a
schedule should be set for the exit
interview used to debrief the agency
Director or his designee, on the sys-
tems audit outcome. As part of this
scheduling, the Regional QA Coordi-
-------
April 1985
Section 2.0.11
Audit Team Initial Interview of Reporting Organization Director
'Audit Group 1
Interview with Key Personnel
Audit Group 2
Interview Planm
Interview Labors
Visit Labo
Witness Op
Review Sample R
Custot
Select Port/o
Initiate Auc
ng Manager
ory Director
ratory
erations
eceiving and
lY
n of Data
lit Trail
Establish Data Audit Trail
Through Laboratory Operations
to Data Management. Function
_ Meet to _
Discuss
Findings
i
Intervi
Operation
Visit Sites (Af,
Visit Sites (R
Visit Audit a
Fa
Select Por
Initiate A
w Field
s Manager
ency Selected)
eg/on Selected)
nd Calibration
ility
ion of Data
udit Trail
Establish Trail Through Field
Operations to Data Management
\
i
Finalize Audit Trails and Complete Data Audit
Prepare Audit Results nummary of
(a) overall operations tb) data audit findings
lc) laboratory operations (d) field operations
Initiate Requests for Corrective Action Implementation Requests fCA/ft)
Discuss Findings with Key Personnel QA Officer
Exit Interview with Reporting Organization Director to Obtain
Signatures on CAIR
On-Site Audit Complete
Figure 11 -2. On-site activities.
nator should indicate any special re-
quirements such as access to specific
areas or activities. The Regional QA
Coordinator should inform the
agency QAO that he will receive a
questionnaire, precision and accu-
racy data, and completeness "data
from NADB programs NA273 and
NA288 which is to be reviewed or
completed. He should emphasize that
the completed questionnaire is to be
returned to the EPA Region within
one (1) month of receipt. The addi-
tional information called for within
e questionnaire is considered as a
inimum, and both the Region and
e agency under audit should feel
free to include additional informa-
tion.
The Regional Audit Team may use
this initial contact or subsequent con-
versations to obtain appropriate
travel information, pertinent data on
monitoring sites to be visited, and
assistance in coordinating meeting
times.
Once the completed questionnaire
has been received, it should be re-
viewed and compared with the crite-
ria and information discussed in Sec-
tion 11.2 and with those documents
and regulations included by refer-
ence in Section 11.5. The Regional
QA Audit Team should also use the
PARS and NADB NA273 and NA288
to augment the documentation re-
ceived from the reporting organiza-
tion under audit. This preliminary
evaluation will be instrumental in se-
lecting the sites to be evaluated and
in the decision on the extent of the
monitoring site data audit. The Re-
gional Audit Team should then pre-
pare a checklist detailing specific
points for discussion with agency
personnel.
The Regional Audit Team could be
made of several members to offer a
wide variety of backgrounds and ex-
pertise. This team may then divide
into groups once on-site, so that
both audit coverage .and time utiliza-
tion can be optimized. A possible di-
vision may be that one group
assesses the support laboratory and
headquarters operations while
another evaluates sites, and
subsequently assesses audit and
calibration information. The team
leader should reconfirm the
proposed audit schedule with the
reporting organization immediately
prior to travelling to the site.
11.4.2 On-Site Activities—The Re-
gional QA Audit Team should meet
initially with the agency's Director or
his designee to discuss the scope,
duration, and activities involved with
the audit. This should be followed by
a meeting with key personnel identi-
fied from the completed question-
naire, or indicated by the agency
QAO. Key personnel to be inter-
viewed_during the audit are those in-
dividuals with responsibilities for:
planning, field operations, laboratory
operations,QA/QC, data manage-
ment, and reporting. At the conclu-
sion of these introductory meetings,
the Regional Audit Team may begin
work as two or more independent
groups. A suggested auditing
method is outlined in Figure 11.2.
To increase uniformity of site in-
spections, it is suggested that a site
checklist be developed and used.
The importance of the data pro-
cessing systems audit cannot be
overstated. Thus, sufficient time and
effort should be devoted to this activ-
ity so that the audit team has a clear
understanding and complete docu-
mentation of data flow. Its impor-
tance stems from the need to have
documentation on the quality of am-
bient air monitoring data for all the
criteria pollutants for which the
agency has monitoring requirements.
The data processing systems audit
will serve as an effective framework
for organizing the extensive amount
of information gathered during the
audit of laboratory, field monitoring,
and support functions within the
agency.
-------
Saction 2.0.11
April 1986
Travel Back to Regional Headquarters
1
I
1
1
1
1
1
1
1
r
I
1
!'
1
1
I
1
1
i
r
I
i
Audit Team Works Toget
Internal Review at Re
Incorporate Comments a
Issue Copies to Reporting
for Distribution and
her to Prepare Report \
-
gional Headquarters \
[
nd Revise Documents \
I
Organization Director
Written Comment
Incorporate Written Comments Received
from Reporting Organization
l
Submit Final Draft Report for
Internal Regional Review .
-~ ----- i - . -
1
I
Revise Report and Incorporate Comments
as Necessary
!
' 1
1
Prepare Final Copies
—-——-— ,
1
Distribute to Reporting Organization
Director, OAQPS and Region
Flgun 11-3, 'Post-audit activities.
The entire audit team should pre-
pare a brief written summary of find-
ings organized into the following
areas: planning, field operations, lab-
oratory operations, quality assur-
ance/quality control, data manage-
ment, and reporting. Problems with
specific areas should be discussed
and an attempt made to rank them in
order of their potential impact on
data quality. For the more serious of
these problems, Corrective Action
Implementation Request (CAIR)
forms should be initiated. An exam-
ple form is provided in Figure 11-4.
The forms have been designed such
that one is filled out for each major
deficiency noted that requires formal
corrective action.
The format, content, and intended
use of CAIRs is fully discussed in
Section 11.4.5 of this document.
Briefly, they are request forms for
specific corrective actions. They are
initiated by the Regional QA Audit
Team and signed upon mutual
agreement by the agency's Director
or his designee during the exit inter-
view.
The audit is now completed by
having the Regional Audit Team
members meet once again with key
personnel, the QAO and finally with
the agency's Director or his designee
to present their findings. This is also
the opportunity for the agency to
present their disagreements. The
audit team should simply state the
audit results including an indication
of the potential data quality impact.
During these meetings the audit
team should also discuss the sys-
tems audit reporting schedule and
notify agency personnel that they
will be given a chance to comment in
writing, within a certain time period,
on the prepared audit report in ad-
vance of any formal distribution.
11.4.3 Post-Audit Activities—The
major post-audit activity is the prepa-
ration of the Systems Audit Report.
The report format is presented in
Section 11.4.4.
To prepare the report, the audit
team should meet and compare ob-
servations with collected documents
and results of .interviews and discus-
sions with key personnel. Expected
QA Project Plan implementation is
compared with observed accomplish-
ments and deficiencies and the audit
findings are reviewed in detail.
Within thirty (30) calendar days of
the completion of the field work, the
audit report should be prepared and
submitted.
The Systems Audit Report is sub-
mitted to the audited agency to-
gether with a letter thanking agency
personnel for their assistance, time
and cooperation. It is suggested that
the body of the letter be used to reit-
erate the fact that the audit report is
being provided for review and writ-
ten comment. The letter should also
indicate that, should no written com-
ments be received by the Regional
QA Coordinator within thirty (30) cal-
endar days from the report date, it
will be assumed acceptable to the
agency in its current form, and will
be formally distributed without fur-
ther changes.
If the agency has written com-
ments or questions concerning the
audit report, the Regional Audit
Team should review and incorporate
them as appropriate, and subse-
-------
April 1986
Section 2.0.11
Corrective Action Implementation Request (CAIR)
Reporting Organization.
State or Local Agency
Deficiency Noted:
Agreed-upon Corrective Action:
Schedule for Corrective Action Implementation:
Signed.
Director.
QA Officer.
Audit Team Member.
.Date
.Date
.Date
Corrective Action Implementation Report:
Signed.
Signed.
Director.
figure JJ-4. Example of a CAIR Form.
QA Officer.
.Date
.Date
-------
Section 2.0.11
10
April 1985
quentty prepare and resubmit a re-
port In final form within thirty (30)
days of receipt of the written com-
ment. Copies of this report should be
sent to the agency Director or his de-
signe'e for his internal distribution.
The transmittal letter for the
amended report should indicate offi-
cial distribution and again draw at-
tention to the agreed-upon schedule
for Corrective Action Implementation.
11.4.4 Audit Reporting—The Sys-
tems Audit Report format discussed
in this section has been prepared to
be consistent with guidance offered
by the STAPPA/ALAPCO Ad Hoc Air
Monitoring Audit Committee. The
format is considered as acceptable
for annual systems audit reports sub-
mitted to the QAQPS. Regional Audit
Team members shall use this frame-
work as a starting point and include
additional material, comments, and
information provided by the agency
during the audit to present an accu-
rate and complete picture of its oper-
ations and performance evaluation.
At a minimum, the systems audit
report should include the following
six sections:
Executive Summary—summarizes
the overall performance of the
agency's monjtoring program. It
should highlight problem areas need-
ing additional attention and should
describe any significant conclusions
and/or broad recommendations.
Introduction—describes the pur--
pose and scope of the audit and_
identifies the Regional Audit Team
members, key agency personnel, and
other section or area leaders who
were interviewed. It should also
indicate the agency's facilities and
monitoring sites which were visited
and inspected, together with the
dates and times of the on-site audit
visit. Acknowledgement of the coop-
eration and assistance of the Director
and the QAO should also be consid-
ered for inclusion.
Audit Results—presents sufficient
technical detail to allow a complete
understanding of the agency opera-
tions. The information obtained dur-
ing the audit should be organized
using the recommended subjects and
the specific instructions given below.
It will be noted that the report format
follows the four-area organization of
the short-form questionnaire.
A. Network Design and Siting
1} Network Size—Provide an
overview of the network size
and the number of local agen-
cies responsible to the state for
network operation.
2) Network Design and Siting—De-
scribe any deficiencies in net-
work design or probe siting dis-
covered during the audit.
Indicate what corrective actions
are planned to deal with these
deficiencies.
3) Network Audit—Briefly discuss
the conclusions of the last net-
work annual audit and outline
any planned network revision
resulting from that audit.
4) Non-criteria Pollutants—Briefly
discuss the agency's monitoring
and quality assurance activities
related to non-criteria pollu-
tants.
B. Resources and Facilities
1) Instruments and Methods—De-
scribe any instrument non-
conformance with the require-
ments of 40 CFR 50, 51, 53, and
58. Briefly summarize agency
needs for instrument replace-
ment over and above non-
• conforming instruments.
2) Staff and Facilities—Comment
on staff training, adequacy of
facilities and availability of NBS-
traceable standard materials
and equipment necessary for
the agency to properly conduct
the bi-weekly precision checks
and quarterly accuracy audits
required under 40 CFR Part 58,
Appendix A.
3) Laboratory Facilities—Discuss
any deficiencies of laboratory
procedures, staffing and facili-
ties to conduct the tests and
analyses needed to implement
the SLAMS/NAMS monitoring
the Quality Assurance, plans.
C. Data and Data Management
1) Data Processing and Submittal—
Comment on the adequacy of
. the agency's staff and facilities
to process and submit SAROAD
air quality data as specified in
40 CFR 58.35 and the reporting
requirements of 40 CFR 58, Ap-
pendices A and F. Include an in-
dication of the timeliness of
data submission by indicating
the fraction of data which are
submitted more than forty-five
(45) days late.
2) Data Review—A brief discussion
of the agency's performance in
meeting the 75% criteria for
data completeness. Additionally,
discuss any remedial actions
necessary to improve data re-
porting.
3) Data Correction—Discuss the ad-
equacy and documentation of
corrections and/or deletions
made to preliminary ambient air
data, and their conistency with
both the agency's QA Manual
and Standard Operating Proce-
dures, and any revised proto-
cols.
4) Annual Report—Comment on
the completeness, adequacy
and timeliness of submission of
the SLAMS Annual Report
which is required under 40 CFR
58.26.
D. Quality Assurance/Quality Control
1) Status ofQuality Assurance Man-
ual—Discuss the status of the
Agency's Quality Assurance
Plan. Include an indication of its
approval status, the approval
status of recent changes and a
general discussion of the con-
sistency, determined during the
systems audit, between the
Agency Standard Operating Pro-
cedures and the Quality Assur-
ance Plan.
2) Audit Participation—Indicate fre-
quency of participation in an
audit program. Include as nec-
essary, the agency's participa-
tion in the National Perform-
ance Audit Program (NPAP) as
required by 40 CFR Part 58.
Comment on audit results and
any corrective actions taken.
3) Accuracy and Precision—As a
goal, the 95% probability limits
for precision (all pollutants) and
TSP accuracy should be less"
than ±15%. At 95% probability
limits, the accuracy for all other
pollutants should be less than
±20%. Using a short narrative
and a summary table, compare
the reporting organization's
performance against these
goals over the last two years.
Explan any deviations.
Discussion—includes a narrative of
the way in which the audit results
above are being interpreted. It
should clearly identify the derivation
of audit results which affect both
data quality and overall agency oper-
ations, and should outline the basis
in regulations and guideline docu-
ments for the specific, mutually-
agreed upon, corrective action rec-
ommendations.
Conclusions and Recommenda-
tions—should center around the
overall performance of the agency's
monitoring program. Major problem
areas should be highlighted. The
salient facts of mutually agreed upon
corrective action agreements should
be included in this section. An
equally important aspect to be con-
sidered in'the conclusion is a deter-
-------
April 1985
11
Section 2.0.11
mination of the homogeneity of the
agency's reporting organizations and
the appropriateness of pooling the
Precision and Accuracy data within
the reporting organizations. The
checklist in Figure 11 -5 should be
included and submitted with the
supporting documentation.
Appendix of Supporting Documen-
tation—contains a clean and legible
copy of the completed short-form
questionnaire and any Corrective Ac-
tion Implementation Request Forms
(CAIR). Additional documentation
may be included if it contributes sig-
nificantly to a clearer understanding
of audit results.
11.4.5 Follow-up and Corrective Ac-
tion Requirements—An effective cor-
rective action procedure for use by
the Regional QA Audit Team follows.
As a means of requesting corrective
actions identified during the on-site
audit, the auditor completes one
copy of the form, shown in Figure
11-4, for each major deficiency
noted. These CAIR forms are pre-
sented to, and discussed with, the
agency's Director or his designee,
and its QAO during the-exit inter-
view. Once agreement has been
reached, both the auditor and the Di-
rector sign th'e form. The original is
given to the agency Director or his
designee and a copy is retained by
the auditor. A photocopy of the com- •
pleted CAIR is included in the audit
report. It is taken to be the responsi-
bility of the agency to comply with
agreed-upon corrective action re-
quests in the specified time frame.
11.5 Criteria for the Evalua-
tion of State and Local
Agency Performance
This section is designed to assist
the Regional Audit Team in interpre-
tation of the completed questionnaire
received back from the agency prior
to the on-site interviews. It also pro-
vides the necessary guidance for top-
ics to be further developed during
the on-site interviews.
This section is organized such that
the specific topics to be covered and
the appropriate technical guidance
are keyed to the major subject areas
of the long-form questionnaire (Sec-
tion 11.7). The left-hand side of the
page itemizes the discussion topics
(and the right-hand side provides cita-
tions to specific regulations and
guideline documents which establish
the technical background necessary
for the evaluation of agency perform-
ance. A more complete bibliography
of EPA guideline documents is pre-
sented in 11.8.
-------
Section 2.0.11
12
April 1985
11.5.1 Planning
Topics for Discussion
Background Documents
General information on reporting organization and
status of Air Program, QA Plan and availability of
SOPs
Conformance of network design with regulation, and
completeness of network documentation
Organization staffing and adequacy of educational
background and training of key personnel
Adequacy of current facilities and proposed modifica-
tions
115.2 Field Operations
Topics for Discussion
Routine operational practices for SLAMS network,
and conformance with regulations
• Types of analyzers and samplers used for SLAMS
network
* Adequacy of field procedures, standards used and
field documentation employed for SLAMS network
* Frequency of zero/span checks, calibrations and credi-
bility of calibration equipment used
• Traceability of monitoring and calibration standards
• Preventive maintenance system including spare parts,
tools and service contracts for major equipment
* Record keeping to include inspection of some site log
books and chain-of-custody procedures
• Data acquisition and handling system establishing a
data audit trail from the site to the central data pro-
cessing facility
• State Implementation Plan
• U.S. EPA QAMS 005/80
• Previous Systems Audit report
• QA Handbook for Air Pollution Measurement Sys-
tems, Vol. II—Ambient Air Specific Methods, Section
2.0.1.
• 40 CFR 58 Appendices D and E
• OAQPS Siting Documents (available by pollutant)
• QA Handbook for Air Pollution Measurement Sys-
tems, Vol. I—Principles, Section 1.4 Vol. II—Ambient
Air Specific Methods, Section 2.0.5
Background Documents
" QA Handbook for Air Pollution Measurement Sys-'
terns. Vol. II, Section 2.0.9
«.QA Handbook for Air Pollution Measurement Sys-
tems, Vol. II
« 40 CFR 50 plus Appendices A through G (potentially
KforPM 10)
« 40 CFR 58 Appendix C—Requirements for SCAMS an-
alyzers
• QA Handbook for Air Pollution Measurement Sys-
tems, Vol. II
« Instruction Manuals for Designated Analyzers
• QA Handbook for Air Pollution Measurement Sys-
tems, Vol. II—Ambient Air Specific Methods Section
2.0.9
• QA Handbook for Air Pollution Measurement Sys-
tems, Vol. II—Ambient Air Specific Methods Section
2.0.7
» 40 CFR 58 Appendix A Section 2.3
« QA Handbook for Air Pollution Measurement Sys-
tems, Vol. II, Section 2.0.6
« QA Handbook for Air Pollution Measurement Sys-
tems, Vol. II—Ambient Air Specific Methods Sections
2.0.3 and 2.0.9
11.5.3 Laboratory Operations
Topics for Discussion
• Routine operational practices for manual methods
used in SLAMS network to include quality of chemi-
cal and storage times
• List of analytical methods used for criteria pollutants
and adherence to reference method protocols
• Additional analyses performed to satisfy regional,
state or local requirements
• Laboratory quality control including the regular usage
of duplicates, blanks, spikes and multi-point calibra-
tions
• Participation in EPA NPAP and method for inclusion
of audit materials in analytical run
Documentation and traceability of laboratory mea-
surements such as weighing, humidity and tempera-
ture determinations
Background Documents
40 CFR 50 Appendices A and B, and QA Handook,
Vol. II
40 CFR 58 Appendix C; "List of Designated Reference
and Equivalent Methods"
Refer to locally available protocols for analysis of
aldehydes, sulfate, nitrate, pollens, hydrocarbons, or
other toxic air contaminants.
U.S. EPA APTD-1132 "Quality Control Practices in
Processing Air Pollution Samples"
40 CFR 58 Appendix C; "List of Designated Reference
and Equivalent Methods"
40 CFR 58 Appendix A Section 2.4
QA Handbook for Air Pollution Measurement Sys-
tems, Vol. II, Section 2.0.10
40 CFR 58 Appendix C; "List of Designated Reference
and Equivalent Methods"
40 CFR 58 Appendix C; "List of Designated Reference
and Equivalent Methods"
-------
April 1985
13
Section 2.O.11
• Preventive maintenance in the laboratory to include
service contracts on major pieces of instrumentation
• Laboratory record keeping and chain-of-custody pro-
cedures to include inspection of logbooks used
• Adequacy of Laboratory facilities. Health and Safety
practices and disposal of wastes
• Data acquisition, handling and manipulation system
establishing data flow in the laboratory, data back-up
system and data reduction steps
• Data validation procedures, establishing an audit trail
for the laboratory to the central data processing facil-
ity
11.5.4 Data Management
Topics for Discussion
• Data flow from field and laboratory activities to cen-
tral data processing facility
• Extent of computerization of data management sys-
tem and verification of media changes, transcriptions
and manual data entry
• Software used for processing and its documentation;
to include functional description of software, test
cases and configuration control for subsequent revi-
sions
• System back-up and recovery capabilities
• Data screening, flagging and validation
• Data correction procedures and key personnel al-
lowed to correct ambient air data
• Reports generated for in-house distribution and for
submittal to EPA
• Responsibiffty for preparing data for entry into the
SAROAD and PARS systems and for responsibility for.
its final validation prior to submission
11.5.5 QA/QC Program
Topics for'Discussion
• Status of QA Program and its implementation
• Documentation of audit procedures, integrity of audit
devices and acceptance criteria for audit results
• Participation in the National Performance Audit Pro-
gram for what pollutants and ranking of results
• Additional internal audits such as document reviews
or data.processing audits
• Procedure and implementation of corrective action
• Frequency of performance and concentration levels
for precision checks for each criteria pollutant
11.5.6 Reporting
Topics for Discussion
• Preparation of precision and accurancy summaries
for the PARS system
• Other internal reports used to track performance and
corrective action implemenation
• Summary air data reports required by regulations
• Completeness, legibility and validity of P & A data on
Form 1
• 40 CFR 58 Appendix C; "List of Designated Reference
and Equivalent Methods"
• QA Handbook for Air Pollution Measurement Sys-
tems, VoL II, Section 2.0.6
• Handbook for Analytical Quality Control in Water and
Wastewater Laboratories
QA Handbook for Air Pollution Measurement Sys-
tems, Vol. II, Sections 2.0.3 and 2.0.9
Annual Book of ASTM Standards, Part 41, 1978.
Standard Recommended Practice for Dealing with
Outlying Observations (E 178-75)
Background Documents
QA Handbook for Air Pollution Measurement Sys-
terns. Vol. II, Section 2.0.3
QA Handbook for Air Pollution Measurement Sys-
tems, Vol. II, Section 2.0.9
QA Handbook for Air Pollution Measurement Sys-
tems, Vol. II, Sections 2.0.3 and 2.0.9
Validation of Air Monitoring Data, EPA-600/4-80-030
Screening Procedures for Ambient Air Quality Data,
EPA-450/2-78-037
QA Handbook for Air Pollution Measurement
Systems, Vol. II, Section 2.0.9
•. Aeros Manual Series, Vol. II, Aeros User's Manual,
EPA-450/2-76-029 .
Background Documents
40 CFR 58 Appendix A and QAMS 005/80
QA Handbook for Air Pollution Measurement Sys-
tems, Vol. II, Sections 2.0.11 and 2.0.12
40 CFR 58 Appendix A
QA Handbook for Air Pollution Measurement Sys-
tems, Vol. II, Section 2.0.10
• 40 CFR 58 Appendix A
Background Documents
• PARS User's Manual (in preparation)
• 40 CFR 58 Appendix A
40 CFR 58 Appendices F and G
40 CFR 58 Appendix A
-------
Section 2.0.11 14 April 1985
Reporting Organization Homogeneity Checklist
Yes No
1, field operations, for all local agencies, conducted by a common team of field operators?
2. Common calibration facilities are used for all local agencies?
3, Precision checks performed by common staff for all local agencies?
4. Accuracy checks performed by common staff for all local agencies?
5. Otta handling follows uniform procedures for all local agencies? j
6. Central data processing facilities used for all reporting? ' _;
7. Tracaabllity of all standards established by one central support laboratory? ' _,
5. One central analytical laboratory handles all analyses for manual methods? •
Figure 11-5. Example of Reporting Organization Homogeneity Checklist
-------
April 1986
15
Section 2.0.11
11.6 Systems Audit
Questionnaire (Short-Form)
The short-form questionnaire has
been designed specifically for use in
annually reviewing state and local
agencies' air monitoring programs. If
the Regional QA Coordinator decides
that a more rigorous systems audit
and site inspections are necessary,
he can utilize appropriate section(s)
of the Long-Form Questionnaire
(Section 11.7). This questionnaire has
been designed around the format
recommended by STAPPA/ALAPCO
in the National Ambient Air Monitor-
ing Questionnaire and is organized
around four (4) major topics consis-
tent with the reporting format out-
lined in Section 11.4.4. They are:
A. Network Design and Siting
B. Resources and Facilities
C. Data Management, and
D. Quality Assurance and Quality
Control
NATIONAL AIR MONITORING SYSTEMS AUDIT
QUESTIONNAIRE
(SHORT FORM)
Agency,
Address.
Telephone Number (Area Code).
Number.
Reporting Period (beginning-ending dates).
Organization Director
Air Program Supervisor.
Data Management Supervisor.
Quality Assurance Officer
Questionnaire Completed
On-Site Visit
Date:
(date)
. Audit Team Members:
(by)
Affiliation of Audit Team .
SHORT FORM QUESTIONNAIRE
TABLE OF CONTENTS
Page No.
A. NETWORK DESIGN AND SITING
1. Network Size
2. Network Design and Siting
3. Network Review
4. Non-Criteria Pollutants
B. RESOURCES AND FACILITIES
1. Instruments and Methods
2. Staff and Facilities
3. Laboratory Operations and Facilities
4. Standards and Traceability
C. DATA AND DATA MANAGEMENT
1. Timeliness of Data
2, Data Review
3. Data Correction
4. Annual Report
SF-2
SF-3
SF-3
SF-4
SF-4
SF-5
SF-5
SF-6
SF-7
SF-8
SF-8
SF-3
D. QUALITY ASSURANCE/QUALITY CONTROL
1. Status of Quality Assurance Program
2. Audit Participation
3. Precision and Accuracy Goals •
SF-9
SF-9
SF-rO
SF-1
-------
Section 2.0.11 18 April 1985
A. NETWORK DESIGN SITING
7. NETWORK SIZE
(a) Complete the table below for each of the criteria pollutants monitored as part of your air monitoring network,
Include only those sites that are presently operating and those which are temporarily inoperative (off line less
than 30 days}. Do not include additional monitors which are collocated or index sites.
Number of Monitors
SO2 NO2 CO O3 fSP Pb
NAMS
SLAMS
(excluding NAMS)
SPM
TOTAL
(b) SLAMS Network Description
1. Whatls tha date of the most current official SLAMS Network Description? ;
2. Whara is it available for public inspection?: '
3. Does It include for each site the following?
YES NO
SAROAD Site /D#
Location .
Sampling and Analysis Method .
Operative Schedule
Monitoring Objective and Scale of Representativeness
Any Proposed Changes
(c) For each of the criteria pollutants, how many modifications (SLAMS including NAMS) have been made since the
last systems audit? (List the total SLAMS and NAMS).
Date of last systems audit.
SF-2
-------
April 1985
17
Section 2.0.11
Pollutant
Sulfur Dioxide
Nitrogen Dioxide
Carbon Monoxide
Ozone
Added
Number of Monitors
Deleted
Relocated
Lead
(d) Briefly discuss changes to the Air Monitoring Network planned for the next audit period. (Equipment is discussed
in Part B). . -
2. NETWORK DESIGN AND SITING
Indicate by SAROAD Number any non-conformance with the requirements of 40 CFR 58, Appendices D and E.
Monitor
Site ID (SAROAD)
Reason for Non-Conformance
SO,
CO
NO2
f&f
PM-IO
Pb
3. NETWORK REVIEW
Please provide the following information on your previous internal Network Review required by 40 CFR 58.20d.
Review performed on: Date: _ __ _ _______ _
Performed by: _ _ _ __ _ _
Location and Title of Review Document:
Briefly discuss all problems uncovered by this review.
SF-3
-------
8«otlon 2.0.11 18 April 1985
4, NON-CRITERIA POLLUTANTS
Does your agency monitor and/or analyze for non-criteria and/or toxic air pollutants? Yes No
If ysst please complete the form below.
• . Monitoring SOP Available
Pollutant Method/Instrument Yes/No
B. RESOURCES AND FACILITIES
1. INSTRUMENTS AND METHODS
(a) Please complete the table below to indicate which analyzers do not conform with the requirements of 40 CFR 53
for NAMS, SLAMS, or SIP related SPM's.
_ „ Site Comment on
Pollutant Number Make/Model Identification Variances
CO
-SO2 " '.'••'.
NO2
03
pH-J»
Pb
(b) Please comment briefly on your currently identified equipment needs.
SF-4
-------
ApriHSSS 19 Section 2.0.11
2. STAFF AND FACILITIES
(a) Please indicate the number of people available to each of the following program areas:
Comment on Need for
Program Area Number Additional Personnel
Network Design and Siting
Resources and Facilities
Data and Data Management
QA/QC
(b) Comment on your agency's need for additional physical space (laboratory, office, storage, etc.).
3. LABORATORY OPERATION AND FACILITIES
(a) Is the documentation of Laboratory Standard Operating Procedures complete? Yes • No
Please complete the table below.
Analysis . Date of Last Revision
Sfc
10
Pb
S04
NO3
SO2
(bubblers)
NO2
Others (list by pollutant)
(b) Is sufficient instrumentation available to conduct your laboratory analyses? Yes No
SF-5
-------
Section 2.0.11
20
ApriM985
If no, please Indicate instrumentation needs in the table below.
Instrument
Needed
Analysis
New or
Replacement
Year of
Acquisition
4. STANDARDS AND TRACEABILITY
(a) Please complete the table for your agency's laboratory standards.
Parameter
Primary
Standard
Secondary
Standard
CO
N02
SO2
Weights
Temperature
Moisture
Barometric Pressure
Flow
Lead
Other (specifiy)
Recertification
Date
SF-6
-------
April 1985
21
Section 2.0.11
(b) Please complete the table below for your agency's site standards (up to 7% of the sites, not to exceed 20 sites).
Parameter
Primary
Standard
Secondary
Standard
Recertification
Date
CO .
NO,
SO2
C. DATA AND DATA MANAGEMENT
T. TIMELINESS OF DATA
For the current calendar year or portion thereof which ended at least 135 calendar days prior to the receipt of this
questionnaire, please provide the following percentages for required data submitted.
% Submitted on Time*
Monitoring
Qtr.
SO2
CO
NO,
PH-lo
Pb
1 (Jan. 1-March 31)
2 (Apr. 1-June 30)
3 (July 1-Sept. 30)
4 (Oct. 1-Dec. 31)
•"On-time" = within 135 calendar days after the end of the quarter in which the.data were collected.
SF-7
-------
Section 2.0.1 1
22
April 1 985
2. DATA REVIEW
What fraction of the SLAMS sites (by pollutant) reported less than 75% of the data (adjusted for seasonal monitorinq and
site start-ups and terminations)?
Calendar Year
Pollutant
Percent of Sites
< 75% Data Recovery
/si 2nd 3rd 4th
Quarter Quarter Quarter Quarter
Ozone
Nitrogen Dioxide
Sulfur Dioxide
Carbon Monoxide
Lead .. - . .
3. DATA CORRECTION
(a) Are changes to submitted data documented in a permanent file?
Yes No
// no, why not?
anlePnjeft
aCC°rding tO a
Standard Operating Procedure or your Agency Quality Assur-
Yes
NO
If not according to the OA Project Plan, please attach a copy of your current Standard Operating Procedure.
(c) Who has signature authority for approving corrections?
(name} (Program Function) "
4. ANNUAL REPORT
(a) Please provide the dates annual reports have been submitted in the last two years.
SF-8
-------
April 1986 23 Section 2.0.11
(b) Does the agency's annual report fas required in 40 CFR 58.26) include the following?
YES NO
1. Data summary required in Appendix F.
2. Annual precision and accuracy information described in Section && of Appendix A.
3. Location, date, pollution source and duration of all episodes reaching the significant
harm levels.
4. Certification by a senior officer in the State or his designee.
(c) Describe any deficiencies which cause the answer to part (b) of this question to be No.
D. QUALITY ASSURANCE/QUALITY CONTROL
1. STATUS OF QUALITY ASSURANCE PROGRAM
(a) Does the agency have an EPA-approved quality assurance program plan?*
Yes No
•' If yes, have changes to the plan been approved by the EPA?
Yes No
Please provide:
Date of Original Approval
Date of Last Revision
Date of Latest Approval.
(b) Do you have any revisions to your QA Program Plan still pending?
Yes No
2. AUDIT PARTICIPATION
(a) Date last systems audit was conducted?.
By whom? '
(b) Does the agency participate in the National Performance Audit Program (NPAP) as required under 40 CFR 58
Appendix A?*
• Yes No
*lf answer is No, give a brief summary of the deficiencies.
SF-9
-------
Saetlon 2.0.1 1 24 April 1985
(c) Please complete the table below.
Parameter Audited Date of Last NPAP Audit
SO2 (Continuous)
CO
Pb
fJeF Qovioo
GOjfbubbhrl
/V 0A ( COAT/AJ u o us-)
ft/Q. fhsihh.'A. 1
I " ^•'JC 1 UQtJiJt Ol /
3. PRECISION AND ACCURACY GOALS'
As a goal, the 95 percent probability limits for precision (all pollutants) and TSP accuracy should be less than + 75
psrcenf.
-------
April 1985 25 Section 2,0.11
(b) Accuracy Goals
# of Reporting Precision
Pollutant Organization Qtr/Yr Qtr/Yr Qtr/Yr Qtr/Yr
NO2
SO,
CO
f&P-
Pb
(c) To the extent possible, describe problems preventing the meeting of precision and accuracy goals.
SF-11
-------
Section 2.0.11
26
April 1986
11.7 Systems Audit Ques-
tionnaire (Long-Form)
The long-form systems audit ques-
tionnaire which follows is intended
to provide a complete picture of
agency ambient air monitoring oper-
ations and quality assurance imple-
mentation. J[h_e_followin£ Instructions
might prove helpTfurin completing
this survey questionnaire.
1. For ease in completing the ques-
tionnaire, it is not necessary to
type. Filling it out legibly in black
Ink is acceptable.
2. Feel free to elaborate on any point
or question in the form. Use addi-
tional pages as necessary to give
a complete response.
3. When necessary, include copies of
documents which will aid in un-
derstanding your response.
4. Please pay careful attention in
cornjpleting the questionnaire. The
information supplie'd will have~a
direct bearing on the conclusions
drawn and recommendations
made concerning the evaluation
of your organization's program.
5. The Regional Quality Assurance
Coordinator or a member, of his
staff may be contacted for assis-
tance in completing the question-
naire.
SYSTEMS AUDIT QUESTIONNAIRE (LONG FORM)
GENERAL INFORMATION
Questionnaire completion date.
On-site systems audit date
Reporting period
Agency name and address.
Mailing address (if different from above).
Telephone number (FTS).
Commercial ( )
Agency Director
Agency QA Officer
Reporting organizations making up this agency.
Systems audit conducted by.
Affiliation of audit team
Key Personnel:
'Planning
Completed Questionnaire
Interviewed
Field Operations.
Laboratory Operations.
QA/QC
Data Management.
Reporting
Persons Present during exit interview
LF-1
-------
April 1985 27 Section 2.0.11
LONG FORM QUESTIONNAIRE
TABLE OF CONTENTS
PAGE NO.
A. NETWORK MANAGEMENT
1. General LF-3
2. Network Design and Siting LF-5
3. Organization, Staffing and Training LF-7
4. Facilities LF-8
B. FIELD OPERATIONS
1. Routine Operations LF-9
2. Quality Control ' LF-11
3. Preventive Maintenance LF-14
4. Record Keeping LF-15
5. Data Acquisition and Handling LF-16
C. LABORATORY OPERATIONS
1. Routine Operations LF-17
2. Quality Control LF-19
3. Preventive Maintenance LF-21
4. Record Keeping LF-22
5. Data Acquisition and Handling LF-23
6. Specific Pollutants
TSP LF-23
Lead ' LF-25
D. DATA ANB DATA MANAGEMENT
7. Data Handling LF-26
2. Software Documentation LF-27
3. Data Validation and Correction LF-28 •
4. Data Processing LF-29
5. Internal Reporting LF-32
6. External Reporting LF-33
E. QUALITY ASSURANCE/QUALITY CONTROL
«
7. Status of Quality Assurance Program LF-35
2. Audits and Audit System Trace-
ability L.F-3S
3. National Performance Audit Pro-
gram (NPAP) and Additional
Audits LF-37
4. Documentation and Data Process-
ing Review LF-38
5. Corrective Action System LF-39
6. Audit Result Acceptance Criteria LF-39
LF-2
-------
Section 2.0.11 28 April 1985
A. NETWORK MANAGEMENT
7. GENERAL
(a) Provide an organization chart clearly showing the agency's structure and its reporting organizations. (Attach
sheet(s) as necessary.)
(b) What is the basis for the current structure of the agency's reporting organizations?
Yes No
Field operations for all local agencies, conducted by a common team of field operators? •
Common calibration facilities are used for all local agencies?
Precision checks performed by common staff for all local agencies?
Accuracy checks performed by common staff for all local agencies? •_
Data handling follows uniform procedures for all local agencies?
Central data processing facilities used for all reporting?
Traceability of all standards established by one central support laboratory? .
One central analytical laboratory handles all analyses for manual methods? _^___
(c) Does the agency feel that the data for the reporting organizations it contains can be pooled?
Yes No Please comment on either answer
(d) Briefly describe any changes which will be made within the agency's monitoring program the next calendar year.
(e) Complete the table below for each of the criteria pollutants monitored as part of your air monitoring network.
Number of Monitors
• : P*-'0
SOZ NO2 CO O3 ?&> Pb
NAMS
SLAMS (excluding NAMS)
SPM
TOTAL
(f) What is the date of the most current official SLAMS Network Description?.
/. Where is it available for public inspection?.
LF-3
-------
April 1985 29 Section 2.0.11
//. Does it include for each site the following?
YES NO
SAROAD Site /D# .
Location
Sampling and Analysis Method
Operative Schedule
Monitoring Objective and Scale of Representativeness
Any Proposed Changes
(g) For each of the criteria pollutants, how many modifications (SLAMS including NAMS) have been made since the
last systems audit? (List the total SLAMS and NAMS)
Date of last systems audit . .
Number of Monitors
Pollutant Added Deleted Relocated
Sulfur.Dioxide . •
Nitrogen Dioxide '
Carbon Monoxide •
Ozone
Lead
(h) Briefly discuss changes to the Air Monitoring Network planned for the next audit period. (Discuss equipment
needs in Section B.3.g)
(i) Does an overall SLAMS/NAMS Monitoring Plan exist?
Yes Wo
(j) Has the agency prepared and implemented Standard Operating Procedures for all facets of agency operation?
Yes No
If no, list subject of any missing SOPs .
(k) Do the Standard Operating Procedures adequately address at least the Woven ff# item quality control program
required by Appendix A to 40 CFR 58? Yes No Comment
LF-4
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Section 2.0.11 30 April 1985
(I) Clearly identify by section number and/or document title, major changes made to documents since the last on-
site review.
Title/Section # Pollutants) Affected
(m) Does the agency have an implemented plan for operations during emergency episodes? Yes No
Indicate latest revision, approval date and current location of this plan.
Document Title.
Revision Date _
Approved
(n) During episodes, are communications sufficient so that regulatory actions are based on real time data?
Yes No
M Identify the section of the emergency episode plan where quality control procedures can be found.
2. NETWORK DESIGN AND SITING
(a) Indicate By SAROAD Number any non-conformance with the requirements of 40 CFR 58, Appendices- D and E.
Site ID
Monitor (SAROAD) Reason for Non-Conformance
SO,
03
CO
NO2
PM-IO
Pb
(b) Please provide the following information on your previous Network Review required by 40 CFR 58.20d.
Review performed on: Date
Performed by: .
Location and Title of Review Document: •
LF-5
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April! 986 31 Section 2.0.11
Briefly discuss all problems uncovered by this review.
(c) Have NAMS Hard Copy Information Reports (NHCIRs) been prepared and submitted for all monitoring sites
within the network?
Yes No
(d) Does each site have the required information including:
. YES NO
SAROAD identification number?
Photographs/slides to the four cardinal compass points?
Startup and shutdown dates? .
Documentation of instrumentation?
Reasons for periods of missing data? •
(e) Who has custody of the current network documentation?
___
(f) Does the current level of monitoring effort, site placement, instrumentation, etc., meet requirements imposed by
current grant conditions? Yes No Comment __—
(g) How often is the network design and siting reviewed?
Date of last review.
(h) Please provide a summary of the monitoring activities conducted as the SLAMS/NAMS network by the agency
as follows:
I. Monitoring is seasonal for (indicate pollutant and month of high and low concentrations).
Month(s)
High Low
Pollutant Concentration Concentration Collocated
. ' ' Y/N
' Y/N
' Y/N
' . , Y/N
Y/N
Y/N
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Section 2.0.11 32 April 1985
//. Monitoring is year-round for (indicate pollutant)
Pollutant Collocated
Y/N
Y/N
Y/N
Y/N
Y/N
(I) Does the number of collocated monitoring sites meet the requirements of 40 CFR 58 Appendix A?
Yes No Comment -
(j) Does your agency monitor and/or analyze for non-criteria air and/or toxic air pollutants? Yes No
If yes, please complete the form below.
Monitoring . SOP Available
Pollutant Method/Instrument Yes/No
3. ORGANIZATION, STAFFING AND TRAINING
(a) Please indicate the key individuals responsible for the following:
Agency Director , .
SLAMS Network Manager
Quality Assurance Officer .
Field Operations Supervisor
Laboratory Supervisor
Data Management Supervisor
SLAMS Reporting Supervisor
(b) Please indicate the number of people available to each of the following program areas:
,,„_,__. .. " Comment on Need for
Program Area Number Additional Personnel
Network Design and Siting
Resources and Facilities
Data and Data Management
QA/QC
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April! 985 33 Section 2.0.11
(c) Does the agency have an established training program?
Yes No
I. Where is this documented? „
(rev date)
//. Does it make use of seminars, courses, EPA sponsored college level courses? Yes No
III. Indicate below the three (3) most recent training events and identify the personnel participating in them.
Event Dates Participant(s)
(d) Does the agency subscribe to recognized publications? Please provide a list of periodicals. Are periodicals avail-
able to all personnel?
Periodical Title Distribution
4. FACILITIES
(a) Identify the principal facilities where the work is performed which is related to the SLAMS/NAMS network? (Do
not include monitoring sites but do include any work which is performed by contract or other arrangementsT~
Facility Location Main SLAMS/NAMS Function
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Section 2.0.11
34
April 1986
(b) Please review the entries on the above table. Ara there any areas of facilities which you believe should be up-
graded? Please identify by location.
(c) Are there any significant changes which are likely to be Implemented to agency facilities before the next systems
audit? Comment on your agency's needs for additional physical space (laboratory, office, storage, etc.)
Facility
Function
Proposed Changs - Date
B. FIELD OPERATIONS
1. ROUTINE OPERATIONS
(a) Is the documentation of Monitoring Standard Operating Procedures complete?
Yes No
Please complete the table below.
Pollutant
Monitored
Date of Last Revision
PM-IO
Pb
SO,
NO,
(continuous)
{bubbler*}
CO
Others (list by pollutants)
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April 1985 35 Section Z.O.I 1
(b) Are such procedures available to all field operations personnel?
Yes No Comment
(c) Are standard operating procedures prepared and available to field personnel which detail operations during
episode monitoring?
Yes No Comment
(d) For what does each reporting oganization within the agency monitor? Provide the list requested below.
Reporting Organization • # of Sites Pollutants
(e) On the average, how often are most of your sites visited by a field operator? per
(f) Is this visit frequency consistent for all reporting organizations within your agency? Yes No
If no, document exceptions • • • '.
(g) On the average, how many sites does a single site operator have responsibility for?.
(h) How many of the sites of your SLAMS/NAMS network are equipped with manifold(s) #
I. Briefly describe most common manifold type..
//. Are manifolds cleaned periodically? Yes No
If yes, how often? per
///. If the manifold is cleaned, what is used?.
IV. Are manifold(s) equipped with a blower? Yes No '
V. Is there sufficient air flow through the manifold at all times?
Yes Wo
Approximate air flow is
(flow units}
VI. Is there a conditioning period for the manifold after cleaning? Briefly comment on the length of time the condition-
ing is performed.
LF-10
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Section 2.0.11 36 April 1985
(!) What material Is used for instrument lines?
(j) Has the agency obtained necessary waiver provisions to operate equipment which does not meet the effective
reference and equivalency requirements? Yes No
Comment on Agency use of approved/non-approved instrumentation..
(k) Please complete the table below to indicate which analyzers do not conform with the requirements of 40 CFR 53
for NAMS, SLAMS, or SIP related SPM's.
Site Comment on
Pollutant Number • Make/Model Identification Variances
CO
NO2
03
(I) Please comment briefly and prioritize your currently identified instrument needsT
2. QUALITY CONTROL
(a) Are field calibration procedures included in the documented Standard Operating Procedures? Yes
No
Comment on location (site, lab, office) of such procedures.
(b) Are multipoint calibrations performed? Indicate both the frequency and pollutant.
Reporting Organization Pollutant Frequency
(c) Are calibrations performed in keeping with the guidance offered in Section 2.0.9 Vol. II of the Quality Assurance
Handbook for Air Pollution Measurement Systems? Yes N.o ^fcl
' • w
If no, why not?.
LF-11
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April 1985 37 Section 2.0.11
(d) Are calibration procedures consistent with the operational requirements of Appendices to 40 CFR 50 or to ana-
lyzer operation/instruction manuals? Yes No
If no, briefly explain deviations.
(e) Have changes been made to calibration methods based on manufacturer's suggestions for a particular instru-
ment? Yes ___^ No
Are these also documented? Yes •No
(f) ^Jh"*dfrd?Ate"al5- US*Bd f?r calibrations meet tne requirements of appendices to 40 CFR 50 (EPA. reference
methods} and Appendix A to 40 CFR 58 (traceability of materials to NBS-SRMs or CRMs)? Yes. No
Comment on deviations ;
(g) Are all flow-measurement devices checked and certified?
Yes No Comment
(h) What are the authoritative standards used for each type of flow measurement? Please list them in the table be-
low, indicate the frequency of calibration standards to maintain field material/device credibility.
Flow Devices • Primary Standard Frequency of Calibration
(i) Where do field operations personnel obtain gaseous standards?
Are those standards certified by: Y v
The agency laboratory?
EPA/EMSL/RTP standards laboratory?
A laboratory separate from this agency but part of the same reporting organization?
The vendor?
NBS?
(j) Does the documentation include expiration date of certification? • Yes ' No
Reference to primary standard used? Yes No
What traceability protocol is used? ___
Please attach an example of recent documentation of traceability (tag, label, log sheet).
}(k) Is calibration equipment maintained at each site? Yes No
For what pollutants? ___
LF-12
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Section 2.0.11 38 April 1985
(II How is the functional integrity of this equipment documented?
(m) Please complete the table below for your agency's site standards (up to 7% of the sites, not to exceed 20 sites).
Primary Secondary Recertification
Parameter Standard Standard Date
CO
NO2
S02
(n) Are level. 1 zero and span (z/s) calibrations (or calibration checks) made for all continuous monitoring equipment
and flow checks made for TSP samplers? Yes No
Please complete table below:
Span Cone.
Pollutant (ppm) Frequency
L Continuous analyzers
Flow Rate Frequency
O —a -
II, 7W Samplers .
(o) Does the agency have acceptance criteria for zero/span checks? Yes No Comment.
I. Are these criteria known to the field operations personnel?
Yes No
//. Are they documented in standard operating procedures?
Yes No
LF-13
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April 1986 39 Sactfon 2.0.11
If not, indicate document and section where they can be found.
'"' 3 d°YeUsmentS di^ussedI" W above indicate when zero/span adjustments should and should not be
Indicate an example . ^
IV. Are zero and span check control charts maintained? Yes No
(P> checks?"9 Wlth 4° °FR 5S reaulations' are a"Y neeasaary zero and span adjustments made after precision
Yes No
. If no, comment on why not.
(q) Are precision check control charts maintained? Yes No
(r) Who has the responsibility for performing zero/span checks?
' meets
Please comment on any discrepancies.
W Please Fdemify Person(S) .wftn the responsibly for performance of precision checks on continuous analyzers.
Person(s) . . -
Title .
3. PREVENTIVE MAINTENANCE
• special training in performing preventive maintenance? Briefly comment
ib) Is this training routinely reinforced? Yes - No
If no, why not? J
^oZ^ZXSSSSZ'li ±e%r !nStrUmem ^f^ers? ^cate be,OW or
UF-14
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Section 2.0.11 40 April 1985
(f) Comment briefly on the adequacy and availability of the supply of spare parts, tools and manuals available to the
field operator to perform any necessary maintenance activities. Do you feel that this is adequate to prevent any
significant data loss? — ———
(g) Is the agency currently experiencing any recurring problem with equipment or manufacturer(s)? If so, please
identify the equipment and/or manufacturer, and comment on steps taken to remedy the problem.
4, ^RECORD KEEPING
(a) Is a log book(s) maintained at each site to document site visits, preventive maintenance and resolution of site
operational problems and corrective actions taken? Yes No Other uses ;—:
(b) Is the logbook maintained currently and reviewed periodically?
Yes No Frequency of Review
(c) Once entries are made and all pages filled, is the logbook sent to the laboratory for.archiving?
Yes No •
// no, is it stored at other location(s) (specify)
(d) What other records are used? ' ' YES NO
Zero/span record? .
Gas usage log? '
Maintenance log?
Log of precision checks?
Control chans?
A record of audits? . '
Please describe the use and storage of these documents.
(e) Are calibration records or at least calibration constants available to field operators? Yes No Please
attach an example field calibration record sheet to this questionnaire.
LF-15
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April 1885 41 Section 2.0.11
5. DATA ACQUISITION AND HANDLING
(a) With the exception ofTSP are instrument outputs (that is data) recorded to (a) stripcharts, (b) magnetic tape
acqu,s,t,on system (c) digit,zed and telemetered directly to agency headquarters? Please complete the table
below for each of the reporting organizations, or agencies within the overall P.O.
Beportiny Organization Pollutants
(b) Is there stripchart backup for all continuous analyzers? Yes No
(c) Where is the flow of high-volume samplers recorded at the site?
For samplers with flow controllers? Log sheet , Dixon chart , Other (specify)-
On High-volume samplers without flow controllers? Log sheet , Dixon chart , Other (specify)
equ'pment are available to th*field
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Section 2.0.11
42
April 1986
C. LABORATORY OPERATIONS
1. ROUTINE OPERATIONS
(a) What analytical methods are employed in support of your air monitoring network?
Analysis
Methods
Pb
SO4
NO3
SO2
NO2
Others (list by pollutant)
(b) Are bubblers used for any criteria pollutants in any agencies? Yes
No
indicates the number of sites where bubblers are used, the agency and pollutantfs}.
If yes, attach a table which
(c) Do any laboratory procedures deviate from the reference, equivalent, or approved methods? Yes No
If yes, are the deviations for lead analysis , fSft filter conditioning or other (specify below)?
(d) Have the procedures and/or any changes been approved by EPA? Yes
Date of Approval
No
LF-17
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April 1985 43 Section 2.O.1 1
(e) Is the documentation of Laboratory Standard Operating Procedures complete? Yes No Please
complete the table below. - -
Analysis Method
•f&ft.
Pb
S04
N03
SO,
NO2
Others (list by pollutant)
(f) I? sufficient instrumentation available to conduct your laboratory analyses? Yes No ' If no ol ease
indicate instrumentatio ' - - - ' ' please
indicate instrumentation needs in the table below.
Instrument */,,,.. -. ..
... . , /VGVv Or Yf*£)r nf
Needed _ Analysis Replacement AcquisMon
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Section 2.0.11 44 April 1985
2, QUALITY CONTROL
(a) Please complete the table for your agency's laboratory standards.
Primary Secondary decertification
Parameter Standard Standard Date
CO
NO2
SO2
Weights
Temperature
Moisture
Barometric Pressure
Flow
Lead
Sulfate
Nitrate
(b) Are all chemicals and solutions clearly marked with an indication of shelf life? Yes No
(c) Are chemicals removed and properly disposed of when shelf life expires? Yes No
(d) Are only ACS chemicals used by the laboratory? Yes No
(e) Comment on the traceability of chemicals used in the preparation of calibration standards—
IF-19
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April 1985 45 Section 2.0.11
(f) Does the laboratory:
Purchase standard solutions such as those for use with lead or other AA analysis? Yes No Make them
themselves? Yes No If the laboratory staff routinely make their own standard solutions, are procedures
for such available? Yes No Where?— Attach an example.
(g) Are all calibration procedures documented? Yes No
Where? ___^_^_^__
(title) (revision)
Unless fully documented, attach a brief description of a calibration procedure.
(h) Are at least one duplicate, one blank, and one standard or spike included with a given analytical batch? Yes
No Identify analyses for which this is routine operation.
(i) Briefly describe the laboratory's use of data derived from blank analyses.
Do criteria exist which determine acceptable/non-acceptable blank data? 'Please complete the table below.
Pollutant ' Blank Acceptance Criteria
SO2 . _ _ _ _ -
• NO2 ' ' • • _ _ _ ; _ ; _ •
SO4 __ _
N03 . _
Pb
Other
(j) How frequently and at what concentration ranges does the lab perform duplicate analysis? What constitutes ac-
ceptable agreement? Please complete the table -below.
Pollutant Frequency Acceptance Criteria
S02
' NO2 _ __ _ '
SO4
NO3 _ _ _ _
Pb
Other
LF-20
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Section 2.0.11 .46 April 1985
(k) How does the lab use data from spiked samples? Please indicate what may be considered acceptable percentage
recovery by analysis? Please complete the table below.
Pollutant % Recovery Acceptance Criteria
SO2 Bubblers
NO2 Bubblers
SO4 ,
N03
Pb
TSP • ! -
voc . ;
Other :
(I) Does the laboratory routinely include samples of reference material obtained from EPA within an analytical
batch? Yes No
If yes, indicate frequency, level, and material used.
(m) Are mid-range standards included in analytical batches? Yes No If yes, are such standards included
as a QC check (span check) on analytical stability? Please indicate the frequency, level and compound used in the
space provided below.
(n) Do criteria exist for "real time" quality control based on the results obtained for the mid-range standards dis-
cussed above? Yes No If yes, briefly discuss them below or indicate the document In which they
can be found.
(o) Are appropriate acceptance criteria documented for each type of analysis conducted? Yes No Are
they known to at least the analysts working with respective instruments? Yes A/o
3, PREVENTIVE MAINTENANCE
(a) For laboratory equipment, who has responsibility for major and/or minor preventive maintenance?
Person . Title
(b) Is most maintenance performed: in the lab? Yes No in the instrument repair facility? Yes
No at the manufacturer's facility? Yes No
(c) Is a maintenance log maintained for each major laboratory instrument?
Yes No Comment
LF-21
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April 1986 47 Section 2.0.11
(d) Are service contracts in place for the following analytical instruments:
YES NO
Analytical Balance
Atomic Absorption Spectrometer '
Ion Chromatograph
Automated Colorimeter
4. RECORD KEEPING
(a) Are all samples that are received by the. laboratory: logged- in? Yes No assigned a unique labora-
tory sample number? Yes No routed to the appropriate analytical section? Yes No
Discuss sample routing and special needs for analysis (or attach a copy of the latest SOP which covers this).
Attach a flow chart if possible.
(b) Are logbooks kept for all analytical laboratory-instruments? Yes Wo
(c) Do these logbooks indicate:
YES NO
, analytical batches processed? • :
quality control -data?. •
calibration data? '.
results of blanks, spikes and duplicates?
initials of analyst?
(d) Is there a logbook which indicates the checks made on: weights? Yes No _^_ humidity indicators?
Yes No balances? Yes No thermometer(s)? Yes No
(e) Are logbooks maintained to track the preparation of filters for the field? Yes No Are they current?
Yes No __^__ Do they indicate proper use of conditioning? Yes No Weighings? Yes
No Stamping and numbering? Yes No
(f) Are logbooks kept which track filters returning from the field for analysis? Yes No
(gi How are data records from the laboratory archived?
Where?
Who has the responsibility? Person.
Title
How long are records kept? Years .
(h) Does a chain-of-custody procedure exist for laboratory samples? Yes No
(i) Has chain-of-custody been documented and implemented as part of standard laboratory procedures? Yes
k No If yes, indicate date, title and revision number where it can be found.
UF-22
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Section 2.0.11
48
April 1985
5. DATA ACQUISITION AND HANDLING
(a) Identify those laboratory instruments which make use of computer interfaces directly to record data. Which ones
use stripcharts? integrators?
(b) Are QC data readily available to the analyst during a given analytical run? Yes No
(c) For those instruments which are computer interfaced, indicate which are backed up by stripcharts?.
(d) What is the laboratory's capability with regard to data recovery? In case of problems, can they recapture data or
are they dependent on computer operations? Discuss briefly.
(e) Has a user's'manual been prepared for the automated data acquisition instrumentation? Yes No
Comment '
Is it in the analyst's or user's possession? Yes No Is it current? Yes
No
(f) Please provide below a data flow diagram which establishes, by a short summary flow chart: transcriptions, vali-
dations, and reporting format changes the data goes through before being, released to the data management •
group. Attach additional pages as necessary.
6. SPECIFIC POLLUTANTS: T3f* AND LEAD
f§£ PH-IO
(a) Are filters supplied by EPA used at SLAMS sites? Yes /Vo
Comment '.
(b) Do filters meet the specifications in the Federal Register 40 CFR 50? Yes No Comment
(c) Are filters checked for surface alkalinity? Yes No
Indicate frequency
Id) Are filters visually inspected via strong light from a view box for pinholes and other imperfections? Yes
No // no, comment on way imperfections are determined? '
(e) Are filters permanently marked with a serial number? Yes
plished:. '
No
Indicate when and how this is accom-
(f) Are unexposed filters equilibrated in controlled conditioning environment which meets or exceeds the reauire-
ments of 40 CFR 50? Yes No If no, why not?
LF-23
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April 1985 49 Section 2.O.11
(g) Is the conditioning environment monitored? Yes No
Indicate frequency
Are the monitors properly calibrated? Yes No
Indicate frequency
(h) Is the balance checked with Class "S" weights each day it is used? Yes No If no, indicate frequency
of such checks
(i) Is the balance check information placed in QC logbook? Yes No
If no, where is it recorded? '.
(j) Is the filter weighed to the nearest milligram? Yes No If not, what mass increment.
(k) Are filter serial numbers and tare weights permanently recorded in a bound notebook? Yes No If
no, indicate where ^___ZIIII_ZZZZ__
(I) Are filters packaged for protection while transporting to and from the monitoring sites? Yes No
(m) How often are filter samples collected? (Indicate average lapse time (hrs.) between end of sampling and labora-
tory receipt.)
(n) Are field measurements recorded in logbook or on filter folder? •
(o) Are exposed filters reconditioned for at least 24 hrs in the same conditioning environment as for unexposed
filters? Yes No .
If no, why not?.
(p) Are exposed filters removed from folders, etc., before conditioning? Yes No
(q) Is the exposed filter weighed to the nearest milligram? Yes No
(r) Are exposed filters archived? Yes No When?
Where? :
Indicate retention period.
(s) Are blank filters reweighed? Yes No If no, explain why not.
If yes, how frequently?.
N°
LF-24
analyses °ther than Pb and ™** which are
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Section 2.0.11 60 ApriM985
(u) Are sample weights and collection data recorded in a bound laboratory logbook? Yes No On data
forms? Yes No
M Are measured air volumes corrected to reference conditions as given in CFR regulations (Q3ta of 760 mm Hg and
25"C) prior to calculating the Pb concentration? Yes No
If not, indicate conditions routinely employed for both internal and external reporting.
LEAD
(a) Is analysis for lead being conducted using atomic absorption spectrometry with air acetylene flame?
Yes No
If not, has the agency received an equivalency designation of their procedure?.
(b) Is either the hot acid or ultrasonic extraction procedure being followed precisely? Yes No Which?
(c) Is Class A borosilicate glassware used throughout the analysis? Yes No
(d) Is all glassware scrupulously cleaned with detergent, soaked and rinsed three times with distilled-deionized
water? Yes No If not, briefly describe or attach procedure.
M If extracted samples are stored, are linear polyethylene bottles used? Yes No Comment.
(I) Are all batches of glass fiber filters tested for background lead content? Yes No At a rate of 20 to
30 random filters per batch of 500 or greater? Yes No Indicate Tale ~~
tg) Are ACS reagent grade HNO3 and HCI used in the analysis? Yes No If not, indicate grade used
(h) Is a calibration curve available having concentrations that cover the linear absorption range of the atomic absorp-
tion instrumentation? Yes No Briefly describe
(1) Is the stability of the calibration curve checked by alternately remeasuring every 10th sample a concentration
S1 \ng Pb/ml; &10 n<7 Pb/ml? Yes No If not, indicate frequency.
LF-25
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April 1985 51 Section 2.0.11
(j) Are measured air volumes corrected to reference conditions as given in CFR regulations (Qstd of 760 mm Hg and
25°C) prior to calculating the Pb concentration? Yes No If not, indicate conditions routinely em-
ployed for both internal and external reporting.
(k) • In either the hot or ultrasonic extraction procedure, is there always a 30-min H^O soaking period to allow
trapped in the filter to diffuse into the rinse water? Yes No Comment
(I) Is a quality control program in effect that includes periodic quantification of (1) lead in 3/4" x 8" glass fiber filter
strips containing 100-300 |xg Pb/strip, and/or (2) a similar strip with 600-1000 jig strip, and (3) blank filter strips
with zero Pb content to determine if the method, as being used, has any bias? Yes No Comment on
lead QC program or attach applicable SOP. ZZZI__ -
(m) Are blank Pb values subtracted from Pb samples assayed? Yes No ^_^ If not, explain why.
D. DATA AND DATA MANAGEMENT
1. DATA HANDLING
(a) Is there a procedure, description, or a chart which shows a complete data sequence from point of acquisition to
point of submission of data to EPA? Yes No
Please provide below .a data flow diagram indicating both the data flow within the reporting organization and the
data received from the various local agencies.
(b) Are data handling and data reduction procedures documented?
For data from continuous analyzers? Yes No
For data from non-continuous methods? Yes No
(c) In what format and medium are data submitted to data processing section? Please provide separate entry for
each reporting organization.
Reporting Organization Data Medium Format
(d) How often are data received at the processing center from the field sites and laboratory? at least once a
week? every 7- 2 weeks? once a month?
(e) Is there documentation accompanying the data regarding any media changes, transcriptions, and/or flags which
have been placed into the data before data are released to agency internal data processing? Describe.
LF-26
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Section 2.0.11 52 April 1985
(f) How are the data actually entered to the computer system? Digitization of stripcharts? Manual or computerized
transcriptions? Other?
(g) Is a double-key entry system used for data at the processing center? Yes No Are duplicate card decks
prepared? Yes No /f no, why not?
(hi Have special data handling procedures been adopted for air pollution episodes? Yes No 'If yes,
provide brief description. .
2. SOFTWARE DOCUMENTATION
(a) Does the agency have available a copy of the AEROS Manual? Yes No Comment
(b) Does the agency have the PARS user's guide available? Yes • No __ ._ Comment (provide guide #)
(c) Does the Data Management Section have complete software documentation? Yes No
Comment
If yes, indicate the implementation date and latest revision dates for such documentation.
(d) Do the documentation standards follow the guidance offered by the EPA Software Documentation Protocols?
Yes No
If no, what protocols are they based on?.
lei What is the origin of the software used to process air monitoring data prior to its release into the SAROAD/NADB
database?
I. Purchased? Yes No ; Supplier.
Date of latest version
LF-27
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April 1985 53 Section 2.0.11
//. Written in-house? Yes No / Latest version.
Date
///. Purchased with modifications in-house? Yes No
Latest version Date
IV. Other (specify)
(f) Is a user's manual available to data management personnel for all software currently in use at the agency for
processing SLAMS/NAMS data?
Yes No Comment.
(g) Is there a functional description either: included in the user's manual? Yes No separate from it
and available to the users? Yes No '_
(h) Are the computer system contents, including ambient air monitoring data backed up regularly? Yes Nn
Briefly describe, indicating at least the media, frequency, and backup-media storage location
(i) What is the recovery capability (how much time and data would be lost) in the event of a significant computer
problem?
(j) Are test data available to evaluate the integrity of the software? Yes Nn Is it 'properly documented?
Yes ~~No . .
3. DATA VALIDATION AND CORRECTION . •
(a) Have validation criteria, applicable to all pollutant data processed by the reporting organization been established
and documented? Yes No
If yes, indicate document where such criteria can be found (title, revision date).
(b) Does documentation exist on the Identification and applicability of flags (i.e., identification of suspect values)
within the data as recorded with the data in the computer files? Yes No,
(c) Do documented data validation criteria employ address limits on and for the following:
1. Operational parameters, such as flow rate measurements or flow rate changes.
//. Calibration raw data, calibration validation and calibration equipment tests.
III. All special checks unique to a measurement system .
IV. Tests for outliers in routine data as part of screening process .
LF-28
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Section 2.0.11 54 April 1985
V, Manual checks such as hand calculation of concentrations and their comparison with computer-calculated data
(d) Are changes to data submitted to NADB documented in a permanent file? Yes No If no, why
not?
(e) Are changes performed according to a documented Standard Operating Procedure or your Agency Qualitv Assur-
ance Project Plan? Yes No-
If not according to the QA Project Plan, please attach a copy of your current Standard Operating Procedure.
(f) Who has signature authority for approving corrections?
(Name) (Program Function)
ummaries prepared at each critical point in tl
(he applicable block of data to the next level <
Please indicate the points where such summaries are performed.
(g) Are data validation summaries prepared at each critical point in the measurement process or information flow
and forwarded with the applicable block of data to the next level of validation? Yes No
(h) What criteria are applied for data to be deleted? Discuss briefly.
(i) What criteria are applied to cause data to be reprocessed? Discuss.
(j) Is the group supplying data provided an opportunity to review data and correct erroneous entries?
Yes No If yes, how?
Are corrected data resubmitted to the issuing group for cross-checking prior to release? Yes No
4, DATA PROCESSING
(a) Does the agency generate data summary reports? Yes No
Are the data used for in-house distribution and use? Yes No
Publication? Yes No
Other (specify)
LF-29
-------
April 1985 BS Section 2.0.11
(b) Please list at least three (3) reports routinely generated, providing the information requested below.
Report Title Distribution • Period Covered
(c) Have special procedures been instituted for pollution index reporting? Yes No // yes, provide
brief description. . . • .
(d) Who at the agency has the responsibility for submitting data to SAROAD/NADB? (name) _
(title) !
Is the data reviewed and approved by an officer of the agency prior to submittal? Yes No
(name) ; ; (title) !,
(e) Are those persons different from the individuals who sumbit data to PARS? Yes No If yes,
provide name and title of individual responsible for PARS data submittal.
(name) . (title) ' , PARS
' Data review and approval (name) :
, (title) , r_^___
(f) How often are data submitted to: ~
SAROAD? : ; ._
PARS? :
(g) How and/or in what form are data submitted?
TO SAROAD? !
TO PARS?
(h) Are the recommendations and requirements for data coding and submittal, In the AEROS User's Manual followed
closely for SAROAD? Yes No Comment on any routine deviations in coding procedures.
(I) Are the recommendations and requirements for data 'coding and submittal, in the PARS User's Guide, followed
closely? Yes No Comment on any routine deviations in coding and/or computational'procedures.
(j) Does the agency routinely request a hard copy printback on submitted data:
from SAROAD/NADB? Yes No
from PARS? Yes No
LF-30
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Section 2.0.11 66 April 1985
fk) Are records kept for at least 3 years by the agency in an orderly, accessible form? Yes No
If yes, does this include raw data , calculation , QC data , and reports ? If no, please
comment.
(I) In what format are data received at the data processing center? (Specify appropriate pollutant.)
(a) concentration units __. (b) % chart (c) voltages (d) other
(m) Do field data include the following documentation?
_ Site ID? Yes No
Pollutant type? Yes No
Date received at the center? Yes No
Collection data (flow, time date)? Yes No
Date of Laboratory Analysis (if applicable) Yes No
Operator/Analyst? Yes No
(n) Are the appropriate calibration equations submitted with the data to the processing center? Yes No
If not, explain.
(o) Provide a brief description of the procedures and appropriate formulae used to convert field data to concentra-
tions prior to input into the data bank.
SO,
N02.
CO.
03.
TSP.
cwyrwc.
Pb.
Other.
LF-31
-------
April 1985 57 Section 2.0.11
(p) Are all concentrations corrected to EPA standard (298°K, 760 mm Hg) temperature and pressure condition before
input to the SAROAD?
Yes No If no, specify conditions used.
(q) Are data reduction audits performed on a routine basis? Yes No If yes,
at what frequency?-
are they done by an independent group?.
(r) Are there special procedures available for handling and processing precision, accuracy, calibrations and span
checks? Yes No
If no, comment.
If yes, provide a brief description: Span check data,
Calibration data '.
Precision data
Accuracy data •
(s) Are precision and accuracy data checked each time they are recorded, calculated or transcribed to ensure that
incorrect values are not submitted to EPA? Yes No Please comment and/or provide a brief de-
scription of checks performed.
ftj /s a final data processing check performed prior to submission of any data? Yes. No.
If yes, document procedure briefly : __ '
If no, explain.
5. INTERNAL REPORTING
(a) What reports are prepared and submitted as a result of the audits required under 40 CFR -Appendix A?
Report Title . . . Frequency
(Please include an example audit report and, by attaching a coversheet, identify the distribution such reports are
given within the agency.)
(b) What internal reports are prepared and submitted as a result of precision checks also required under 40 CFR 58
Appendix A?
RePQrt Frequency
(Please include an example of a precision check report and, identify the distribution such reports receive within
the agency.)
LF-32
-------
Sactlon 2.0,11 B8 April 1986
(c) Do either the audit or precision reports Indicated include a discussion of corrective actions initiated based on
audit or precision results?
Yes No // yes, identify report(s) and section numbers.
(d) Does the agency prepare Precision and Accuracy summaries other than Form 1? Yes No If no,
please attach examples of recent summaries including a recent Form 7.
(e) Who has the responsibility for the calculation and preparation of data summaries? To whom are such P and A
summaries delivered?
Name Title . Type of Report Recipient
(f) Identify the individual within the agency who receives the results of the agency's participation in the NPAP and
the internal distribution of the results once received.
Principal Contact.for NPAP is (name, title)
Distribution is.
(name) • (title)
6. EXTERNAL REPORTING
(a) For the current calendar year or portion thereof which ended at least 135 calendar days prior to the receipt of this
questionnaire, please provide the following percentages for required data submitted.
%Submitted on Time*
Monitoring Qtr. SO2 CO ' O3 NO2 W Pb
1 (Jan. 1-March 31)
2 (Apr. 1-June 30)
3 (July 1-Sept. 30)
4 (Oct. 1-Dec. 31)
'"On-Time" - within 135 calendar days after the end of the quarter in which the data were collected.
(b) Identify the individual within the agency with the responsibility for preparing the required 40 CFR 58 Appendix F
and G reporting inputs.
Name Title .
LF-33
-------
April 1985
59
Section 2.O.11
(c) Identify the individual within the agency with the responsibility for reviewing and releasing the data.
Name : : Title
(d) Does the agency regularly report the Pollutant Standard Index (PSI)? Briefly describe the media, coverage, and
frequency of such reporting.
(e) What fraction of the SLAMS sites (by pollutant) reported less than 75% of the data (adjusted for seasonal moni-
toring and site start-ups and terminations)?
FY
Pollutant
Percent of Sites
<75% Data Recovery
1st Quarter 2nd Quarter 3rd Quarter 4th Quarter
Ozone • • .
Nitrogen Dioxide
Sulfur Dioxide
Carbon Monoxide
PW-io
T-— *„/ C* ,«W«W D«^*,*«. /„*
Lead
(f) Does the agency's annual report (as required in 40 CFR 58.26) include 'the following?
Data summary required in Appendix F. '
Annual precision and accuracy information described in Section 5.2 of Appendix A.
Location, date, pollution source and duration of all episodes reaching the significant
harm levels.
Certification by a senior officer in the State or his designee.
!gl Please provide the dates at which the annual reports have been submitted for the last 2 years.
. YES NO
LF-34
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Section 2.0.11 60 April 1985
£ ClUAUTY ASSURANCE/QUALITY CONTROL
1. STATUS OF QUALITY ASSURANCE PROGRAM
(a) Does the agency have-an EPA-approved quality assurance program plan? Yes No
If yes, have changes to the plan been approved by the EPA? Yes No
Please provide: Date of Original Approval Date of Last Revision
Date of Latest Approval
(b) Do you have any revisions to your QA Program Plan still pending? Yes No
(c) Is the QA Plan fully implemented? Yes No Comment:
(d) Are copies of QA Pla.n or pertinent sections available to agency personnel? Yes No. If no, why
not? •.
(e) Which individuals routinely receive updates to QA Plan?
2. AUDITS AND AUDIT SYSTEM TRACEABILITY
(a) Does the agency maintain a separate audit/calibration support facility laboratory: Yes No
(b) Has the.agency documented and implemented specific audit procedures? Yes No
(c) Have audit procedures been prepared in keeping with the requirements of Appendix A to 40 CFR 58?
Yes No
If no, comment on any EPA approved deviations.
(d) Do the procedures meet the specific requirements for independent standards and the suggestions regard/no per-
sonnel and equipment? Yes No Comment:
M Are SRM or CRM materials used to routinely certify audit materials? Yes No
(f) Does the agency routinely use NBS-SRM or CRM materials? Yes No For audits only? For
calibrations only? For both? For neither, secondary standards are employed '
LF-35
-------
April 1985 61 Section2.0.11
. (g) Please list below areas routinely covered by this review, the date of the last review, and changes made as a direct
result of the review.
Pollutants Audit Method Audit Standard
CO
03
NO2 ' ' '
(continuous)
SO2
PM-/O
(h) Are SRM or CRM materials used to establish traceability of calibration and zero/span check materials provided to
. field operations personnel? Yes _ No _
(!) Specifically for gaseous standards, how is the traceability of audit system standard materials established? Are
they: purchased certified by the vendor? _ __ _ ___ _ . _
certified by the QA support laboratory which is part of this agency?
Other? (Please comment briefly below)..
(j) Are all agency traceability and standardization methods used documented? Yes - No Indicate docu-
ment where such methods can be found. •
(k) Do the. traceability and standardization methods conform with the guidance of Section 2.0.7 Vol. II of the Hand-
book for Air Pollution Measurement Systems?
For permeation devices? Yes No For cylinder gases? Yes No
(I) Does the agency have identifiable auditing equipment (specifically intended for sole use) for audits?
Yes No If yes, provide specific identification
(m) How often is auditing equipment certified for accuracy against standards and equipment of higher authority?.
LF-36
-------
Section 2.0.11 62 April! 985
^if! *!]? afudit^u!Pment^ecks performed, have pass/fail (acceptance criteria) been decided for this
eqwpment? Ind.cate what these cntena are with respect to each pollutant. Where are such criteria documented?
Pollutant ' Criteria
3. NATIONAL PERFORMANCE AUDIT PROGRAM (NPAP) AND ADDITIONAL AUDITS
M Prl^mhe'ndMdUal Wlth P"marV responsibilitY for the reW'r*d participation in the National Performance Audit
For gaseous materials? (name, title) __
For laboratory materials? (name, title).
If yes, has the agency included QA requirements with this agreement? Yes No
Is the agency adequately familiar with their QA program? Yes No
(c) Date last systems audit was conducted:
By whom?—
(d) Please complete the table below
Parameter Audited Date of Last NPAp
SO,
CO
Pb
flerOjiA.s
Oy
NO,
LF-37
-------
Apr/11986 63 Section Z.O.It
(e) Does the agency participate in the National Performance Audit Program (NPAP) as required under 40 CFR 58
Appendix A? Yes No
If no, why not? Summarize below.
4. DOCUMENTATION AND DATA PROCESSING REVIEW
(a) Does the agency periodically review its record-keeping activities? Yes No
Please list below areas routinely coverd by this review, the date of the last review, and changes made as a direct
result of the review.
Area/Function Date of Review Changes? Discuss Changes
: Y/N
' Y/N
Y/N
(b) Are data audits (specific re-reductions of strip charts or similar activities) routinely performed for criteria pollutant
data reported by the agency? Yes No
If no, please explain.
(c) Are procedures for such data audits documented? Yes No
(d) Are they consistent with the recommendations of Sections 2.3-2.9 of Vol. II of the QA Handbook for Air Pollution
Measurement Systems? • ' •
Yes No If no, why not?.
(e) What is the frequency and level (as a percentage of data processed) of these audits?
Poll. Audit Freq. Period of Data Audited % of Data Rechecked
(f) ldentify_the criteria for acceptable/non-acceptable result from a data provessing audit for each pollutant, as
appropriate.
Pollutant Acceptance Criteria Data Concentration Level
(g) Are procedures documented and implemented for corrective actions based on results of data audits which fall
outside the established limits? Yes No
If yes, where are such corrective, action procedures documented?
LF-38
-------
Section 2.0.11 64 April 1985
5. CORRECTIVE ACTION SYSTEM
la) Does the agency have a comprehensive Corrective Action program in place and operational? Yes
No
(b) Have the procedures been documented? Yes No As a part of the agency QA Plan? Yes
No As a separate Standard Operating Procedure? Yes No Briefly describe it or attach a
copy.
(c) How is responsibility for implementing corrective actions on the basis of audits, calibration problems, zero/span
checks, etc. assigned? Briefly discuss.
(d) How does the agency follow up on implemented corrective actions?.
(e) Briefly describe two (2) recent examples of the ways in which the above corrective action system was employed
to remove a problem area with
I. Audit Results:
II. Data Management:
6. AUDIT RESULT ACCEPTANCE CRITERIA
(a) Has the agency established and has it documented criteria to define agency-acceptable audit results?
Yes No
Please complete the table below with the pollutant, monitor and acceptance criteria.
Pollutant • Audit Result Acceptance Criteria
CO
03
NO2
^f (continuous}
SOy
-A/p
I TT1T J*
LF-39
-------
April 1985 65 Section 2.0.11
(b) Were these audit criteria based on, or derived from, the guidance found in Vol. II of the QA Handbook for Air
Pollution Measurement System, Section 2.0.12? Yes /Vo___
If no, please explain.
If yes, please explain any changes or assumptions made in the derivation.
What corrective action may be taken if criteria are exceeded? If possible, indicate two examples of corrective
actions taken within the period since the previous systems audit which are based directly on the criteria dis-
s*nccart ah\n\/o
(c)
cussed above.
Corrective Action # 1
Corrective Action #2.
(d) As a goal, the 95 percent probability limits for precision (all pollutants) and TSP accuracy should be less than
± 15 percent. At 95 percent probability limits, the accuracy for all other pollutants should be less than
±20 percent. Using a short narrative and a summary table, compare the reporting organization's performance
against these goals over the last year. Explain any deviations.
NOTE: Precision and accuracy are based on reporting organizations; therefore this question concerns the reporting
organizations that are the responsibility of the agency. A copy of a computer printout has been provided which con-
tains the precision and accuracy data submitted to EMSL for each of the agency's reporting organizations. The print-
out, containing at least the last four completed calendar quarters of precision and accuracy data, was obtained using
the NADB program NA273. This data should be verified using agency records. If found in error, please initiate correc-
tions. Based on the data provided or corrections thereto, complete the tables below indicating the. number of report-
ing organizations meeting the goal stated above for each pollutant by quarter.
{Report, level 2 checks unless otherwise directed by Regional Office.)
I. Precision Goals
Precision
Pollutant # of Reporting Organization Qtr/Yr Qtr/Yr Qtr/Yr Qtr/Yr
03 . '.'''.
NO?
SO,
CO
*&*>
Pb
LF-40
-------
Section 2.0.11 66 April 1985
//. Accuracy Goals
*
Precision
Pollutant # of Reporting Organization Qtr/Yr Qtr/Yr Qtr/Yr Qtr/Yr
N02
SO2
CO
PM-/0
Pb
M To the extent possible, describe problems preventing the meeting of precision and accuracy goals.
LF-41
-------
April 1985
67
Section 2.0.11
11.8 Bibliography
Guideline documents for the
SLAMS Air Program, arranged in de-
scending chronological order, the
most recent ones first.
Reference
Report Title
EPA-600/4-83-023
June 1983
EPA-600/7-81-010
May 1981
EPA-QAMS-005/80
December 1980
EPA-600/4-80-030
June 1980
EPA-600/4-79-056
September 1979
EPA-600/4-79-057
September 1979
EPA-600/4-79-019
March 1979
EPA-450/4-79-007
February 1979
EPA-600/4-78-047
August 1978
EPA-450/2-78-037
July 1978
EPA-450/3-78-013
April 1978
EPA-450/3-77-018
December 1977
EPA-600/4-77-027a
May 1977
EPA-450/3-77-013
April 1977
EPA-450/2-76-029
December 1976
EPA-450/2-76-005
April 1976
^EPA-600/9-76-005
March 1976
EPA-450/2-76-001
February 1976
Guideline on the Meaning and Use of Preci-
sion and Accuracy Data Required by 40 CFR
Part 58 Appendices A and B
A Procedure for Establishing Traceability of
Gas Mixtures to Certified National Bureau of
Standards SRMs
Interim Guidelines and Specifications for
Preparing Quality Assurance Project Plans
Validation of Air Monitoring Data
Transfer Standards for Calibration of Air Moni-
toring Analyzers for Ozone
Technical Assistance Document for the Cali-
bration of Ambient Ozone Monitors
Handbook for Analytical Quality Control in
Water and Wastewater Laboratories
Guidance for Selecting TSP Episode Monitor-
ing Methods
Investigation of Flow Rate Calibration Proce-
dures Associated with the High Volume
Method for Determination of Suspended Par-
ticulates
Screening Procedures for Ambient Air Quality
Data
Site Selection for the Monitoring of Photo-
chemical Air Pollutants
Selecting Sites for Monitoring Total Sus-
pended Particulates
QA Handbook for Air Pollution Measurement.
Systems, Vol. II—Ambient Air Specific
Methods
Optimum Site Exposure Criteria for SO2 Moni-
toring
Aeros Manual Series, Vol. II—Aeros User's
Manual
Aeros Manual Series, Vol. V—Aeros Manual of
Codes
QA Handbook for Air Pollution Measurement
Systems, Vol. I—Principles
Aeros Manual Series, Vol. I—Aeros Overview
-------
Section 2.0.11 68 April 1985
Reference Report Title
EPA-450/3-75-077 Selecting Sites for Carbon Monoxide Monitor-
September 1975 ing
APTD-1132 Quality Control Practices in Processing Air Pol-
March 1973 lution Samples
47 FR 54912, Dec. 6, 1982; Amendments to reference methods for SO2,
48 FR 17355, Apr. 22, 1983 TSP and CO in 40 CFR Part 50 Appendices A,
B, and C
Proposed amendments to 40 CFR Part 58 are pending.
Proposed revision (Handbook. Vol. II. Sections 2.0.7 and 2.0.9 are pending).
-------
June 1984
Section 2.O.12
12.0 AUDIT PROCEDURES FOR USE BY STATE AND LOCAL AIR MONITORING
AGENCIES
12.1 Introduction
Appendix A1 outlines the minimum
quality assurance requirements for
state and local air monitoring sta-
tions (SLAMS). All subsequent revi-
sions to Appendix A have been in-
cluded in the preparation of this
document.2 Quality assurance guide-
lines for PSD monitoring are found in
Appendix B.3
This section describes performance
audit procedures for each automated
and manual monitoring method ref-
erenced in Appendix A. In additfon,
quality assurance and quality control
are defined, standard traceability pro-
cedures are discussed, and data in-
terpretation procedures are specified
relative to the requirements of Ap-
pendix A.1
12.2 Quality Assurance and
Control
Emphasis''on quality assurance is
increasing in the environmental com-
munity. Since its introduction in the
manufacturing industry 30 years ago,
quality assurance has expanded in
scope to include all phases of envi-
ronmental monitoring.
Quality assurance consists of two
distinct and equally important func-
tions. One function is the assessment
of the quality of the monitoring data
by estimating th.eir precision and ac-
curacy. The other function is the con-
trol and improvement of data quality
by implementing quality control poli-
cies and procedures and by taking -
corrective actions. These two func-
tions form a control loop where the
assessment indicates when data
quality is inadequate and where the
.control effort must be increased until
the data quality is acceptable.
Each agency should develop and
implement a quality control program
consisting of policies, procedures,
specifications, standards,.corrective
measures, and documentation neces-
sary to:
1. Provide data of adequate quality
to meet monitoring objectives and
2. Minimize loss of air quality data
because of malfunctions and out-
of-control conditions
The selection and degree of specific
control measures and corrective ac-
tions depend on a number of factors
such as the monitoring methods and
equipment, field and laboratory con-
ditions, monitoring objectives, level
of data quality required, expertise of
assigned personnel, cost of control
procedures, and pollutant concentra-
tion levels.
12.3 Standard Traceability
Traceability is the process of trans-
ferring the accuracy or authority of a
primary standard to a field-usable
standard. Gaseous standards (perme-
ation tubes and devices and cylin-
ders of compressed gas) used to ob-
tain audit concentrations of CO, S02,
and NO2 must be working standards
certified by comparison to NBS-
SRM's. Traceability protocols are
available for certifying a working
standard by direct comparison to an
NBS-SRM.4-5 Direct use of an NBS-
SRM is discouraged because of the
limited supply and expense. NBS-
SRM availability and ordering proce-
dures are given in Reference 6.
Test concentrations for O3 must be
obtained by means of an UV photo-
metric calibration procedure (Subsec-
tion 12.10.4) or by a certified transfer
standard.7 Flow measurements must
be made by an instrument that is
traceable to an authoritative volume
or other standard.8-9
12.4 General Discussion of
Audit Procedures
The benefits of a performance
audit are twofold. From a participant
standpoint, agencies are furnished a
means of rapid self-evaluation of a
Table 12;1. Audit Procedures
Pollutant
specific monitoring operation. The
EPA is furnished a continuing index •
of the validity of the data reported to
the air quality data bank.
The performance audit is'used to
validate and document the accuracy
of the data generated by a measure-
ment system. A list of the specific
audit procedures which are outlined
in this section is contained in Table
12.1. Procedures which use the prin-
ciples of dynamic dilution, gas phase
titration, UV photometry, and flow
rate measurement are presented.
The general guidelines for per-
formance audits are the same for all
procedures.
1. A performance audit should be
conducted only if calibration data
are available for the analyzers or
• samplers being audited.
2. A performance audit should be
conducted only if the site operator
or representative is present, unless
written permission is given to the
auditor before the audit.
3. Before the audit, a general proce-
dures protocol, including the audit
policy and special instructions
from the auditor, should be pro-
vided to the agency to be audited.
4. A signed acknowledgment.that
the audit has been completed
should be obtained from the sta-
tion operator.
5. The auditor should discuss the
audit results with the site operator
or representative at the conclusion
of the audit. A form showing the
• audit concentrations, station re-
sponses, and other pertinent data
recorded by the auditor should be
Audit procedure
Sulfur dioxide
Nitrogen dioxide
Carbon monoxide
Ozone
Total suspended paniculate
Dynamic dilution—permeation tube
Dynamic dilution—compressed gas cylinder
Gas phase titration
Dynamic dilution—compressed gas cylinder
Multiple compressed gas cylinders
Ultraviolet photometry
Flow rate measurement
-------
Section 2.0.12
June 1984
given to the site operator or repre-
sentative; the form must indicate
that the results are not official until
the final report is issued. If the site
operator or representative is not
on-site at the conclusion of the
audit, the auditor should contact
the agency before leaving the area
or promptly when returning to the
base of operations.
6. The auditor should document the
verification of his equipment be-
fore and after the audit; this verifi-
cation includes calibration and
traceability data. This information
and a written record of the audit
should be kept in a bound note-
book in a secure location.
7. The auditor should use specific
procedures that are consistent with
the performance audit procedures
manual. Any deviation from these
must be approved by the agency
performing the audit.
8. All audit equipment and stand-
ards including standard gases, per-
meation tubes, flow measuring ap-
paratus, and temperature and
pressure monitors should be refer-
enced to primary standards.
9. Verification of the total audit sys-
tem output by performing an audit .
on calibrated instrumentation
should be"conducted before the
audit. The verification instrumenta-
tion should be calibrated using an
independent set of equipment and
• standards.
10. Upon arrival at the audit site, all
equipment should be inspected for
transit damage. Each auditor
should have a quality control
checklist or a specified procedure
that can be used to verify system
integrity.
Before starting the audit, the auditor
should record the following data: the
site address, operating agency, type
of analyzer being audited, zero and
span settings, type of in-station cali-
bration used, and general operating
procedures. These data may be used
later to determine the cause-of dis-
crepancies between the audit con-
centrations and station responses.
The auditor should also mark the
data record with a stamp similar to
the one shown in Figure 12.1 to ver-
ify that the audit was performed and
to prevent the audit data from being
transcribed and mistaken for ambient
monitoring data. Before disconnect-
ing a monitor or sampler from its
ambient sampling mode, have the
station operator make a note on the
data acquisition system to indicate
that an audit is being performed.
Performance A udit by
PEDCo Environmental, Inc.
11499 Chester Road
Cincinnati, Ohio 45246-0)'00
Date .
Start.
Stop-
Auditor.
Parameter.
Location —
Figure 12.1 Audit identification stamp.
All station responses should be
converted by the station operator to
engineering units (e.g., ppm or
|j.g/m3) by using the same proce-
dures used to convert the actual am-
bient data. This procedure allows
evaluation of the total monitoring
system—the station operator, equip-
ment, and procedures.
Upon completion of the audit, all
monitoring equipment must be re-
connected and returned to the con-
figuration recorded before initiating
the audit. Before the auditor leaves
the station, audit calculations should
be performed to ensure that no ex-
traneous or inconsistent differences
exist in the data. Sometimes a
recording mistake is found after leav-
ing the station, and the error cannot
be rectified without returning to the
test site.
12.5 Sulfur Dioxide Audit
Procedure Using Dynamic
Permeation Dilution
12.5.1 Principle—Audit concentra-
tions are generated by a dynamic
system which dilutes an S02 perme-.
ation source with clean, dry air. This
method can be used to audit all com-
mercially available SOa/total sulfur
analyzers. Several variations in clean,
dry air must be made to accommo-
date operating characteristics of cer-
tain analyzers. The procedure, its ap-
plicability, precision and accuracy,
and apparatus requirements are dis-
cussed in the following subsections.
12.5.2 Applicability—The dynamic
dilution method can be used to sup-
ply SOZ audit concentrations in the
range of 0 to 0.5 ppm. Concentra-
tions for challenging other operating
ranges such as 0 to 50 ppb, 0 to 0.2
ppm, 6 to 1.0 ppm, and 0 to 5 ppm
can also be generated by using this '
procedure.
-12.5.3 Accuracy—The accuracy of
. the audit procedure should be
within ±2.5% if the SO2 permeation
source is referenced and if gas flow
rates are determined using EPA-
recbmmended procedures.
12.5.4 Apparatus—An audit system
which uses a dynamic permeation di-
lution device to generate concentra-
tions is illustrated in Figure 12.2. The
eight components of the system are
discussed below.
1. Permeation Chamber—A
.constant-temperature chamber capa-
ble of maintaining the temperature
around the permeation tube to an ac-
curacy of ±0.10°C is required. The
permeation oven should be equipped
with a readout that.is sensitive
enough to verify the temperature of
the permeation device during normal
operation.
2. Flow Controllers—Devices capa-
ble of maintaining constant flow
rates to within ±2% are required.
Suitable flow controllers include
stainless steel micrometering valves
in tandem with a precision regulator
and with mass flow controllers, capil-
lary restrictors, and porous plug re-
strictors.
3. Flowmeters—Flowmeters capa-
ble of measuring pollutant and dilu-
ent gas flow rates to within ±2% are .
required. NBS-traceable soap bubble
-------
June 7984
Section 2.0.12
Clean
Dry
Air
Flow
Controller
Flowmeter
Flow
Controller
Flowmeter
Output
Manifold
Vent
£xtra Outlets Capped
When Not in Use
Figure 12.2. Schematic diagram of a permeation audit system.
To Inlet of Analyzer
Being Audited
flowmeters, calibrated mass flow
controllers or mass flowmeters, and
calibrated orifice, capillary, and
porous plug restrictors are suitable.
4. Mixing Chamber—A glass cham-
ber is used to mix SO2 with dilution
air. The inlet and outlet should be of
sufficient diameter,so that the cham-
ber is at atmospheric pressure under
normal operation, and sufficient tur-
bulence must be created in the
chamber to facilitate thorough mix-
ing. Chamber volumes in the range
of 100 to 500 cm3 are sufficient.
Glass Kjeldahl connecting flasks are
suitable mixing chambers.
5. Output Manifold and Sample
Line—An output manifold used to
supply the analyzer with an audit at-
mosphere at ambient pressure
should be of sufficient diameter to
ensure a minimum pressure drop at
the analyzer connection, and the
manifold miist be vented so that am-
bient air will not mix with the audit
atmosphere during system opera-
tions. Recommended manifold mate-
rials are glass or Teflon. The sample
line must be nonreactive and flex-
ible; therefore. Teflon tubing is pre-
ferred.
6. Dilution Air Source—The diluent
source must be free of sulfur con-
taminants and water vapor; clean dry
air from a compressed gas cylinder
(Grade 0.1) may be used. When au-
diting a flame photometric analyzer,
a diluent source which contains ap-
proximately 350 ppm CO2 is re-
quired. A clean air system may be
used; however, the system must not
remove the CO2 from the ambient
airstream.
In all cases, the O2 content of the
diluent air must be 20.9 ±0.2%. Gas
manufacturers that blend clean dry
air do not always adhere to the exact
ambient proportions of 02 and N2; in
these cases, the O2 content should
be verified by paramagnetic re-
sponse.
7. Sulfur Dioxide Permeation
Tube—An SO2 permeation tube with
NBS traceability is used as the pollu- .
tant source. Permeation rates be-
tween 0.5 to 1.5 (j.g/min fulfill the au-
diting requirements. Traceability is
established by referencing the per-
meation device to an NBS-SRM
(number 1625, 1626, or 1627).
8. Permeation Tube Storage—A
storage device capable of keeping
the permeation tube encased in dry
air is required; small cases contain-
ing Drierite or silica gel will serve
this purpose. The useful life of a per-
meation tube will vary among ven-
dor types {a 9-mo life can be used
for estimating purposes); low tem-
perature (2° to 5°C) will prolong the
tube life. Do not freeze the perme-
ation tube.
12.5.5 Procedure—Equipment Setup
—Remove the permeation tube from
the storage case, insert it into the
permeation chamber, and start the
carrier flow (approximately 50 cm3'
min) across the tube. Set the perme-
ation temperature at the desired set-
ting and allow the permeation source
to equilibrate. For changes of 1° or
2°C, an equilibrium period of 3 h
should suffice. For changes of 10°C
or when the source is removed from
low temperature storage, an equi-
librium period of 24 h is advisable.
Several commercially available per-
meation calibrators use a carrier flow
to maintain a constant temperature
around the tube during transport. In
this instance, equilibration is not nec-
essary because the oven temperature
is continuously maintained within
±0.10°C of the desired permeation
temperature.
Audit sequence—After all the
equipment has been assembled and
-------
Section 2.0.12
June 1984
set up, have the station operator
mark the strip chart recorder to indi-
cate that an audit is beginning. The
auditor's name, start time, date, and
auditing agency should be entered; if
it is not possible to record written
comments on the chart, record the
start and stop times to preclude the
use of audit data as monitoring data.
After recording these data, discon-
nect the analyzer sample line from
the station manifold and connect it to
the audit manifold, as shown in Fig-
ure 12.3. Cap the sample port on the
station manifold. (The audit atmos-
phere must be introduced through
any associated filters or sample pre-
treatment apparatus to duplicate the
path taken by an ambient sample.)
Record the analyzer type and other
identification data on the data form
(Table 12.2J.
Conduct the audit as shown in
steps 1-5 below.
1. Introduce into the audit mani-
fold a clean dry air gas at a flow
rate in excess of 10% to 50% of the
analyzer sample demand. Allow
the analyzer to sample the clean
dry air until a stable response is
obtained; that is, until the re-
sponse does not vary more than
±2% of the measurement range
over a 5-min period. Obtain the
station response and concentration
from the station operator, and
record the data in the appropriate
blanks on the data form.
2. Generate SLAMS audit concen-
trations (which are compatible with
the analyzer range) as audit atmos-
pheres consistent with the require-
ments in Appendix A.1
Station Manifold
T T T
To Analyzers
Audit point
1
2
3
4
Concentration range
(ppm)
0.03-0.08
0.15-0.20
0.35-0.45
0.80-0.90
Generate the concentrations by ad-
justing the dilution air flow rate
(FD) and the permeation device air
flow rate (Fc) to provide the neces-
say dilution factor. Calculate the
concentrations as follows.
[S02] =
PR X 103
x 3.82 x 10~4
Equation 12-1
where
[SOJ = SO2 audit concentration,
ppm,
PR = permeation flow rate at
the specified tempera-
ture, p.g SO2/min,
FC = carrier flow rate over the
permeation tube, stand-
ard liters/min, and
FD = diluent air flow rate,
standard liters/min.
103 converts liters to m3, and the
3.82 x 10~4 converts p-g SO2/cm3 to
ppm SO2 at 25°C and 760 mm Hg.
3. Generate the highest audit con-
centration first, and consecutively
generate audit points of decreasing
concentration. Allow the analyzer
to sample the audit atmosphere
until a stable response is obtained.
Obtain the station response and
concentration from the station op-
erator, and record the data in the
appropriate spaces in Table 12.2.
Station
Analyzer
Data
System
(Teletype
\Printout
. in
Volts
{Audit Manifold-*- Exhaust
4. If desired, additional points at up-
scale concentrations different from
those specified in step 2 may be
generated. Generation of these au-
dit concentrations plus a post audit
clean dry air response will enhance
the statistical significance of the
audit data regression analysis.
5. After supplying all audit concen-
trations and recording all data, re-
connect the analyzer sample line to
the station manifold. Make a nota-
tion of the audit stop time and
have the station operator make a
note on the data recorder to indi-
. cate the stop time. Have the station
operator check all equipment to
ensure that it is in order to resume
normal monitoring activities.
12.5.6 Calculations- — Tabulate the
data in Table 12.2 in the appropriate
blank spaces.
% difference — The % difference is
calculated as follows.
% Difference =
x 100,
Flgutt 12.3. Schematic of configuration utilized in auditing the gas analyzers.
Equation 12-2
where
CM = the station measured concen-
tration, ppm
CA = the calculated audit concentra-
tion, pprn.
Regression analysis — Calculate by
the method of least squares the
slope, intercept, and correlation coef-
ficient of the station analyzer re- •
sponse data (y) versus the audit con-
centration data (x). These data can
be used to interpret the analyzer per-
formance.
12.5.7 ffeferences— References 4
through 6 and 10 and 11 provide ad-
ditional information on this S02 audit
procedure.
12.6 Sulfur Dioxide Audit
Procedure Using Dynamic
Dilution of a Gas Cylinder
12.6.1 Principle — A dynamic dilu-
tion system is used to generate SO2
concentrations in air for auditing
continuous ambient analyzers. The
audit procedure consists of diluting a
gas cylinder of low S02 concentra-
tion with clean dry dilution air. Trace-
ability is established by referencing
the gas cylinder to an NBS-SRM.
This procedure can be used to audit
all commercially available SO2/total
sulfur analyzers.
Variations in clean dry air must be
made to accommodate operating
characteristics of certain analyzers.
-------
June 1984
Section 2.0.12
Table 12.2.
Station
Sulfur Dioxide Audit Data Report
Address
TA
Analyzer
Calibration standard
Last calibration date
Calibration comments
Zero setting
Span setting
Audit system
Audit standard
Clean, dry air _
mm Hg;
Date
Start time
mm Hg Auditor
Frequency
Serial number
. Span source
Range
Data acquisition system
Recorder
Bubble flowmeter serial number
; P
psig; [ ] =.
Catalytic oxidizer Yes
ppm
No
Flow correction:
Dilution air response
Other response _
P \
A "W^OX
760 mm I
Audit PointT
Dilution flow measurement
Volume
T, .
T2
T3
Analyzer response _
Other response
298 K
TA + 273 ,
% Chan;
mm
% Chart;
Flowmeter
Volume
Audit concentration
VDC;
cm-3
min
ppm
ppm
Audit'Point II
Dilution flow measurement
Volume
T,
Analyzer response _
Other response
cm-
mm
% Chart;
Flowmeter
Audit concentration
VDC;
min
ppm
ppm
-------
Section 2.0.12
June 1984
Table 12.2 (continued)
Audit Point III
Dilution flow measurement
Volume
7,
7>
r3 :—
Analyzer response
Other response
Audit Point IV
Dilution flow measurement
Volume '.
T,
Analyzer response —
Other_response .
Audit Point V
Dilution flow measurement
Volume
T,
Ta
Analyzer response
Other response
MethnH
Flowmeter
mm
Volume
(*X*f
Audit concentration
% Chart;
rm
Flowmeter
mm
Volume
(*)(**
Audit concentration
% Chart;
Cm
mm
(CF){^
% Chan;
' Volume
, T
Audit concentration
l/oc;
cmj
min
ppm
cmj
min
ppm
cnv*
min
ppm
Permeation temperature
°r-
Permeation rate
^g/min
-------
June 1984
Section 2.0.12
Table 12.2 (continued)
Gas flow rates,
std cm3/min
Point
number
QC
QD
Audit
concentration,
ppm
Analyzer response
Difference
ppm
mV/
% chart
Analyzer-audit,
ppm
Regression analysis [audit concentration (x) vs. analyzer response (y)J
y = mx + b
Slope (m)
Intercept (b)
Correlation (r)
Comments:
The procedure, its applicability, accu-
racy, and apparatus requirements are
discussed in the following subsec-
tions.
12.6.2 Applicability—Dynamic dilu-
tion can be used to supply SOj audit
concentrations in the range of 0 to
0.5 ppm. Concentrations for challeng-
ing other operating ranges such as 0
to 50 ppb, 0 to 0.2 ppm, 0 to 1.0
ppm, and 0 to 5 ppm can also be
readily generated by using this pro-
cedure.
12.6.3 Accuracy—The accuracy of
the audit procedure should be within
±2.5% if the SO2 gas cylinder con-
centration is referenced and if gas
flow rates are determined using EPA-
recommended procedures.
12.6.4 Apparatus—An audit system
which uses a dynamic dilution device
to generate audit concentrations is il-
lustrated in Figure 12.4. The seven
Clean
Dry
Air
Flow
Controller
Flowmeter
Fo f -^
Mixing
Chamber
Std
(50 ppm)
Flow
Controller
Flowmeter
FP
Vent •
Extra Outlets Capped
When Not in Use
Output
Manifold
a
^
Ft
'I'
To Inlet of Analyzer
Being Audited
Flgur* 12.4 Schematic diagram of a dilution audit system.
-------
Section 2.0.12
June 1984
components of the device are dis-
cussed below.
1. Gas Cylinder Regulator—A
stainless steel gas regulator is ac-
ceptable. A low deadspace, two-
stage regulator should be used to
achieve rapid equilibration. A purge
assembly is helpful.
2. Flow Controllers—Devices capa-
ble of maintaining constant flow
rates to within ±2% are required.
Suitable flow controllers include
stainless steel micrometering valves
in tandem with a precision regulator,
mass flow controllers, capillary re-
strictors, and porous plug restrictors.
3. Flowmeters—Flowmeters capa-
ble of measuring pollutant and dilu-
ent gas flow rates to within ±2% are
required. NBS-traceable soap bubble
flowmeters, calibrated mass flow
controllers or mass flowmeters, and
calibrated orifice, capillary, and
porous plug restrictors are suitable
for flow determination.
4. Mixing Chamber—A glass or
Teflon chamber is used to mix the
S02 with dilution air. The inlet and
outlet should be of sufficient diame-
ter so that the chamber, is at atmos-
pheric pressure under normal opera-
tion, and sufficient turbulence must
be created in the chamber to facili- .
tate thorough mixing. Chamber vol-
umes in the range of 100 to 500 cm3
are sufficient. Glass Kjeldahl connect-
ing flasks are suitable mixing cham-
bers.
5. Output Manifold and Sample
Line—An output manifold used to
supply the analyzer with an audit at-
mosphere at ambient pressure
should be of sufficient diameter to
ensure a minimum pressure drop at
the analyzer connection, and the
manifold must be'vented so that am-
bient air will not mix with the audit
atmosphere during system opera-.
tions. Recommended manifold mate-
rials are glass or Teflon. The sample'
line must be nonreactive and flex-
ible; therefore, Teflon tubing is pre-
ferred.
6. Dilution Air Source—The dilu-
ent source must be free of sulfur
contaminants and water vapor; clean
dry air from a compressed gas cylin-
der (Grade 0.1) may be used. When
auditing a flame photometric ana-
lyzer, a diluent source which contains
approximately 350 ppm C02 is re-
quired. A clean air system may be
used; however, the system must not
remove the C02 from the ambient
airstream.
In all cases, the 02 content of the
diluent source must be 20.9 =0.2%.
Gas manufacturers that blend the
clean dry air do not always adhere to
the exact ambient proportions of O2
and N2; in these cases, the 02 con-
tent should be verified by paramag-
netic response.
7. Sulfur Dioxide Gas Cylinder—A
compressed gas cylinder containing
50 to 100 ppm S02 in air is used as
the dilution source. This cylinder
must be traceable to an NBS-SRM
(number 1661, 1662, 1663, or 1664).
12.6.5 Procedure—Equipment
setup—Assemble the audit equip-
ment as required, and verify that all
equipment is operational. If a dilution
air system equipped with a catalytic
oxidizer is used, allow the oxidizer to
warm up for 30 min. Connect the gas
regulator to the SO2 cylinder, and
evacuate the regulator as follows.
1. With the cylinder valve closed,
connect a vacuum pump to the
evacuation outlet on the regulator
and start'the pump.
2. Open and close the evacuation
port.
3. Open .and close the cylinder
valve.
4. Open and close the evacuation
port.
5. Repeat steps 2 through 4 five
more times to be sure all 02 impu-
rities are removed from the regula-
tor.
If the regulator does not have an
evacuation port but has a supported
diaphragm, the procedure can be
conducted at the gas exit port.
For regulators that do not have an
evacuation port but have an unsup-
Station Manifold
ported diaphragm, use the following
procedure:
1. Connect the regulator to the-
cylinder, and close the gas exit
port.
2. Open and close the cylinder valve
to pressurize the regulator.
3. Open the gas exit port, and allow
the gas to purge the regulator.
4. Repeat steps 2 and 3 five more
times; then close the gas exit port,
and open the cylinder valve. (The
regulator should remain under
pressure.) Connect the gas cylinder
to the audit device.
Repeat the procedure for each cylin-
der.
Audit sequence—Before discon-
necting the analyzer from the station
manifold, mark the data recorder to
indicate that an audit is beginning.
The auditor's name, start time, date,
and auditing organization should be
recorded. If it is not possible to
record written comments, the start
and stop times should be recorded to
preclude the use of audit data as
monitoring data. After recording
these data, disconnect the analyzer
sample line from the station mani-
fold, and connect it to the audit man-
ifold, as shown in Figure 12.5. Cap
the sample port on the station mani-
fold. (The audit atmosphere must be.
introduced through any associated
filters or sample pretreatment ap-
paratus to duplicate the path taken
by an ambient sample.) Record the
analyzer type and other identification
data on the data form (Table 12.3).
Conduct the audit by following
steps 1 through 5 below.
T T T T
To Analyzers
»
i m
Station
Analyzer
n
Data
Acquisition
System
(Audit Manifold-*- Exhaust
Figure 12.5 Schematic of configuration utilized in auditing the gas analyzers.
-------
June 1984
Section 2.0.12
Table 12.3.
Station
SO2 Audit Data Report
Date
Address
Start time
mm Hg;
mm Hg Auditor
Analyzer
Calibration standard
Last calibration date
Frequency
Serial number
source
Range
Calibration comments
Zero setting
Span setting
Audit system
Audit standard
Clean, dry air _
Flow correction:
Dilution air flow
Volume
r,
TZ~
7-5
Data acquisition system
Recorder
Bubble flowmeter serial number
PA - PH2o\ ( 298 K
760mm I
273
cm
mm
psig; I 1 =.
Catalytic oxidizer Yes
No
VV
3-
cm
min
Dilution air response
Other response _
Audit Point I
Pollutant flow measurement
Volume
Analyzer response _
Other response
% Chart;
cmj
mm
'DO
% Chart;
Flowmeter
fc\(Volume\ =
\ F/\ f I
Audit concentration
VDC;
cmj
min
ppm
ppm
-------
Section 2.0.12
10
June 1984
Audit Point II
Pollutant flow measurement
Volume
T2
T3
Analyzer response
Other response
Audit Point III
Pollutant flow measurement
Volume
Audit Point IV
Pollutant flow measurement
Volume .
r,
T2
Analyzer response _
Other response
Audit Point V
Pollutant flow measurement
Volume
r,
Analyzer response _
Other response
cm-3
Flowmeter
mm
(r \(v°lume\ -
Audit concentration
Cm
mm
/c\/Volume\ =
% Chart;
Audit concentration
VDC;.
Flowmeter
mm
I r \(Volume\ _
(CF)(~J~)--
% Chan;
Audit concentration
VDC;
C/T7J
min
ppm
ppm
TI
T,
Analyzer response
•tf -
Other response
(c,\(Volume\
\ r)\ T 1
Audit concentration
v.rh*rf ' i/ .
cm3
mm
nnm
: HfJI11
cmj
min
ppm
ppm
cmj
min
ppm
ppm
-------
June 1984
11
Section 2.O.12
Regression analysis [audit concentration (x) vs. analyzer response (y)]
Slope (m)
Intercept (b)
Correlation (r)
Comments:
Auditor
Audit method
Zero setting
Station calibration source
Span setting
Equivalency reference no.
Point
number
Flow rates
Analyzer response
Pollutant
cm3/mm
Total,
cm3/mm
Audit
concentration,
ppm
ppm
% Chart
orMV
Difference
Analyzer
audit,
•ppm
Regression analysis [audit concentration (x) vs. analyzer response (y)]
y = mx + b
Slope (m)
Intercept (b)
Correlation (r)
Comments:
-------
Section 2.0.12
12
June 1984
1. Introduce into the audit mani-
fold a clean dry air-gas at a flow
rate in excess of 10% to 50% of the
analyzer sample demand. Allow
the analyzer to sample the clean
dry air until a stable response is
obtained; that is, until the re-
sponse does not vary more than
±2% of the measurement range
over a 5-min period. Obtain the
station response and concentration
from the station operator and
record the data in the appropriate
blanks on the data form.
2. Generate the SLAMS audit con-
centrations (which are compatible
with the analyzer range) as audit
atmospheres consistent with the
requirements in Appendix A.1
Audit point
1
2
3
4
Concentration range
(ppm)
0.03-0.08
0.15-0.20
0.35-0.45
0.80-0.90
Generate the audit concentrations
by adjusting the pollutant flow rate
(FPJ and the total flow rate (FT) to
provide the necessary dilution fac-
tor.
Calculate the audit concentration
as follows.
(S02J » p£ x [S02)STD Equation 12-3
where
(SO2J » audit concentration of
SO2, ppm,
Fp = pollutant flow rate,
cm3/min
FT « total flow rate, cm3/
min [equal to the sum
of the pollutant flow
rate (FP) and the dilu-
tion flow rate (FD)],
and
(SOjlsro ^concentration of the
standard cylinder,
ppm.
3. Generate the highest audit con-
centration first, and consecutively
generate audit points of decreasing
concentration. Allow the analyzer
to sample the audit atmosphere
until a stable response is obtained.
Obtain the station response and
concentration from the station op-
erator, and record the data in the
appropriate spaces in Table 12.3.
4. If desired, additional points at up-
scale concentrations different from
those specified in step 2 may be
generated. Generation of these au-
dit concentrations plus a post audit
clean dry air response will enhance
the statistical significance of the
audit data regression analysis.
5. After supplying all audit sample
concentrations and recording all
data, reconnect the analyzer sam-
ple line to the station manifold.
Make a notation of the audit stop
time. Have the station operator
make a note on the data recorder
to indicate the stop time, and
check all equipment to ensure that
it is in order to resume normal
monitoring activities.
12.6.6 Calculations — Record the
data in Table 12.3 in the appropriate
spaces.
% difference — The % difference is
calculated as follows.
% difference =
_ s*
x 100,
Equation 12-4
where
Cto = the station-measured concen-
tration, ppm, and
CA = the calculated audit concentra-
tion, ppm
Regression analysis — Calculate by
the method of least squares the
slope, intercept, and correlation coef-
ficient of the station analyzer re-
sponse data (y) versus the audit con-
centration data (x). These data can
be used to interpret the analyzer per-
formance.
12.6.7 References — References 4
through 6 and 10 and 11 provide ad-
ditional information on this SO2 audit
procedure.
12.7 Nitrogen Dioxide Audit
Procedure Using Gas Phase
Titration
12.7.1 Principle — The auditing pro-
cedure is based on the gas phase re-
action between NO and O3
NO + O3 -» NO2 + O2. Equation 12-5
The generated NO2 concentration is
equal to the NO concentration con-
sumed by the reaction of O3 with ex-
cess NO.
The NO and NOX channels of the
chemiluminescence NOX analyzer are
audited with known NO concentra-
tions produced by a dynamic dilution
system which uses clean dry air to
dilute a gas cylinder containing NO
in nitrogen. After completion of the
NO-NOX audits, stoichiometric mix-
tures of NO2 in combination with NO
are generated by adding 03 to
known NO concentrations. These
audit data are used to evaluate the
calibration of the NO-NOX-NO2 ana-
lyzer channels and to calculate ana-
lyzer converter efficiency.
12.7.2 Applicability—The procedure
can be used to supply audit concen-
trations of NO-N02-NOX in the
range of 0.010 to 2.0 ppm.
12.7.3 Accuracy—The accuracy of
the audit procedure should be within
±2.5% if the NO gas cylinder concen-
tration is referenced and if the gas
flow rates are determined by using
EPA-recommended procedures.
12.7.4 Apparatus—Audit system—A
typical gas phase titration system is
illustrated in Figure 12.6. All connec-
tions and components downstream
from the O3 generator and the pollu-
tant source must be constructed of
nonreactive (glass or Teflon) mate-
rial. The seven components of the
system are discussed below.
1. Flow Controllers—Devices capa-
ble of maintaining constant flow
rates to within ±2% are required.
Suitable flow controllers include
brass (for air) or stainless steel (for
NOX) micrometering valves in
tandem with a precision regulator,
mass flow controllers, capillary re-
strictors, and porous plug restrictors.
2. Flowmeters—Flowmeters capa-
ble of measuring pollutant and dilu-
ent gas flow rates to within ±2% are
required. NBS-traceable soap bubble
flowmeters, calibrated mass flow
controllers or mass flowmeters, and
calibrated orifice, capillary, and
porous plug restrictors are all suit-
able for flow determination.
3. Gas Cylinder Regulator—A non-
corrosive two-stage stainless steel -
regulator with an evacuation port is
suggested.
4. Ozone Generator—An O3 gener-
ator that produces a stable concen-
tration is required during the gas
phase titration sequence of the audit.
An ultraviolet lamp generator is rec-
ommended.
5. Reaction Chamber—A glass
chamber used for the quantitative re- •
action of O3 with NO should have
sufficient volume, 100 to 500 cm3, for
the residence time to be s2 min.
Elongated glass bulbs such as Kjel-
dahl connecting flasks are suitable.
6. Mixing Chamber—A glass or
Teflon chamber is used to mix the
NO, NO2, or O3 with dilution air. The
inlet and outlet should be of suffi-
cient diameter so that the chamber is
at atmospheric pressure under nor-
mal operation, and sufficient turbu-.
-------
June 1984
13
Section 2.0.12
o
Cleat
Dry
Air
kWWH
n
\
}
N
St
— *•
^•^H
a
4—1
•N
0
d
Flow
Controller
- Flowmetar
Flow
Controller
51==
- Flowmeter
1 Flow
Controller
Vent +
Extra Outlet
When Not
»
Fo
Roaction
\Fxo
Output
Manifold
1"
Mixing
Chamber
Ft
ii U, I," -1
s Capped )f
'" Us* To Inlet of Analyzer
Being Audited
Figure 12.6 Schematic diagram of a gas phase titration audit system.
lence must be created in the cham-
ber to facilitate thorough mixing.
Chamber volumes in the range of
150 to 250 cm3 are sufficient. Glass
Kjeldahl connecting flasks are suit-
able mixing chambers.
7. Output Manifold and Sample
Line—An output manifold used to
supply the analyzer with an audit at-
mosphere at ambient-pressure
should be of sufficient diameter to
ensure a minimum pressure drop at
the analyzer connection, and the
manifold must be vented so that am-
bient air will not mix with the audit
atmosphere during system opera-
tions. Recommended manifold mate-
rials are glass or Teflon. The sample
line must be nonreactive and flex-
ible; therefore. Teflon is preferred.
Dilution air system—Clean dry air
from a compressed gas cylinder
(Grade 0.1) is a suitable source for
dilution air; however, if large vol-
umes of clean dry air (s>5 liters/min)
are required, purified compressed air
is preferred. The clean dry air must
be free of contaminants such as NO,
NO2, 03 or reactive hydrocarbons
that would cause detectable re-
sponses on the NOX analyzer or that
might react with NO or NO2 in the
audit system. The air can be purified
to meet these specifications by pass-
ing it through silica gel for drying, by
treating it with 03 to convert any NO
.to N02, and by passing it through ac-
hivated charcoal (6-14 mesh) and a
molecular sieve (6-16 mesh, type 4A)
to remove NO2, 03, or hydrocarbons.
Silica gel maintains its drying effi-
ciency until it has absorbed 20% of
its weight; it can be regenerated in-
definitely at 120°C. Addition of cobalt
chloride to the surface of the gel pro-
vides a water absorption indicator. A
transparent drying column is recom-
mended. The activated charcoal and
molecular sieve have a finite absorp-
tion capability; because it is difficult
to determine when the capability has
been exceeded, both should be re-
placed either before each audit or.
after 8 hrs of use.
Nitric oxide gas cylinder—A com-
pressed gas cylinder containing 50 to
100 ppm NO in N2 is used as the NO
dilution source. This cylinder must
be traceable to an NBS-SRM (num-
ber 1683, 1684, 1685, 1686, or 1687).
12.7.5 Procedure—Equipment
setup—Assemble the audit equip-
ment as required, and verify that all
equipment is operational. If a clean,
dry air system equipped with a cata-
lytic oxidizer and/or 03 lamp is used,
allow the oxidizer and/or 03 lamp to
warm up for 30 minutes. Connect the
gas regulator to the NO cylinder, and
evacuate the regulator.as follows:
1. With the cylinder valve closed,
connect a vacuum pump to the
evacuation outlet on the regulator,
and start the pump.
2. Open and close the evacuation
port.
3. Open and close the cylinder
valve.
4. Open and close the evacuation
port.
5. Repeat steps 2 through 4 five
more times to be sure all O2 impu-
rities are removed from the regula-
tor.
If the regulator does not have an
evacuation port but has a supported
diaphragm, the procedure can be
conducted at the gas exit port.
For regulators that do not have an
evacuation port but have an unsup-
ported diaphragm, use the following
procedure:
1. Connect the regulator to the
cylinder, and close the gas exit
port.
2. Open and close the cylinder valve
to pressurize the regulator.
3. Open the gas exit port, and"
allow the gas to purge the regula-
tor.
4. Repeat steps 2 and 3 five more
times, close the gas exit port, and
open the cylinder valve. Connect
the dilution air source and NO
cylinder to the audit device as
shown in Figure 12.6. Use 1/8-in.
o.d. tubing of minimum length for
the connection between the NO
cylinder and the audit device.
Dynamic parameter specifica-
tions — The flow conditions used in
the GPT audit system are selected to
assure a complete N0-03 reaction.
The gas flow rates must be adjusted
according to the following relation-
ships:
PR = [NOJnc x tR s> 2.75 ppm-min,
Equation 12-6
(NO]RC
rNO
FO
FNO
Equation 12-7
"HC
2 min,
, R FO + FNO
Equation 12-8
where
PR=dynamic parameter
specification, determined
empirically, to ensure
complete reaction of the
available O3/ ppm-min,
[NO]RC = NO concentration in the
reaction chamber, ppm,
tR = residence time of the re-
actant gases in the reac-
tion chamber, min,
i = concentration of the NO
gas cylinder, ppm,
FNO = NO flow rate, standard
cm3/min,
FO = 03 generator air flow rate,
standard cm3/min, and
VRC= volume of the reaction
chamber, cm3.
-------
Section 2.0.12
14
June 1984
The flow conditions to be used in
the GPT audit system are selected
according to the following sequence:
1. Determine FT, the total flow rate
required at the output manifold (FT
* analyzer(s) demand plus 10% to
50% excess).
2. Determine FNO, the flow rate of
NO required to generate the lowest
NO concentration required at the
output manifold during the GPT
(approximately 0.15 ppm).
0.15 x FT
(NOJsro
12-9
3. Measure the system's reaction
chamber volume; must be in the
range of approximately 100 to 500
cm3.
4. Compute Fo.
Fo
FNO x VRC
2.75
Equation 12-10
5. Compute tR, using Equation 12-8;
verify that tR s 2 min.
6. Compute F0.
FO » FT - FO ~ FNO Equation 12-11
where
FO ™ diluent air flow, standard
cm3/min.
Adjust FQ to the value determined
above. FO should not be further ad-
justed during the NO-NOX or NO2
audit procedures; only FNO (or FD)
and the 03 generator settings are ad-
justed during the course of the audit.
Audit sequence—After all the
equipment has been assembled and
set up, have the station operator
mark the strip chart recorder to indi-
cate that the audit is beginning. In-
formation such as the auditors'
name, start time, date, and auditing
organization should be entered. If it
is not possible to enter written com-
ments, the start and stop times
should be recorded to precluoe the
use of audit data as monitoring data.
After recording the data, disconnect
the analyzer sample line from the
station manifold, and connect it to
the audit manifold, as shown in Fig-
ure 12.7. Cap the sample port on the
station manifold. The audit atmo-
sphere must be introduced through
any associated filters or sample pre-
treatment apparatus to duplicate the
path taken by an ambient sample.
Record the analyzer type and other
identification data on the data form
(Table 12.4).
Station Manifold A
T T T T
To Analyzers
Test
Atmosphere
Station
Analyzer
Data
System
-{.A udit Manifold -*• Exhaust
Figure 12.7 Schematic of configuration utilized in auditing the gas analyzers.
Conduct the NO-NOX and NO2
audits as follows:
NO-NOX Audit— The NO-NOX
audit involves generating concentra-
tions to challenge the calibration of
the NO and NOX channels of the ana-
lyzer. Data collected during this audit
are used to construct a calibration
curve that will be used later for cal-
culating the NO2 audit concentra-
tions.
NO-NOX Audit Procedure —
1. Introduce clean dry air into the
audit manifold at a flow rate in ex-
cess of 10% to 50% of the analyzer
sampje demand. Allow the analyzer
to sample the clean dry air until a
stable response is obtained; that is,
until the response does not vary
more than ±2% of the measurement
range over a 5-min period. Record
the readings for the NO, NOX, and
N02 channels, and have the station
operator report the audit responses
in concentration units. Record these
data and the responses of all three
channels in table 12.4.
2. Generate upscale NO audit con-
centrations corresponding to 10%,
20%, 40%, 60%, and 90% of the full-
scale range of the analyzer by adjust-
ing the flow rate of the NO standard.
For each audit concentration level
generated, calculate the NO concen-
tration.
FP
(NO) = ; x
Equation 12-12
where
[NO] = NO-NOX audit concentra-
tion, ppm (the NO2 im-
purity in the stock stand-
ard should be
negligible),
Fp = pollutant flow rate, cm3/
min,
FT = total flow rate, cm3/min,
and
= concentration of the
standard cylinder, ppm.
NOTE: Alternatively, the upscale
NO audit concentrations may be
generated by maintaining a con-
stant pollutant, flow rate (FP) and
varying the dilution air flow rate
(FD). In this case, the entries for
dilution air flow and pollutant
flow in Table 12.4 should be re-
versed and clearly indicated.
3. Generate the lowest audit con-
centration level first and consecu-
tively generate audit points of in-
creasing concentration. Allow the
analyzer to sample the audit atmo-
sphere until a stable response is ob-
tained. Record the audit concentra-
tion.
Obtain the station response and
concentration from the station opera-
tor for the NO, NOX, and N02 chan-
nels, and record the data in the ap-
propriate spaces in Table 12.4.
4. Prepare audit calibration curves
for the NO and NOX channels by
using least squares. Include the zero
air points. (The audit concentration is
the x variable; the analyzer response
in % chart is the y variable.) The NO
audit calibration curve will be used
to determine the actual audit concen-
trations during the generation of the
NO2 atmospheres.
The NOX audit calibration curve
will be used to determine NO2 con-
verter efficiency.
NO2 Audit—The N02 audit in-
volves generating N02 concentra-
-------
June 1984
15
Section 2.O.I2
Table 12.4.
*faf/on
Gas Phase Titration Audit Data Report
Date
Address
TA
Start time
mm Hg;
mm Hg; Auditor
Analyzer
Calibration standard
Last calibration date
Frequency
Serial number
. Span source
Range
Calibration comments
Flow settings
Span settings
Zero settings
Other settings _
Audit system
NO
NO
NOX
NOX
NO2
N02
Audit standard
Bubble flowmeter serial number
P psig; '[ ] =.
Clean, dry air supply
Flow correction:
Dilution air flow:
Volume
T,
PA ~ PH2o
760mm
298 K
TA + 273
Flowmeter
mm
Volume
ppm
(C)
cmj
min
Ozone generator flow:
Volume
7,
T2 .
T3
cm0
Flowmeter
mm
Volume
cm-3
min
Analyzer response clean dry air
% Chan
'DC
NO
NOX
NO2
ppm
-------
Section 2.0.12
16
June 1984
Table 12.4 (continued)
PART I. NO-NOX AUDIT
NO-NOX Audit Point I (10%)
Pollutant flow measurement
Volume _
T2
T3
cnr3
mm
Flowmeter
yolume
NO, NOX audit concentration .
cnr1
min
ppm
Analyzer response
% Chart
VDC
NO
NOX
NO2
ppm
NO-NOX Audit Point II (20%)
Pollutant flow measurement
Volume _
T2
T3
Analyzer response
cm-2
Flowmeter
mm
Volume
-
% Chart
NO, NOX audit concentration .
VDC ( )
NO
NOX
NO,
cm-3
min
ppm
ppm
NO-NOX Audit Point III (40%)
*
Pollutant flow measurement
Volume
r,
T2
T3
Analyzer response
cm0
Flowmeter
mm
% Chart
NO, NOX audit concentration
VDC ( )
NO
NOX
NO2
cmj
min
ppm
PPm
-------
June 1984
17
Section 2.0.12
Table 12.4 (continued)
NO-NOX Audit Point IV (60%)
Pollutant flow measurement
Volume _
T2
Analyzer response
NO
NOX
NO2
mm
% Chart
Flowmeter
/ Volume'
NO, NOX audit concentration .
VDC . ( )'
cm-3
min
ppm
ppm
NO-NOX Audit Point V (90%)
Pollutant flow measurement
Volume
Analyzer response
NO
NOX
NO2
NO-NOX audit calibration equation (y = mx + b)
NO audit concentration (x)
vs. analyzer response in
% chart (y)
Slope (m) =.
Intercept (b) .=.
Correlation- (r) =.
mm
% Chart
Flowmeter
\ / Volume-
A T
NO, NOX audit.concentration _^.
VDC ( )
NOX audit concentration (x)
vs. analyzer response in
% chart (y)
Slope (m) =.
Intercept (b) =.
Correlation (rj —.
min
ppm-
ppm
PART II. NO2 AUDIT
NO2 Audit Point I
Analyzer response
% Chart
NO
NOX
VDC
O3 generator setting =
I 1* ORIG
ppm
ppm
-------
Section 2.0.12
18
June 1984
Table 12.4 (continued)
% Chart
NO
NOX
VDC
= [NO]»ORIC - (NO]*REM = .
REM
ppm
ppm
ppm
% Chart
VDC
ppm
NO,
N02 Audit Point II
Analyzer response
% Chan
VDC
NO
NO*
I ]* ORIG
'ppm
ppm
O3 generator setting =.
"Calculated concentration from NO or NOX audit calibration equation (y = mx + b).
N02 Audit Point III
Analyzer response
% Chart VDC ( ' ) 11*
A/n
NOX
[NO,!* = //VO/*CfflG - fNO]*fjEM =
% Chart VDC ( ) ppm
NO,
% Chart VDC < ) [' ]*
NO
NO..
O7 aenerator setting =
% Chart VDC ( ) [ ]*
NO
NOX
[N0,l* = fNOl*ORlr; - [NOI*nEM =
% Chart VDC ( ) 11*
NO,
REM
nnm
DOm
ORIC
REM
oom
'Calculated concentration from NO or NOX audit calibration equation (y = mx + b).
-------
June 1984
19
Section 2.0.12
Table 12.4 (continued)
NO2 Audit Point IV
Analyzer response
% Chart
VDC
NO
NOX
O3 generator setting
[ 1* ORIG
% Chan
NO
NOX
VDC ( > [ 1* REM
ppm
. :— ppm
IN02]A = [NO]*ORIC - (NO]*REM = ppm
% Chart.
NO2
/DC '
NO2 Audit Point V
Analyzer response
% Chan
NO
NOX
V,
DC
O3 generator setting = .
[ ]* ORIG
• ppm
ppm
NO
NOX
% Chart Voc ( ) [ }* nEM
; ppm
ppm
(N02]A = [NO]*omG - [NO]*REM= ppm
% Chart
NO2
'DC
"Calculated concentration from NO or NOX audit calibration equation (y = mx + b).
-------
Section 2.0.12
20
Juno 1984
Tabla 12.4 (continued)
PART III, DATA TABULATION
NO channel
Analyzer— NO
Concentration,
Point Audit concentration, ppm ppm Response
Difference
Analyzer-audit,
ppm %
Zero
10%
20%
40%
60% ' ' ' '
90%
Slope (m) ; Intercept (b)
NOX channel
.; Correlation (r)
Audit concentration, ppm
Analyzer—NOX
Difference
Point NO NOg NOX total
Concentration,
ppm
Response
Analyzer-audit,
ppm
Zero
10%
20%
40%
60%
90%
Analyzer response (ppm) = m (audit) + b
Slope (m) ; Intercept (b) =
.; Correlation (r)
-------
June 1984
21
Section 2.0.12
Table 12.4 (continued)
NO2 channel
Analyzer—NO2
Difference
Point Audit concentration, ppm
Concentration,
Response
Analyzer-audit,
ppm
Zero
Analyzer response (ppm) =* m (audit) + b
Slope (m) = ; Intercept (b) =
.; Correlation (r) =.
Converter efficiency
Point number
[NO2]A, ppm
[NO2]CoNV, ppm
Percent converter efficiency
-------
Section 2.0.12
22
June 1984
lions in combination with approxi-
mately 0.10 ppm of NO to challenge
the calibration of the NO2 channel of
the analyzer. The NO2 audit concen-
trations are calculated from the re-
sponses of the NO channel of the an-
alyzer using the NO audit calibration
equation obtained during the NO-
NOX audit.
NO* Audit Procedure—
1. Verify that the O3 generator
air flow rate (F0) is adjusted to the
value determined earlier (Dynamic
parameter specifications).
2. Generate the SLAMS audit con- •
centrations (which are compatible
with the analyzer range) consistent
with the Appendix A1 requirements.
Audit point
1
2
3
4
Concentration range
(ppm)
0.03-0.08
0.15-0.20
0.35-0.45
0.80-0.90
3. Generate an NO concentration
which is approximately 0.08 to 0.12
ppm higher than the NO2 audit con-
centration level required. Allow the
analyzer to sample this concentration
until a stable response is obtained;
that is, until the response does not
vary more than ±2 % of the
measurement range over a 5-minute
period. Record the NO and NOX re- "
sponses on the data form. Calculate
and record {NOJ0RiG and [NOX]ORIG
using the NO and NOX audit calibra-
tion equations derived during the
NO-NOX audit.
4. Adjust the O3 generator to gen-
erate sufficient 03 to produce a de-
crease in the NO concentration
equivalent to the NO2 audit concen-
tration level required. After the ana-
lyzer response stabilizes, record the
NO and NOX responses on the data
form. Calculate and record [NOJREM
and (NO?]REM using the NO and NOX
audit calibration equations derived
during the NO-NOX audit.
{Note: (NO]REM should be approxi-
mately 0.08 to 0.12 ppm for each
audit point.)
5. Calculate and record the N02
audit concentration [NO2JA.
(N02)A = (NOlORl<3 - [NO]REM
Equation 12-13
6. Obtain the NO2 station response
and concentration from the station
operator and record on the data
form.
7. Generate the highest audit con-
centration level first, and consecu-
tively generate audit points of de-
creasing N02 concentration. Allow
the analyzer to sample the audit at-
mospheres until stable responses are
obtained. Obtain the necessary data
• and record in the appropriate spaces
in Table 12.4.
8. If desired, additional points at
.upscale concentrations different from
those specified in step 2, may be
generated. These additional audit
points plus the zero air point (ob-
tained at the start of the audit) will
enhance the statistical significance of
the audit data regression analysis.
9. After supplying all audit sample
concentrations and recording all
. data, reconnect the analyzer sample
line to the station manifold. Make a
notation of the audit stop time. Have
the station operator make a note on
the data recorder to indicate the stop
time, and check all equipment to en-
sure that it is in order to resume nor-
mal monitoring activities.
Converter efficiency—[Np2]CONV is
calculated for each audit point using
Equation 12-14 and is used to deter-
mine the NOX analyzer converter effi-
ciency using Equation 12-15.
[NOJoRiG and [NOX]REM are calcu-
lated from the NOX audit calibration
equation.
(N02]CONV = [N02JA - ([NOX]ORIG
-(NOX]REM)
Equation 12-14
% converter _ [NO2]CONV
efficiency ~ [NO2]A x 10°
Equation 12-15
12.7.6 Calculations—Record the au-
dit data in the appropriate spaces of
Table 12.4.
Percent difference—The % differ-
ence is calculated as follows:
% difference =
*
Equation 12-16
where
CM = station-measured concentra-
tion, ppm, and
CA = calculated audit concentration
ppm.
Regression analysis—Calculate by
least squares the slope, intercept,
and correlation coefficient of the sta-
tion analyzer response data (y) ver-
sus the audit concentration data.
These data can be used to interpret
analyzer performance.
12.7.7 Deference—References 4
through 6, 8, 10, and 12 provide ad-
ditional information on the N02 audit
procedure.
12.8 Carbon Monoxide Audit
Procedure Using Dynamic Di-
lution of a Gas Cylinder
12.8.1 Principle—A dynamic cali-
bration system used to generate CO
concentrations for auditing continu-
ous ambient analyzers, consists of di-
luting a CO gas cylinder with clean
dry air.
12.8.2 Applicability—Dynamic dilu-
tion can be used to audit all types of
CO analyzers; CO concentrations in
the range of 0 to 100 ppm can be
generated.
12.8.3 Accuracy—The accuracy of
the audit procedure should be within
±2.5% if the CO gas cylinder concen-
tration is referenced and if gas flow
rates are determined using recom-
mended procedures.
12.8.4 Apparatus—An audit system
which uses a dynamic dilution device
to generate audit concentrations is il-
lustrated in Figure 12.8. The seven
components of the system are dis-
cussed below.
1. Gas cylinder regulator. A brass
regulator is acceptable. A low dead-
space, two-stage regulator should be
used to achieve rapid equilibration.
2. Flow controllers. Devices capa-
ble of maintaining constant flow
rates to within ±2% are required.
Suitable flow controllers include
brass micrometering valves in
tandem with a precision regulator,
mass flow controllers, capillary re-
strictors, and porous plug restrictors.
3. Flowmeters. Flowmeters capa-
ble of measuring pollutant and dilu-
ent gas flow rates to within ±2% are
required. NBS-traceable soap bubble
flowmeters, calibrated mass flow
controllers or mass flowmeters, and
calibrated orifice, capillary, and
porous plug restrictors.are suitable
4. Mixing chamber, A glass.or
Teflon chamber is used to mix the
CO with dilution air. The inlet and
outlet should be of sufficient diame-
ter so that the chamber is at atmo-
spheric pressure under normal oper-
ation, and sufficient turbulence must
be created in the chamber to facili-
tate thorough mixing. Chamber vol-
umes in the range of 100 to 250 cm3
are sufficient. Glass Kjeldahl connect-
ing flasks are suitable mixing cham-
bers.
5. Output manifold and sample
line. An output manifold used to
supply the analyzer with an audit at-
-------
June 1984
23
Section 2.Oil2
Extra Outlets Capped
When Not in Use
To Inlet of Analyzer
Being Audited
Figure 12.8 Schematic diagram of a dilution audit system.
mosphere at ambient pressure
should be of sufficient diameter to
ensure a minimum pressure drop at
the analyzer connection, and the
manifold must be vented so that am-
bient air will not mix with the audit
atmosphere during system opera-
tions. Recommended manifold mate-
rials are glass or Teflon. The sample
line must be nonreactive and flex-
ible; therefore. Teflon tubing is pre-
ferred.
6. Dilution air source. The diluent
source must be free of CO and water
vapor. Clean dry air from a com-
pressed gas cylinder is suitable
choices for dilution air. A catalytic
oxidizer connected in line is one
method of scrubbing CO from the di-
lution air.
7. CO gas cylinder. A compressed
gas cylinder containing 100 to 200
ppm CO in an air or N2 matrix is
used as the CO dilution source. If the
CO standard is contained in a N2 ma-
trix the zero air dilution ratio cannot
be less than 100:1. This cylinder
must be traceable to an NBS-SRM
(number 1677, 1678 1679, 1680 or
1681).
12.8.5 Procedure—Equipment setup
—Assemble the audit equipment as
required, and verify that all the
equipment is operational. If a clean
dry air system equipped with a cata-
lytic oxidizer is used, allow the oxi-
dizer to warm up for 30 min. Connect
.the gas regulator to the CO cylinder,
land evacuate the regulator as fol-
lows:
1. With the cylinder valve closed,
connect a vacuum pump to the evac-
uation outlet on the regulator, and
start the pump.
2. Open and close the evacuation
port.
3. Open and close the cylinder
valve.
4. Open and close the evacuation
port.
5. Repeat steps 2 through 4 five
more times to be sure all O2 impuri-
ties are removed from the regulator.
If the regulator does not have an
evacuation port but has a supported
diaphragm, the procedure can be
conducted at the gas exit port.
For regulators that do not have an
evacuation port but have an unsup-
" ported diaphragm, use the following
procedure:
1. Connect the regulator to the
cylinder, and close the gas exit port.
2. Open and close the cylinder valve
to pressurize the regulator.
3. Open the gas exit port,, and allow
the gas to purge the regulator.
4. Repeat steps 2 and 3 five more
times; then close the gas exit port,
and open the cylinder valve. (The.
regulator should remain under pres-
sure.) Connect the gas cylinder to the
audit device.
Repeat the procedure for each
cylinder.
Audit sequence—After all the
equipment has been assembled and
set up, have the station operator
mark the strip chart recorder to indi-
cate that an audit is beginning. Infor-
mation such as the auditor's name,
start time, date, and auditing organi-
zation should be entered. If it is not
possible to enter written comments.
the start and stop times should be
recorded to preclude the use of audit
data as monitoring data. After
recording the data, disconnect the
analyzer sample line from the station
manifold, and connect it to the audit
manifold, as shown in Figure 12.9.
Cap the sample port on the station
manifold. The audit atmosphere
must be introduced through any as-
sociated filters or sample pretreat-
ment apparatus to duplicate the path
taken by an ambient sample. Record
the analyzer type and other identifi-
cation data on the'data form
(Table 12.5).
Conduct the audit as follows:
1. Introduce into the audit manifold
a clean dry. air at a flow rate in ex-
cess of 10% to 50% of the analyzer
sample demand. Allow the analyzer
to sample the clean dry air until a
stable response is obtained; that is,
until the response does not vary
more than ±2% of the measurement
range over a 5-min period. Obtain
the station response and concentra-
tion from the station operator, and
record the data in the appropriate
spaces on the data form.
2. Generate the SLAMS audit con-
centrations (which are compatible
with the analyzer range) as audit at-
mospheres consistent with the Ap-
pendix A1 requirements.
Audit point
1
2
3
4
Concentration range,
(ppm)
3-8
15-20
35-45
80-90
Generate the audit concentrations by
adjusting the pollutant flow rate (FP)
and the total flow rate (FT) to provide
the necessary dilution factor.
Calculate the audit concentration
as follows.
[CO] = ^ x [CO]STD Equation .12-17
where
[CO] = audit concentration of
CO, ppm
FP = pollutant flow rate, cm3/
min
FT = total flow rate, cm3/min
[equal to the sum of the
pollutant flow rate (FP)
and the dilution flow
rate (FD)J, and
[COlsTD = concentration of the
standard cylinder, ppm.
3. Generate the highest audit con-
centration level first, and consecu-
-------
Section 2.0.12
24
June 1984
Table 12.5. Carbon Monoxide Audit Data Report
Date
Address
TA
Start time
°C; PA
mm Hg;
Analyzer —
Calibration standard
Last calibration date
Frequency
Serial number
_ Span source
Range
Calibration comments
Data acquisition
Zero setting
Span setting
Data acquisition system
^_ Recorder
Bubble flowmeter serial number
Audit standard
n, dry air _
; P
ig; [ ] = •
Flow correction:
Dilution air flow:
Volume
/PA ~ PH2Q\ f 298 K \ =
\760mm) \TA + 273J
Flowmeter
mm
Volume
Clean, dry air response
Other response
% Chart;
VDC;
Audit Point I
Pollutant flow measurement
Volume
T,
Flowmeter
Analyzer response _
Other response
% Chart;
mm
Audit concentration
VDC;
ppm
No
cm-3
min
ppm
mn
ppm
ppm
-------
June 1984
25
Section 2.O.I2
Table 12.5 (continued)
Audit Point II
Pollutant flow measurement
Volume
Analyzer response
Other response
Audit Point III
. Pollutant flow measurement
Volume ' .
7, _
7i _
Analyzer response
Other response _
Audit Point IV
Pollutant flow measurement
Volume
T2
T3
Analyzer response _
Other response
Audit Point V
Pollutant flow measurement
Volume
r,
T2
T3
Analyzer response _
Other response
rn7
%
Cm
mm
% Chart;
Cm
mm
Chart:
Flowmeter
'A T
Audit concentration
Flowmeter
ff,\jVolume\
(Cf:)(—^r~)--
Audit concentration
VDC;
lr\(yolume\
\Cf)\ T 1 ~
Audit concentration
Flowmeter
(Cf)(^p?)
Audit concentration
— VDC;
cnr3
min
ppm
ppm
cmj
min
ppm
cmj
min
ppm
cmj
min
ppm
Ppm
-------
Section 2.0.12
28
June 1984
matrix are used as the audit gases.
These cylinder must be traceable to
an NBS-SRM (number 1677, 1678,
1679,1680, or 1681), and must be
within the following concentration
ranges: 3 to 8 ppm, 15 to 20 ppm, 35
to 45 ppm, and 80 to 90 ppm.
12.9.5 Procedure—Equipment
setup—Assemble the audit equip-
ment as required and verify that all
the equipment is operational. If a
clean dry air system equipped with a
catalytic oxidizer is used for a zero
air source, allow the oxidizer to
warm up for 30 min. Connect the gas
regulator to a CO cylinder, and evac-
ulate the regulator as follows:
1. With the cylinder valve closed,
connect a vacuum pump to the evac-
uation outlet on the regulator and
start the pump.
2. Open and close the evacuation
port.
3. Open and close the cylinder
valve.
4. Open and close the evacuation
port.
5. Repeat steps 2 through 4 five
more times to be sure all 02 impuri-
ties are removed, from the regulator.
If the regulator does' not have an
evacuation port but has a supported
diaphragm, the procedure can be
conducted at the gas exit port.
For regulators that do not have an
evacuation port but have an unsup-
ported diaphragm, use the following
procedure:
1. Connect the regulator to the
cylinder, and close the gas exit
port.
2. Open and close the cylinder
valve to pressurize the regulator.
3. Open the gas exit port, and
allow the gas to purge the regula-
tor.
4. Repeat steps 2 and 3 five more
times; then close the gas exit port,
and open the cylinder valve. (The
regulator should remain under
pressure.) Connect the gas cylinder
to the audit device.
Repeat the procedure for each
cylinder.
Audit sequence—After all the
equipment has been assembled and
set up, have the station operator
mark the strip chart recorder to-indi-
cate that an audit is beginning. Infor-
mation such as the auditor's name,
start time, date, and auditing organi-
zation should be entered. If it is not
possible to enter written comments,
the start and stop times should be
recorded to preclude the use of audit
1ata as monitoring data. After
acording the data, disconnect the
analyzer sample line from the station
manifold, and connect it to the audit
manifold, as shown in F:igure 12.11.
Cap the sample port on the station
manifold. The audit atmosphere
must be introduced through any as-
sociated filters or sample pretreat-
ment apparatus to duplicate the path
taken by an ambient sample. Record
the analyzer type and other identifi-
cation data on the data form
(Table 12.6).
Conduct the audit as follows:
1. Introduce into the audit mani-
fold a zero air gas at a flow rate in
excess of 10% to 50% of the analyzer
sample demand. Allow the analyzer
to sample the zero air until a stable
response is obtained; that is, until
the response does not vary more
than ±2% of the measurement range
over a 5-min period. Obtain the sta-
tion response and concentration
from the station operator, and record "
the data in the appropriate spaces on
the data form.
2. Generate the SLAMS audit con-
centrations (which are compatible
with the analyzer range) as audit at-
mospheres consistent with the Ap-
pendix A1 requirements.
Audit point
1
2
3
4
Concentration
range,
ppm
3-8
15-20
35-45
80-90
3. Generate the highest audit con-
centration level first, and consecu-
Station Manifold
tively generate decreasing concentra-
tions. The audit concentration equals
the CO gas cylinder concentration.
4. If desired, additional points at
upscale concentrations different from
those specified in step 2 may be gen-
erated. Generation of these audit
concentrations plus a post audit
clean dry air response will enhance
the statistical significance of the
audit data regression analysis.
5. After supplying all audit concen-
trations and recording all data, re-
connect the analyzer sample line to
the station manifold. Make a notation
of the audit stop time. Have the sta-
tion operator make a note on the
data recorder to indicate the 'stop
time, and check'all equipment to en-
sure that it is in order to resume nor-
mal monitoring activities.
12.9.6 Calculations—Record the
data in Table 12.6 in the appropriate
spaces.
% difference—The % difference is
calculated as follows:
% difference =
CM - CA
x 100,
CA
Equation 12-19
CM = station-measured concentra-
tion, ppm
CA. = the calculated audit concen-
tration, ppm.
Regression analysis—Calculate by
least squares the slope, intercept,
and correlation coefficient of the sta-
tion analyzer response data (y) ver-
sus the audit concentration data (x).
These data can be used to interpret
the analyzer performance.
T T T T
To Analyzers
Test
Atmosphere
1 J— 1
Station
Analyzer-
Data
Acquisition
System
(Teletype
\Printout
H . «
in \
Volts
-(Audit Manifold-*- Exhaust
Figure 12.11. Schematic of configuration utilized in auditing the gas analyzers.
-------
27
Section 2,0.1 Z
ng the gas analyzers.
e station analyzer re-
3 (y) versus the audit con-
iata (x). These data can
interpret the analyzer per-
srences—References 4
nd 10 and 13 provide ad-
irmation on the CO audit
bon Monoxide Audit
e Using Multiple
ation Gas Cylinders
ic/p/e—Separate corn-
s-cylinders which contain
concentrations are sup-
ess to a vented manifold;
r which is being audited
ch concentration until a
3nse results.
ilicability—The procedure
I to audit all types of CO
oncentrations of CO in
f 0 to 100 ppm can be
12.9.3 Accuracy—The accuracy of
the audit procedure should be within
±2.5% if the CO gas cylinder concen-
tration is referenced and if gas flow
rates are determined using EPA-
recommended procedures.
12.9.4 Audit Apparatus—A system
used to generate audit concentra-
tions is illustrated in Figure 12.10.
The six components of the system
are described below.
1. Gas cylinder regulator. A brass
cylinder regulator is acceptable. A
low deadspace, two-stage regulator
should be used to achieve rapid
equilibration.
2. Flow controllers. Devices capa-
ble of maintaining constant flow
rates within ±2% are required. Suit-
able flow controllers include brass
micrometering valves in tandem with
a precision regulator, mass flow con-
trollers, capillary restrictors, and
porous plug restrictors. :
3. Flowmeters. Flowmeters capa-
ble of measuring pollutant gas and
diluent air gas flow rates within ±2%
are required. NBS:traceable soap
bubble flowmeters, calibrated mass
flow controllers or mass flowmeters,
and calibrated orifice, capillary, and
porous plug restrictors are suitable
for flow determination.
4. Output manifold and sample
line. An output manifold is used to
supply the analyzer with an audit at-
mosphere at ambient pressure. The
manifold should be of sufficient di-
ameter to ensure a minimum pres-
sure drop at the analyzer connection,
and the manifold must be vented so
that ambient air will not mix with the
audit atmosphere during system op-
erations. Recommended manifold
materials are glass or Teflon. The
sample line must be nonreactive and
flexible; therefore. Teflon tubing is
preferred.
5. CO gas cylinders. Compressed
gas cylinders containing CO in an air
'Under
lulator
Vent-
Extra Outlets Capped
When Not in Use
Output
Manifold
JJ U
-IT'
Fr
To Inlet of Analyzer
Being Audited
Schematic diagram of a dynamic audit system.
-------
Section 2.0.12
26
June 1984
Table 12.5 (continued)
PARTI
Location
Analyzer/model number
Serial number
Auditor _
Start time
Zero setting
PART II
Date
Pollutant cylinder no.
Pollutant cylinder concentration
Stop time
Span setting
Time constant
Point
number
cm3/min FT/ cm3/min
Audit
concentration,
ppm
Analyzer
Analyzer concentration, %
response ppm difference
Zero
Zero
PART III. REGRESSION ANALYSIS
Analyzer response (ppm) = m (audit) + b
Slope (m) ; Intercept (b)
Comments:
; Correlation (r) =.
-------
Juno 1984
29
Section 2.0.12
Table 12.6. Carbon Monoxide Audit Data Report
PARTI
Location
Analyzer/model number.
Serial number
Auditor
Start time
Zero setting.
PART II
Date
Pollutant cylinder no.
Pollutant cylinder concentration
Stop time .
Span setting
Time constant
Point
number
Audit
cylinder
number
NBS reference
audit
concentration,
pom
Analyzer
Response
Concentration,
ppm
%
difference
Zero
Zero
PART III. REGRESSION ANALYSIS
Analyzer response (ppm) = m (audit) + b
Slope (m) = ; Intercept (b) = ; Correlation (r) =.
Comments:
-------
Section 2.0.12
30
June 1984
12.9.7 References—References 4
through 6 and 10 and 13 provide ad-
ditional information on the CO audit
procedure.
12.10 Ozone Audit Procedure
Using Ultraviolet Photometry
12.10.1 Principle—O3 concentra-
tions are generated by using a UV
generator (transfer standard), and
each atmosphere is verified by using
UV photometry. The UV photometry
procedure for 03 audits is based on
the Lambert-Beer absorption law:
Transmittance = r- - e"ac1
•o
Equation 12-20
where
a = the absorption cofficient of O3 at
254 nm =* 308 ±4 atm~1 cm~1 at
O'C and 760 torr,
c » the 03 concentration, atm, and
I = the optical path length, cm.
12.10.2 Applicability—The proce-,
dure can be used to audit all types of
commercially available 03 analyzers
which operate in the range of 0 to
1 ppm.
12.10.3 Accuracy—The accuracy of
the audit procedure should be within
±2.5% if the O3 source is a photome-
ter or transfer standard, and flow
rates are determined using EPA-
recommended procedures.
12.10.4 Apparatus—An UV photo-
metric system which is used for au-
diting O3 analyzers is illustrated in
Figure 12.12. The system consists of
an O3 source and a standard UV pho-
tometer. Components of the system
are discussed below.
1. Ozone generator. An O3 gener-
ator that produces a stable 03 con-
centration is required. An UV lamp
generator is recommended.
2. Flow controllers. Devices capa-
ble of maintaining constant flow
rates to within ±2% are required.
Suitable flow controllers include
micrometering valves in tandem with
a precision regulator, mass flow con-
trollers, capillary restrictors, and
porous plug restrictors.
3. Flowmeters. Flowmeters capa-
ble of measuring clean dry air flow
rates to within ±2% are required.
NBS-traceable soap bubble flowme-
ters, calibrated mass flow controllers
or mass flowmeters, and calibrated
orifice, capillary, and porous plug re-
strictors are suitable.
4. Mixing chamber. A glass or
Teflon chamber-is used to mix the O3:
with dilution air. The inlet and outlet *
should be of sufficient diameter so
that the chamber is at atmospheric
pressure under normal operation,
and sufficient turbulence must be
created in the chamber to facilitate
thorough mixing. Chamber volumes
.in the range of 100 to 500 cm3 are
\
Clean
Dry
Air
Flow
Controller
-
Flowmeter
Fo .
Fo
Controller
Generator
Mixing
Chamber
Flow
Controller
Output
Manifold
Vent
1
Extra Outlets Capped
When Not in Use
To Inlet of Analyzer
Being Audited
Two-Way
Valve
Vent
r
UV Photometer
Detector
Absorption Cell
Signal
Processing
Electronics
Optics
0 Source
°
Flowmeter
Flow
Controller
Pump
Exhaust
Figure 12.12 Schematic diagram of an ultraviolet photometric audit system.
-------
June 1984
31
Section 2.0.12
sufficient. Glass Kjeldahl connecting
flasks are suitable mixing chambers.
5. Output manifold. An output
manifold is used to supply the ana-
lyzer with an audit atmosphere at
ambient pressure. The manifold
should be of sufficient diameter to
ensure a minimum pressure drop at
the output ports, and the manifold
must be vented so that ambient air
will not mix with the audit atmo-
sphere during system operations.
6. Sample line and connecting
lines. The sample line and connect-
ing lines downstream of the 03 gen-
erator must be made of a nqnreac-
tive material such as Teflon.
7. Dilution air system. Clean dry
air from a compressed gas cylinder
(Grade 0.1) is a suitable source of di-
lution air; however, if large volumes
of air (5 liters/min or greater) are re-
quired, purified compressed air is
preferred. The clean dry air must be
free of contaminants, such as NO,
N02, O3, or reactive, hydrocarbons.
The air can be purified to meet these
specifications by passing it through
silica gel for drying, by treating it
with 03 to convert any NO to NO2,
and by passing it through activated
charcoal (6-14 mesh) and a molecular
sieve (6-16 mesh, type 4A) to remove
• N02, 03, or-hydrocarbons.
Silica gel maintains its drying effi-
ciency until it has absorbed 20% of
its weight; it can be regenerated in-
definitely at 120°C. Addition of cobalt
chloride to the surface of the gel pro-
vides a water absorption indicator. A
transparent drying column is recom-
mended. Activated charcoal and a
molecular sieve have a finite absorp-
tion capability; because it is difficult
to determine when the capability has
been exceeded, both should be re-
placed either before each audit or
after 8 h of use.
8. Ultraviolet photometer. The UV
photometer consists of a low-
pressure mercury discharge lamp,
collimator optics, an absorption cell,
a detector, and signal-processing
electronics, as illustrated in Fig-
ure 12.12. The photometer must be
capable of measuring the transmit-
tance, \l\0, at a wavelength of 254 nm
with sufficient precision for the
standard deviation of the concentra-
tion measurements not to exceed the
greater of 0.005 ppm or 3% of the
concentration. Because the low-
pressure mercury lamp radiates at
several wavelengths, the photometer
must incorporate suitable means to
be sure that no O3 is generated in
the cell by the lamp and that at least
99.5% of the radiation sensed by the
detector is 254-nm radiation. This
goal can be achieved by prudent se-
lection of optical filter and detector
response characteristics. The length
of the light path through the absorp-
tion cell must be known with an ac-
curacy of at least 99.5%. In addition,
the cell and associated plumbing
must be designed to minimize loss of
O3 from contact with cell walls and
gas handling components.
9. Barometer. A barometer with an
accuracy of ±2 torr is required to de-
termine the absolute cell pressure.
10. Temperature indicator. A tem-
perature indicator accurate to ±1°C is
required to determine the cell tem-
perature.
12.10.5 Procedure
Equipment setup — Assemble the
audit equipment according to Fig-
ure 12.12. Allow the photometer and
•O3 generator to warm up for approxi-
mately 1 h or until the normal oper-
ating cell temperature, 6° to 8°C
above ambient, is attained.
Photometer adjustment (Dasibi) —
Several checks are made after the
photometer has reached normal- op-
eration temperature.
1. Switch the photometer to sam-
ple frequency. Using Table 12.7,
record and calculate the mean of five
consecutive readouts. The mean
sample frequency should be between
45.0 and 49.0.
2. Switch the photometer to con-
trol frequency. Using Table 12.7,
record and calculate the mean of five
consecutive readouts. The mean con-
trol frequency should be between
23.0 and 28.0.
3. Switch the photometer to span.
Record this span number and calcu-
late a new span number as follows:
Span number = 45.684 x
V
.6\
273.16 )'
Equation 12-21
where
Pb = barometric pressure, mm Hg,
and
Tc = cell temperature, °C.
Dial in the new span number on the
photometer, and display the correct
entry.
4. Switch the selector to the oper-
ate position, and adjust the flow ro-
tometer to 2 (Vmin. Using the offset
adjust control on the front panel of
the photometer, set the instrument to
read between 0.005 and 0.010 while
sampling clean dry air.
5. Determine the true zero display
reading by recording 10 consecutive
display updates from the panel
meter. Calculate the mean of these
10 readings.
Audit sequence—1. Adjust the
clean dry air flow rate through the 03
generator to meet the range specifi-
cations of the station analyzer and
the 03 output capability of the gener-
ator. Adjust the dilution clean dry-air
flow rate so that an excess air flow
rate of 10-to 50% of the station ana-
lyzer and photometer sample de-
mand is generated. Mark the data ac-
quisition system to indicate that an
audit is beginning, and disconnect
the sample line from the station
manifold. Plug the disconnected
sample port to the station manifold.
2. Connect the audit analyzer and
photometer to the-output manifold,
as shown in Figure 12.12. Allow the
station analyzer and photometer to
sample the clean dry air until a sta-
ble response is obtained; that is,
until the response does not vary
more than ±2% of the measurement
range over a 5-min period. Obtain
the analyzer response from the sta-
tion operator, and. record the data
and the photometer response in the
appropriate spaces in Table 12.7.
3. Generate the following SLAMS
audit concentrations (which are com- .
patible with the analyzer range) as
audit atmospheres consistent with
the Appendix A1 requirements.
Audit point
1
2
3
4
Concentration
range, ppm
0.03-0.08
0.15-0.20
0.35-0.45
0.80-0.90
Record ten consecutive display up-
dates of the photometer for each
audit point. Calculate and record the
mean of these ten updates. Record
the station analyzer response. Both
the photometer and station analyzer
readings should be taken only after a
stable response is exhibited by both
instruments. Calculate the audit con-
centrations.
[O3] = RD - Rz, Equation 12-22
where
[O3] = the audit concentration of O3,
ppm,
RO = the mean of the 10 photo-
meter display updates, and
RZ = the average photometer
clean dry air offset.
-------
Section 2.0.12
32
June 1984
Table 12.7. Ozone Audit Data Report
Station -
Date
Address
Start time
TA
mm Hg;
mm Hg Auditor
Analyzer
Last calibration date
Frequency
Serial number
Range
Calibration comments
Zero setting
Span setting
Data acquisition system
Recorder
Audit system
Serial number
Clean, dry air supply
Sample frequency —
Control frequency
Cell temperature (Tc)
Span number calculation: 45.S84 x (76°pmm} x (7%+7|73) -
Observed span number
Dilution air:
Photometer display
Average
Analyzer response
% Chart;'
ppm
Other response
Audit Point I
Photometer display
Average
1 setting
Analyzer
Audit [03]
Chart;
ppm
ppm
Other response
Audit Point II
Photometer display
Average
Sleeve setting
cm
Audit [O3]
Analyzer response
% Chart;
ppm
ppm
Other response
-------
June 1984
33
Section 2.0.12
Table 12.7 (continued)
Audit Point III
Photometer display
Average
Sleeve setting
Analyzer response _
Other response
Audit Pomt IV
Photometer display
Average
Sleeve setting
Analyzer response _
Other response
Audit Point V
Photometer display
Average
Sleeve setting
Analyzer response _
Other response
AUDIT RESULTS
cm
% Chart; •
Audit [O3]
- VDC; _
ppm
ppm
cm
Audit [O3]
% Chart;
ppm
ppm.
cm
Audit [O3]
% Chart;
ppm
ppm
Point
number
Analyzer
Audit concentration.
ppm
Response
Concentration
ppm
difference
1
2
3
4.
5
6
Regression analysis (y = mx + b)
Analyzer response (ppm) = m (audit) + b
Slope (m) =
Intercept (b) =
Correlation (r) =
-------
Section 2.0.12
34
June 1984
4. Generate the highest audit con-
centration level first by adjusting the
O3 output of the generator, the
amount of dilution air, or the amount
of clean dry air flowing through the
generator. Then consecutively gener-
ate the decreasing concentrations.
5. If desired, additional points at
upscale concentrations different from
those specified in step 3 may be gen-
erated. Generation of these audit
concentrations plus a post audit
clean dry air response will enhance
the statistical significance of the
audit data regression analysis. ,
6. After supplying all audit concen-
trations and recording all data, re-
connect the analyzer sample line to
the station manifold. Make a notation
of the audit stop time. Have the sta-
tion operator make a note on the
data recorder to indicate the stop
time, and check all equipment to en-
sure that it is in order to resume nor-
mal monitoring activities.
12.10.6 Calculations—Record the
data in Table 12.7 in the appropriate
spaces.
% difference—The % difference is
calculate as follows:
% difference
where
CM - CA
x 100,
Equation 12-23
CM 3 the station-measured concen-
tration, ppm, and
CA « the calculated audit concentra-
tion, ppm.
Regression analysis — Calculate by
least squares the slope, intercept,
and correlation coefficient of the sta-
tion analyzer response data (y) ver-
sus the audit concentration data (x).
These data can be used to interpret
the analyzer performance.
12.10.7 References— References 7,
10, and 14 provide additional infor-
mation on the O3 audit procedure.
12.11 Total Suspended Par-
ticulate Sampler Audit Proce-
dure Using a Reference Flow
Device (ReF)
Principle — An ReF device is
one type of orifice transfer standard
and is used to audit a TSP hi-vol
sampler. The ReF device (Figure
12.13} uses orifice plates to audit the
sampler flow rate by measuring the
pressure drop caused by the flow of
air through a restricting orifice. A
calibration equation is used to trans-
late this pressure drop into a flow
Figure 12.13. Reference flow (Ref) audit device.
rate at either standard or actual con-
ditions.
12.11.2 Applicability—The proce-
dure can be used to audit hi-vol sam-
plers with or without flow controllers
operating in the flow range of 0.5 to
2.4 std m3/min. Other types of orifice
transfer standards may be used fol-
lowing the same procedures.
12.11.3 Accuracy—The accuracy of
the audit procedure is approximately
2% when traceability is established
by calibrating the ReF device to a
Rootsmeter or other primary volume
measurement device.-
12.11.4 ' Apparatus—ReF device—
An ReF device is an interfacing unit
that attaches to the filter holder of a
TSP hi-vol sampler. The device typi-
cally exhibits a sensitivity of 0.01 m3/
min per 0.1-in. pressure change. The
ReF device is equipped with five air-
restricting orifice plates which are
used one at a time to vary the flow
rate of the hi-vol sampler. A slack
tube water manometer accompanies
the ReF device and measures the
pressure drop caused by the flow re-
striction of the plates. A cylindrical
plexiglass windflow deflector should
be attached to the top of the ReF de-
vice to protect it from ambient air
flow.
Differential .manometer—A tube
manometer capable of measuring at
least 16 in. of water is required.
Barometer—A barometer capable
of measuring atmospheric pressure
with an accuracy of ±2 torr is re-
quired.
Temperature indicator—An indica-
tor accurate to' ±1°C is required to.
determine ambient temperature'.
. Glass fiber filter—Glass fiber filters
with at least 99% efficiency for col-
lection of 0.3-p.m diameter particl.es
are suitable.
12.11.5 Procedure—Samplers
equipped with flow controllers—A
hi-vol sampler equipped with a flow
controller is typically calibrated in
terms of standard flow rate. Audit
calculations are performed as shown
in Section 12.11.6.
Note: It is imperative to know
whether the hi-vol was calibrated in
terms of actual conditions at the time
of calibration, seasonal average con-
ditions, or the flow rates have been
corrected to standard temperature
and pressure. The comparison be-
tween audit and station flow rates
MUST be made with the same units
and corrections.
Conduct the audit as follows:
1. Remove the filter holder clamp
from the sampler. If a filter is in
place for an upcoming sampling
period, have the station operator re-
move the filter and store it until the
audit is completed. Attempt to sched-
ule audits so they do not interfere
with normal sampling runs
-------
June 1984
35
Section 2.0.12
2. Place a clean glass fiber filter on
the filter screen, and place the ReF
device on top of the filter. Securely
fasten the ReF device to the holder
using the four wingnuts at each cor-
ner of the sampler filter holder.
3. With no resistance plate in the
ReF device, close the lid and fasten it
using the two wingnuts. Place the
wind deflector in position, and then
connect and zero the water manome-
ter. .
4. Start the sampler motor and
allow it to stabilize. A warm-up time
•of .2:5 min should be allowed. Record
the pressure drop shown on the
manometer (in. H2O), ambient tem-
perature (°C), barometric pressure
(mm Hg), and station flow rate (ob-
tained from the station operator) on
the data form in Table 12.8. If the
barometric pressure cannot be deter-
mined by an audit barometer (be-
cause of high elevations that exceed
the limits of the barometer), deter-
mine the barometric pressure (PA) as
follows:
PA = 760 - (elevation in meters
x 0.076). Equation 12-24
5. At the conclusion of the audit,
have the station operator replace the .
filter and reset; the sampler timer as
it was before the audit.
Samplers without flow controllers
—A hi-vol sampler not equipped with
a constant flow controller is typically
calibrated in terms of actual flow
rates. Audit calculations are per-
formed as shown in Subsection
. 12.11.6.
Note: It is imperative to know
whether the hi-vol was calibrated, in '
terms of actual conditions at the time.
of calibration, seasonal average con-
ditions, or the flow rates have been
corrected to standard temperature
and pressure. The comparison be-
tween audit and station flow rates
MUST be made with trie same units
and corrections.
Conduct the audit as. follows.:
1. Remove the filter holder clamp
from the sampler. If a filter is in
place for an upcoming sampling pe-
riod, have the station operator re-
move the filter and store it until the
audit is completed. Attempt to sched-
ule audits so they do not interfere
with normal sampling runs.
2. Place the ReF device on the filter
holder, and secure the device to the
holder by tightening the four
wingnuts at each corner of the sam-
ple filter holder.
3. Place the 18-hole resistance plate
in the ReF device, close the lid, and
fasten the lid using the two
wingnuts. Place the wind deflector in
position, and then connect and zero
the water manometer.
4. Start the sampler motor and
allow it to stabilize. A warm-up time
of 2:5 min should be allowed. Record
the pressure drop shown on the
manometer (in. H20), ambient tem-
perature (°C), barometric pressure
(mm Hg), and station flow rate (ob-
tained from the station operator) on
the data form in Table 12.8. If the
barometric pressure cannot be deter-
mined by an audit barometer (be-
cause of high elevations that exceed
the limits of the barometer), deter-
mine the barometric pressure by
using Equation 12-24.
5. Repeat steps 3 and 4 using the
remaining resistance plates.
6. At the conclusion of the audit,
have the station operator replace t^e
filter and reset the sampler timer as
it was before the audit.
12.11.6 Calculations—Calculate the
audit flow rate at standard conditions
for those hi-vols with flow rates cor-
rected to standard temperature and
pressure.
For samplers calibrated in terms of
actual or seasonal average condi-
tions — Calculate the audit flow rate
in terms of actual conditions.
/760
Pb\/298\ ..
--
Equation 12-25 .
where
Qstd = standard flow rate,
m3/min
m and b = calibration coefficients
determined during cali-
bration of the ReF device,
using flow rates corrected
to standard conditions
AH = pressure drop shown on
the manometer, in. H2O .
Pb = barometric pressure,
mm Hg, and
Ta = ambient temperature in
degrees Kelvin (273.16
Perform this calculation for each
flow rate comparison and calculate
the % difference for each audit point
as follows.
% difference = -^-= — - x 100,
r~A
Equation 12-26
where
FS = the station-measured flow
rate, std m-Vmin, and
FA = the audit flow rate, std m3/min.
Equation 12-27
where
Qact = the actual flow rate, m3/min
Qstd = the standard flow rate,
m3/min
Pb = the barometric pressure, mm
Hg, and
Ta = the ambient temperature in
degrees Kelvin (273.16 + °C). -
Note: If seasonal temperature and
barometric pressure were used
in the calibration of the hi-vol
sampler, then:
Pb= seasonal barometric pres-
sure, mm Hg, and
Ta = seasonal ambient tempera-
ture in degrees Kelvin (273.16
+ °C)
convert from m3/min to ft3/min by
multiplying by 35.31.
12.11.7 References — References 8
and 9 provide additional information
on the TSP audit procedure.
12.12 Data Interpretation
Interpretation of quality assurance
audit results is not well defined, and
audit data must be assembled and
presented so that interpretation is
possible. Subsection 12.12.1 dis-
cusses the data reporting require-
ments specified in Appendix A1. In
addition to these requirements, op-
tional data interpretation methods,
including case .examples, are in Sub-
section 12.12.2.
1 2. 1 2. 1 SLAMS Reporting Require-
ments — Refrence 1 specifies the min-
imum data reporting procedures for
automated and manual methods.
Compare the station responses ob-
tained for each audit point.
f^ _ s*
% difference = — ^~ — - x 100
t-A
Equation 12-29
where
CM = the station-measured re-
sponse, in concentration units,
and
CA = the audit values, in concentra-
tion units.
This comparison indicates the % dif-
ference for each audit concentration
generated and each analyzer re-
sponse recorded.
-------
Section 2.0.12
36
June 1984
Table 12.8. Hi-vol Sampler Audit Data Report
Station location
Data
Time
Barometric pressure
Temperature —
Sampler model number
Flow controller number .
Serial number
Plate Audit manometer ' Audit
number ' reading, in. H2O flow
Sampler
Difference
Response
Flow
m3/min
No plate
18
13
10
Audit device ID number
Other information:
Qstd; Slope (m) =.
Qact; Slope (m) =.
Regression coefficient
; Intercept (b) = .
; Intercept (b) = .
Audited by:
Authorized by:
-------
June 1984
37
Section 2.0.12
Table 12.9. Example Audit Data for an SO2 Analyzer
SLAMS
concentration
range, ppm
0.03 to 0.08
0.1 5 to 0.20
0.35 to 0.45
Audit
concentration,
ppm
0.044
0.165
0.412
Station
analyzer
response, ppm
0.042
0.159
0.394
%
difference
-4.6
-3.6
-4.4
Table 12.9 contains example audit
data for an S02 analyzer operating
on a 0- to 0.5-ppm range. As indi-
cated by the data set, the station an-
alyzer shows a negative deviation of
approximately 4% when compared to
the audit concentrations.
A % difference calculation is used
to evaluate manual method audit
data. For example, a hi-vol sampler
with a flow controller is audited
using an ReF device. A one-point
audit is performed at the normal op-
erating flow rate with a glass fiber fil-
ter on the device. The audit and sta-
tion flow rates are compared on the
basis of % difference using Equation
12-29 and are designated as CA and
CM, respectively.
12.12.2 Least Squares—The data
analysis described in Appendix A1
calculates the % accuracy of the
audit data at specific operating levels
within an analyzer's range. Because.
this method compares the operating
differences at a maximum of four
points, its use in determining overall
analyzer performance is limited.
With an increase in the number
and range of audit points generated,
linear regression analysis can be
used to aid in evaluating analyzer
performance data. This method in-
volves supplying a zero concentra-
tion and five upscale concentrations
corresponding to approximately 10%,
20%, 40%, 60%, and 90% of the ana-
lytical range. The regression coeffi-
cients are calculated by designating
the audit concentration (ppm) as the
abscissa (x variable) and the station
analyzer response (ppm) as the ordi-
nate (y. variable). The resultant
straight line (y = mx + b) minimizes
the sum of the squares of the devia-
tions of the data points from the line.
Table 12.10 summarizes the calcu-
lations by the method of least
squares, and Table 12.11 lists criteria
which may be used to evaluate the
regression data in terms of analyzer
performance. The slope and intercept
describe the data set when fitted to a
line; the correlation coefficient de-
scribes how well the straight line fits
the data points. Presently, there are
no published criteria for judging ana-
lyzer performance. Criteria are nor-
mally specified by the operating
agency. Figure 12.14 shows an exam-
pie audit data set that is analyzed
both by the % difference and least
squares technique. The slope shows
an average difference of -4.2%
which agrees with the % difference
data. The zero intercept of 0.000
agrees with the analyzer response
during the audit; this indicates a
nonbias response. The correlation •
coefficient of 0.9999 indicates a linear
response to the audit points. It can
be deduced that the % difference of
the slope index is caused by the cali-
bration source (i.e., the standard pol-
lutant source, flow measurement ap-
paratus, and the dilution air source).
Figure 12.15 illustrates data varia-
tions which may be encountered
when auditing a monitored network.
Figure 12.15(a) represents audit re-
sults in which the analyzer response
agrees perfectly with the generated
audit concentrations. Figure 12.15(b)
represents data from a group of sta-
tions showing constant systematic
differences, (i-.e., differences inde-
'pendent of concentration levels be- -
tween stations and between stations
and the audit system).
A network of stations showing lin-
ear systematic differences that may
or may not be independent of con-
centration is shown in Figure
Point No.
1
2
3
4
5
6
Audit .
Concentration
(ppm/
.000
.044
.103
.165
.294
.412 •
Station
Concentration
(ppm)
.000
.042
.098
.159
.283
.394
% Difference
-4.6
-4.9
-3.6
-3.7
-4.4
r = 0.9999
m = 0.958
b = 0.000
Figure 12.14.
.2 .3
Audit Concentration (ppm)
Example of audit data regression analysis.
-------
Section 2.0.12
38
June 1984
Table 12.10. Least Squares Calcula-
tions' (y ~ mx + b)
— . Vv
x « average x value = =£
7 - average y value ~ ~j
slope « m
N
intercept - b - y - nix
correlation coefficient = r = -
SZY = variance of the y values
'Sv* _
-[N
S2X « variance of the x values
N
aFor convenience Sx ;s used for Zx,-
(and similarly for other sums):
12.15{c). This example is moie repre-
sentative of audit data resulting from
a network of stations. Figure 12.15(d)
and 12.15(e) illustrates two special
cases of the general case shown in
Figure 12.15(c).
Analysis of the data for a grouping
of stations, such as for a given State,
not only yields precision and accu-
racy estimates but may also provide
clues as to the proper corrective ac-
tion to take if larger than acceptable
differences are observed. For exam-
ple. Figure 12.15(d) shows constant
relative differences within stations
that vary among stations. Such data
patterns can result, for example,
from errors in the calibration stan-
dards if high concentration cylinders
and dilution are used for calibration.
Constant systematic (absolute) differ-
ences {within stations), such as Fig-
ure 12,15(b), may indicate contami-
nated zero and dilution air, in which
case all results would tend to be on
one side of the 45' line.
Figure 12.15{e) illustrates a case in
which stations were calibrated using
a high concentration span level, but
not multipoint concentrations or zero
point.
The usfe of regression analysis is
not as straightforward when the in-
tercept is significantly different from
a
Audit Concentration
(a) Audit data from an ideal station.
Audit Concentration
(b) Systematic differences between
station values and audit
values.
Audit Concentration
(c) Linear and systematic differences
between station values and audit
values.
§
CJ
§
o
Audit Concentration
Audit Concentration
(d). (e) Differences resulting from inaccurate
calibration standard.
Figure 12.15. Multiple audit data variations.
zero and/or the correlation is low
(<0.995). In these instances, the audi-
tor must rely on his experience to
draw conclusions about the cause of
a high or low intercept, a low corre-
lation, and the subsequent meaning
of the results. The five most com-
monly encountered audit cases are
discussed in the following subsec-
tions.
Case 7 — The data set and data plot
in Figure 12.16 illustrates a case in
which the % difference and the linear
regression analysis of audit data
must be used jointly to characterize
analyzer performance. .Inspection of
the % difference for each audit point
shows large negative differences at
the low concentrations and small dif-
ferences at the upper concentrations.
The slope of the regression line indi-
cates an overall slope of +2.2% and
a significant intercept of -0.014. The
following statements apply to the re-
gression data.
1. Analyzer zero drift may have oc-
curred.
2. The dilution air source used to
calibrate the analyzer has a bias
(not of sufficient purity).
3. The calibration procedure used
by the operator is not correct.
-------
June 1984
39
Section 2.0.12
Table 12.11. Linear Regression Criteria
Slope
Excellent
Satisfactory ±6% -
Unsatisfactory
Intercept
Satisfactory
Unsatisfactory
s ± 5% between analyzer response and audit
concentration
± 75% between analyzer response and audit
concentration
~> ± 15% between analyzer response and audit
concentration
s ±3% of the analyzer range
> ±3% of the analyzer range
Correlation coefficient
Satisfactory ' 0.9950 to (1.0000) linear analyzer response to audit
concentrations
Unsatisfactory <0.9950 nonlinear analyzer response to audit
concentrations
Point No.
1
2
3
4
5
6 -- -
Audit
Concentration
fppmj
.000
.053
.119
.222
.269
.396
Station
Concentration
Ippm)
-.0/3
.043
.703
.203
. .263
.392
% Difference
—
-18.9
-13.5
- 6.3
- 2.2
• 1.0
.5
.4
I
.3
§
-------
Section 2.0.12
40
June 1984
Point No.
1
2
3
4
S
6
Audit
Concentration
(ppm)
.000
.053
.119
.222
.269
.396
' Station
Concentration
(ppm)
.000
.043
.103
.208
.263
.392
% Difference
_
-18.9
-13.S
- 6.3
• 2.2
• 1.0
o
1
8
I
.4
.3
,2
.1
Without Zero Incarcept
f * 0.3396
m = 1.026
b = 0.0/5
With Zero
Incercapt
r = 0.9991
m = 1.001
b = 0.009
_L
_L
Flgurt 12.17.
•I .2 .3
Audit Concentration (ppm)'
Audit data interpretation—Case 2.
.4
.6
and possibly a significant zero inter-
cept. A graphic plot will verify sus-
pected analyzer nonlinearity.
Case 5—The data illustrated in Fig-
ure 12.20 show the results of an
audit performed on a NOX analyzer.
The regression coefficients show an
overall difference between the audit
concentrations and analyzer re-
sponses of -20.0% and an intercept
of 0.011 ppm. The analyzer response
for the zero concentration and first
four audit concentrations shows a
constant bias which would be ex-
pected for the entire range. Percent
differences for the three remaining
audit levels become increasingly
large. A graphic plot of the audit data
indicates the analyzer converter effi-
ciency is decreasing with increasing
audit concentration.
12.13 References
1. 40 CFR 58, Appendix A—Quality
Assurance Requirements for
State and Local Air Monitoring
Stations (SLAMS), Ambient Air
Quality Surveillance.
2. Ref. 1. July 1, 1984.
3. 40 CFR 58, Appendix B—Quality
Assurance Requirements for Pre-
vention of Significant Deteriora-
tion (PSD) Air Monitoring.
4. Traceability Protocol for Establish-
ing True Concentrations of Gases
Used for Calibration and Audits
of Air Pollution Analyzers, (Proto-
col No. 2). June 15, 1978. Avail-
able from the U.S. Environmental
Protection Agency, Environmen-
tal Monitoring Systems Labora-
tory, Quality Assurance Branch
(MD-77), Research Triangle Park,
NC.
5. Protocol for Establishing Trace-
ability of Calibration Gases Used
With Continuous Source Emis-
sion Monitors. August 25, 1977.
Available from the U.S. Environ-
mental Protection Agency, Envi-
ronmental Monitoring Systems
Laboratory, Quality Assurance
Branch, (MD-77), Research Trian-
gle Park, NC.
6. Catalog of NBS Standard Refer-
ence Materials. NBS Special Pub-
lication 260, U.S. Department of
Commerce, National Bureau of
Standards, Washington, DC.
1984-85 Edition.
7. Transfer Standards for Calibration
of Air Monitoring Analyzers for
Ozone. Technical Assistance Doc-
ument. EPA-600/4-79-056, Envi-
ronmental Monitoring Systems
Laboratory, U.S. Environmental
Protection Agency, Research Tri-
angle Park, NC. September 1979.
8. Quality Assurance Handbook for
Air Pollution Measurement Sys-
tems, Volume II—Ambient Air
Specific Methods. EPA-600/4-77-
0273, Environmental Monitoring
Systems Laboratory, U.S. Envi-
ronmental Protection'Agency,
Research Triangle Park, NC.
9.' Investigation of Flow Rate Calibra-
tion Procedures Associated with
the High Volume Method for De-
termination of Suspended Partic-
ulates. EPA-600/4-78-047, Envi-
ronmental Monitoring Systems
Laboratory, U.S. Environmental
Protection Agency, Research Tri-
angle Park, NC. August 1978.
10. List of Designated Reference and
Equivalent Methods. Available
from the U.S. Environmental Pro-
tection Agency, Office of Re- ,
search and Development, Envi-
ronmental Monitoring Systems
Laboratory, Research Triangle
Park, NC.
11. Use of the Flame Photometric
Detector Method for Measure-
ment of Sulfur Dioxide in Ambi-
ent Air. Technical Assistance
Document. EPA-600/4-78-024,
U.S. Environmental Protection
Agency, Environmental Monitor-
ing Systems Laboratory, Re-
search Triangle Park, NC.
May 1978.
12. Technical Assistance Document
for the Chemiluminescence Mea-
-------
June 1984
41
Section 2.0.12
surement of Nitrogen Dioxide.
EPA-600/4-75-003, Office of Re-
search and Development, Envi-
ronmental Monitoring Systems
Laboratory, U.S. Environmental
Protection Agency, Research Tri-
angle Park, NC. December 1975.
13. Guidelines for Development of a
Quality Assurance Program—
Reference Method for the Contin-
uous Measurement of Carbon
Monoxide in the Atmosphere.
EPA-R4-73-028a, Office of Re-
search and Monitoring, U.S. En-
vironmental Protection Agency,
Washington, DC. June 1973.
14. Technical Assistance Document
for the Calibration of Ambient
Ozone Monitors. EPA-600/4-79-
057, Environmental Monitoring
Systems Laboratory, U.S. Envi-
ronmental Protection Agency,
Research Triangle Park, NC. Sep-
tember 1979.
Point No.
1
2
3
4
S
6
Audit
Concentration
(ppm)
.000
.056
.116
.221
.276
.405
Station
Concentration
(ppm)
•£13
.064
.132
.235
.282
.409
% Difference
14.3
13.8
6.3
2.2
1.0
r = 0.9997
m = 0.980
b = 0.014
.2 .3
Audit Concentration (ppm)
Figurt 12.13. Audit data interpretation—Case 3.
-------
Section 2.0.12
42
June 1984
Point No.
f
2
3
4
5
6
Audit
Concentration
(ppm)
.000
.072
.114
.183
.332
.474
Station
Concentration
(ppm)
.000
.054
.080
.134
.296
.503
% Difference
_
-25.0
-29.8
-26.8
-10.8
+ 6.2
r = 0.9899
m = 1.056
b = 0.029
0&-
I
Figura 12,19.
./ .2 .3
Audit Concentration (ppm)
Audit data interpretation—Case 4.
.4
.5
-------
June 1984
43
Section 2.O.I2
Point No.
1
2
3
4
5
6
7
8
Audit
Concentration
(pom)
.000
.056
.106
.206
.313
.417
.651
.885
Station
Concentration
Ippm)
.000
.049
.094
.180
.273
.355
.540
.703
% Difference
-12.5
-11.3
-12.6
-12.8
-14.9
-17.1
-19.7
1.0,
I
c
o
I
I
.8 -
.6 -
.4 -
r = 0.9991
m = 0.800
b = 0.011
0 .2 .4 .6
Audit Concentration (ppmj
Figure 12.20. Audit data interpretation—Case 5.
.8
1.0
-------
-------
-------
ilia*!.,"'' vu,1.'/ij
iiihr , i: iVjIUit 1
> ! n».-nfj:.n .•'':
".'.i.flE!W S'BH'liJ'., iH'i'lHI
il >>: Hrl.'liii.ViJ IK,- iilili' 1"'
ll'i'i'll B!,i,: •iS-.i'Hri'MSIiBI';-1!;
mwrn,'; ist^«»^
1 <'n .<: IBiip,«!'"! "I mlliiliii f: !i, liJiD1"! .: ii! -'i,
.,'/ r'l'lllil'1! ' .Hii'
>iiilliiii'"i>vi,:i>>l:i iii'i
^-i'i
\J1B5H11
-------
Jan.1983
Section 2.2.0
United States
Environmental Protection
Agency
Environmental Monitoring Systems
Laboratory
Research Triangle Park NC 27711
Research and Development
EPA-600/4-77-027a
&EPA
Test Method
Section 2.2
Reference Method for the
Determination of Suspended
Particulates
in the Atmosphere
(High-Volume Method)
Outline
Section
Summary
Method QA Highlights
Method Description
1. Procurement of Equipment
and Supplies
2. Calibration of Equipment
3. Filter Selection and
Preparation
4. Sampling Procedure
5. Analysis of Samples
6. Calculations and Data
Reporting
7. Maintenance
8. Auditing Procedure
9. Assessment of Monitoring
Data for Precision and
Accuracy
10. Recommended Standards for
Establishing Traceability
11. Reference Method
12. References
13. Data Forms
Summary
Ambient air drawn into a covered
housing and through a filter by a
high-flow-rate blower at 1.1 to 1.7
mVmin (39 to 60 ftVmin) allows total
Number of
Documentation Pages
2.2 ' !
2.2 T
2.2.1
2.2.2
2.2.3
2.2.4
2.2.5
2.2.6
2.2.7
2.2.8
2.2.9
2.2.10
2.2.11
2.2.12
2.2.13
13
4
8
1
2
2
4
1
1
10
1
10
suspended particulates (TSP) in sizes
up to 25 to 50 ^m (aerodynamic
diameter) to collect on the filter
surface. When operated within this
range, the high-volume sampler is
-------
Section 2.2.0
Jan. 1983
capable of collecting TSP samples for
24«hour TSP concentrations ranging
from 2 to 750 //g/std m3. The mass
concentration (/ug/m3)* in ambient air
is computed by measuring both the
mass of TSP collected and the
(standard) volume of air sampled.
This method provides a
measurement of the mass
concentration of total suspended
paniculate matter (TSP) in ambient air
for determination of compliance with
the primary and secondary National
Ambient Air Quality Standards for
Paniculate Matter as specified in
§50.6 and §50.7 of the Code of
Federal Regulations. Title 40. The
measurement process is
nondestructive, and the size of the
sample collected is usually adequate
for subsequent chemical analysis.
Based on collaborative testing, the
relative standard deviation (coefficient
of variation) for single analyst
precision (repeatability) of the method
is 3,0 percent. The corresponding
value for interlaboratory precision
(reproducibility) is 3.7 percent.
The absolute accuracy of the
method is undefined because of the
complex nature of atmospheric
paniculate matter and the difficulty in
determining the "true" paniculate .
matter concentration.
This reference method appears in
Title 40 of the Code of Federal
Regulations. Part 50. Appendix B (as
amended on December 6, 1982, (47
FR 54912), A complete copy of the
Reference Method is reproduced in
Section 2,2 11.
Method QA Highlights
In this quality assurance document
for the TSP Reference Method (high-
volume sampler method), the
procedures are designed to serve as
guidelines for the development of
agency quality assurance programs.
Because recordkeeping is a critical
part of quality assurance activities.
several data forms are included to aid
in the documentation of necessary
data The blank data forms (Section
2,2,13) may be used as they are, or
they may serve as guidelines for
preparing forms more appropriate to
the individual agency; partially filled-
m forms are interspersed throughout
the text to illustrate their uses.
Activity matrices at the end of
pertinent sections provide a review of
'AHhouijn TSP is measured in microqrams per
ftanrltVd cubic meter me "standard" is
'lommonly omitted when reporting TSP
s. ay convention, ;jq/mj for TSP is
to mean pg std m'
the material covered in the text
sections. The material covered in this
section for the TSP'method is briefly
summarized here.
1. Procurement of Equipment
Section 2.2.1 describes the selection
of equipment and the recommended
procurement and calibration checks
for the equipment. It also identifies
the sections of this part of the
Handbook that pertain to specific
equipment and supplies. Figure 1.1
provides an example of a permanent
procurement record.
2. Calibration of Equipment Section
2.2.2 provides detailed calibration
procedures for the analytical balance,
the relative humidity indicator, the
elapsed-time meter, the- flow-rate
transfer standard, and the high-
volume sampler. This section can be
removed (along with the
corresponding sections for the other
methods of this volume of the
Handbook) to serve as a calibration
handbook. Table 2.2 at the end of the
Section summarizes the acceptance
limits for equipment calibration.
3. Filter Selection and Preparation
Section 2.2.3 presents important
considerations for the selection,
identification, equilibration, weighing
check, and handling of filters. The
spectro-quality grade filter is
recommended for use when additional
chemical analyses are anticipated.
4. Sampling Procedure Section 2.2.4
details procedures for filter
installation, performance of
operational checks, sample handling,
and data documentation. Several
photographs are provided to clarify
the installation procedure. Complete
documentation of background
information during the sampling is
one of several quality assurance
activities that are important to future
data validation; particularly important
are any unusual conditions existing
during collection of the sample. Any
such conditions should be noted.
5. Analysis of Samples Section 2.2.5
briefly describes verification of data
from the field, sample inspection,
filter equilibration, and the gravimetric
analysis procedure. The analytical
balance must be checked. The filter
must be equilibrated in a controlled
environment.
6. Calculation and Data Reporting
Section 2.2.6 describes those
activities pertaining to data
calculations and reporting. The final
data review, the data edit or
validation, and the use of standardized
reporting procedures are all important
parts of a quality assurance program.
Independent checks of the data and
calculations are recommended to
ensure that the reported data are both
accurate and precise.
7. Maintenance Section 2.2.7
recommends periodic maintenance
schedules to ensure that the
equipment is capable of performing as
specified.
8. Assessment of Data for Accuracy
and Precision Sections 2.2.8 and
2.2.9 describe the assessment of the
data for accuracy and precision,
respectively. Independent audit
activities provide accuracy checks of
flow rate measurements, filter
weighings, and data processing.
The precision check is performed by
using collocated samplers. The
expected agreement between two
collocated samplers is ±15%.
9. Reference Information Section
2.2.10 discusses the traceability of
measurements to established
standards of higher accuracy, a
necessary prerequisite for obtaining
accurate data.
Sections 2.2.11 and 2.2.1 2 contain
the Reference Method and pertinent
references.
Section 2.2.13 provides blank data
forms for the convenience of the user.
-------
Jan.1983
Section 2.2.1
1.0 Procurement of Equipment and Supplies
Specifications for equipment and
supplies for monitoring ambient air for
total'suspended particulates (TSP) are
provided in the Reference Method, as
reproduced in Section 2.2.11.
Upon receipt of the sampling
equipment and supplies, appropriate
procurement checks should be
conducted to determine their
acceptability, and their acceptability
or rejection should be recorded in a
procurement log. Figure 1.1 is an
example of such a log, and Section
2.2.13 provides a blank copy for the
Handbook user. This log will serve as
a permanent record for future
procurements and for any fiscal
projections for future programs. It will
also help to provide continuity of
equipment and supplies. Table 1-1
provides a matrix of the activities
involved in the procurement of
equipment and supplies.
The following list of equipment,
apparatus, and supplies provides a
reference to sections and subsections
within this part of the Handbook to
guide the user to specific checkout
procedures. Here and throughout the
balance of the text, "section" refers to
the primary divisions of Section 2.2;
"subsection" refers to the
subdivisions within these sections.
Item
Section
Analytical balance
Relative humidity indicator
Elapsed-time meter
Timer
Flow rate transfer standard
Sampler
Filter
Sampler motor
Faceplate gasket
Rotameter
Sampling head
Motor gasket
Flow transducer and recorder
2.2.2
2.2.2
2.2.2
2.2.2
2.2.2
2.2.2
2.2.3
2.2.7
2.2.7
2.2.7
2.2.7
2.2.7
2.2.7
2.1
2.2
2.3
2.4
2.5
2.6
3.1, 3.3
7.1
7.2
7.3
7.4
7.5
'7.6
Table 1.1 A ctivity Matrix for Procurement of Equipment and Supplies
Equipment
Analytical balance
Elapsed-time meter
Timer
Orifice calibration unit (flow
transfer standard)
Sampler
Relative humidity indicator
Acceptance limits
Indicated weight =
standard weight rO.OOOS
g for three to five standard
weights over sample filter
weight range
24 h ~2 min
24 h x3Q min
Calibration flow rate —
actual flow rate ±2%
Sampler complete; no
evidence of damage: flow
-1.1-1.7 m3/min
Indicator reading -
psychrometer reading ±Q%
Frequency and method
of measurement
Action if
requirements
are not met
On receipt, check against
weights of known
accuracy.
On receipt, check against
standard timepiece of
known accuracy.
On receipt, check against
elapsed-time meter.
On receipt, check against
flow-rate primary standard.
On receipt, observe visually
and check operation of all
components.
On receipt, compare with
reading of a wet bulb/dry
bulb psvchrometer.
Request recalibration
by manufacturer/supplier.
Adjust or reject.
Adjust or reject.
Adopt new calibration
curve if no evidence of
damage: reject if damage
is evident.
Reject or repair.
Adjust or replace to attain
acceptance limits.
-------
Section 2.2.1
Jan. 1983
Item description
Hl-VOLSWHSl
Quantity
/z
/oo
Purchase
order
number
JJSJL
Vendor
' ~w*
Date
Ordered
&-/-75
6-/-T5
Received
(o ~IO~ 75
Cost
^/
Dispo-
sition
Ace.
Ace.
Comments
•
Figure 1.1. Example of a Procurement Log.
-------
Jan. 1983
Section 2.2.2
2.0 Calibration of Equipment
Before a TSP sampling program is
undertaken, a wide variety of
sampling and analysis equipment
must be calibrated. The calibration
activities are summarized in Table 2.2
at the end of this section. Many of
these activities will also serve as
initial acceptance checks. All data
and calculations required for these
activities should be recorded in a
calibration log book in which a
separate section is designated for
each apparatus and sampler used in
the program.
2.1 Analytical Balance
The calibration should be verified
(1) when the analytical balance is first
purchased, (2) any time it has been
moved or subjected to rough handling,
and (3) during routine operations
when a standard weight cannot be
weighed within ±0.5 mg of its stated
High-Volume Filter-Weighing Quality Control Log
C/ass-S weights, g
wefght. A set of three to five standard
weights covering the range normally
encountered in weighing filters should
be weighed. If the weighed value of
one or more of the standard weights
does not agree within —0.5 mg of the
stated .value, the balance should be
recalibrated or adjusted by the
manufacturer. The results of all
balance checks should be recorded in
a log book such as the one shown in
Figure 2.1.
Date
7/29/74
7/29/74
7/29/74
7/30/74
7/31/74
7/31/74
7/31/74
7/31/74
7/31/74
8/1/74
8/1/74 •
8/1/74
8/1/74 '
8/1/74
8/1/74 '
8/1/74
8/2/74
8/2/74
8/2/74
8/2/74
8/2/74
8/2/74
8/2/74
8/3/74
8/3/74
8/5/74
8/5/74
8/5/74
8/5/74
8/5/74
3/5/74
8/5/74
8/6/74
8/6/74
8/6/74
8/6/74
8/6/74
8/6/74
8/7/74
8/7/74
8/7/74
8/7/74
8/7/74
8/8/74
9/24/74
9/26/74
Time
1 1:07
12:08
2:40
4:03
9:57
10:56
1 1:57
2:04
3:05
9:03
10:05
11:10
12:12 :
7:43
2:42
' 3:45
8:54
9:56
10:59
12:16
1:55
3:03
4:00
8:41 •
11:15
8:42
9:45
10:44
1 1:46
1:16
2:21
3:15
9:37
1 1:05
12:10
2:10
3:09
4:05
8:50
9:46
1:10
2:20
3:25
9:46
3:50
3'OJ
0.5000
0.5000
0.5002
0.5000 .
0.4996
0.4997
0.4995
0.4996
0.5001
'0.5000
0.4998
0.4999
0.5000
0.4998 '
O.SOOO
0.5001
0.5001
0.5000
O.SOOO
0.5003
0.5001
0.4999
0.5000
O.SOOO
0.4999
0.5002
0.5001
O.SOOO
0.5000
0.5000
0.5OO1
0.5001
O.SOOO
0.4999
0.5000
0.4999
0.5000
O.SOOO
O.SOOO
0.5000
0.4996
0.5001
0.5001
0.5002
O.SOOO
0.5OO1
: _
1.0000
1.0002
1.0003
1.0000
09999
1.0000
. 0.9996
0.9998
1.0000
1.0000
0.9997
0.9997
1.0001
0.9997
1.OO01
1.0001
J.OOOO
1.0001
1.0000
0.9999
1.0002
. 1.0002
0.9999
0 9998
0.9996
1.0002
1.0000
1.0000
1.0000
1.00O1
1.0000
1.0000
1.0000
1.00OO
0.9998
0.9998
0.9998
J.OOOO
1.0000
1.0002
O.9998
1.0OOO
J.OOOO
1.0001
J.OOOO
1.00O1
1-°°01
2.0000
2:0000
2.0001
1 9999
2.0002
2.0000
1.9996
1.9998
2.0002
2 0000
1.9997
1.9997
2.0001
1.9998
2.0002
2.0001
2 000 1
2.0001
2,0001
1.9998
2.0002
2.0001
2.0O01
1 9999
1.9998
2 0002
2.0000
• 2.0000
2.0000
2.0000
2.0000
2.0001
2 0001
2.00OO
1.9997
1.9999
2.OOOO
2.0000
2 0000
2.0003
1.9996
2.0000
2.0000
2 0000
2 0000
2.0001
2. 000 1
Technician
BSM .
DEK
DEK
JLK
DEK
DEK
DEK
DEK
DE'K
DEK
DEK
DEK
DEK
DEK
DEK
DEK
DEK
DEK
DEK
DEK
DEK
DEK
DEK
DEK
DEK
DEK
DEK
DEK
DEK
DEK
DEK
DEK
DEK
DEK
DEK
DEK
DEK
DEK
DEK
DEK
Figure 2.1. Example of balance performance record.
-------
Section 2.2.2
Jan. 1983
2.2 Relative Humidity
Indicator"
The relative humidity indicator used
for monitoring the filter conditioning
environment should be checked
against a wet bulb/dry psychrometer
or the equivalent every 6 months. At
least a two-point calibration should be
made by comparing readings made in
the conditioning environment against
those made outdoors or perhaps just
outside of the conditioning room. If
the difference between the indicator
and the corresponding psychrometer
readings is within ±6%. it Is all right
to continue using the relative
humidity indicator; if not, the indicator
must be calibrated or a new one must
be purchased. Record the results of
(he relative humidity indicator checks
in the calibration log book.
2.3 Elapsed-Time Meter
Every 6 months the elapsed-time
meter should be checked against a
timepiece of known accuracy, either
on site or in the laboratory. If the
indicator shows any signs of being
temperature-sensitive, it should be
checked on site during each season of •
the year. A gain or loss >2 min/24-h
period warrants adjustment or
replacement of the indicator. The
results of these checks should be
recorded in the calibration log book.
2.4 On-Off Timer
The on-off timer should be
calibrated and adjusted quarterly by
using a calibrated elapsed-time meter
as the reference. An example
calibration procedure for one type is
presented below. Figure 2.2 depicts
the connection diagram for calibration
of a particular kind of timer. The steps
in the procedure are:
1, Plug a correctly wired timer into
an electrical outlet.
2. Set the timer to the correct time.
3. Set the on and off time-trippers
for a 24-h test.
4. Plug the test light into one of the
output plugs, and plug an •
elapsed-time meter into the
other,
5, Check the system by manually
turning the switch on and off.
6, Allow the system to operate for
the 24-h test period, and
determine the time elapsed on
the elapsed-time meter. If the
elapsed time is 24 h ±30 min, the
timer is acceptable for field use;
if not, adjust the tripper switches
and repeat the test. Record the
calibration data in a timer
calibration log such as that
shown in Figure 2.3. Section
Indicator Lamp
On-Off Timer
l± 15 min/24 h)
Elapsed- Time Meter
(±2 min/24 h)
Figure 2.2. Diagram of a timer calibration system.
2.2.13 provides a blank copy for
the Handbook user.
2.5 Flow Rate Transfer
Standard
Calibration of the high-volume
sampler's flow indicating or control
device is necessary to establish
traceability of the field measurement
to a primary standard via a flow-rate
transfer standard. The calibration
procedure provided here applies to a
conventional orifice-type flow transfer
standard. Other types of transfer
standards may be used if the
manufacturer or user provides an
appropriately modified calibration
procedure that has been approved by
EPA (see 40 CFR, Part 58, Appendix
C, Section 2.8).
Upon receipt and at 1 -year
intervals, the calibration of the
transfer standard orifices should be
certified with a positive displacement'
standard volume meter (such as a
Rootsmeter) traceable to the National
Bureau of Standards (NBS). Orifice
units should be visually inspected for
signs of damage before each use, and
they should be recalibrated if the
inspection reveals any nicks or dents
in the orifice.
The following equipment is required
for certification of an orifice transfer
standard.
1. Positive-displacement, standard
volume meter (such as Rootsmeter)
traceable to NBS.
2. High-volume air pump (high-
volume sampler blower).
3. Resistance plates or variable
voltage regulator.
4. Stopwatch
5. Thermometer
6. Barometer
7. Manometers [1 mercury (Hg), 1
water, or equivalent).
The following step-by-step
procedure for certification of an orifice
transfer standard is adapted from the
Reference Method.1 An orifice.
transfer standard certification
worksheet (Figure 2.4) is provided for
documentation of certification data.
1. Record on the certification
worksheet the standard volume meter
serial number; transfer standard type,
model, and serial number; the person
performing the certification; and the
date.
2.- Observe the barometric pressure
and record it as PI (item 8)..
3. Read the .ambient temperature in
the vicinity of the standard volume
meter and record it as T, (item 9) (K =
°C + 273).
4. Connect the orifice transfer
standard to the inlet of the standard
volume meter. Connect the mercury
manometer to measure the pressure
at the inlet of the standard volume
meter. Connect the orifice (water)
manometer to the pressure tap on the
orifice transfer standard. Connect a
high-volume air pump (such as a
high-volume sampler blower) to the
outlet side of the standard volume
meter. (See Figure 2.5 for an example
of the calibration setup.)
5. Check for leaks by temporarily
clamping both manometer lines (to
avoid fluid loss) and blocking the
orifice with a large-diameter rubber
stopper, wide cellophane tape, or
other suitable means. Start the high-
volume air pump and note any change
in the standard volume meter reading.
The reading should remain constant.
If the reading changes, locate any
leaks by listening for a whistling
sound and/or retightening all
connections, making sure that all
gaskets are properly installed.
-------
Jan. 1983
Section 2.2.2
•§ 2
•i 1
Ja-S
•Q
-------
Section 2.2.2
Jan. 1983
I
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AW
\Atinl or D (cm)
of water
2 1
2s*
S ads
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§
§
-------
Jan. 1983
Section 2.2.2
Mercury
Manometer
ft p
\ '<
"il
jj
lilj
g?;;
zn ,- >
n
Thermometer
Barometer
Orifice Transfer Standard
Positive
Displacement
Dial No. 5
Uncompensated
Variable
Voltage
Transformer
Figure 2.5. Example of orifice transfer standard calibration setup.
6. Check the level of the positive -
displacement meter table, and adjust
the legs if necessary.
7. After satisfactorily completing
the leak check, shut off motor,
unclamp both manometer lines, and
zero the water and mercury
manometers by sliding their scales
until the zero is even with the
meniscus, as illustrated in Figure 2.6.
8. Achieve the appropriate flow rate
through the system, either by means
of the variable flow resistance in the
transfer standard or by varying the
voltage to the air pump. (Use of
resistance plates is discouraged
because the leak check must be
repeated each time a new resistance
plate is installed.) At least five evenly
distributed different but constant flow
rates are required, at least three of
which must be in the specified flow
rate interval (1.1 to 1.7 mVmin [39-
60 ftVmin]).
9. Start the blower motor, adjust
the flow, and allow the system to run
for at least 1 min to attain a constant
motor speed. Observe the standard
volume meter dial reading and
simultaneously start the stopwatch.
Error in reading the meter dial can be
minimized by starting and stopping
the stopwatch on whole numbers
(e.g., 0046.00). .
10. Record the initial meter reading
(V,) in Column 1. Maintain this
constant flow rate until at least 3 m3
of air have passed through the
standard volume meter. Record the
standard volume meter inlet pressure
manometer reading as AP (Column 5),
and the orifice manometer reading as
AH (Column 7). Be sure to indicate
the correct units of measurement.
1 1. After at least 3 m3 of air have
passed through the system, note the
standard volume meter reading and
simultaneously stop the stopwatch.
Record the final meter reading (Vi) in
Column 2 and the elapsed time (t) in
Column 3.
12. Calculate the volume measured
by the primary standard volume meter
(Vm) at meter conditions of
temperature and pressure (using
Equation 1 of the work sheet) and
record in Column 4.
Vm = V, - V,
Equation 2-1
13. Correct this volume to standard
volume (std m3) by using Equation 2
of the work sheet:
Vsta = V,
, /PI . APV TsjA
V p- A T, /
Equation 2-2
where:
Vs,d = standard volume, std m3;
Vm = actual volume measured by
the primary standard volume
meter, m3 (Column 4 of work
sheet)
Pi = barometric pressure during
calibration, mm (in.) Hg (Item
8 of work sheet)
AP=differential pressure at inlet to
primary standard volume meter,
mm (in.) Hg (Column 5 of work
sheet)
Psia = 760 mm Hg (29.92 in. Hg)
. TSM = 298 K
Ti = ambient temperature during
calibration, K (Item 9 o.f work
sheet).
14. Calculate the standard
volumetric flow rate (std mVmin) by
using Equation 3 of the work sheet:
CUid = YJU<<
t Equation 2-3
where:
QSW = standard volumetric flow
rate, std mVmin at 760 mm
Hg and 298 K
t = elapsed time, minutes
15. Record Qstd to the nearest 0.01
std m3/min in column 6 of the work
sheet. Repeat steps 9 through 15 for
at least four additional constant flow
rates evenly spaced over the
approximate range of 1.0 to 1.8 std
mVmin (35-64 ftVmin).
16. For each flow, compute
\/AH (P,/P,,d) (298/T,) (Column 7a),
and plot these values against Qstd as
shown in Figure 2.7. Be sure to use
consistent units (mm or in. Hg) for
barometric pressure. Draw the orifice
transfer standard certification curve or
calculate the linear least squares
slope (m) and intercept (b) of the
certification curve:
\/AH (P,/P3,d) (298/T,) = m Q,,d + b.
A certification graph should be
readable to 0.02 std mVmin.
-------
Section 2.2.2
Jan. 1983
•3-r
• 2-\
• H
O-i
• 7
- 2 —
- 1 -
2-E
Mercury
Manometer
Zeroed ,__
, = 70mm
Water
Manometer
Zeroed
Figura 2.6. How to read mercury and water manometers.
40
3,0
2.0
10
-4-
•3
2 •
• ; •
o
=- t -
r 2~
=- 3-
4-
-3-
- 2-
^L-J
Mercury
Manometer
Reading
Pm = 7Omm
=• 0-
E-2-E
- 3 -
/>, = 3 //7.
Water
Manometer
Reading
P< = 3.0in.
0
o.o
Slope (m) = 2.062
Intercept fb) = -0.056
I I I I I i i i l M i i i I i i i i I i i i i I i i t i I i i i i I
_1_L
17. If any calibration point does not
fall within ±2% of the line, rerun that
point, recalculate, arid replot. The
percent deviation can be calculated by
comparing each Y from Column 7a
against the corresponding Ycai
calculated from the slope and
intercept using Equation 2-4:
std + b
Equation 2-4
The percent deviation 'for each point is
then calculated using Equation 2-5.
% deviation =Y - Ycai Y 1 00
Yca,
Equation 2-5
18. For subsequent use- of the
transfer standard, calculate Qsia as
m x. f
Equation 2-6
or determine Q5td for each value of:
J\
0,25 O.50 Q.75 1.00 1.25 1.50
1.75
Figure 2.7, Example of on/ice transfer standard calibration relationship.
JWV T2 ,
from the certification graph.
where:
P2 = barometric pressure at time of
2.00 Hi-Vol calibration
TZ = temperature at time of Hi-Vol
calibration
-------
Jan. 1983
Section 2.2.2
2.6 Calibration of High-
Volume Sampler
Each high-volume sampler must
incorporate a flow rate measurement
device capable of indicating the total
sampler flow rate. This device may be
an electronic mass flowmeter, an
orifice or orifices located in the
sample air stream together with a
suitable pressure indicator (such as a
manometer or an aneroid pressure
. gauge), or any other type of flow
indicator (including a rotameter)
having comparable precision and
accuracy. It must be possible to
calibrate the flow rate measurement
device to a flow rate that is readable
(in corresponding units) to the nearest
0.02 std mVmin. A pressure recorder
with an orifice device that provides a
continuous record of the flow may be
used.
The concentration of TSP in the
ambient air is-computed as the mass
of collected particles, divided by the
volume of air sampled, corrected to
standard conditions of 760 mm Hg
and 298 K, and then expressed in
micrograms per standard cubic meter
(fjg/sld m3). When samples are
collected at temperatures and
pressures significantly different from
standard conditions, the corrected
concentrations may differ
substantially from actual
concentrations (micrograms per actual
cubic meter), particularly at high
elevations.
Calibration of a high-volume
sampler refers to calibration of the
sampler's flow rate indicator so that it
provides accurate measurements of
the sample flow rate from which the
volume of the sampled air can be
calculated. Details of the calibration
procedure vary somewhat depending
on (1) the type of flow indicator used,
(2) whether the sampler is equipped
with an automatic flow controller, and
(3) whether the calibration is to
incorporate the geographical average
barometric pressure and seasonal
average temperature at the sampling
site. The basic procedure for nonflow-
controlled samplers is given in
Subsection 2.6.2, whereas the
variations in the procedure necessary
for flow-controlled samplers are
presented in Subsection 2.6.3.
Orifice-type flow indicators are
sensitive to changes in both
temperature and barometric pressure.
Because ambient temperature and
barometric pressure vary from day to
day, the calibration procedure
contains a formula to correct for this
variability. Errors resulting from
normal daily fluctuation are relatively
small, however, compared with
barometric differences due to
elevation and seasonal temperature
changes. Thus, if the modest errors
due to daily changes are acceptable,
the average barometric pressure for a
given elevation and the seasonal
average temperature for that location
can be incorporated directly into the
sampler calibration with little error
being introduced in the calculated
flow rate.
When this is done, the sampler is
calibrated for the average temperature
and pressure conditions at the site,
and no further temperature or
pressure corrections are needed for
the flow indicator reading to be used
to determine the sampler flow rate.
The relationship between the flow
indicator reading and the standard
volume flow rate then becomes a very
simple one. This relationship also can
be easily reduced to a simple three-
column table (indicator reading,
winter flow rate, and summer flow
rate) suitable for use even by
nontechnically oriented operators.
The average barometric pressure for
a site can be estimated from the
altitude of the site, either by using an
altitude-pressure table or by reducing
the sea level pressure of 760 mm Hg
by 26 mm Hg for each 305 m (1000
ft) of altitude. The average pressure
could also be determined by averaging
onsite barometer readings or nearby
weather station or airport
measurements (station pressure,
uncorrected) over several months. The
seasonal average temperature for a
site can be estimated from onsite
temperature readings or nearby
weather station records over the
season. Ideally; the average
temperature should reflect the
temperature at the time of day at
which the flow indicator would
normally be read; however, an
average determined from 24-hour
mean temperature records would be
acceptable. For most sites, two
seasonal average temperatures
(summer and winter) are sufficient;
for sites where climatic changes are
severe, however, four seasonal
average temperatures may be needed
to accommodate the changes. Where
computers are used to process TSP
data, monthly average temperatures
could be used. Ideally, the
seasonal average temperature
should generally be within ±15°C of
the local ambient temperature at the
time the flow indicator is read. If daily
temperature changes at the site are
too drastic to be represented by a
seasonal average (±15°C) actual
temperature corrections should be
used each time a flow reading is-
obtained.'
Once a decision has been made on
whether to incorporate an average
barometric pressure and a seasonal
average temperature into the
calibration, the appropriate expression
for plotting or calculating the sampler
calibration can be selected from Table
2-.1. The use of this expression is
explained in Subsection 2.6.2.
2.6.1 Calibration Schedule - High-
volume-sampler flow-rate devices
should be calibrated with a certified
flow-rate transfer standard such as an
orifice calibration unit (1) upon
receipt, (2) after motor maintenance,
(3) any time the flow rate device is
repaired or replaced, and (4) any time
the difference between the sample
flow rate and a one-point audit
deviates more than ±7 percent.
2.6.2 Sampler Calibration Procedure
- The procedures for multipoint
calibration of a high-volume sampler
are specified in 40 CFR 50, Appendix
B (reproduced in Section 2.2.11). To
facilitate these procedures, calculation
data forms have been developed to aid
-in making the calibrations. These
forms also may be used for the
calibration of other types of high-
volume flow measuring devices.
Table 2.1. Expressions for Plotting Sampler Calibration Curves
Type of sampler For actual pressure For incorporation of
flow rate measuring
device
and temperature
corrections
Mass flowmeter
Orifice and pressure
indicator
Rotameter, or orifice
and pressure
recorder having
square root sca/e"
geographic average pressure and
seasonal average temperature
I
I
IP2\(298
"This scale is recognizable by its nonuniform divisions: it is the most commonly
available for high-volume samplers.
-------
8
•*-*-•
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Jan. 1983
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with f " SamP'ers
may be ca SW C0ntro"''"9
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ca'/bration, th^ ?nCiCator- After
m-echan/s -
,
-------
Jan. 1983
Section 2.2.2
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-------
Section 2.2.2
10
Jan. 1383
6O.O
50.0
4O.O
30.0
20,0
70,0
Slope (m) = 32.773
Intercept = 3.3'51
Corr. Coff. = .9991
i I I f i i I l i i i I i ill Mi i
0,0 0.25 0.50 0.75 7.00 7.25 /.50 7.75 2.00
Flgura 2.9. Example of a high-volume sampler calibration relationship.
provided the previous operating
history of the sampler demonstrates
that the flow rate is stable and
reliable, In this case, the flow
indicator may remain uncalibrated,
but it should be used to indicate any
relative change between initial and
final flows, and the sampler should be
recalibrated more often to minimize
potential loss of samples because of
controller malfunction. The following
procedures should be used.
1, Set the flow controller for a flow
near the lower limit of the flow range
(1.1 std mVmin) to allow maximum
control range.
2, Install a clean filter in the
sampler and carry out steps 2 through
5 and 7 through 9 of Subsection 2.6.2.
No resistance plate should be used
with the flow rate transfer standard.
3, Following calibration, add one or
two additional clean filters to the
sampler, reconnect the transfer
standard, and operate the sampler to
verify that the controller maintains the
same calibrated flow rate; this is
particularly important at high
altitudes, where the flow control
range may be reduced.
following procedures may be used.
(Refer to Figure 2.11, a photographic
copy of the rotameter, to identify the
working components in this
procedural step for adjusting the
rotameter.)
1. Attach the rotameter to the high-
volume sampler motor.
2. Turn on motor and adjust to
selected flow rate.
3. If adjustment is necessary, hold
the rotameter vertically and loosen
the locking nut by turning it
counterclockwise.
4. Turn the adjusting screw to the
desired setting (clockwise to lower the
ball, or counterclockwise to raise the
ball).
5. Be sure the ball continues to
read the desired setting after the
adjustment is made and as the locking
nut is tightened.
6. Seal both the locking nut and the
adjustment screw with glue to as-sure
that the setting does not change. Do
not cover the exhaust orifice. . '
7. Proceed with calibration of
rotameter as specified in Subsection
2.6.2.
2.6.4 Rotameter Calibration
Procedure • High-volume samplers
equipped with rotameters are
calibrated by using the same
procedures and forms as specified in
Subsection 2,6 2. Should adjustment
of the rotameter be necessary, the
-------
Jan. 1983
Section 2.2.2
2. 7 0.
anrf or/y/ce- on/f assembled for 'calibration with flow
-------
Section 2.2.2
12
Jan. 1983
Spring-Clip
Backing Plate
Spring-Clip Support
Adjusting Screw
Locking Nut
Exhaust Orifice
Tapered Plastic Tube ~
Scale
Inlet Port
Ball
Base Screw
Backing Plate - V
Figure 2,11. Example of high volume sampler rotameter.
-------
Jan. 1983
13
Section 2.2.2
Table 2.2. Activity Matrix for Calibration of Equipment
Equipment
Acceptance limits
.Frequency and method
of measurement
Action if
requirements
are not met
Analytical balance
Relative humidity indicator
On-off timer
Elapsed-time meter
Flow-rate transfer standard
Sampler
Indicated weight = true
weight ±0.0005 g
Indicator reading =
psychrometer reading ±6%
±30 min/24 h
±2 min/24 h
Indicated flow rate (from
previous calibration) =
actual flow rate ±2%
Indicated flow rate = actual
individual calibration
points ±5% of linearity
Gravimetvic test-weighing
at purchase and during
periodic calibration checks;
use three to five standard
weights covering normal
range of filter weights.
Compare with reading of
wet bulb/dry bulb psychro-
meter on receipt and at
6-mo intervals.
Check at purchase and
quarterly with elapsed-
time meter.
Compare with a standard
timepiece of known
accuracy at receipt and at
. 6-mo intervals.
Check at receipt and at 1 -yr
intervals against positive-
displacement standard
volume meter; recalibrate
or replace orifice unit if
damage is evident.
Calibrate with certified
transfer standard on
receipt, after maintenance
on sampler, and any time
audit deviates more than
4.70/1
Have balance repaired
and/or. recalibrated.
Adjust or replace to attain
acceptance limits.
Adjust or repair.
Adjust or replace time
indicator to attain accept-
'ance limits.
Adopt new calibration
curve.
Recalibrate.
-------
-------
Jan. 1983
Section 2.2.3
3.0 Filter Selection and Preparation
Suppliers of glass fiber filters for
measurement of TSP have two grades
of materials—the standard or
traditional grade that has been in use
for more than 20 years and a spectro-
quality grade. Because the spectro-
quality grade contains less organic
and inorganic contaminants, it is
recommended for use where
additional chemical analyses are
anticipated. A filter with low surface
. alkalinity is preferred to avoid positive
interferences from absorption of acid
gases while sampling. Ideally, surface
alkalinity should be between pH 6.5
and 7.5; however, most commercially
available glass fiber filters have a pH
of >7.5. Filters having a pH of
between 6 to 10 are acceptable. An
activity matrix for filter selection and
preparation is presented as Table 3.1
at the end of this section.
3.1 Selection
Only filters having a collection
efficiency of >99 percent for particles
of 0.3-pm diameter (as measured by
the OOP tesrASTM-D2986-71) are to
be used. The manufacturer should be.
required to furnish proof of the
collection efficiency of a batch of new
filters. The collection efficiency should
be recorded in the procurement log.
Figure 1.1 of Section 2.2.1.
Each filter should be visually
inspected using a light table. Loose
fibers should be removed with a soft
brush. Discard or return to the
supplier the filters with pinholes and
other defects-such as tears, creases,
or lumps.
3.2 Identification for Filters
Not Numbered by the
Supplier
A serial number should be assigned
to each filter. The number should be
stamped on two diagonally opposite
corners—one stamp, on each side of
the filter. Gentle pressure should be
used in application to avoid damaging
the filter.
3.3 Equilibration
Each-filter should be equilibrated in
the conditioning environment for 24 h
before weighing to minimize errors in
the weight; longer periods of
equilibration will not affect accuracy.
The conditioning environment
temperature should be between 15°
and 30°C (59° to 86°F) and should
not vary more than ±3°C (5°F); the
relative humidity (RH) should be
<50% and not vary more than ±5%. A
convenient working RH is 40%.
3.4 Weighing
Clean filters are usually processed
in lots—that is, several at one time.
Clean filters must not be folded or
creased prior to their weighing or use.
Before the first filter is weighed, the
balance should be checked by
weighing a standard Class-S weight
of between 3 and 5 g. Actual and
measured weights, the date, and the
operator's initials should be recorded,
as shown in Figure 2.1.
, If the actual and measured values
differ by more than ±0.5 rng (0.0005
g), the values should be reported to
the supervisor before proceeding. If
the actual and measured values agree
within ±0.5 mg, each filter should be
weighed to the nearest milligram.
Each filter should be weighed within
30 seconds after removing it from the
equilibration chamber, and the tare
weight and the serial number of each
filter should be recorded in the
laboratory log (Figure 3.1). Section
2.2.13 contains a blank copy of Figure
3.1 for the Handbook user. Note:
Silicone-treated high volume filters
have been found to have a static
charge problem. This problem can be
eliminated by placing an antistatic
device containing a low-level alpha
radiation source within the balance
chamber. These devices are
commercially available.
3.5 Handling
A quantity of filters sufficient for a
>3-mo period for each sampler should
be numbered and weighed at one
time. Pack the filters in their original
container (or a box of similar size) so
that each filter is separated by a sheet
of SVz-by-l 1 -in. tracing paper. Be sure
the filters are stacked in the box in
numerical order so that the operator
will use the proper filter first.
In addition to the filters, the field
operator should be supplied with
preaddressed return envelopes to
protect the filters during mailing;
these can be printed front and back to
serve as a sample record data form,
as shown in Figure 3.2. Section
2.2.13 contains a blank copy of Figure
3.2 for the Handbook user.
-------
Section 2.2.3
Jan. 1983
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-------
Jan. 1983
Section 2.2.3
Comments
Figure 3.2. Hi- Vol field data form.
Hi-Vol Data Record
Project
Station
Site and/or Sampler No.
SAROAD Site Code
Sample Date
Filter No.
Flow Reading initial
final _
Average Flow Rate .
Running Time Meter initial
final _
Total Sampler Time
Total'Air Volume
Net TSP Weight
TSP Concentration
Optional
Temperature
initial .
finaJ
average
Operator
. std m3
. fjg/stcf mj
Barometric Pressure
-------
Section 2.2.3
Jan. 1983
TabtaS. 1. Activity Matrix for Filter Selection and Preparation
Activity
Acceptance limits
Frequency or method
of measurement
Action if
requirements
are not met
Selection and collection
efficiency
Integrity
Identification
Equilbration
Weighing procedure
Handling
Efficiency of>99% in 0.3-
pm diameter particle
collection.
Nopinholes, tears, creases.
etc.
Identification number in
accordance with specifica-
tions
Equilibration in controlled
environment for >24 h;
constant humidity chamber
With FtH of <50%
constant within ±5%;
temperature between 15°
and 3O°C with less than
±3°C variation
Indicated filter weight
determined to nearest mg
within 30 s after removing
'from the equilibration
chamber.
Filter in protective folder:
envelopes undamaged.
Manufacturer's proof of
OOP testASTM-D2986-71
Visual check of each filter
with tight table
Visual check of each filter
The room or chamber
conditions and the equili-
bration period a re observed
for each sample.
Observation of weighing
procedure.
Visual check of each filter.
Reject shipment or return
to supplier.
Discard filter.
Identify properly or discard
filter.
Repeat equilibration.
Reweigh after re-equilibra-
tion.
Replace undamaged filters.
discard damaged filters
-------
Jan. 1983
Section 2.2.4
4.0 Sampling Procedure
The activity matrix presented as
Table 4.2 at the end of this section
summarizes the sample collection
activities and the operational checks.
4.1 Filter Installation
Care must be taken to assure that
the clean weighed filters are not
damaged or soiled prior to installation
in the high-volume sampler. They
should be kept in a protective folder or
box and must not be bent or folded.
The use of filter cassettes (Figure 4.1)
that can be loaded and unloaded in
the laboratory may be used to
minimize damage to the filter.
Damaged or soiled filters must be
discarded.
The following procedures are used
to install a filter.
1. Open the shelter and remove the
faceplate of the sampler by loosening
the four wingnuts and swinging the
bolts outward.
2. Wipe all dirt from the support
screen and faceplate.
3. Center the filter with the rough
side up on the wire screen so that the
gasket will form an "airtight seal on
the outer edge (1 cm) of the filter
when the faceplate is in position.
When aligned correctly, the edges of
the filter will be parallel both to the
edges of the screen behind it and to
the faceplate gasket above it. Poorly
aligned filters show uneven white
borders {Figure 4.2) around the filter.
4. Tighten the four wingnuts just
enough to prevent leakage when the
filter is aligned and the faceplate is in
Figure 4.1. High volume sampler filter cartridge assembly.
place. Excessive tightening may cause
the filter to stick or permanently
damage the gasket.
5. Close the shelter and run the
sampler for at least 5 min to establish
run-temperature conditions.
6. Record the flow indicator reading
and, if needed, the barometric
pressure (P3 maiai) and the ambient
temperature (T3 imnai), then stop the
sampler. Note: No onsite pressure or
temperature measurements are
necessary if the sampler flow
indicator does not require pressure or
temperature corrections (e.g., a mass
flowmeter) or if average barometric
pressure and seasonal average
temperature for the site have been'
incorporated into the sampler
calibration. For individual pressure
and temperature corrections, the
ambient pressure and temperature at
the time of the flow indicator reading
can be obtained by onsite
measurements or from a nearby
weather station. Barometric pressure'
readings obtained from airports must
be station pressure, not corrected to
sea level, and may need to be
corrected for differences in elevation
between the sampler site and the
airport. For samplers having flow
recorders but not constant flow
controllers, the average temperature
and pressure at the site during the
sampling period should be estimated
from U.S. Weather Bureau or other
available data.
7. Determine the flow rate from the
sampler's calibration relationship
(Subsection 4.4) to verify that it is
operating within the acceptable range
of 1.1 to 1.7 mVmin (39-60 ftVmin).
If not within this range, use a
different filter or adjust the sampler
flow rate. Warning: Substantial flow
adjustments may affect the calibration
of orifice-type flow indicators and may
necessitate their recalibration.
• 8. Record the sample identification
information (filter number, site
location or identification number,
sample date) and the initial flow rate
(or flow indicator reading and
temperature .and barometric pressure
if needed) on the Hi-Vol field data
form (Figure 4.3). See Subsection 4.7
for proper documentation.
,9. Set the timer to start and stop
the sampler such that the sampler
runs 24 hours, from midnight to
midnight local time.
-------
Section 2.2.4
Jan. 1983
Figure 4.2, Nonunifarm borders resulting from poorly aligned filters.
4.2 Retrieval of Exposed
Filter and Post-Sampling
Checks
1 As soon as practical following
the sampling period, run the sampler
lor ai least 5 mm to reestablish run-
temperature conditions.
2. Record the flow indicator reading
and. if needed, the barometric
pressure (P3 i,n=i) and the ambient
temperature (T3 lmai).
3. Stop the sampler, remove the
faceplate, and lift the exposed filter
from the supporting screen by
grasping it gently at the ends, not at
the'corners.
4. Check the filter for signs of air
leakage. Leakage may result from a
worn faceplate gasket (Figure 4.4) or
from an improperly installed gasket. If
signs of leakage are observed, void
the sampler, determine the cause, and
take corrective actions before starting
another sampling period. A gasket
generally deteriorates slowly; thus the
operator can decide well in advance
(by the increased fuzziness of the
sample outline) when to change the
gasket before a total failure results.
5. Visually inspect the gasket face
to see if glass fibers from the filter are
being left behind due to
overtightening of the faceplate
wingnuts and the consequent cutting
of the filter along the gasket interface.
6. Check the exposed filter for
physical damage that may have
occurred during or after sampling.
Physical damage after sampling would
not invalidate the sample if all pieces
of the filter were put in the folder;
however, sample losses due to
leakages during the sampling period
or losses of loose particulates after
sampling (e.g., loss when folding the
filter) would invalidate the sample, so
mark such samples "void" before
forwarding them to the laboratory.
7. Check the appearance of the
particulates. Any changes from
normal color, for example, may
indicate new emission sources or
construction activity in the area. Note
any change on the filter folder along
with any obvious reasons for the
change.
8. Fold the filter lengthwise at the
middle with the exposed side in; if the
collected sample is not centered on
the filter (i.e., the unexposed border is
not uniform around the filter), fold so
that only the deposit touches the
deposit. Results of an improperly
folded filter are illustrated in Figure
4.5, where smudge marks from the
deposit extend across the borders; this
can reduce the value of the sample if
the analyses for which the sample
was collected need to be divided into
equal portions.
9. Place the filter in its numbered
folder.
10. Determine the final flow rate
from the sampler's calibration
relationship (see Subsections 4.3 and
4.4) and record it on the data record
along with other pertinent information
(see Figure 4.3).
11. Remove the sampler's flow
recorder chart and place the chart
inside the filter folder with the inked
side against the folder and the
backside against the filter.
4.3 Flow Readings
4.3.1 Rotameters -Jo obtain a valid
measurement, make flow rate
-------
Jan. 1983
Section 2.2.4
Project
Station
Hi-Vol Data Record
SPC.CIAL 3TUM
Comments
CITY
CUEAN//V6 ON.
Site and/or(
SAROADSiU Code
. Sample Date
Filter No.
Flow Reading initial '•
final /'
Average Flow Rate
/
Running Time Meter initial OOOO
final
Total Sampler Time
Total Air Volume, /o69!>
Net TSP Weight Q.
. std m3
TSP Concentration /5
Optional
. fjg/std m3
Temperature
Barometric Pressure
initial
final
, average
Operator
Figure 4.3. Example of completed Hi-Vol field data form.
measurements while the sampler is at
normal operating temperature, after a
warmup time of >5 min.
1. Connect the rotameter to the
sampler with the same tubing used
during calibration, and place or hold
it in a vertical position at eye level.
2. Read the widest part of the float
(ball), and use the calibration
, relationship (see Subsection 4.4) to
convert the reading to Qstd (mVmin)
and record to the nearest 0.025ta
mVmin.
3. Measure the flow rates at the
beginning and end of each sampling
period. Observe the flow rate for >1
min after connecting the rotameter to
the sampler, before taking a reading. If
a gradual change in flow rate is
observed, do not take a reading until
equilibrium is reached; a gradual
change is usually observed when the
rotameter is at a substantially
different temperature from that of the
sampler exhaust air, and thus
equilibration may require 2 or 3 min.
4.3.2 How Recorders - The
following procedure is for a high-
volume sampler equipped with a flow
recorder.
2. Remove any moisture by wiping
the inside of the recorder case with a
clean cloth. Carefully insert the new
chart into the recorder without
bending the pen arm beyond its limits
of travel. An easy way to do this is to
raise the pen head by pushing in on
the very top of the pen arm with the
right hand while inserting the chart
-------
Section 2.2.4
Jan. 1983
Figura 4.4. Example of air leakage around the filter due to worn faceplate gasket or to
improper installation.
with the left hand Be careful not to
damage or weaken the center tab on
the chart, but be sure the.tab is
centered on the slotted drive so that
the chart will rotate the full 360
degrees in 24 h without binding or
slipping. A properly installed chart is
shown in Figure 4.6.
3. Check to see that the pen head
rests on zero (i.e., the smallest circle
diameter on the chart). If not, tap the
recorder lightly to make certain that
the pen arm is free.
4. Check the time indicated by the
pen. If it is in error, rotate the chart
clockwise by inserting a screwdriver
or coin into the slotted drive in the '
center of the chart face until the time
is correct. If the sampler is started
with a timer switch, the correct time
is the starting time on the timer
(usually midnight).
5. Using an eyedropper, put a small
amount of ink into the hole in back of
the pen. tip. Use of cartridge-type pens
will, minimize problems with inking.
6. Turn the sampler on (never turn
it on until a filter is in place because
the transducer and recorder may be
damaged), and observe it long enough
to know whether the transducer and
recorder are operating properly.
4.4 Determination of Flow
Rates
High-volume sampler flow rate
readings must be converted to units of
std mVmin (25°C, 760 mm Hg) for
use in calculating TSP concentrations.
Expressions for converting sampler
flow rate readings (I) to standard
conditions are .given in Table 4.1.
Instructions for the use of this table
and the flow measuring device
calibration relationships (Figures 2.8
or 2.9) to obtain the sampling flow
. rate Qjtd (mVmin) are given in
Subsections 4.4.1 and 4.4.2.
No onsite pressure or temperature
measurements are necessary if the
sampler flow indicator does not
require pressure or temperature
corrections (e.g., a mass flowmeter) of
if average barometric pressure and
seasonal average temperature for the
site have been incorporated into the
sampler calibration. For individual
pressure and temperature corrections,
the ambient pressure and temperature
at the time of flow indicator reading
can be obtained by onsite
measurements or from a nearby
weather station. Barometric pressure:
readings obtained from airports must •
be station pressure, not corrected to
sea level, and may need to be
corrected for differences in elevation
between the sampler site and the
airport. For samplers having flow
recorders but not constant flow
controllers, the average temperature
and pressure at the site during the
sampling period should be established
from Weather Bureag or other
available data.
4.4.1 , Samplers Without Continuous
Flow Recorders - For a sampler
without a continuous flow recorder,
determine the appropriate expression
to be used (from Table 4.1)
corresponding to the one used in
calibration (from Table 2.1). Using this
appropriate expression, determine Qsta
for the initial flow rate from the
sampler calibration curve, either
graphically or from the transposed
regression equation (see Figure 2.8):
Q5td=J_ ([Appropriate expression from
m Table 4.1 ] - b)
Equation 4-1
Similarly, determine Qstd from the
final flow reading, and calculate the
average flow.Qstd as one-half the sum
of the initial and final flow rates.
4.4.2 Samplers With Continuous
Flow Recorders - For a sampler with a
continuous flow recorder, determine
the average flow rate reading (I) for
the period. Determine the appropriate
expression from Table 4.1
corresponding to the one used in
calibration (from Table 2.1). Then
using this expression and the average
flow rate reading, determine Q3ld from
the sampler calibration relationship,
either graphically or from the
-------
Jan. 1983
Section 2.2.4
Figure 4.5. Example of smudged filter border resulting from an improperly folded filter.
Table 4.1. Expressions for Determining Flow Rate During Sampler Operation
Expression .__
For use when geographic.
average pressure
Type of sampler For actual pressure
flow rate measuring and temperature
device corrections
Mass flowmeter /
Orifice and pressure \l 1 ( P* \/25S\
indicator y [ p )\ j )
Rotameter. or orifice
and pre<;<:i/rf>
recorder having . /\l/P3\/298\
square root scale * y \ pM J\f3)
'This scale is recognizable by its nonuniform divisions
available for high-volume samplers.
temperature have been
incorporated into the
sampler calibration
1
1
and is the most commonly
transposed regression equation (see
Figure 2.8 and Equation 4-1 above):
If the trace shows substantial flow
change during the sampling period,
greater accuracy may be achieved by
dividing the sampling period into
intervals, calculating an average
reading for each interval, determining
• Q5td for each interval, and finally
•computing the average Qstd for the
whole sampling period.
Calculate the total air volume
sampled by the following equation:
V = Qstd t Equation 4-2
where: .
V= total .air volume sampled, in •
standard volume units (std m3.);
Qstd = average standard flow rate, std
mVmin;
t = sampling time, min.
4.5 Sampling Flow Rate
Checks
The two types of sampling flow rate
checks recommended are discussed in
the following Subsections (4.5.1 and
4.5.2).
4.5.1 Initial Flow Rate Check - Initial
flow rate measurements should be
monitored for each sampler to
determine whether corrective action is
needed.
1. Record the initial and final flow
rates for each sample in the log book
maintained with the sampler. A
sampler equipped with a continuous
recorder should be observed for at
least 5 min. before the initial flow rate
is recorded.
2. Average the initial flow rate
measurements for the first four
samples after each calibration. Check
future initial flow rates that deviate
more than ±10% from this average
for samplers on which a manometer
or a flow recorder is used and ±15
percent for samplers on which a
rotameter is used. If the change has
been gradual over time, recalibrate. If
large deviations occur between
successive samples, repeat the flow
reading after 5 minutes. If the second
reading is within the above limits,
continue normal operations; if not,
check the line voltage and/or replace
the filter.
3. Perform a calibration check if
neither of the above checks identifies
the trouble. If the calibration check is
satisfactory, continue normal
operations; if not, perform a complete
calibration.
4.5.2 Operational Flow Rate Check -
It is recommended that a one-point
operational flow check be made on
each sampler at least once every 2
weeks. The purpose of this check is to
-------
Section 2.2.4
Jan. 1983
•> * r^~ I . ' ™ , s"•. r9
/-,/ ;-^..^ -^
ILT-U^M
Figure 4.6. Flow rats recorder with chart installed.
track the in-control conditions of the
sampler calibration. The same flow
rate transfer standard used to
calibrate the high-volume sampler
may be used for the operational flow
check.
1, Operate the sampler at its
normal flow rate with flow check
device in place. Determine Q,,a' for the
check point from the calibration of the
flow check device, and determine the
measured flow rate from the
sampler's calibration (see Subsections
4 3, and 4.4) Use the following
procedure for plotting the check data.
2. Calculate the percentage
difference (% D) between the known
check flow measurement and the flow
measured by the sampler's normal
flow indicator (Equation 4-1). Let Qa
represent the known flow rate and Qm
the measured flow rat'e for the flow
check:
=/
\
Equation 4-3
Thus if Qm = 1.48 mVmin and Qa =
1.42 mVmm
then:
% D =/
i =/1.48 - 1.42\
V 1.42 /
100 = +4%
If the % D is not within ±7 percent for
any one check, recalibrate before
resuming the sampling.
3. Record the Qm. the Qa, and the %
D on an X-and-R chart (Figure 4.7)
under "Measurement Result. Items 1
and 2." Record the % D in the cells
preceded by the "Range R." The % D
can be positive or negative, so retain
the sign of the difference, since it may
indicate trends and/or consistent
biases. More information on the
construction of a quality control chart
and the interpretation of the results
are in Appendix H, Volume I of this
Handbook.2
4. Repeat the above for each
operational flow rate check, plot all
points on the chart, and connect the
points by drawing connecting lines.
Tentative limits are ^4.7 percent
(warning lines) and ±7 percent (out-
of-control lines). Out-of-control points
indicate possible problems in
calibration or instrument errors. When
out-of-control results are obtained,
recalibrate the sampler prior'to further
sampling. After 15 to 20 points are
plotted, new control and warning
limits may be derived, as described in
Appendix H of Volume I of this
Handbook.2 Do not increase the
control and warning limits; however,
more stringent limits may be
established. _
5. Forward the X-and-R chart to the
QA supervisor for review.
4.6 Time Measurements
Start and stop times for samplers
not equipped with a timer switch or
an elapsed-time meter are recorded
by the operator who starts and stops
the sampler. If more than one
operator is involved, each should set
his/her watch to a common reference
to achieve accurate times; such a
reference could be an office clock that
is checked daily or the local telephone
company, which gives the time of day.
The time measurement procedure is
as follows:
1. Take the start and stop times for
samplers equipped with timer
switches from the timers' start and
stop settings.
2. Check the timer clock, and set it,
if necessary, for the correct times at
each filter change.
3. Use an el-apsed-time meter'to
determine the number of minutes
sampled because timers cannot be set
or read to within less than =30 min.
4.7 Documentation
The following information should be
recorded on the filter folder or on a
field data record form (Figure 4.3) by
the persons indicated, and it should
be verified with a signature.
4.7.1 The Operator Who Starts the
Sample
1. Station location
2. Project number
3. Site number
4. Sampler ID number
5. Filter number
-------
Jan. 1983
Section Z.Z.4
-------
Section 2.2.4
Jan. 1983
6, Sample date
7, Initial flow reading (if using
rotameter) and/or initial temperature
and barometric pressure if required.
8, Unusual conditions that may
affect the results (e.g., subjective
evaluation of pollution that day,
construction activity, meteorology) •
9, Signature.
4.7.2 The Operator Who Removes
the Sample
1. Elapsed time
2. Final flow reading (or be sure
that the flow rate chart accompanies
the sample) and final temperature and
barometric pressure if required.
3, Existing conditions that may
affect the results
4, Signature.
4.7.3 The Operator Who Transfers
the Sample to the Laboratory Record
1, Receiving date initialed
2. Shipping date initialed.
Table4.2. Activity Matrix for Sampling Procedure
Activity
Filter installation
Flow checks
Elapsed time
Sample handling
Documentation
Acceptance limits
Frequency and method
of measurement
Action if
requirements
are not met
Filter rough side up,
centered on screen, edges
parallel to edges of screen
and to faceplate gasket;
gasket tightened to prevent
leakage
1) Sampler flow rate within
acceptable range of 1.1 to
1.7 m3/min (39-60 ft3/min)
21 Stabilized initial flow
rate = established initial
• flow rate ±10% for
pressure transducer or
±15% for rotameter
3) Sampling time 24 ±1 h
No evidence of malfunction
in post-sampling check
Names, sampling dates,
times; sample, filter, and
, station numbers; unusual
conditions: flow rates: and
handling dates recorded on
sample envelope
Visually check each
exposed filter.
Check flow rate at each
filter change
Check on and off settings
of timers.
Visually check each sample
for tears, missing pieces.
or leakage.
Visually check each sample
data record
Void the filter: install
substitute filter.
1) Determine cause of flow
problem and correct;
measure line voltage,
change the filter, check
calibration and calibrate
sampler.
Reset timer.
Void the sample; correct
the cause of malfunction.
Complete or correct the
documentation; if unavail-
able, void the sample.
-------
Jan. 1983
Section 2.2.5
5.0 Analysis of Samples
A matrix summarizing the major
quality assurance activities for sample
analyses is presented as Table 5.1 at
the end of this section.
5.1 Sample Documentation
and Inspection
Upon receipt of the sample from the
field the following procedure should
be followed:
1. Remove the filter folder from its
shipping envelope and examine the
Hi-vol Field Data Record (Figure 4.3)
to determine whether all data needed
to verify the sample and to calculate
the concentration have been provided.
Void the sample if data are missing
and unobtainable from the field
operator or if a sampler malfunction
(e.g., faceplate gasket leakage) is
evident.
.2. Record the filter number on the
Hi-vol Field Data Record and on the
Laboratory Data Log {Figure 3.1).
3. Examine the shipping envelope.
If sample material has been dislodged
from the filter, recover as much as
possible by'brushing it from the
envelope onto the deposit on the filter
with a soft camel's-hair brush.
4. Examine the filter. If insects are
embedded in the sample deposit,
remove them with Teflon-tipped
tweezers, but disturb as little of the
sample deposit as possible. If more
than 10 insects are observed, refer
the sample to the supervisor for a
decision to accept or reject it.
5. Record the data verification, the
sample inspection, and removal of
insects under "Remarks" in-the
Laboratory Data Log. •
5.2 Filter Equilibration
The following procedure should be
used to equilibrate the exposed filters
in a conditioning environment for 24
h; up to 48 h may be needed for very
damp filters.
1. Use an eqilibration chamber with
a desiccant or an environmentally
controlled weighing room to maintain
an RH of <50 percent at 1 5° and
30°C (59° to 86°F). An air-conditioned
room may be used for equilibration if
it can be maintained at an RH of
<50% that is constant within =5%
and an air temperature between 15~
and 30°C that is constant within
=3°C (5°F) while the filters are
Table 5. J. Activity Matrix for Analysis of Samples
equilibrating. A convenient working
RH is 40 percent. Keep a hygrometer
in the room.
2. Check the RH daily.
3. Record the hygrometer readings
and any equilibration chamber
malfunctions, discrepancies, or
maintenance in trie Laboratory Data
Log.
5.3 Gravimetric Analysis
A balance check should be
performed as specified in Subsection
2.1.
1. Weigh the exposed filters to the
nearest milligram (mg) on the
analytical balance.
2. Weigh the filters in the
conditioning environment if practical;
if not, be sure that the analytical
balance is as close as possible to the
conditioning chamber where it is
relatively free of air currents and
where it is at or near the temperature
of the chamber. Weighing should take
place within 30 seconds after
removing filters from the equilibration
chamber.
3. Record the weight in the
Laboratory Data Log and on the High
Volume Field Data Record.
A ctivity
Acceptance limits
Frequency and method
of measurement
Action if
requirements
Documentation verification
and sample inspection
Filter equilibration
Gravimetric analysis
" Complete documentation;
no evidence of malfunction
or sample loss; 24 h; RH <50% within
±5%; temperature constant
within ±3°Cat 15°to30°C
(59° to 86°F)
Indicated weight obtained
to nearest milligram within
3O s after removal from
equilibration chamber
Visually check all samples
and documentation.
For each sample, observe
room or chamber conditions
and equilibration period.
Observe filter weighing.
Void the sample
Repeat equilibration for 24
h at properly controlled
conditions.
Report to supervisor;
reweigh after equilibration
for 24 h at controlled
-------
-------
Jan. 1983
Section 2.2.6
6.0 Calculations of TSP Concentrations and Data Reporting
A matrix summarizing the quality
control activities for the calculations
and the data-reporting requirements
is presented in Table 6.1.
6.1 TSP Concentration
Equation 6-1 should be used to
calculate the total air volume sampled.
V = Q5td t Equation 6-1
where:
V = Total air volume sampled, in
standard volume units, std m3;
Qstd = average standard flow rate, std
mVmin;
t = sampling time, min.
Equation 6-2 should be used to
calculate the TSP sample
concentration.
= (W,-Wt)1Q8
V
Equation 6-2
where
TSP = concentration of TSP, //g/std
m3,
Wf=weight of exposed filter, g
Wi = tare weight of filter, g.
All original calculations should be
recorded in the Laboratory. Data Log
(Figure 3.1).
6.2 Data Documentation
and Reporting
All daily concentration levels should
be recorded in micrograms per
standard cubic meter (//g/std m3),
with .the required identifying
information, on the SAROAD Daily
Data form (Figure 6.1). See AEROS
User's. Manual, OAQPS No. 1.2-039,
for detailed instructions.
Table 6.1. Activity Matrix for Calculations and Data Reporting
Activity
Acceptance limits
Frequency and method
of measurement
Action if
requirements
are not met
Sample volume and .
concentration .
Data documentation and
reporting
All needed data available
Complete documentation
for calculation of concen-
tration; all sample and data
identification numbers
matched; no evidence of
malfunction or sample loss;
all needed data available
Visually check data records
for each sample.
Visually check data record
and data log for each
sample.
Void the sample.
Void, the sample.
-------
Section 2.2.6
Jan. 1983
24'Hour or Greater Sampling Interval
t
Agency
S/rje/M'- Tokjn
City Name,
^jQ& /v&r"~fri SYV"CCv
Site Address
T5P 2.4 hour
Project
Day St
19 20 21
1
i
|
1
1
i
I
1
,
; .
0
\
O
1
i
i,
n
*
i
i
;
Time Interval
rsp
Name
PARAMETER
Cods
/
/
/
0
/
23 24 25 26 27
O
/
c
) /
O
Hf 28 29 . 3O 31 32
22 33 34 35 36.
O
O
O
O
1
-
t
0
O
1
i
1
a
,•
I
«
1
7
-------
Jan. 1983
Section 2.2.7
7.0 Maintenance
Scheduled or preventive
maintenance of the sampling
equipment reduces voided samples,
downtime, and remedial maintenance.
Because the sampling equipment is
operated only intermittently, the
frequency of maintenance is a
function of the actual hours of use.
Normally, two or three preventive
maintenance activities are required
each year. When possible,
maintenance is-best performed in the
laboratory rather than in the field.
Motors on which maintenance has
been performed can then be carried to
the field for installation and
calibration. Table 7.1 at the end of
this section summarizes the quality
assurance activities of major
maintenance checks. All maintenance
activities should be recorded in a log
book.
7.1 Sampler Motor
Motor brushes usually require
replacement after 400 to 500 h of
operation at normal line voltage (115
V). The procedure is as follows:
1. Replace the brushes before they
are worn to the point that
damage can occur to the
commutator of the Hi-Vol motor.
The optimum replacement
interval must be determined from
experience.
2. Follow the manufacturer's
instructions for replacing the
brushes.
3. Recalibrate the high-volume
sampler after the brushes are
replaced. Do not recalibrate the-
motor until after an initial break-
in period for the proper seating
of the brushes against the
armature; this period usually
requires running the sampler for
several hours against a
resistance equivalent to a clean
filter or a No. 18 calibration
plate.
4. Refer to the flow diagram in
Figure 7.1 for the various steps
required for motor maintenance.
5. Record all sampler maintenance
operations (with dates performed
and the operator's initials) in the
sampler log book and on a
gummed label (Figure 7.2)
attached to the sampler.
7.2 Faceplate Gasket
A worn faceplate gasket is
characterized by a gradual blending of
Open the Motor Housing
Remove Motor
Inspect-Armature •
-*• If Bad
-Replace Armature
Change Brushes
I
~"~ Check Motor -
If Good
Reassemble
Final Test
Field
Calibration
If Bad
Remove
Usable Parts
Discard Motor
Figure 7.1. Flow diagram for high volume sampler motor maintenance.
the interface between the collected
particulates and the clean filter
border. Any decrease in the sharpness
of this interface indicates the need for
a new gasket.
1. Remove the old gasket with a
knife.
2. Clean the surface properly.
3. Seal a new gasket to the
faceplate with rubber cement or
double-sided adhesive tape.
Hi-vol motor number.
Site location
Last maintenance
Last calibration
Checked by
Next maintenance due
Next calibration due
Figure 7.2. Example of a gummed label
for a high-volume sampler.
4. Record all gasket replacements
with dates and operator's initials in
'the sampler log book.
7.3 Rotameter
1. Clean and recalibrate the
rotameter of a sampler when the float
behaves erratically or when moisture
or foreign matter is detected in the
rotameter.
2. Clean the rotameter prior to
routine calibration (alcohol is a
satisfactory cleaning solvent).
3. Refer to the flow diagram (Figure
7.3) for the required maintenance
steps.
7.4 Sampling Head
Leaks in the sampling head occur
infrequently. The welded seams and
the condition of the guide pins on the
top surface of the head should be
visually checked initially. Should a
-------
Section 2.2.7
Jan. 1983
Figure 7.3.
Disassemble
Clean
\
ymii
I
Examine
Reassemble
Calibrate
Maintenance sequence for
rotameter.
defect be suspected, the following
procedure should be followed:
1. Assemble the sampling head to
the motor.
2. Install a filter for resistance.
3. Apply a soap solution to the
suspect problem area.
4. Disassemble the sampling head.
5. Examine the inside of the head
for soap bubbles.
6. Repair or discard the sampling
head if a leak is indicated by
soap solution being inside of the
head.
7.5 Motor Gaskets
Two gaskets are used with each
sampler motor. The top rubber gasket
is approximately 3/16-in. thick and
the bottom foam rubber gasket is
approximately 3/4-in. thick.
1. Inspect both gaskets for wear or
deterioration.
2. Replace if necessary.
7.6 Flow Transducer and
Recorder
Routine maintenance is not
required for this device. Should a
malfunction occur, replace the old
recorder with a new one.
Table 7.7. Activity Matrix for Maintenance"
Equipment
Sampler motor
Faceplate gasket
Rotameter
Motor gaskets
Sampling head
Acceptance limits
Frequency and method
of measurement
Action if
requirements
are not met
400-50O h of motor brush
operation: no malfunction
No leaks at the filter seal
No foreign materials:
stable operation
Leak-free fit
No leaks
Visually check upon receipt
and after, each 400 h of
operation.
Visually check after each
sampling period.
Visually check at each
reading.
Visually check after each
400 h of operation.
Visually check after each '
4OO h of operation.
Replace 'motor brushes;
perform other maintenance
as indicated.
Replace the gasket.
Clean; replace if damaged.
Replace gaskets.
Replace sampling head.
-------
Jan. 1983
Section 2.Z.8
8.0 Auditing Procedure
An audit is an independent
assessment of the accuracy of data.
Independence is achieved by having
the audit made by an operator other
than the one conducting the routine
measurements and by using audit
standards and equipment different
from those routinely used in
monitoring. The audit should be a true
assessment of the accuracy of the
measurement process under normal
operation—that is, without any special
preparation or adjustment of the
system. Routine quality assurance
checks by the operator are necessary
for obtaining good quality data, but
they are not part of the auditing
procedure.
• Three performance audits and one
systems audit are detailed in
Subsections 8.1 and 8.2. These audits
are summarized in Table 8.2 at the
end of this section. See Sections
2.0.11 and 2.0.12 of this volume for
detailed procedures for systems audits
and performance audits, respectively.
Proper implementation of an
auditing program serves a two-fold
purpose: to ensure the integrity of the
data and to assess the accuracy, of the
data. A technique for estimating the '
accuracy of the data is given in
section 2.0.8 of this volume.
8.1 Performance Audits
Performance audits conducted by
another operator/analyst provide a
quantitative evaluation of the quality
of the data produced by the total
measurement system (sample
collection, sample analysis, and data
processing). Performance audits of
three individual portions of the total
measurement system are
recommended:
1. Flow rate calibration
2. Exposed filter reweighing
3. Data processing.
8.1.1 Audit of Flow Rate Calibration -
The frequency of audits of the flow
rate depends on the use of the data
(e.g., for PSD3 air monitoring or for
SLAMS4). It is recommended that the
flow rate of each high-volume
sampler be audited each quarter. Any
type flow-rate transfer device
acceptable for use in calibration of
high-volume samplers may be used as
the audit flow-rate reference
standard; however, the audit standard
must be different from the standard
used to calibrate the high-volume
samplers. The audit standard must be
calibrated with a positive-
displacement standard volume meter
(i.e.. Roots meter) traceable to the
National Bureau of Standards. See
Subsection 2.2 for procedures used to
certify flow rate transfer standards.
With the audit device in place, the
high-volume sampler should be
operated at its normal flow rate. The
differences in flow rate (in std
mVmin) between the audit flow
measurement (X) and the flow
indicated by the sampler's normal
flow indicator (Y) are used to calculate
accuracy as described in Section 2.0.8
of this volume.
Great care must be taken in
auditing high-volume samplers having
flow regulators because the
introduction of the audit device can
cause abnormal flow patterns at the-
point of flow sensing. For this reason,
the orifice of the flow audit device
must be used with a normal glass
fiber filter in place (and without
resistance plates) in auditing flow-
regulated high-volume samplers, or
other steps should be taken to assure
that flow patterns are not disturbed at
the point of flow sensing.
Detailed procedures and forms used
to perform flow rate audits are given
in Section 2.0.12 of this volume.
8.1.2 A udit of Exposed Filter
Reweighing - To avoid possible loss of
volatile components, exposed filters
should be weighed, including any
necessary reweighing, as soon after
collection and equilibration as
practical. Thus, it may be impossible to
have lot sizes of more than 10 or 20
exposed filters. The procedure is as
follows:
1. Select randomly and reweigh
four re-equilibrated filters out of
every group of 50 or less. (This
would mean 100 percent
checking if four or fewer exposed
filters were weighed at one
time). For groups of 50 to 100,
reweigh 7 from each group.
These suggested starting
frequencies may be altered,
based on experience and data
quality. Decrease the frequency if
past experience indicates that
the data are of good quality, or
increase it if the data are of poor
quality. It is more important to be
sure that the sample is
representative of the various
conditions that may influence
data quality than to adhere to a
fixed frequency.
2. Reweigh all filters in a lot if any
audit weight differs by more than
±5.0 mg from the original
weight.
3. Accept the lot with no change if
all.audits are within ±5.0 mg of
the originals.
4. Record the original and the audit
weights in milligrams (mg) on an
X-and-R chart (Figure 8.1). Plot
the difference (d), defined as:
d = original weight - audit weight.
Equation 8-1
Tentative warning and control
limits of ±3.3 and ±5.0 mg,
respectively, are recommended
until sufficient data are obtained
to support an alteration of these
limits. Out-of-control points.
indicate the need for
recalibration of the balance'
and/or improved operator
technique. Do not increase the
limits; however, more stringent
limits may be established if
experience warrants.
5. Forward the X-and-R chart to the
supervisor for review.
6. Reweigh all of the remaining
exposed filters in the lot if the
balance requires recalibration or
the operation technique is
changed.
8.1.3 Audit of Data Processing. - For
convenience, the data processing
should be audited soon after the
original calculations have been
performed. This allows corrections to
be made immediately. This also allows
•for possible retrieval of additional
explanatory data from field personnel '
when necessary. The procedure is as
follows:
1. Use the audit rate of Subsection
8.1.2.
2. Starting with the raw data on the
data form or on the flow rate
recorder chart, independently
compute the concentration (in fjg
TSP/m3) and compare it with the
corresponding concentration
reported on the SAROAD form. If
the mass concentration
computed by the audit check Oug
TSP/m3)a does not agree (within
round-off error) with the original
-------
Section 2.2.8
Jan. 1983
II
-------
Jan. 1983
Section 2.2.8
value (fjg TSP/m3)m. recheck all
samples in the lot and correct
them as necessary.
3. Record the audit values in the
data log, and report them along
with the original vatues to the
supervisor for review. The audit
value is always given as the
correct value, based on the
assumption that a discrepancy
between the two values is
always double-checked by the
auditor.
8.2 Systems Audit
A systems audit is an on-site
inspection and review of the quality of
the total measurement system (sample
collection, sample analysis, data
processing, etc.), and it is normally a
qualitative appraisal. The procedure is
as follows:
1. Conduct a systems audit on
receipt of a new monitoring
system and as appropriate
thereafter to audit possible
degradation or significant
changes in system operation.
2. Use the preliminary checklist
given in Figure 8.2. Check the
questions for applicability to the
particular local, State, or Federal
agency.
See Sections 2.0.11 and 2.0.12 of
this volume for detailed procedures -
and forms for systems audits and
performance audits, respectively.
Table 8.2. Activity Matrix for Auditing Procedure
Audit
Flow rate
Acceptance limits
Percentage difference.
Frequency and method
of measurement
Once each quarter
Action if
requirements
are not met
Recalibrate before
resuminq samolina.
Exposed filter reweighing
Data processing
Systems
X
within 37%
Audit weight = original
weight 35 mg
Audit concentration agrees
with original reported con-
centration within round-off
error
Method described in this
section of the Handbook
Perform 7 audits/100
filters, or 4 audits/<50
filters; use analytical
balance; condition filters
for 24 h before weighing.
Independently repeat cal-
culation of JSP concentra-
tion from data record for 7
samples per 100 (minimum
of 4 per lot).
At beginning of a new
monitoring system and
periodically as appropriate, '
observe procedures and
use checklist.
'Reweigh all filters in the
lot.
Recheck all calculations.
Initiate improved methods
and/or training programs.
-------
Section 2.2.8 4 Jan. 1983
Checklist for Use by Auditor for Hi-Vol Method
1 What type of hi-vol samplers are used in the network?
2 How often ar-e the samplers run? la) daily fbj once every 6 days Id once every 12 days Id) other
3 What type of filter and how many are being used?
4 Are there any preexposure checks for pin holes or imperfections run on the filters?
5 What is the collection efficiency for your fitters-' ,
5 What is the calibration procedure for the hi-vol sampler'
7 Which statement most closely estimates the frequency of flow rate calibration? (a) once when purchased (b) once when
purchased, then after every sampler modification (cl when purchased, then at regular intervals thereafter
3 Are flow rates measured before and after the samp/ing period?'
Yes No 1_
9 Is there a loo. book for each sampler for recording flows and times? Yes No
10 Are titters conditioned before initial and final weighings? If so. for how long? At what
percentage humidity? _ ;_ ;
/ / Is the balance checked periodically? // so. how often? With which standard weights?
12 How often are the hi-vof filters weighed? : '
How are the data from these weighings handled?
13 Are all weighings and serial numbers of filters kept in a log book at.the laboratory?
14 What is the approximate time delay between sample collection and the final weighing? ___^_^_ days
Figure 8.2. Example of simplified checklist for use by auditor for hi-vol method.
-------
Jan. 1383 1 Section 2.2.9
9.0 Assessment of Monitoring Data for Precision and Accuracy
9.1 Precision
For each monitoring network.
collocate an additional sampler at a
minimum of one site (two sites are
required for SLAMS") as follows:
1. Select a site with the highest . • .
expected geometric mean
concentrations.
2. Locate the two high volume
samplers within 4 m of each
other, but at least 2 m apart to .- ..
preclude air flow interference.
3. 'Identify one of the two samplers
at the time of installation as the
sampler for normal routine
monitoring; identify the other as
the duplicate sampler.
4. Be sure that the calibration,
sampling, and analysis procedure
are the same for the collocated
sampler as for all other samplers
in the network.
5. Operate a collocated sampler
whenever its associated routine
sampler is operated.
6. Use the differences in the
concentrations (+g TSP.'std m3)
between the routine and '
duplicate samplers to calculate . - .
the precision as described in
- Section 2.0.8 of this Handbook.
Based on the results of a
collaborative test,5 percent difference
(Equation 8-1 of Section 2.0.8) should
•not exceed 31 5%.* An example
calculation is given in Section 2.0.8 of
this Handbook.
9.2 Accuracy
The accuracy of the high-volume
method for measurement of TSP is
assessed by auditing certain portions
of the measurement process, as
described in Section 2.2^8. The
calculation procedure for single
instrument accuracy is given in - '
Section 2.0.8 of this volume of the
Handbook.
•This 315% is calculated at the 99 7 probability
interval This means that if the two samplers do
agree, chances are less than 3 out of 1000 that a
difference larger than I 5°'o will be observed
-------
-------
Jan. 1983 1 Section 2.2.10
10.0 Recommended Standards for Establishing Traceability
For data of the desired quality to be
achieved, two considerations are
essential: (1) the measurement
process must be in a state of
statistical control at the time of the
measurement, and (2) the
combination of systematic errors and
random variation (measurement
errors) must yield a su+tably small
uncertainty. Evidence of good-quality
data requires the performance~of
quality control checks and
independent audits of the
measurement process; documentation
of the data on a quality control chart;
and the use of materials, instruments,
and measurement procedures that
can be traced to an appropriate
performance standard.
Data must be routinely obtained by
repeating measurements of Standard
Reference samples (primary,
secondary, and/or working standards),
and a condition of process control
must be established. The working
calibration standards should.be
traceable to standards c; higher
accuracy, sjjc'h as those' listed here.
10.1 Recommended
Standards for Establishing
Traceability
1. Class-S weights of NBS
specifications are recommended for
the analytical balance calibration. See
Subsection 2,1 for details on balance
calibration checks.
2. A positive displacement
rootsmeter is recommended for
calibrating the flow rate transfer
standard that is used to calibrate the
high-volume sampler. See Subsection
2.6 for details on high-volume
sampler calibration.
3. A positive displacement
rootsmeter (including a resistance
plate) is recommended for calibrating
the device used to audit the high-
volume-sampler flow-rate calibration.
See Subsection 8.1 for details on
flow-rate calibration audits.
4. The elapsed-time meter, checked
semiannually against an accurate
timepiece, must be within 32
min/day.
-------
-------
-------
"I II I III
-------
Section No. 2.3
Revision No. 0
Date July 1, 1979
Page 1 of 5
Section 2.3
REFERENCE METHOD FOR THE DETERMINATION OF
NITROGEN DIOXIDE IN THE ATMOSPHERE
(CHEMILUMINESCENCE)
OUTLINE
Section
SUMMARY
METHOD HIGHLIGHTS.
METHOD DESCRIPTION
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
PROCUREMENT OF APPARATUS
AND SUPPLIES
CALIBRATION OF EQUIPMENT
OPERATION AND PROCEDURE
DATA REDUCTION, VALIDATION,
AND REPORTING
MAINTENANCE
AUDITING PROCEDURE
ASSESSMENT OF MONITORING
DATA FOR PRECISION AND
ACCURACY
RECOMMENDED STANDARDS FOR
ESTABLISHING TRACEABlLlTY
REFERENCE METHOD
REFERENCES
DATA FORMS
Documentation
2.3
2.3
2.3.1
2.3.2
2.3.3
2.3.4
2.3.5
2.3.6
2.3.7
Number of
Pages
1
3
8
27
10
5
2
12
1
2.3.8
2.3.9
2.3.10
2.3.11
9
1
17
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Section No. 2.3
Revision No. 0
Date July 1, 1979
Page 2 of 5
SUMMARY
Concentrations of nitrogen dioxide (NO2) in ambient air are
determined indirectly by photometrically measuring the light
intensity, at wavelengths greater than 600 nm, resulting from
the chemiluminescent reaction of nitric oxide (NO) with ozone
(03). NO - is first quantitatively reduced.to NO by a converter.
The NO, which commonly exists in association with NO-, passes
through the converter unchanged, resulting in a total NO
H
(nitrogen oxides) concentration of NO + NO,,. A portion of the
ambient air is also reacted with O3 without having passed
through the converter, and the NO concentration measured. This
value is subtracted from the NO concentration yielding the
X
concentration of NO_.
-The.NO and the NO + NO2 measurements may.be made either con-
currently with a dual channel detection system or cyclically with
a single channel system as long as the cycle time is not greater
than 1 min.
References 1 and 2 were used extensively for the method
description. Reference 3 was used in the development of effec-
tive quality assurance procedures.
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Section No. 2.3
Revision No. 0
Date July 1, 1979
Page 3 of 5
METHOD HIGHLIGHTS
In this quality assurance document for the NO- Reference
Method the procedures are designed to serve as guidelines for
the development of agency quality assurance programs. Because
recordkeeping is a critical part of quality assurance activities,
several data forms are included to aid in--the documentation of
necessary data. The blank data forms (Section 2.3.11) may be
used as they are, or they may be used as guidelines for preparing
forms more- appropriate to the individual agency; partially
filled-in forms are interspersed throughout ,the text of the.
method description to illustrate their uses. Activity matrices
at the end of pertinent sections can be used for quick review of
the material covered in the text sections. Following is a brief
summary of the material covered in this N02 method description.'
1- Procurement of Equipment ' - •
. Section 2,3.1 gives the specifications, criteria, and design
features of the equipment and material required for the operation
and quality assurance of a continuous NO analyzer. The selec-
X
tion of the correct equipment and-supplies is a prerequisite to
a quality assurance program. This section is designed to provide
a guide for the procurement and initial check of equipment and
supplies. •
2 - Calibration of Equipment
Section 2.3.2 provides procedures and forms to be used in
the -selection and checking.of calibration equipment, performing a
multi-point calibration, and evaluation of calibration data.
Subsections. 2.1, 2.2, and 2.3 deal primarily with minimum accept-
able requirements for equipment and standards to be used in the
generation of NO2 concentrations. Detailed procedures for the
acceptance of NO2, GPT calibrators are also given. Subsection
2.4 provides a step-by-step description of the recommended cali-
bration procedures for an NO2 chemiluminescence analyzer along
with example calculations. The data form (Figure 2.1 of Sec-
-------
Section No. 2.3
Revision No. 0
Date July 1, 1979
Page 4 of 5
tion 2.3.2) is to be used in documentation of calibration data.
The primary element of quality control is dynamic instrument
calibration.
3. Operation and Procedure
Section 2.3.3 outlines protocol to 'be followed by the
operator during each site visit. Checks should include visual
inspection of the shelter, sample introduction system, analyzer
and recorder. In addition analyzer performance checks consisting
of zero, span, and precision points are to be made. To provide
for documentation and accountability of activities, a checklist
similar to the example provided in Figure 3.1 of Section 2.3.3
should 'be compiled and then filled out by the field-operator as
each activity is completed. Analyzer Level 1 zero and span
checks must be carried out at least once every two weeks. Level
2 zero and span checks should be conducted in between the Level 1
checks at a frequency desired by the user. Span concentrations
for &oth levels should be between 70 .and 90% of the measurement
range. A one point precision check is to. be done every two weeks
at an NO, concentration between 0.08 and 0.10 ppm. Data forms
£t
similar to Figures 3.2 and 3.3 of Section 2.3.3 are to be used in
documenting the analyzer performance checks. An essential part
of the quality assurance program is a scheduled series of checks
for the purpose of verifying the operational status, of the moni-
toring system.
4. Data Reduction
Section 2.3.4 describes procedures to be used for editing of
strip charts and for data reduction. Data collected on. strip
charts serve no useful function until converted into meaningful
units (ppm, [ig/m ) by hourly averaging and application of a cali-
bration relationship. These data must then be transcribed into
an appropriate data' format such as the SAROAD Hourly Data form.
5. Maintenance
Section 2.3.5 addresses recordkeeping and scheduled activ-
ities pertinent to preventive and corrective maintenance. A sam-
-------
Section No. 2.3
Revision No. 0
Date July 1, 1979
Page 5 of 5
pier maintenance log is presented in Figure 5.1 of Section 2.3.5.
Preventive and corrective maintenance are necessary to minimize
loss of air quality data due to analyzer malfunctions and out of
control conditions.
6• Assessment of Data for Accuracy and Precision
Section 2:3.6 discusses system and performance audits along
with audit procedures and forms. Accuracy of data is assessed by
performing an independent audit.
Multipoint performance audits used to assess the accuracy of
the data collection are discussed in Subsection 6.1. Examples of
an audit summary form and audit calculation form are presented in
Figures 6.1 through 6.4. Data reduction audit is discussed, in
Subsection 6.2 and a systems audit in Subsection 6.3. Figure 6.5
presents an ' example checklist that may be used by the auditor.
Section 2.3.7 describes the techniques for assessment of
accuracy and precision. " .
7• Reference Information
Section 2.3.8 discusses the traceability of measurements to
established standards of higher accuracy, a necessary prereq-
uisite for obtaining accurate, data.
Sections 2.3.9 and 2.3.10 contain the Reference Method and
pertinent references.
Section 2.3.11 contains blank data forms for the convenience
of the user.
-------
-------
section No. 2.3.1
Revision No. 0
Date July 1, 1979
Page 1 of 8
METHOD DESCRIPTION
1.0 PROCUREMENT OF APPARATUS AND SUPPLIES
The measurement of NO_ in ambient air requires basic sam-
pling equipment and other supplies. These include, but are not
limited to, the.following:
1. Reference Method NO2 chemiluminescent analyz.er (see
Subsection 1.1 for an address for obtaining an up-to-date list of
analysers).
2. Strip chart recorder or data logging system,
3. Sampling lines,
4. • Sampling manifold,
5. Calibration equipment,
6. NBS calibration standard,
7. Working gas traceable to NBS standard,
8.' Zero air (Reference 2),
'9. Spare parts,
10. Record forms, and .
11. Independent audit system.
Purchases of these supplies should be recorded in a log book to
provide a reference for future procurement needs and for future
fiscal planning. An example of this log is Figure 1'. 1. Quality
assurance activities for procurement of apparatus and supplies
are summarized in Table 1.1 at the end of this section.
-1-1 Oxides- of Nitrogen Chemiluminescent Analyzer
Chemiluminescent NOx analyzers, currently available for the
measurement of NO2 in ambient air, are competitively priced.
However, price differences do become apparent when options are
ordered. Available options range from automatic zero and span
functions to complete telemetry systems that transmit daily zero
and span checks and real-time data from the site to a central
location. Although these options have advantages, their absence
from the basic monitor will not detract from performance. The
-------
c
OJ
S
o
o
I C
o o
C.T-
W ->
u
.
"
!- O =
= c
o-
Si
M
Section No. 2.3.1
Revision No. 0
Date July 1, 1979
Page 2 of 8
.
N
n
^s ^
3
-p
-------
Section No. 2.3.1
Revision No. 0
Date July 1, 1979
Page 3 of 8
necessity and desirability of options will be dictated by field
personnel availability, site accessibility, and budget limita-
tions.
Only analyzers designated by EPA as a reference or an equiv-
alent method should be purchased. When purchasing, the buyer
should request that the manufacturer supply documented proof that
the- analyzer does perform within specifications (Table 4.1,
Section 2.0.4). The best evidence is a strip chart recording
showing the specific analyzer's zero drift, span drift, elec-
tronic noise, rise time, fall time, and lag time. -The strip
chart will also serve as a reference to determine whether the
performance of the analyzer has deteriorated at a later date. In
addition, the user should reverify these performance characteris-
tics either during the initial calibration or by using abbrevi-
ated forms of the test procedures provided in Ambient Air Moni-
toring Reference and Equivalent Methods. 40 CFR 53, Federal'
Register-, Vol. 40, 'No. 33, pp. 7052-7060, February 18, 1975.
Acceptance of the analyzer should be 'based on results from
these performance tests. Once accepted, reference and equivalent
analyzers are warranted by the manufacturer to operate within the
required performance limit for one year.
An up-to-date list of analyzers designated.as reference' or
equivalent methods 'for NO2 is available by writing to:
U.S. Environmental Protection Agency
Environmental Monitoring Systems Laboratory
Department E, MD-77
Research Triangle Park, North Carolina 27711
1-2 Strip Chart Recorder
Recorders are commercially available in a wide variety of
prices and specifications. Factors to be considered when pur-
chasing a recorder are:
1. Compatibility with the output signal of the analyzer,
2. Chart width (a minimum of 15 cm (6 in.) is recommended
for the desired accuracy in data reduction,
3. Chart speed (at least 2.5 cm (1 in.) per hour),
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Section No. 2.3.1
Revision No. 0
Date July 1, 1979
Page 4 of 8
4. Response time,
5. Precision and reliability,
6. Flexibility of operating variables (speed, range), and
7. Maintenance requirements.
1.3 Sampling Lines and Manifold
Sampling lines and manifolds should be constructed of Teflon
or glass to minimize possible- reaction and degradation .of the
oxides of nitrogen. The residence time within the sampling line
should be minimized to reduce the possibility of interreaction.
For example, the reaction of ambient concentrations of NO and 03
in the sample lines and manifold would lead to erroneous measure-
ments .
1.4 Calibration Equipment
To ensure accurate measurements of the NO and N02 concentra-
tions, calibrate the analyzer at the time of installation,- and
recalibrate it:
"1. no later than three months after the most recent, cali- -
bration or performance audit which indicated analyzer response to
be acceptable; or
2. following any one of the activities.listed below:
a. an interruption of more than a few days in ana-
lyzer operation;
• b. any repairs which might affect its calibration;
c. physical relocation of the analyzer; or
d. any other indication (including excessive zero or
span drift) of possible significant inaccuracy of the analyzer.
Following any of the activities listed in item 2 above,-a level 1
zero and span check should be made to determine if a calibration
is necessary. If the analyzer zero and span drifts do not exceed
the calibration limits in Table 9.1 of Section 2.0.9, Subsection
9.1.3, a calibration need not be performed. If either the zero
or span drift exceed their respective calibration limit, investi-
gate the cause of the drift, take corrective action and calibrate
the analyzer.
-------
Section No. 2.3.1
Revision No. 0
Date July I, 1979
Page 5 of 8
When purchasing or designing a calibration system, be sure
that the calibration system meets the guidelines outlined in the
revised Appendix F, Federal Register, Vol. 41, No. 232, p. 52688,
December 1, 1976. Calibration procedures are also detailed in
the Technical Assistance Document (TAD).2 '
.Two methods for dynamic multipoint calibration of nitrogen
dioxide analyzers are' specified in the Federal Register.1
1. Alternative A: .Gas phase titration (GPT) of an NO
standard with O3 to generate known concentrations of NO_.
2. Alternative B: NC>2 permeation tube, a dynamic dilution
•system to produce known concentrations of NO-, and -an NO
cylinder.
Only alternative A, GPT, is discussed' in this document.'
Those wishing to use alternative B should read Section 2 of the
TAD. Alternative A requires four major components. They are.
I- Working NO gas standard,
2. Stable O3 generator, . '
3. Source of zero air,2 and
4. GPT system.
The NO standard must be traceable to a National 'Bureau of
Standards, Standard Reference Material (NBS-SRM).3 An acceptable
protocol to demonstrate the traceability of commercial cylinder
gas to NBS-SRM cylinder gas is described in Section 2.0.7 of this
volume of the Handbook.
Zero air (free of contaminants that can cause a detectable
response with the oxides of nitrogen analyzer or that can react
with either NO, q>3, or NO2) is commercially available, or it can
be generated by the user. Detailed procedures for generating
zero air are in TAD.2
.The equipment that is needed to carry out the calibration is
commercially available, or it can be assembled by the user. When
purchasing a calibrator or its components, certain factors must
be considered.
1. Traceability of the certified calibration gases to an
NBS-SRM.
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Section No. 2.3.1
Revision No. 0
Date July 1, 1979
Page 6 of 8
2. Accuracy of the flow-measuring device (rotameter, mass
flow meter, bubble meter).
3. Maximum and minimum flows of dilution air and calibra-
tion gases.
4. Stability of the 03 generation.
5. Ease of transporting the calibrator from site to site.
As a precaution, all new GPT apparatus should be checked out
against a calibrator of known reliability..
1.5 Spare Parts and Expendable Supplies
In addition to the basic equipment discussed above, it is
necessary to maintain an inventory of spare parts and expendable
supplies. The manufacturer's manual contains a section de-
scribing the parts that require periodic replacement and the
frequency of replacement. Based on these requirements, the
management of the monitoring network can determine which parts
and the quantity of each that should be available at all times.
A generalized list of spare parts and expendable supplies is
provided below (for specific requirements refer to the manufac-
turer's manual):
1. Particulate filters,
2. Sampling lines,
3. Pump diaphragms,
4. Dryer columns,
5. Activated charcoal,
6. Recorder chart paper,
7. Recorder 'ink or pens,
8. Calibration gas,
9. Record forms, and
10. Spare fittings and glassware assortment.
1-6 Reanalysis of Calibration Working Standards
All working standards used for calibration purposes should
be reanalyzed by the, user at least once every 6 mo.
Section 2.0.7 (in particular, Subsections 7.1.2 and 7.1.5)
describes the procedures for analysis and for reanalysis of
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Section No. 2.3.1
Revision No. 0
Date July 1, 1979
Page 7 of 8
cylinder gases). Flow-measuring devices should be recalibrated
by following the procedures and schedules in Section 2.1.2.
1.7 Record Forms
Record keeping is a critical part of all quality assurance
programs. Standard forms similar to those that appear in this
manual should be developed for individual programs. Three things
to consider in.the development of record forms are:
1. Does the form serve a necessary function?
2. Is the documentation complete?
3. Will the forms be' filed in such a manner that they can
easily be retrieved when needed? :
1-8 Audit Equipment
Personnel, equipment, and reference materials used in con-
ducting audits must be independent from those normally used in
calibrations and operations.
Known concentrations of N02 can be generated by the GPT of
NO with 03 to produce NO2 or by the use-'of an NO2 permeation tube
and a dynamic dilution system. All audit gas standards must be
traceable to NBS-SRM's as described by the protocol in Sec-
tions 2.3.2 and 2.0.7. All flow rates should be measured using
a calibrated soap .bubble meter or an equivalently accurate pro-
cedure.
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Section No. 2.3.1
Revision No. 0
Date July 1, 1979
Page 8 of 8
Table 1.1
ACTIVITY MATRIX FOR PROCUREMENT
OF EQUIPMENT AND SUPPLIES
Equipment/
Supplies
Chemiluminescent
analyzer
Recorder
Sample lines
and manifold
Calibration
equipment
Working stan-
dard NO cylin-
der gas or N0_
permeation
tube
Record forms
Audit equip-
ment
Acceptance limits
Meets performance
specifications in
Table 4.1, Sec 2.0.4
Compatible with output
signal of analyzer;
chart width of 150 mm
(6 in.) is recommended
Constructed of Teflon
or glass
Meets guidelines of
reference 1 and
Sec 2.3.2
Traceable to NBS-SRM;
meets limits in trace-
ability protocol for
for accuracy and sta-
bility (Sec 2.0.7)
Develop standard forms
Must not be the same
as used for calibra-
tion
Frequency and method
of measurement
Manufacturer should
provide a strip chart
recording the specif-
ic analyzer's per-
formance; reverify
performance speci-
fications at initial
calibration
Check upon receipt
Check upon receipt
See Sec 2.3-9
Analyzed against an
NBS-SRM; see proto-
col in Sec 2.0.7
N/A
System must be
checked out against
known standards
Action if
requirements
are not met
Manufacturer
should make
proper adjust-
ments and re-
run the per-
formance check
Return equipment
to supplier
Return equip-
ment to supplier
Return equipment/
supplies to sup-'
plier
Obtain new work-
ing standard and
check for trace-
ability
Revise forms
as appropriate
Locate problem
and correct
or'return to
supplier
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section No. 2.3.2
Revision No. 0
Date July 1, 1979
Page 1 of 27
2.0 CALIBRATION OF EQUIPMENT
The accuracy and precision of data derived from air moni-
toring instrumentation are dependent on the quality control pro-
cedures used, primarily the dynamic instrument calibration. Cal-
ibration determines the relationship between the observed and the
true values of the variable being measured.
Dynamic calibration involves introducing gas samples of
known concentrations into an instrument in order to adjust the
instrument to a predetermined sensitivity and to produce a cali-
bration relationship.. This relationship is derived from the
instrumental response to successive samples of different known
concentrations. These standard gas mixtures may be introduced in
a decreasing order of concentrations to minimize response times.
As a minimum, three reference points and a zero point are recom-
mended...^ define this.relationship. The true values of the cali-
bration gas must be traceable to NBS-SRM's (Section 2.0.7). -
Most present-day monitoring instrument systems are subject
to drift and variation in internal parameters and cannot be
expected to maintain accurate calibration over long periods of
time. Therefore, it is necessary to dynamically check the cali-
bration relationship on a predetermined schedule. Precision is
determined by a one-point check at least once every two weeks.
Accuracy is determined by a three-point audit once each quarter:
Zero and span checks must be used to document within-cpntrol
conditions, these checks are also used in data reduction and
validation. Table 2.1 at the end of this section summarizes the
quality assurance activities for calibration.
2.1 Calibration Gases
2-1-1 Compressed NO in Nitrogen - The NBS-SRM's provide refer-
ences against which all calibration gas mixtures must be
compared (Section 2.0.7). The steps required to compare the
concentration of a commercial, working calibration standard to
an NBS-SRM are described in Subsection 7.1 of Section 2.0.7.
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Section No. 2.3.2
Revision No. 0
Date July 1, 1979
Page 2 of 27
Subsections 7.1.4 and 7.1.5 .describe the verification and re-
analysis of cylinder gases.
2.1.2 NO^ Permeation Tubes - The steps required to compare the
concentration of a commercial working calibration standard to an
NBS-SRM are described in Subsection 7.3.3 of Section 2.0.7; see
Subsection 7.3.6 for the reanalysis pf permeation tubes.
2.2 Dilution Gases • "
2
Zero air (free of contaminants that could cause a detect-
able response with the oxides of nitrogen analyzer or that can
react with either NO, O3/ or NO2) is commercially available, or
can be generated by the user. Detailed procedures for gener-
ating zero air are in TAD.2
2.3 Dynamic Multipoint Calibration Principles
Two methods for dynamic multipoint calibration of nitrogen
dioxide are specified in the Federal Register.1
JL. Alternative A: Gas phase titration (GPT) of an NO
standard with O3 to generate known concentrations of NO_.
2. Alternative B: NO- permeation tube and a dynamic
dilution system to produce known concentrations of NO? .
Both methods provide reliable results when correct calibration
procedures are followed. Experience has shown, however, that NO._
permeation tubes may become unreliable if not handled properly."
Furthermore, the conditions tha-t contribute to the degradation of
the tubes are not well understood at this time, so care should be
exercised by those using alternative B for calibrating NO
analyzers. Analyzers that require calibration of NO or NO chan-
nels must use an NO standard and a dynamic dilution system to
generate known concentrations. Both alternatives require the use
of an NO calibration gas to determine the efficiency of the
analyzer's NO2 to NO converter. Only alternative A (GPT) is
discussed in this document; those using alternative B (NO
permeation tube) should refer to TAD.2
2.3.1 Gas Phase Titration (GPT) - The principle of GPT is
based on the rapid gas phase reaction between NO and 0_ which
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o
Section No. 2.3.2
Revision No. 0
Date July 1, 1979
Page 3 of 27
produces stoichiometric quantities of NO, as shown by the follow-
N02 + 02.
Given the NO concentration is known for this reaction, the re-
sultant concentration of NO2 can be determined. Ozone is added
to excess NO in a dynamic calibration system, and the NO channel
of the chemiluminescent analyzer detects the changes in NO
concentration. A'fter the addition of O3, the observed decrease
in NO concentration on the calibrated NO channel is equivalent to
•the concentration of NO2 produced. The amount of NO generated
may be varied- by adding varying amounts of O3 from a stable
generator.
Dynamic calibration systems based on this principle are
commerically available, or may be assembled by the user. A
recommended calibration system is described in the Federal
Register and detailed in TAD.2 Persons desiring to assemble
their own calibration system's should follow the procedures in
TAD.2
Both the assembled and the purchased calibration systems
must meet the following conditions before being used for NO'
calibrations.
1. Use an NO standard gas traceable to an NBS-SRM.
2. Have a stable O3 source with an adjustable output.
3. Have a minimum total flow output that exceeds the
analyzer flow demand by at least 10%.
4. Be capable of generating an NO concentration that is
approximately 9'0% of the upper range limit (URL) of the NO
range to be calibrated.
5. Have a reaction chamber residence time of <2 min.
6. Have a dynamic parameter specification of ^2.75 ppm-min
at the operating conditions at which the calibration will be
performed.
It has been determined empirically that the NO-O reaction
goes to completion (<1% residual O3) if the NO concentration in
-------
Section No. 2.3.2
Revision No. 0
Date July 1, 1979
Page 4 of 27
the reaction chamber (ppm) multiplied by the residence time (min)
of the reactants in the chamber is >_2.75 ppm-min. The theory
behind the development of this equation is in the Federal
1 2
Register and in TAD.
2.3.2 GPT Calibrator Check Procedure - The following procedures
and equations should be used to determine whether an existing GPT
calibration system will meet required conditions for a specific
calibration.
For calibrators that have known pre-set flow rates, use
Equations 2-5 and 2-6 of steps 7 and 8 to -verify the required
conditions. If the calibrator does not meet specifications,
follow' the complete procedure to determine what flow modifica-
tions must be made.
1. Select an NO standard gas that has a nominal concentra-
tion in the range of 50 to 100 ppm. Determine the exact concen-
tration [NO]STDa by referencing against an NBS-SRM, as dis-
cussed in Section 2.0.7.
2. Determine the volume (cm ) of the calibrator reaction
chamber (VRC)- If the actual volume is not known, estimate the
volume by measuring the approximate dimensions of the chamber and
using an appropriate formula such as V = ^nr for a sphere or
2 "
V = rtr 1 for a cylinder. The reaction chamber should riot be con-
fused with the mixing chamber where the dilution air and the gen-
erated NO2 are mixed.
3. Determine the required minimum total flow output (FT)
using Equation 2-1,
F = analyzer flow demand (cm /min) x i'. Equation 2-1
If more than one analyzer is to be calibrated at the same time,
multiply FT by the number of analyzers.
<§
Throughout this method description the notation [NO] will denote
the concentration of NO; similarly for [NO_] and [NO ].
-------
Section No. 2.3.2
Revision No. 0
Date July 1, 1979
Page 5 of 2.7
4. Calculate the NO concentrations [NO] needed to
approximate 90% of the URL of the NO2 analyzer to be calibrated,
using Equation 2-2,
'•N0^OUT = URL of analYzer (ppm) * 22_. Equation 2-2
OUT _.
5. Calculate the NO flow (FNO) required to generate the
NO concentration [NO]OUT/ using Equation 2-3,
_ [NO]OUT X FT
FNO -- '• TNOT - ' ' Equation 2-3
L JSTD
6. Calculate the required flow through the ozone gen-
erator (FQ), using Equation 2-4,'
F -X FNO X VRC ^
*0 -]/ 2.75.ppm-min ~ FNO' Equation 2-4
7. Verify that the residence time (tR) in the reaction
chamber is <2 rain, using Equation 2- 5,
_ RC
tR ~ F—+~F— -2 min- Equation 2-5
O rNO
8. Verify that the dynamic parameter specification (P ) of
the. calibrator's reaction chamber is I2.75ppm-min using
Equation 2-6,
Note: if tR is >2 min or if PR is <2.75 ppm-min, changes'in flow
conditions (FT/ FQ, FNQ) or in the reaction chamber volume (V ),
or both will have to be made, and tR and PR will have to be^e-
calculated. '
9. After Equations 2-5 and 2-6 are satisfied, calculate
the diluent air flow (FD) using Equation 2-7,
-------
Section No . 2.3.2
Revision No. 0
Date July 1, 1979
Page 6 of 27
FD = FT " F0 ~ FNO' Equation 2-7
2.3.3 Example Calculation - Following is an example calculation
that can be used to determine whether an existing GPT calibrator
will meet the required conditions for a specific calibration.
For this example, it is assumed that only the volume of the
reaction chamber, VRC/ and the concentration of the NO standard,
[NO]STD, are known. All flow settings (FNQ, FQ/ FT/ and FD) will
be calculated. In many uses, these flow settings are known and
need only to be substituted in Equations 2-5 and 2-6 to verify
the required conditions. Before doing any calculations, the URL
and flow demand of the analyzer being calibrated must be known.
Operating parameters are determined from the operations manual:
Upper range limit =0.5 ppm, and
Flow demand = 2500 cm /min..
Volume of calibrator reaction chamber is determined by physical
measurement;
VRC = 180 cm3.
The concentration of the. NO standard gas to be used is de-
termined by reference against an NBS-SRM (Section 2.0.7),
[NO]STD =50.5 ppm.
1. Determine the minimum total flow (F_) required at the
output manifold using Equation 2-1,
FT = 2500 cm3/min (iI2) = 2750 cm3/min. .
Because low flows are difficult to control and measure, it is
often advantageous to set a higher total flow than needed.
2. Determine the highest NO concentration, [NO] , re-
quired at the output manifold, using Equation 2-2,
-------
Section No. 2.3.2
Revision No. 0
Date July 1, 1979
Page 7 of 27
Qf)
[NO]OUT = °*5 ppm (} = °-45
3. Calculate the NO flow (FNQ) required to generate the NO
concentration [NO]QUT, using Equation 2-3,
v - 0-45 ppm x 2750 cm3/min _ OA c ,,3 , .
FNQ -- 50. -5 ppm - -- 24-5 cm /min-
4. Calculate . the require^ flow rate of the ozone generator
(FQ) using Equation 2-4,
L
r -1/5
•O -y
• 3
0.5 ppm x 24.5 cm /min x 180 cm Oy1 c 3 , .
2.7 - - -- 24'5 cm /min
2.75 ppm-min
= /80984 cm6/mih2 - 24.5 cm3
3
'80984 cm /min - 24.5 cm /min = 260.08 cm /min.
5. Verify that the residence time (tR) in the reaction
chamber is <2 min. using Equation 2-5,
3
> _ ^___ 180 cm « /-^ •
t-.. - = : = = Q.63 mi-n.
260.08 cmj/min'•+ 24.5 cm /min
6. Verify the dynamic parameter specification (P_) of the
• ^
calibrator reaction chamber, using Equation 2-6 and previously
determined, values,
'PR = 50.5 ppm x '. 24 5 cm3/min
260.. 08 cm /min + 24.5 cm3/min
v 180 cm ^ „,_
3 5—: =2.75 ppm-min.
260.08 cnT/min + 24.5 cm /min
7. Calculate the diluent air flow (FD) required at the
mixing chamber, using Equation 7,
FD = 2750 cm3/min - 260.08 cm3/min - 24.5 cm3/min = 2465 cm3/min
-------
Section No. 2.3.2
Revision No. 0
Date July 1, 1979
Page 8 of 27
2.4 Calibration Procedures
The procedures for multipoint calibration of an oxides of
nitrogen analyzer by GPT of an NO standard with 0_ are specified
1
in the Federal Register. To facilitate these procedures, opera-
tional and calculation data forms, have been developed. These
forms will aid in conducting a calibration and in providing for
the quality assurance checks. Detailed descriptions of the
calibration ' theory and procedure's for GPT are in the Federal
1 2
Register and in TAD.
Documentations of 'all data on the station, instrument, cali-
brator, - reference standard, and calibration procedures are of
prime importance since the validity of the 'data collected by the
instrument is dependent on its calibration.
2.4.1. General Calibration Recommendations - Calibration must be•
performed with a calibrator that meets all conditions specified
in Subsection 2.3.2. Flow settings (with the exception of the NO
flow," FNQ) and the concentration of the NO standard, [NO]STD,
used in the GPT' calibration for NO2 must be the same as those
used in the calculations of specified conditions.
The user should be sure that all flow meters are calibrated
under the conditions of use against a reliable standard such as a
soap bubble meter or wet test meter. All volumetric flow rates
should be corrected to 25°C (78°F) and 760 mm (29.92 in.). Hg.
Calibrations of flow meters are discussed in TAD2.
Precaution must be taken to remove 02 and other contaminants
from the NO pressure regulator and the delivery system prior to
the start of calibration to avoid .any conversion of the standard
NO to NO2. Failure to do so can cause significant errors in
calibration. This problem may be minimized by:
1. Carefully evacuating the regulator, when possible,
after it has been connected to the cylinder and before opening
the cylinder valve;
2. Thoroughly flushing the regulator and the delivery
system with NO after opening the cylinder Valve;
-------
Section No. 2.3.2
Revision No. 0
Date July 1, 1979
Page 9 of 27
3.- Not removing the regulator from the cylinder between
calibrations unless absolutely necessary.
o
Further discussion of these procedures is given in TAD .
2.4.2 Calibration Procedure for NO and NO , - The GPT requires
J\
the use of the NO channel of the analyzer to determine the amount
of NO2 generated by titration. Therefore, it is necessary "to
calibrate and determine the linearity of the NO channel before
proceeding with the NO2 calibration. In some analyzers it is
also necessary to calibrate the NO channel. This can be done
^t
simultaneously with the NO calibration. The following procedure
uses the calibration data form, Figure 2.1, to aid in the collec-
tion and documentation of calibration data. During the calibra-
tion, the analyzer should be operating in its normal sampling
mode, and the test atmosphere should pass through all filters,
scrubbers, conditioners., and other components used during normal
ambient sampling and as much of the ambient air inlet system as
is practicable-. All operational adjustments to. the. analyz.er
should be completed prior to the calibration.
1. Record the station name and address on the calibration
data form.. Identify individual stations by their official names
and addresses. Where appropriate, station name, and address
should be the same as those appearing on the SAROAD site identi-
fication form for that station. This will help to eliminate any
confusion by persons not familiar with the station.
2. Identify the person performing the calibration and re-
cord the-date of calibration.
3. Identify the analyzer being calibrated. The manufac-
turer's name, model, and serial number should be recorded.
4. Identify the calibration apparatus used. If the cali-
brator was purchased, record the manufacturer's name, model, and
serial number. Calibrators, assembled by the user should be
assigned an identification number so' that calibrations can be
referenced to that particular apparatus.
5. Identify, by supplier and cylinder number, the refer-
ence standard to be used. Record the concentration of the cali-
-------
Section No. -2.3.2
Revision No. 0
Date July 1, 1979
Page 10 of 27
2.
3.
6.
7.
Station
Calibrated by
Analyzer mfgr.
S7C/?7£
SJo/AJo,///a
NO reference standard
Supplier
Concentration [N0]0 ''
Std
NO- impurity,
Reference to NBS-SRM
By
Zero knob setting
Span knob setting
Temperature
Date
- 79
4. Calibrator mfgr.
Model
S/N
G-P-r
Cylinder number ^
Cylinder pressure /s-p o jt?S~/'<3
o ^^
/L<9-
Date
NO
NO NO
Barometric pressure
Equations used for NO/NO3;/NO calibration
Equation 2-8
WOUT - F7C
fNO
Equation 2-9
(NO
'
Equations 2-10, -1QA, -10B
Response {% scale) = [NO1OUT 100 + Zv,^.
URL N0
For N02 substitute [NO2]QUT and ZNQ .
For NO substitute [NO l_,_ and Zwn .
"NO.
Equation 2-11
- [NO]
REM
FNO + F0 + FD
If tNO2'lMp ~ ° use Equation 2-11A.
Equation 2-11A
FNO =• f-low rate of NO standard.
FQ = flow rate of air through 0,
generator. •
FD = flow rate of dilution air.
.concentration at the
output manifold.
[NO]-T = concentration of the
undiluted NO standard.
[NO2lIMp = concentration of NO_
impurity in the
. standard NO cylinder.
URL = upper range limit.
• ^NO-'oRIG = concentration of NO
before 03 is added
during GPT.
'REM
during GPT.
after O3 is added
ZNO' ZNO ' 2N00 = recorder re-
x 2 sponse to
zero air.
Figure 2.1 Example of a calibration data form (front side)
-------
Section NO. 2.3.2
Revision No. 0
Date July 1, 1979
Page 11 of, 27
NO/NO CALIBRATION AND LINEARITY CHECK
j\,
Calibration
points NO/NO
X
Zero
80% URL-
1
2
1
F + F
D 0'
3, .
cm /mm
£720'
3-3-
(NO]OUT,
ppm
0.0
0.'/-fiS'
0. 3.0O
o. /oo
4
NO
recorder,
% scale
S. 0
%t. o
¥$. o
If. 0
[N°xW
ppm
e> o
0. &S"
0. 3. oo
O . Joo
. 6
NO
recorder,
% scale
s:o
ft. o
vs~. o
zz'. o
NO2 CALIBRATION BY GPT
Calibration
points NO
Zero
ORIG
80% URL
1
2
7'
[N0x],
ppm
^-^5"
0. . /O
12 •
N02
recorder'
% scale
^. o
ff. o
4S<5~. O
15. 0
Figure 2.1. Example of a calibration data form (backside).
-------
Section No. 2.3.2
Revision No. 0
Date July 1, 1979
Page 12 of 27
bration gas and the amount of NO2 impurities for each cylinder as
determined by the user. Do not use cylinders with pressures <200
psig for calibration. It has been shown that, for some concen-
tratioiis, gases in cylinders become unstable at low pressures
(Section 2.0.7). Provide a record of NBS-SRM traceability for
any cylinder used in a calibration, and include' the date and the
name of the person who conducted the referencing.
6. Record the zero and the span knob settings after the
calibration is complete so that these settings can be used at a
later date to determine changes in the instrument performance
-characteristics.. Note: Some analyzers may have separate zero
controls for NO, NOx/ and NO2/- others may have separate zero con-
trols only for NO and NO ; still others may have only one zero
X
control common to all three channels.
7. Record the shelter temperature and barometric pressure
at the time of calibration.
, 8. Use the, NO/NO v part of. the data form (Figure 2.1) for
"
the systematic recording of data determined during 'calibration of
the NO and NOX channels of the analyzer. Because zero and cali-
bration adjustments differ between analyzers, the manufacturer's
.manual should be consulted before calibration is performed.
a. Auto ranging analyzers should be calibrated on
all ranges which are likely to "be used. Select the operating
range of the analyzer to be calibrated. Precision and accuracy
for NO2 calibration are best obtained when all three channels of
the analyzer are set to the same range.
b. Connect the recorder output cable(s) of the ana-.
lyzer to the input terminals of the strip chart recorder (s') .
Make all adjustments to the analyzer based on the appropriate
strip chart readings. Analyzer responses in the procedures given
herein refer to recorder responses.
c. Adjust flows of the diluent air and the 0_ genera-
tor air to obtain the flows determined in Subsection 2.3.2. Be
sure that the total air flow exceeds the total demand of the
-------
Section No. 2.3.2
Revision No. 0
Date July 1, 1979
Page 13 of 27
analyzer (s) connected to the output manifold so that no ambient
air will be pulled into the manifold vent. Record the sum of the
flows of diluent air (FD) and O3 generator air (FQ) in column 1
of Figure 2.1.
d. Allow the analyzer to sample zero air until stable
NO, NOX/ and N02 responses are obtained. After the responses
have, stabilized, adjust the analyzer zero control(s). (Offset-
ting the analyzer zero adjustments to +5% of scale is recommended
to facilitate observing the negative zero drift. ) Record the
stable zero air responses under column 4 for NO and column 6 for
NOx. Record the NO2 zero air response in column 12, Figure 2.1.
e. Adjust the NO flow from the standard NO cylinder
to generate an NO concentration of approximately 80% of the URL
of the NO channel. Measure the NO flow (FNQ) and record it under
column 2 on the SO'% URL line.
f. Calculate the exact NO concentration [NO]Q ,
using Equation 2-8, '
fNOl FNO X
L JOUT ~ F - +~~F - + F ' Equation 2-8
Calculate the exact NO concentration [NO ]nTTrr, using
. " - X UU -L
Equation 2-9,
[NO 1 - X (IN°3STD + f „.
L xJOUT ~ F ITT — +~F - : - • Equation 2-9
Record the [NO]QUT .under column 3 and the [NOx]QUT under column 5
on the 80% URL line.
g. Sample the generated concentration until the NO
and the NOx responses have stabilized. Adjust the NO span con-
trol to obtain a recorder response as determined by Equation
2-10,
Recorder response (% scale) = f URgUT x 100 U ZNQ . Equation 2-10
-------
Section No. 2.3.2
Revision No. 0
Date July 1, 1979
Page 14 of 27
where URL = nominal upper range limit of the NO channel being
calibrated, ppm. Note: Some analyzers may have separate span
controls for NO, NO , and NO,; others may have separate span con-
*» £+
trols only for NO and NO ; while still others may have only one
,X
span control common to all three channels. If only one span con-
trol is available, make the span adjustment on the NO. channel.
When adjusting the analyzer's NO span control, substitute the
J^
[NOX]QUT and the ZNQ 'in Equation 2-10 to determine the recorder
response. If substantial adjustments of the span controls are
necessary, recheck the zero span adjustments by repeating steps f
and g. Record the NO" recorder response under column 4 and the
NO recorder response under column 6 on the 80% URL line.
«Jt
h. After the zero and the 80% URL points .have been
set, determine two approximately evenly spaced points between
zero and 80% URL without further adjustment to the instrument.
These-additional points can be generated by either increasing the
dilution flow (FD) or by decreasing the FNQ. For each concentra-
tion generated, calculate the .exact NO and NO concentrations
X
using Equations 2-8 and 2-9. Record the required information for
each point under the appropriate column in the NO/NO table in
Figure 2.1.
9. Plot the- analyzer responses, expressed in % chart at
the NO recorder
-------
Section No. 2.3.2
Revision No. 0
Date July 1, 1979
Page. 15 of 27
100
CJ
z
'Q
UJ
O
Fi tted calibration
1 ine
Tolerance limits for instrument
1inearity check, +2%
Figure 2.2. Example of an NOx calibration relationship.
-------
Section No. 2.3.2
Revision No. 0
Date July 1, 1979
Page 16 of 27
Calibration
point
Zero
80% URL
1
2
•
Concentration ,
ppm
X
o
a. 40
#. 2o
O. /o
x2
O
0./L
d.O*!
0.0}
Recorder
reading,
% scale
y
JT
.0
-?.r
Zx =
Ix2 =
, Zy =
, Iy2 =
, Zxy =
5"
„ x = Ix/n =
/ y = ly/n =
and
n = number of calibration points.
The equation of the line fitted to the data is written as
Y = y + b(x-x) = (y-bx) + bx = a + bx,
where Y =• predicted mean response for corresponding x,
b = slope of the fitted line, and
a = intercept where the line crosses the y-axis.
b =
Zxy -
n
,2 .
oo. o
n
a = y - bx =
. 00
Figure 2.3. Calculation form for the method of least squares.
-------
Section No. 2.3.2
Revision No. 0
Date July 1, 1979
Page 17 of 27
set of' points. On the y-axis of the graph, locate and plot the y
intercept (a). Using the equation y = a + bx, calculate the
predicted y value using the 80% URL concentration for the x
value. Plot this second point on the graph. Draw a straight
line through these two points to give ' a best-fit line.
Figure 2:2 shows a calibration line plotted using this procedure.
Steps 9 and 10 should be repeated 'for the NO values.
X
11. After the best-fit line has been drawn for the NO and
the N0x calibrations, determine whether the analyzer response is
linear. To be considered linear, no calibration point should
differ from the best-fit line by more than 2% of full scale. A
simple test for linearity can be made by plotting a point 2% of
scale above and 2% of scale below the point where the fitted line-
crosses the 0.4-ppm line. Repeat this procedure where the fitted.
line crosses the 0.1-ppm line. .Draw a straight line through the'
. +2% points and the -2% points (Figure 2.2). These two lines de-
fine the limits between which the calibration points can fall and
the calibration curve be considered linear. Repeat any points
falling outside .these limits to eliminate calibration errors; if
the repeated points still fall outside the limits, consult the
manufacturer's manual on how to correct the nonlinearity.
2 •4 •3 Gas Phase Titration Procedure for NO,. - Having completed
the calibration of the NO and NOx channels, the NO2 channel may
now be calibrated by GPT. The Figure 2.1 (backside of the
calibration data form) allows for the systematic recording of the
data determined during the calibration of the NO£ channel of the
analyzer. Do not readjust zero and span knob .settings for the NO
and the NO channels.
.X
1. The N02 zero adjustment was made in step 8-d of the
N0/N0x calibration and need not be repeated. Record the de-
termined response under column 12 of the N02 calibration table.
2. N02 impurities, [NO2lIMp, found in the reference
standard must be recorded under column 10; if there is no impu-
rity, disregard this column.
-------
Section No. 2.3.2
Revision No. 0
Date July 1, 1979
Page 18 of 27
3. Adjust the NO flow (FNQ) to generate an NO concentra-
tion near 90% of the URL. Dilution air and O3 generator air
flows* should be the- same as used in the calculation of specified
conditions in Subsection 2.3.2. Sample this NO concentration
until the NO and NO responses stabilize. Using the NO calibra-
*i
tion relationship determined in step. 10, measure and record the
NO concentration under column 8, [NO]~_.T-,. Using the NO 'cali-
UKJ.LJ x
bration relationship obtained in step 10, measure and record the
NO concentration under column 7 [NO ]. Record both values on
X X
the line marked "ORIG."
4. Adjust the O3 generator to produce sufficient O3 to
decrease the NO concentration from 90% to 10% of full scale.
This will be equivalent to 80% of the URL of the uncalibrated' N02
channel. The decrease must not exceed 90% of the NO concentra-
tion determined in step 3 . After the analyzer responses stabi-
lize, determine the new NO and NO concentrations from their re-
x
spective calibration relationships . Record the NO concentration
**
under column 7, and the NO concentration under column 9, -..
Ktrl
The [NO]OR_G. will be the same value determined in step 3.
5. Calculate the resulting NO2 concentration, [NO-] ,
using Equation 2-11, and record it under column 11, [NO2]QUT.
= CNO]ORIG - [N°]REM + • Equation 2-11
NO 0 D
If there was no NO2 impurity in the NO reference standard,
Equation 2-llA may be used to Calculate [NO-] Q _.
[N02]OUT = -[NO]ORIG ~ [NO]REM' ' . Equation 2-llA
6. Adjust the NO2 span control to obtain a recorder re-
sponse using Equation 2-10A. This equation is derived from
Equation 2-10 by substituting ' [NO_2]QUT and ZNQ for [NO]QUT and
ZNO'
-------
Section No. 2.3.2
Revision No. 0
Date July 1, 1979
Page 19 of 27
[NO ]
Recorder response (% scale) = (—* x 100) + ZXT^
UKIj NO_
Equation 2-10A
Note: If the analyzer has only one or two span controls, the
span adjustments are made on the NO channel or on the NO and NO
channels, and no further adjustment .is made here for NO . If
substantial adjustment of the NO2 span control is necessary, it
may be necessary to . recheck the zero and span adjustments.
Record the NO2 recorder response under column 12.
7. •• While maintaining all other conditions, adjust the
ozone generator to obtain two other concentrations of NO evenly
spaced between the 80% URL point and the zero point. Record the
information for each point on the respective lines of the NO
calibration table.
.8, Repeat steps 9, 10, and 11 of Subsection 2.4.2 for the
N02 .recorder reading, column -12, and the corresponding calculated
concentration [NO2"]QUT, column 11. . -
2•4•4 Example NO and NO2 Calibration -
1. Complete steps 1 through 5 and step 7 of the NO/NO
calibration before starting the calibration, to document all in-
formation concerning the station, analyzer, calibrator reference
standard, and person performing the calibration. Because
analyzers have different operating characteristics, consult the.
manufacturer's operation manual before starting the calibration
procedure.
.2. Select the operating range (ppm) of the analyzer to be
calibrated. For this example, assume •that - all three channels
(NO, N0x, and N02) will be calibrated on the range of 0 to
0.5-ppm.
3. Be sure that the recorders are operating properly and
are connected to the correct output terminals of -the analyzer.
4. Connect the analyzer's sample line to the manifold of
the calibrator.
-------
Section No. 2.3.2
Revision No. 0
Date July 1, 1979
Page 20 of 27
5. Adjust the diluent air flow (FD) and the O3 generator
air flow (FQ) to obtain the flows close to those determined in
Subsection 2.3.2. Remeasure these flows for each calibration:
3
FD = 2460 cm /min @ STP, and
i
O
Fn = 260 cm /min @ STP.
Record the sum of.FD and FQ under column 1,
FD + FQ = 2720 cm3/min @ STP.
6.- Allow the analyzer to sample the zero air until the NO,
NO , and NO0 responses stabilize. Then adjust the analyzer zero
: «?V ^
control(s), and offset the analyzer zero adjustments to +5% of
scale to facilitate observing any negative zero drift. Record
the stable zero air responses of 5% under column 4 for NO and •
column 6 for NO . Record the NO., zero air response in column 12'.
x z
7. Adjust the NO flow from 'the, standard NO cylinder to
generate an NO concentration of approximately 80% of the URL of
the NO channel; and measure the NO flow (F ), and record under
column 2 on the 80% URL line.
3
F = 22 cm /min.
8. Calculate the exact NO. concentration .[NO]QUT using
Equation 2-8,
[NO]OUT = 2720 +°22 = 0'405 ?**'
Record this value on the 80% URL line of column 3. Calculate the
exact N0x concentration [NOx]OUT, using Equation 2-9,
rxio i - 22 x (50.5 + 0) _ . __
CN°x]OUT 2720 + 22 = °-405 PPm-
Record this value on the 80% URL line of column 5.
9. Sample the generated concentration until the NO and NO
X
responses have stabilized. Calculate the expected recorder
-------
Section No. 2.3.2
Revision No. 0
Date July 1, 1979
Page 21 of 27
response (% scale) for this concentration, using Equation 10,
Response (% scale) = (g'^05 x 100) + 5 = 86%.
Adjust the NO span.control to obtain a recorder reading of 86% of
scale, and record this reading on the 80% URL line of column 4.
Substitute the NO values in Equation 2-10; a response of
X
86% is determined. Adjust the NO span control and record this
X
reading under column 6.
10. Generate two approximately evenly spaced points be-
tween zero and the 80% URL by changing either FNQ or F_. In this
example, F was changed. Allow each trace to stabilize before
moving to the next calibration point. When each trace has stabi-
lized, record the required data in the appropriate column of the
NO/NO calibration table.
Jt
11. Plot the analyzer response in % chart from column 4
(y-axis) versus the corresponding calculated concentration
[NO]QUT from column 3 (x-axis.). A straight line of best fit is
now calculated by the method of least squares. For this example,
the slope (b) is 200 with a y-intercept of 5%. Plot the calibra-
tion relationship as in Figure 2.2. To check linearity, draw the
+2% and -2% lines parallel to this calibration line. In this.
example, the analyzer response is linear. ' • •
12. Adjust the NO flow (FNQ) to generate an NO concentra-
tion near 90% of the NO range. For this example, a concentration
90
of TOO x °'50 ppm (or °'45 ppm) is used- Tnis value need only be
approximated. After, the response has stabilized, use the NO
calibration relationship determined' in step 11 to arrive at the
actual concentrations. Record this value oh the' line marked
"ORIG" under column 8 [NO]ORIQ. If the NOx channel is moni-
tored, determine NO . concentrations from the NO calibration
x ' X
relationship, and record the values under column 7.
13. Adjust the O3 generator to produce sufficient. 0_ to
reduce the NO concentration from 90% of full scale (0.45 ppm) to
of full scale (0.05 ppm). Determine the actual NO concentra-
-------
Section No. 2.3.2
Revision No. 0
Date July 1, 1979
Page 22 of 27
' . ' *
tion remaining from the calibration relationship, and record the
value on the 80% URL line .under column 9 [NO]...,,.... [NO]^nTO is
Khjl"] UKlLr
the same value determined in step 12.
14. The resulting NO2 concentration is now calculated.
Because there were no NO2 impurities present in the NO standard
cylinder, Equation 2-11A may be used.
[NO2]QUT = 0.45 - 0.05 = 0.40 ppm NO2.
15. Calculate the required recorder response using
Equation 2-10,
Recorder response (% scale) = '(—-^ x 100) + 5 = 85%.
Adjust the NO2 span control to obtain a recorder response of 85%.
Record this value under column 12.
..16. Adjust the ozone generator for two additional concen-
trations of NO2/- approximately evenly spaced between the 80% URL
point and the zero point. Record the required data under the
appropriate columns of the NO2 calibration table (Figure 2.1).
17. Plot the analyzer response in % chart from column 12
(y-axis) versus the corresponding calculated concentration
t^a-'oUT from column 11 (x-axis). Proceed as in step 11 to
determine a straight line of best fit and linearity.'
-------
Section No. 2-3.2
Revision No. 0
Date July 1, 1979
Page 23 of 27
Calibration
point
Zero
set point
80% URL
1
2
1
tN°2W
(x)
o.o
0. 40
J. 2.0
0. /O.
2
tN°xWG
^. ^r
-------
0.5
0.4
1. 0.3
n.
Q.
o
o
0.2
0.1
0.1
Section No. 2.3.2
Revision No. 0
Date July 1, 1979
Page 24 of 27
Efficiency- = Slope x
0.2
0.3
[N°2JOUT' Ppm
Figure 2.5. Converter efficiency relationship
-------
Section No. 2.3.2
Revision No. 0
Date July 1, 1979
Page 25 of 27
2.5 Determination of NO^ to NO Converter Efficiency
A data form (Figure 2.4) has been developed for determining
the converter efficiency. The following procedure is for use
with this data form.
1. Values for columns 1, 2, and 3 of the converter effi-
ciency data form are taken directly, from the NO2 table of the
calibration data form.
•a. Column 1 [NO2]OUT is from column 11 [NO2].0UT of the
table. .
b. Column 2 [N0x] ORIG is from the line marked "ORIG" of
column 7 [NO ] of the table; this value will be the same for all-
•«*• ' . '
lines of column 2.
c. Column 3 tN°x3REM is from the appropriate calibration
points of column 7 of the table.
2. Calculate -the quantity of NO2 converted to NO, labeled
for each point using Equation 2-12.
, [N°2]CONV = [N02]OUT * ([NOx]ORIG ~ [N°x3REM)- Equation 2-12
3. Plot [N02]CONV (y-axis) versus [NO2]QUT (x-axis), the
converter efficiency curve (Figure 2.5), and calculate the slope
(b) of the curve using either an appropriate calculator or the
calculation form (Figure 2.3) for the method of least squares.
4. Multiply the slope (b) of the curve by 100 to determine
average converter efficiency; if the efficiency is <96%, either
replace or service the converter.
2 . 6 Calibration Frequency
To ensure accurate measurements of the NO and NO- concentra-
tions, calibrate the analyzer at the time of installation, and
recalibrate it:
1. no later than three months after the most recent cali-
bration or performance audit which indicated analyzer response to
be acceptable; or
2. following any one of the activities listed below:
-------
Section No. 2.3.2
Revision No. 0
Date July 1, 1979
Page 26 of 27
a. an interruption of more than a few days in ana-
lyzer operation;
b. any repairs which might affect its calibration;
c. physical relocation of the analyzer; or
d. any other indication (including excessive zero or
span drift) of possible significant inaccuracy of the analyzer.
Following any of the" activities listed in item 2 above, the zero
and span should be checked to- determine if" a calibration .is
necessary. If the analyzer zero and span drifts do not exceed
the calibration limits in Table 9.1 of Section 2.0.9, Subsection
9.1.3, a calibration need-not be performed. If either the zero
or span drift exceed their respective calibration limit, investi-
gate the cause of the drift, take corrective action and calibrate
the analyzer.
-------
Section No. 2.3.2
Revision No. 0
Date July 1, 1979
Page 27 of 27
Table 2.1. ACTIVITY MATRIX FOR CALIBRATION PROCEDURES
Calibration
Activities
Acceptance limits
Frequency and method
of Measurement
Action if
requirements
are not met
Calibration
gases
Sec 2.0.7, Subsec 7.1-
Assayed against an
NBS-SRM quarterly
Sec 2.0.7
Working gas
standard is
unstable and/
or measurement
method is out
of control;
take corrective
action such as
obtaining new
calibration gas
Dilution gas
Zero air, free of
contaminants;
and Sec 2.0.7,
Subsec 7.1
See TAD
2
Return to sup-
plier, or take
appropriate cor-
rective action
with generation
system
Multipoint
calibration
(GPT)
1.
t_, < 2 min
K —
PR > 2.75 ppm-min
Method
.1. Subsec 2.3.2
2. Use calibration
procedure in Subsec
2.4; also TAD and
the Federal Register
3. Converter Effi-
ciency > 96%
2. Subsec 2.4,
TAD , Federal
Register and
Fig 2.1; see Sub-
sec 2. 1 for fre-
quency
3. Subsec 2.5 and
and Figs 2.4 and
2.5
1. Adjust flow
conditions and/
or reaction
chamber; volume
to meet sug-
gested limits
2. Repeat the '•
calibration ..
3. Replace or
service the
converter
-------
-------
Section No. 2.3.3
Revision No. 0
Date July 1, 1979
Page 1 of 10
3.0 OPERATION AND PROCEDURE
Essential to quality assurance are scheduled checks for
verifying the operational status of the monitoring system. The
operator should -visit the site at least once each week. Every
two weeks a Level 1 zero and span check must be made on the
analyzer.' Level 2 zero and span checks should be conducted at a
frequency desired by the user.
In addition .an independent precision .check between 0.08 and
0.10 ppm must be carried out at least once every two weeks.
Table 3.1 at the end of this section summarizes the quality
assurance activities for .routine operations.' A discussion of
each activity appears in the following sections.
To provide for documentation and accountability of activi-
ties, a checklist should be compiled and then filled out by the
field operator as each activity is completed. An example check-.
list is Figure 3.1.
In Subsections 3.1 and 3.2, reference is made to the sam-
pling shelter and the sample inlet .system. The design and con-
struction of these components of the sampling system" are not
within the scope of this document. An in-depth study of'these is
reported • in Field Operations Guide for Automatic Air Monitoring
Equipment, Publication No. APTD-0736, PB 202-249 and PB 204-650
U.S. Environmental.'Protection Agency, Office of Air Programs,
October 1972.
3.1 Shelter
The shelter's role in quality assurance is to provide a
temperature-controlled environment' in which the sampling equip-
ment can operate- at optimum performance. The mean shelter tem-
perature should be between 22° and 28°C (72° and 82°F). • A
thermograph should be installed at the shelter to record daily
fluctuations in temperature continuously. Fluctuations greater
than ±2°C (±4°F) may cause the electronic components of the
analyzer to drift and may introduce error into the data; thus the
fluctuations outside of the specifications should be identified,
-------
Section No. 2.3.3
Revision No. 0
Date July 1, 1979
Page 2 of 10
Site
Site
Site
ID
OOI
location
address
Inspect thermograph for temperature variations greater
than '±2°C (4°F). Identify time frame of any tempera-
ture level out of tolerance
Comments
Inspect sample introduction system for moisture, parti-
culate buildup, foreign objects, bre§kage, leaks
Comments
Is sample 'line connected to manifold?
Comments
Inspect data recording system
OK
Corrective
action taken
Legibility of trace
Ink supply
Paper supply
Chart speed selector
Signal range switch
0 Time synchronization
Comments
o
o
o
o
o
Inspect analyzer operational parameters
OK
Corrective
action taken
Sample flow rate
Oven temperature light
flashing
Analyzer in sample mode
Zero and span potentiom-
eters locked at correct
setting
Comments
Figure 3.1. Example of an operational checklist (front side).
-------
Signature
Section No. 2.3.3
Revision No. 0
Date July 1, 1979
Page 3 of 10
6 . Zero the analyzer
* 7. Is unadjusted zero within tolerance?
Comments /je^^y- 0£/ 0>£ »: S/..
i/ 8. Span the analyzer.
^ 9. Is unadjusted span within tolerance?
Comments
v 10. Enter. zero and span values on span check data form
vX ll. Return to sample mode
\/ 12. Record cylinder pressure of zero and span tanks
Zero air /3OO
Span air /£
13 . Close valve on zero and span tanks
Figure 3.1. Example of an operational checklist (backside).
-------
Section No. 2.3.3
Revision No. 0
Date July 1, 1979
Page 4 of. 10
and the data for the affected time period should be' flagged to
indicate possible discrepancies.
3.2 Sample Introduction System
The sample introduction system consists of an intake port,
the particulate and moisture traps, the sampling manifold and
blower, and the sampling line to the analyzer. The field opera-
tor, as part of the quality assurance program, should inspect
each of these components for breakage, leaks, and buildup of
particulate matter or other foreign objects; check for moisture
deposition in the sample line or manifold; see that the sample
line is connected to the manifold; .see that any component of the
sample introduction system that is not within tolerance is either
cleaned or replaced immediately. See Section 2.0.2 for more
details.
3.3 Recorder
During each weekly visit to the monitoring site, the field
operator should use the following list to check the recorder for
proper operation:
1. Ink trace for visibility.
2. Ink level in reservoir.
3. Chart paper for supply.
4. Chart speed control setting.
5. Signal input range switch.
6. Time synchronization.
Any operational parameter that is riot within tolerance must be
corrected immediately.
3.4 Analyzer
Specific instructions in the manufacturer's manual should be
read thoroughly before attempting to operate the analyzer. As
part of the quality assurance program, each site visitation
should include a visual inspection of the external operation of
the analyzer, the zero and span checks, and a biweekly precision
point check.
-------
Section No. 2.3.3
Revision No. 0
Date July 1, 1979
Page 5 of 10
3.4.1 Visual Inspection - During the visual inspection, the
field operator should inspect the external operating parameters
of the instrument. The parameters of concern will vary from
instrument to instrument, but in general they will include the
following:
1. .Correct setting of flow meters and regulators;
2. Cycling of temperature control indicators.
3. Temperature level if equipped with a pyrometer.
4. Verification that the analyzer is in the sampling mode
rather than the zero or the calibration mode.
5. Zero and'span potentiometers locked and set at proper
values.
3.4.2 Zero and Span Checks - Zero and span checks must, be used
to document within-control conditions. The purpose is to provide
interim checks on the response of the instrument to known concen-
trations. If a response falls outside of the prescribed limits,
.the analyzer is considered out of control, and '.the, cause must be
determined and corrected. A quality control chart can be used to
provide a visual check to determine if the analyzer is within
control conditions. A zero check should be conducted at the same
time that the span check is performed.
A system of Level 1 and Level 2 zero span checks is recom-
mended. These checks must be conducted in accordance with the
specific guidance given in Subsection 9.1 of Section 2.0.9.
Level 1 zero and span checks must be conducted every two weeks.
Level 2 checks should be conducted in between the Level 1 checks
at a frequency desired by the user. Span concentrations for both
levels should be between 70 and 90% of the -measurement range.
The data should be recorded on the zero span check form, Figure
3.2.
Zero and span data are to be used to:
1. provide data to allow analyzer adjustment for zero and
span drift;
2. provide a decision point on when to calibrate the
analyzer;
-------
Section No. 2.3.3
Revision No. 0
Date July 1, 1979
Page 6 of 10
Site ID
Location
Pollutant
Analyzer
Address 33S&
Serial number
Date
J-/-77
J-/r-77
5-2.9-77
^ /
Technician
<^:.X
^r-. T.
^l.T.
•
Unadjusted
zero,
% chart '
d:o
^r. £
.r. o
•
Span
concentration,
ppm
0. 4o
a.
-------
Section No. 2.3.3
Revision No. 0
Date July 1, 1979
Page 7 of 10
3. provide a decision point on invalidation of monitoring
data.
Items 1 and 2 are described in detail in Subsection 9.1.3 of
Section 2.0.9. Item 3 is described in Subsection 9.1.4 of the
same section.
When the response from a span check is outside the control
limits, the cause for the extreme drift should be determined, and
corrective action should be taken. Some of the causes for drift
are listed below:
1. Lack of preventive maintenance.
2. Fluctuations in electrical power supply.
3. Fluctuations in flow.
4. Change in zero air source.
5. ' Change in span gas concentration.
6. Degradation of photomultiplier•tube.
1. Electronic and physical components not within manufac-
turer's specifications. •
Corrective actions for the above can be found in the manufac-
turer's instruction/operations manual.
3.4.3 Precision Check - For continuous analyzers, a periodic
check is used to assess the data for precision. A one-point
precision check must be carried out at least once every 2 'weeks
on each analyzer at an NO2 concentration- between 0.08 and 0.10
ppm. The analyzer must be operated in its normal sampling mode,
and the precision test gas must pass through all filters, scrub-
bers, conditioners, and other components used during normal
ambient sampling. The standards from which precision check test
concentrations are obtained must be traceable to NBS-SRM. Those
standards used for calibration or auditing may be used.
Precision Check Procedure
1. Connect the analyzer to a precision gas that has a
concentration between 0.08 and 0.10 ppm. An NO- precision gas
may be generated by either the GPT or a NO2 permeation tube. If
-------
** -»t be made
Section No. 2 3
i0n NO. 6
conjunction
Precision.
-------
Section No. 2.3.3
Revision No. 0
Date July 1, 1979
Page 9 of 10
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-------
Section No. 2.3.3
Revision No. 0
Date July 1, 1979
Page 10 of 10
Table 3.1. DAILY ACTIVITY MATRIX
Characteristic
Shelter temper-
ature
Sample in.tro-
duction system
Recorder
Analyzer oper-
ational set-
tings
Analyzer oper-
ational check'
Precision
check
Acceptance limits
Mean temperature be-
tween 22° and 28°C
(72° and 82°F), daily
fluctuations not
greater than ±2°C (4°F)
No moisture, foreign
material, leaks, ob-
structions; sample line
connected to manifold
1. Adequate ink sup-
ply and chart paper
2. Legible ink traces
3. Correct settings of
chart speed and range
switches
4. Correct time
1. Flow and regulator
indicators at proper
settings•
2. Temperature indi-
cators cycling or at
proper levels
3. Analyzer set in
sample mode
4. Zero and span con-
trols locked
Zero and span within
tolerance limits as
described in Subsec
9.1.3 of Sec 2.0.9
Assess precision as
described in Sec 2.0.8
and Subsec 3.4.3
Frequency and method
of measurement
Edit thermograph
_ chart daily for
variations greater
than ±2°C (4°F.)
Weekly visual inspec-
tion
Weekly visual inspec-
tion
Weekly visual inspec-
tion
Level 1 zero and span
every 2 weeks; Level
2 between Level 1
checks at frequency
desired by user
Every 2 weeks,
Subsec 3.4.3
Action if
requirements
are not met
1. Mark strip
chart for the
affected time
period
2. Repair or
adjust tempera-
ture control
system
Clean, repair,
or replace as
needed
1. Replenish
ink and chart
paper supply
2. • Adjust re-
corder time to
agree 'with clock;
note on chart
Adjust or repair
as needed
1. Isolate
source of error,
and repair
2. After cor-
rective action,
recalibrate
analyzer
Calculate, re-
port precision,
Sec 2.0.8
-------
Section No. 2.3.4
Revision No. 0
Date July 1, 1979
Page 1 of 5
4.0 DATA REDUCTION, VALIDATION, AND REPORTING
Quality assurance activities for data reduction, validation,
and reporting are summarized in Table 4.1 at the end of this sec-
tion.
4.1 Data Validation
Monitoring data of poor quality may be worse than -no data.
Data validation 'is one activity of a quality assurance program to
screen data for possible errors or anomalies. Reference 8 recom-
mends several statistical screening procedures for ambient air
quality data that should be applied to identify gross data anom-
alies. Subsections 4.1.1 and 4.1.2 recommend two data validation
checks.
4.1.1 Span Check Drift - The first level of data validation
should be to accept or reject monitoring data based upon routine
periodic analyzer checks. It is -recommended that results from
the Level 1 span checks discussed in Section 2.3.3.be used as the
first level of data validation for accepting data. This means up
to two weeks of monitoring data may be invalidated if the span
drift for a Level 1 span check is equal to or greater than 25%.
For this reason, it may be desirable to perform Level 1 checks
more often than the minimum recommended frequency of every two
weeks.
4.1.2 Edit of Strip Chart
The. strip chart should be edited to detect signs of the
monitoring system's malfunctions that result in traces on the
chart that do not represent "real" data. When reviewing a strip
chart, typical indicators of malfunctions to watch for are:
1. A straight trace (other than minimum detectable) for
several hours.
2. Excessive noise indicated by a vide solid trace, or
erratic behavior such as spikes that are sharper than is possible
with the normal instrument response time. Noisy outputs may
occur when analyzers are exposed to vibrations.
3. A long steady increase or decrease in deflection.
-------
Section No. 2.3.4
Revision No. 0
Date July 1, 1979
Page 2 of 5
4. A cyclic trace pattern with a definite time period
indicating a sensitivity to changes in temperature or parameters
other than NO2 concentration.
5. A trace below the zero baseline that may indicate a
larger than normal drop in ambient room temperature or power
line voltage.
6. Span drift equal to or greater than 25%, Subsec. 9.1.4
in Section 2.0.9.
Void data for any time interval for which a malfunction of
the sampling system is detected.
4.2 Data Reduction
To obtain hourly average concentrations from a strip chart
record, the following procedure may be used.
1.' Be sure the strip chart record for the sampling period
has a zero trace at the beginning and end of the sampling period.
2. Fill in the identification data called'for at the top
of the hourly average data form, Figure 4.1.
3. Use a straight edge to draw a line from the zero base-
line at the start of the sampling period to the zero baseline at
the end of the sampling period. This line represents the zero
baseline to be used for the sampling period.
4. Read the zero baseline in % of chart at the midpoint of
each hour interval, and record the value on the data form.
5. Determine the hourly averages, for the interval of
interest between two vertical hour lines, by placing a transpar-
ent straight edge parallel to .the horizontal chart division lines '
and by adjusting the straight edge between the lowest and highest
points of the trace in that interval so that the area above the
straight edge and bounded by the trace and the hour lines is
estimated to equal the area below the straight edge and bounded
by the trace and'hour lines,'as shown below.
-------
Section-No. 2.3.4
Revision No. 0
Date July 1, 1979
Page 3 of 5.
Llty Z34/TZ7A/ , nff/O
Site location -2,100 TVA/S-^ / *•*/?
L*flG CKc 3T y — "7V7// A/^f^A/'
CALIBRATION CURVE: Slope (b) = ^
Site number 3^
Pollutant ,
&
Check
—
Difference
Ori;
/5
j-j
— ' I..-
••^"•HMBM^M
Check
"
- —i- i •,
y, Add + 5
Ori
2&
•Z-"2~
Check
x, ppm
Orig
0. Og
Check
Figure 4.1. Sample data form for recording hourly averages.
-------
Section No. 2.3.4
Revision No. 0
Date July 1, 1979
Page 4 of 5
Read and record the percentage of chart deflection on the hourly
average data form. Repeat the procedure for all the hour inter-
vals sampled which have -not been marked invalid. Record all
values on the hourly average data form in the column headed
"Reading - Original".
6. Subtract the zero baseline value from the reading value
and record the difference on the hourly averages form.
7. Add the percentage ,of zero offset, +5, to the dif-
ference on the hourly'averages form.
8. Convert the % chart values to N02 concentrations in
ppm using the most recent calibration curve. Record the ppm NO7
values in the last column of the hourly averages form.
An alternative method for converting % chart to ppm is to
use the following' equation and thus to eliminate steps 6, 7, and
8 of the above procedure.
y - y .
PPm = slope / , Equation 4-1
where
y = recorder reading in % scale, from step 5,
YZ = zero baseline in % scale, from step 4, and
Slope = slope of the calibration relationship, as deter-
mined in Section 2.3.2.
4.3 Data Reporting
Transcribe information and data from the hourly averages
form to. a SAROAD hourly data form; see Section 2.0.3 for details
and basic instructions for filling out the SAROAD. If the data
are to be input to the National Aerometric Data Bank, obtain
further instructions from the SAROAD User's Manual, APTD-0663.
.AREA ABOVE LINE
STRAIGHT EDGE ^V^V BE1-°H LINE
1200 1300 1400 T500 f600(
-------
Section No. 2.3.4
Revision No. 0
Date July 1, 1979
Page 5 of 5
Table 4.1. ACTIVITY MATRIX FOR DATA REDUCTION
Activity
Acceptance limits
Frequency and method
of measurement
Action if
requirements
are not met
Data validation
Span check
• drift
Level 1 span check
<25%, Sec 2.3.3
Perform Level 1 check
at least every two
weeks, Sec 2.3.3
Invalidate data;
take corrective
action; increase
frequency of Level
1 checks until
data are acceptable
Edit strip
chart
No signs of malfunc-
tions
Visual.ly edit each,
strip chart; see
Subsec 4:1
Void data for
time, interval
for which
malfunction of
sampling system
is detected
Data reduction
Stepwise procedure
for data reduction
(Subsec 4.2)
For each strip chart,
follow the method
given, in Subsec 4.2
Review the
reduction
procedure
Data reporting
Follow Reference 6 in
transcribing data to
SAROAD hourly data
form
Visually check
Review the
data trans-
cription
procedure
-------
-------
Section No. 2.3.5
Revision No. 0
Date July 1, 1979
Page 1 of 2
5.0 MAINTENANCE
5.1 Preventive Maintenance
Because maintenance requirements vary from instrument • to
instrument, the supervisor should refer • to the manufacturer's
manual for a specific analyzer. After becoming familiar with
these maintenance requirements, the supervisor should develop a
suitable preventive maintenance schedule.
5.2 Corrective Maintenance
. Corrective maintenance is defined as nonscheduled main-
tenance activities that become .necessary due to system malfunc-
tions. A few examples of corrective maintenance are: replacing
a damaged pump diaphragm, cleaning a clogged sample line, and
replacing a N02 converter. The need for corrective maintenance
becomes apparent 'as the 'operator performs the operations de-
scribed in Section 2.3.3.,' When the need for corrective mainte-
nance arises, the operator should refer to the owner's manual for
trouble-shooting procedures. A detailed maintenance record of
corrective activities should be kept on file for each analyzer at
the site to identify reoccurring malfunctions. A maintenance log
appears in Figure 5.1.
-------
Section No. 2.3.5
Revision No. 0
Date July 1, 1979
Page 2 of 2
Site number
Sit? 1 ocat.ion
Site address
Pollutant
Instrument
Serial number
Date
Tech-
nician
Event
initiating
maintenance
Maintenance
activity
Comments
/-SB- 77
c j;
TO
OF ±
AT
J~-/O
TO Sz
c JT
AT
rO JSS.
&V
Figure 5.1 Sample maintenance log.
-------
Section 2.3.6
Date June 5, 1984
Page 1
6.0 AUDITING PROCEDURE
An audit is an independent assessment of the accuracy of
data. Independence is achieved by haying the audit made by an
operator other than the one conducting the routine field mea-
surements and by using audit standards and equipment different
from those routinely used in monitoring. The audit should be a
true assessment of the measurement process under normal op-
erations without any special preparation or adjustment of the
system. Routine quality control checks.(such as zero and span
checks in Section 2.3.3) conducted by the operator are necessary
for obtaining and reporting good quality data, but they are not
considered part of the auditing procedure.
Three audits are recommended: two performance audits and'a
systems audit. The performance audits are described in Subsec-
tions 6.1 and 6.2, and the systems audit is described in Sub-
section 6.3. These audits are summarized in Table 6.1 at the
end of this section.
Proper implementation of an auditing program will serve a
twofold purpose: (1) to ensure the integrity of the data and
(2) to assess .the data for accuracy. The technique for estima-
ting the accuracy of the data is given in Section 2.0.8 of this
volume of the Handbook.
6.1 Performance Audit
A performance audit consists of challenging the continuous
analyzer with known concentrations of NO- within the measurement
range of the analyzer. The difference between the known concen-
tration and the analyzer response is obtained, and an estimate
of the analyzer's accuracy is determined.
6.1.1 Equipment - Personnel, equipment, and reference materials
used in conducting audits must be independent from those nor-
mally used in calibrations and in span checks.
-------
Section 2.3.6
Date June 5, 1984
Page 2
Known concentrations of NO2 can be generated by the GPT of
NO with 03 to produce NO2 or by the use of an NO2 permeation
tube and a dynamic dilution system. The NO and NO channels are
to be audited by dilution of the NO standard with zero air. All
audit gas standards must be traceable to NBS-SRM's as described
by the protocol in Sections 2.3.2 and 2.0.7. All flow rates
should be measured using a calibrated soap bubble meter or an
eguivalently accurate procedure.
Procedures used to generate NO, NOX/ and NO, con-
centrations, although not identical, are somewhat similar to the
procedures described in Section 2.3.2. If during a regular
field audit, the differences recorded for most analyzers are
either negatively or positively biased, a check of the' cali-
brator used in routine calibrations of the analyzers may be
advisable.
6'1-2 Audit Schedule - The recommended audit schedule depends
upon the purpose for which the monitoring data are being col-
lected. For example, Reference 3 requires that each analyzer in
State and Local Air Monitoring Networks (SLAMS.) be audited at
least once per year. Each agency must audit 25% of the refer-
ence . or equivalent analyzers each quarter. If an agency op-
erates less than four reference or equivalent analyzers, it must
randomly select analyzers for reauditing so that one analyzer
will be audited each calendar quarter and each analyzer will be
audited at least once a year.
Reference 7 requires that each PSD reference or equivalent
analyzer be audited at least once a sampling quarter. Results
of these audits are used to estimate the accuracy of ambient air
data.
6'1-3 Audit Procedures for NO. NO^. anj__gr^ _ Audits should be
conducted by challenging the analyzer with at least one audit
gas of known concentration from each of the following ranges
within the measurement range of the analyzer being audited:
-------
Concentration Range, ppm
Audit Point NO
1 0.03 to 0.08
2 0.15 to 0.20
3 0.35 to 0.45
4 0.80 to 0.90
The differences in concentrations (ppm) between the audit values
and the measured analyzer values are used to calculate accuracy,.
as described in Section 2.0.8.
Information on the station, analyzer, audit device, refer-
ence materials, and audit procedures is of prime importance
since the validity of audit results depends on accurate docu-.
mentation. The following procedures and ' audit report forms
(Figures 6.1, 6.2, 6.3, and 6.4) have been developed to aid in
conducting the audit..
Procedure for NO Audit -
1. Record the station name, address, analyzer manufac-
turer-, model, and serial number on the audit summary report.
2. Identify the person(s) performing the audit and the
date that the audit is performed.
3. Record the type of audit device used. If the audit
device was purchased, record the manufacturer's name, model, and
serial number. If the audit device was assembled by the user,
assign it. an identification number so that audits can be ref-
erenced to that particular apparatus.
4. Identify the NO cylinder and the NBS-SRM used to
verify the audit concentration. Reanalyze the NO cylinder every
3 mo, following the protocol in Section 2.0.7. Note: Section
2.0.7 recommends reanalysis every 6 mo; however, since quarterly
audits are recommended for continuous NO, analyzers3'7 and since
the integrity of the audit results must not be subject to chal-
lenge, quarterly reanalyses. of NO cylinders are recommended.
5. Identify the device used to measure the flow rates.
6. Attach appropriate pressure regulator to the NO ref-
erence cylinder, and take care to flush the pressure regulator
-------
Section 2.3.6
Date June 5, 1984
Page 4
1. Station
Analyzer
. v\
2. Audit performed by
3. Audit device used
Date
S-Vs-'VN.
4. NO standard used
^. yj.\n* 2. Concentration
Verified against NBS-SRM
By ^s\v\
Date
5.
6.
Flow measured with
Analyzer response to zero air NO zero = g-. 0 % scale
N02 zero = *r. a % scale
NO zero = <=?•. o % scale
AUDIT SUMMARY
Analyzer
channel
NO
N02
N0x
Audit value,
ppm
0 .000
o . ^**
n. 3oo
o.oso
O . ooo
O.A^.V
a ^rvz
o. oKn
Response,
% scale
!T.£>
V».o
H^.«r
\5.0
^-.^
*0.£.
Kai.3-
\^.1?
Response,
ppm
o .000 .
OM«
a . Sot
o .oso
Q .OOO
o .ans*
0 . l«6,
o .oH^
Percent
difference
(Equation 4)
__-
-V \.V
+• v.s-
o.o
4-aA
-v M ,«r
-V -H. S
Figure 6.1 Example of an audit summary form.
-------
Equation 1
PPM
Y-a
b
Equation 2
r _ V
or F
NO
_ V
avg
Equation 3
[NO].
[NO]
STD
NO
Section 2.3.6
Date June 5, 1984
Page 5
Y " % scale
b = slope of the calibration line
a = intercept of the calibration
line
FT = total flow rate, cm /min
FNQ = flow rate of NOSTD> cm3/min
V « volume measured with soap
bubble meter
Equation 4
X difference
[NO]R - [NO]A
"avg
average time in minutes
[H01
x 100
For N02, substitute [N02]R and (NO]A
For NOX, substitute [NOX)R and tNOxJA
Ecruation 5
Equation 6
"avg
Zero air:
INO]__D • concentration of NO -
standard used, ppm
[NO]A « NO audit concentration, ppm
[NO]R * analyzer NO response, ppm
[NO,]. * NO- audit conform GPT of
n NO1'with Oj, ppm
• NO concentration before
titration with O,, ppm
NO concentration remain-
ing after titration with
O3, ppm
[NO]R = &% scale, 0.000 ppm (Eq. 1, Fig 6.2)
[NO]A SB &. OOP ppm
Audit point: [NOJR = <\I..Q % scale, 0.
[NO]A = p. i\s0 ppm (Eq 3)
ppm (Eq 1, Fig 6.2)
Flow
measurements
Total flow
.
t,
min
O . 3.SO
o. nHo
e>.Zf.r>
o. ar\(a
?> . on^
o . 2,*^
^vg'
min
O- 35*0
o. a^t
V,
cm
\ooo
*
\0
FT/ . cm /min
(Equation 2)
-Hooo
^G. o
Figure 6.2 Example of an NO audit calculation form.
-------
Section 2.3.6
Date June 5, 1984
Page 6
Audit point: [NO:|R =
[NO]A =
% scale< Q-SLO*> ppm (Eg 1, Fig 6'. 2)
ppm (Eg 3)
Flow
measurements
Total flow
t,
min
& . 3£oO
O, 3-xo
o . 3-KO
0. (*ZS
&(*
tavg'
min.
o . 3.^0
0 >(*$£'
v,
cm
\oc?o
\0
FT/ cm /min
(Eguation 2)
•Kooo
\6>. O
Audit point:
[NO]R =
[NO]A"=
scale/ o -OS" ppm (Eq 1)
ppm (Eg 3)
Flow
measurements
Total flow
(FT)
NO flow
t,
min
. J -^<&
o . as-o
<^>. As-0
A. ^rv<=»
-^ . •er<9o
^2, H^O
tavg/
min
o.as'o
^-S^^o
v,
cm3
\ooo
\0
F_, cm /min
(Eguation 2)
•Kexoo
M,,^
NO audit calibration eguation (y = b x +a)
NO audit concentration (x) vs. analyzer response in % scale (y)
Slope (b) = _?^;a .
Intercept (a) = ^
Correlation (r) = \ .
Figure 6.3 Example of an NO audit calculation form.
-------
Section No. 2.3.6
Date June 5, 1984
Page 7
Audit
point
1
2
3
- i
. *
[NO]
scale
2.75 ppm-min, Equation 6-1
[NO]
RC
'NO
O + *NO
Equation' 6-2
Equation 6-3
-------
Section No. 2.3.6
Date June 5, 1984
Page 8
where
P = dynamic parameter specification/ determined
empirically/ to ensure- complete reaction of the
available 03, ppm-min,
[NO]_,_ = NO concentration in the reaction chamber/ ppm,
jKt.
tR - residence time in the reaction chamber, min,
[NO]__ - concentration of the NO gas cylinder, ppm
S__
,
= NO flow rate,- standard cm /min,
FQ * 03 generator air flow rate, standard cm /min, and
V_c « volume of the reaction chamber, cm .
The flow conditions to be used are selected according to
the following sequence:
a. Determine F_, the total flow rate required at the
output manifold (F_ = analyzer (s) demand plus 10% to 50% ex-
cess)". .
b. Determine F , the flow rate of NO required to gen-
erate the lowest NO concentration required at the output mani-
fold during the GPT (approximately 0.15 ppm).
0.15 x Fm . *.• r »
„ _ T Equation 6-4
FNO
c. Measure the system's reaction chamber volume; this
must be in the .range of approximately 100 to 500 cm .
d. Compute F . .
p _1[N°]STD XFNO.X VRC _
01 2.75 ' *NO. Equation 6-5
e. Compute tp, using Equation 6-3; verify that t^ < 2
XV J^ —
min.
-------
Section No. 2.3.6
Date June 5, 1984
Page 9
f. Compute F .
FD FT * F0 ~ FNO, - Equation 6-6
where
FD = diluent air flow, standard cm3/min.
Adjust FQ to the value determined above. FQ should not be
further adjusted during the NO-NOx or NO2 audit procedures; only
FNO (or PD-) and the °3 generator settings are adjusted during
the course of the audit.
9. Connect the analyzer sample line inlet to the glass
manifold of the audit device. The test atmosphere must pass
through all filters, scrubbers, conditioners, and 'other compo-
nents u-sed during normal ambient sampling and as much of the
ambient air inlet system as is practical.
10. Allow the analyzer to sample zero air until stable
responses are obtained. Record the analyzer zero values for all
channels audited in the appropriate spaces of the audit form,
Figure.6.1.
11. Generate the first up-scale audit point by adding the
NO reference gas to the zero air, making sure the generated con-
centrations are within one of the required concentration ranges.
12. After a stable trace is obtained, record the NO chan-
nel response [NO]R in % scale on the NO calculation form, Figure
6.2. Calculate the [NO]R, in ppm using Equation 1 of Figure
6.2, where b and a are the slope and intercept of the station
calibration line. .
13. Attach the soap bubble meter to the audit device
outlet line, and determine the total flow rate (F ) . Do not
adjust the audit device settings. Record the value in Figures
6.2 and 6.3, and calculate the total flow rate using'Equation 2.
14. Disconnect the NO flow line at the audit device re-
action chamber. - Connect the soap bubble meter to the line-
determine the NO flow rate (FNQ) using Equation 2; and record
the value on the calculation form.
-------
Section No. 2.3.6
Date June 5, 1984
Page 10
15. Calculate the audit value [NO]A for first audit point
using Equation 3, and record the results.
16. Repeat steps 11 through .15 for the remaining up-scale
audit points. A minimum of three upscale audit points is rec-
ommended .
17. Transfer the NO audit concentrations and the station
NO response values to the summary form, Figure 6.1.
18.' Calculate • the percentage difference for each audit
point using Equation 4 of Figure 6.2, and record each on Fig-
ure 6.1.
19. Prepare an audit calibration curve for the NO channel
by using least squares-. Include the zero air point. (The audit
concentration is the x variable; the analyzer response in per-
cent scale is the y variable.) The NO calibration curve will be
used to determine the actual audit concentrations during the
generation of the NO_ atmospheres.
Procedure for NO,, Audit Using Gas Phase Titration (GPT) -
1. Generate an NO concentration which is approximately
0.08 to 0.12 ppm higher than the NO2 audit concentration re-
quired. Allow the analyzer to sample this concentration until a
stable response is obtained. Determine the NO concentration
[NO]—,.,, from the NO audit calibration relationship. Record
UKlo
this value for the first audit point in column 1 of the N02
calculation form, Figure 6.4.
2. Add O3 to reduce the NO concentration by an amount
equivalent to the NO_ audit concentration required. After the
analyzer response stabilizes, determine the NO concentration
remaining [NO]..-., 'from the NO audit calibration relationship.
K-CiM
Record this value for the first audit point in column 2 of the
calculation form.
3. Calculate the N0_ audit concentration [NO_]A using
Equation 5 of Figure 6.2 and record in column 3 of the cal-
culation form, Figure 6.4.
-------
Section No. 2.3.6
Date June 5, 1984
Page 11
4. Record the station N02 response [NO2]R in column 4.
5. Repeat steps 1 through 4 for the remaining up-scale
audit points.
6. Transfer the N02 audit concentrations and the station
N02 responses to Figure 6.1.
7. Determine the percentage difference for each point,
using Equation 4 of Figure 6.2. '
Procedure for NO Audit -
Jt""™*^^*^^^^™^^~"
The N0x channel may be audited by-the same method used to
audit the NO channel and by determining converter efficiency
using data from the N0x and NO- audit.
Use Figure 6.1 to report the audit value, the analyzer
response, and the percentage difference. Record the information
on Figures 6.1, 6.2, 6.3, and 6.4. Mark the recorder strip
charts with the following informations •
1. Person conducting the audit.
2. Time and date.of audit.
3. Concentrations of audit points.
4. Identification of each audit point.
6-1'4 Interpretation of Audit Results - Results of the audit
will be used to.estimate the accuracy of the ambient air quality
data. Calculation.of accuracy is described in Subsection 2.0.8.
6.2 Data Reduction Audit
Data reduction involves reading a strip chart record,
calculating an average, and transcribing or recording the re-
sults on the SAROAD form. This independent check of the entire
data reduction should be. performed by an individual other than
the one who originally reduced the data. Initially the data
processing check should be performed 1 day out of every 2 weeks
of data. For two 1-hour periods within each day audited, make
independent readings of the strip chart record and continue
-------
Section No. 2.3.6
Date June 5, 1984
Page 12
through the actual transcription of the data on the SAROAD form.
The 2 hours selected during each day audited should be those for
which either the trace is most dynamic, in terms of spikes or the
average concentration is high.
The data processing check is made by calculating the accu-
racy ,
A =- [N02]R - [N02]CHE(,K
where A » the difference in measured and check values,
[NO.,].., = the recorded analyzer response, ppm, and
^ R
- the data processing NO- concentration, ppm.
> £.
If A exceeds ±0.02 ppm, check all of the remaining data in the
2-week period.
6.3- Systems Audit
A systems audit is an on-site inspection and review of the
quality assurance activities used for the total measurement
system (sample collection, sample analysis,, data processing,
etc.); it is a qualitative appraisal of system-quality.
Conduct the systems audit at the startup of a new moni-
toring system and periodically (as appropriate) as significant
changes in system operations occur.
A checklist for a systems audit is Figure 6.5. Questions
in this checklist should be reviewed for applicability to the
particular local, State, or Federal agency.
-------
YES NO
1
7.
8.
9.
12.
13.
Section No. 2.3.6
Date June 5, 1984
Page 13
Zero, span and precision checks performed weekly or
1 biweekly •*
2. Voltage and temperature variations monitored
3. Flow meters routinely calibrated to ±2 % accuracy
aoains* a ,.oH»*i« ^^-^ such a£J fi .goap bubbfe
4. Flow rates monitored routinely
5. Excessive noise minimized
6. Data processing checks performed
Multipoint calibrations performed routinely and'a
record of these calibrations maintained
Quality control charts maintained for zero and
span checks
Maintenance routinely performed on pertinent
components as per manufacturer's manual
10. Calibration gases traceable'to NBS-SRM's
11. Sample introduction system check made weekly
Particulate filter .(if used) changed frequently
Recording system checked and serviced before
each sampling period
14. Recorded data checked for. signs of system
malfunctions
15" DIoanqUal:Lty re?o;fds maintained—completeness,
accuracy, precision, and representativeness
Figure 6.5 Checklist for use by auditor (measurement
of continuous NO2 in ambient air).
-------
Audit
Multipoint
calibration
audit
Data audit
Section 2.3.6
Date June 5, 1984
Page 14
Table 6.1 ACTIVITY MATRIX FOR AUDIT PROCEDURE
Acceptance limits
The difference in con-
centrations between
the measured values
and the audit values
is used as a measure
of accuracy, Sec
2.0.8
Adhere to stepwise
procedure for data
reduction, Sec 2.3.4;
no difference exceed-
ing +0.02 ppm
Frequency of method
of measurement
At least once per
quarter; Subsec
6". 1.3 for procedure
Perform independent
data processing check
on a sample of the
recorded data, e.g.,
check 1 day out
of every 2 weeks of
data, 2 hours for
each day
Action if
requirements
are not met
Recalibrate
the analyzer
Check all
remaining data
if one or more
data reduction
checks exceed
+0.02 ppm
Systems audit
Method" as described in
this section of the
Handbook
At the startup
of a new monitoring
system, and periodi-
cally as appropriate;
observation and
checklist (Fig 6.5)
Initiate
improved
methods and/
or training
programs
-------
Section No. 2.3.7
Revision No. 1
Date July 1, 1979
Page 1 of 1
7.0 ASSESSMENT OF MONITORING DATA FOR. PRECISION AND ACCURACY
For continuous analyzers, perform a check every two weeks
to assess the' precision of the data. Use these data to esti-
mate single instrument precision as described in Section 2.0.8 of
this volume of the Handbook. The precision check procedures
described in Section 2.3.3 are consistent 'with those given in
References 3.and 7.
Estimates of single instrument accuracy for ambient air
quality measurements from continuous • methods, are calculated
according to the procedure in Section 2.0.8. The .performance of
the audit is described in Section 2.3.6.
-------
-------
Section No. 2.3.8
Revision No. 0
Date July 1, 1979
Page 1 of 1
8.0 RECOMMENDED STANDARDS FOR ESTABLISHING TRACEABILITY
To assure data of desired quality, two considerations are
essential: (1) the measurement process must be in statistical
control at the time of the measurement and (2) the systematic
errors, when combined with the random variation in the measure-
ment process, must result in a suitably small uncertainty. '
Evidence of goo~d quality data includes documentation of the
quality control checks and the independent audits of the measure-
ment process by recording data on specific forms or on a quality
control chart and by using materials, instruments, and measure-
ment procedures that can be traced to appropriate 'standards of
reference. To establish traceability, data must be obtained
routinely by repeat measurements of standard reference samples
(primary, secondary,-and/or working standards), and a condition
of process control must be established. More specifically,
working .calibration standards should be traceable to standards of
higher accuracy, such as those listed below.
NBS-SRM's AVAILABLE FOR TRACEABILITY OF
CALIBRATION AND AUDIT GAS STANDARDS
Cylinder Gases
NBS-SRM4
1683a
'1684a
1685a '
Type
Nitric oxide in N_
Nitric oxide in N9
£•
Nitric oxide in N2
Size,
S. at STP
870
870
870
Nominal .
concentration
50 ppm
100 ppm '
250 ppm
Permeation Tubes
NBS-SRM4
1629
Type
Nitrogen dioxide
Permeation
rate,
(jg/min
at 25°C
. 1.0
Concentration, ppm
at flow rates 'of
1 2/min
0.5
5 £/min
0.1
-------
-------
Section No. 2.3.10
Revision No. 0
Date July 1, 1979
Page 1 of 1
10.0 REFERENCES
1. Environmental Protection Agency, Title 40, Code of
Federal Regulations, Part 50 - Measurement Principle
and Calibration Procedure for the Measurement of
Nitrogen Dioxide in the Atmosphere (Gas Phase Chemi-
luminescence), Federal Register, 41. (232): pp
52688-52692, December 1976.
2. Ellis, Elizabeth C. Technical Assistance Document for
the Chemiluminescence Measurement of Nitrogen Dioxide,
U.S. Environmental Protection Agency, Research Triangle
Park, NC. October 1976. 91 p.
3. Appendix A - Quality Assurance Requirements for State
and Local -Air .Monitoring Stations (SLAMS), Federal
Register, Vol. 44, .No. 92, pp 27574-27582 May 1979.
4. Catalog of NBS Standard Reference Materials. NBS
Special Publication 260, 1975-76 Edition. U.S. Depart-
ment .of Commerce, NBS. Washington, D.C. June 1975.
5. Quality Assurance Handbook for Air Pollution Measure-
ment Systems - Volume I, Principles. EPA-600/9-76-005.
March 1976. . . ,
6. Users Manual: SAROAD (Storage and Retrieval of Aero-
metric Data). PB 201-408, APTD-0663. July 1971.
7. Appendix B Quality Assurance Requirements for Preven-
• tion of Significant Deterioration (PSD) Air Monitoring,
Federal Register. Vol. 44, No. 92, pp 27582-27584 May
1979.
-------
-------
-------
.i: i'lLiii:1!;:!!1'1!:!,;;!,1 .ilillliEiqiliiiiH
-------
Jan. 1983
x°/EPA
United States
Environmental Protection
Agency
Section 2.6.0
Environmental Monitoring Systems
Laboratory
Research Triangle Park NC 27711
Research and Development
EPA-600/4-77-027a
Test Method
Section 2.6
Reference Method for the
Determination of Carbon
Monoxide in the Atmosphere
(Nondispersive Infrared
Photometry)
Outline.
Section
Summary
Method Highlights
Method Description
1. Procurement of Equipment and
Supplies
2. Calibration of Equipment
3. Operation and Procedure
4. Data Reduction, Validation, and
•Reporting
• 5. Maintenance
6. Auditing Procedure
7. Assessment of Monitoring Data
for Precision and Accuracy
8. Recommended Standards for
Establishing Traceability
9. Reference Method
10. References
11. Data Forms
Summary
Measurements of carbon monoxide
(CO) in ambient air are based on the
absorption of infrared radiation by CO
in a nondispersive photometer.
Infrared energy from a source is
passed through a cell containing the
gas sample to be analyzed, and the
quantitative absorption of energy by
CO in the sample cell is measured by
a suitable detector. The photometer is
Number of
Documentation pages
' 2.6 !
' 2.6 T
2.6.1
2.6.2
2.6.3
'2.6.4
2.6.5
2,6.6
2.6.7
2.6.8
.2.6.9
2.6.10
2.6.11
4
6
6
3
2
4
1
3
1
12
sensitized to CO by employing CO gas
in either the detector or in a filter cell
in the optical path, thereby limiting
the measured absorption to one or
more of the characteristic
wavelengths at which CO strongly
absorbs. Optical filters or other means
may also be used to limit sensitivity of
the photometer to a narrow band of
interest. Various schemes may be
used to provide a suitable zero
-------
Section 2.6.0
Jan. 1983
reference for the photometer. The
measured absorption is converted to
an electrical output signal, which is
related to the concentration of CO in
the measurement cell.
An analyzer based on this principle
will be considered a Reference
Method only if it has been designated
as a Reference Method in accordance
with 40 CFR 53.
A current list of all designated
Reference and Equivalent Methods is
maintained by EPA and updated
whenever a new method is
designated. This list may be obtained
from any EPA Regional Office or-from
the Environmental Monitoring
Systems Laboratory. Department E,
MD-77, Research Triangle Park,
North Carolina 27711. Moreover, any
analyzer offered for sale as a
Reference or Equivalent Method after
April 16, 1976. must bear a label or
sticker indicating that the EPA has so
designated it. Further discussion of
the concepts of Reference and
Equivalent Methods appears in
Section 2.0.4 of this Handbook.
Quality assurance procedures for .
measuring CO with a nondispersive,
infrared radiation, automated
sampler are not instrument specific;
therefore, the following quality
assurance functions are applicable to
all CO analyzers"designated as EPA
Reference Methods.
Method Highlights
This section presents procedures for
the Carbon Monoxide (CO) Reference
Method {Nondispersive Infrared
Photometry), which are intended to
serve as guidelines for the
development of agency quality
assurance programs. Because
recordkeeping is critical in quality
assurance activities, example data
forms are included to aid in data
documentation. The blank data forms
(Section 2.6.11) may be used as they
are, or they may serve as a basis for
the preparation of forms more
appropriate to the individual agency;
the partially filled-in forms are
interspersed throughout the method
description to illustrate their uses.
Activity matrices at the end of
pertinent sections provide quick
reviews of the method description.
The CO method is summarized briefly
in the remainder of this section.
1. Procurement of Equipment and
Supplies
Section 2.6,1 gives the
specifications, criteria, and design
features of the equipment and the
supplies needed for the operation of
and quality assurance checks on a
continuous CO analyzer. Selection of
the correct equipment and supplies is
a prerequisite of a quality assurance
program. This section provides a guide
for the procurement and the initial
checks of equipment and supplies.
2. Calibration of Equipment
Section 2.6.2 provides procedures
and forms to be used in performing a
multipoint calibration, and in
evaluating the calibration data.
Subsection 2.1 deals primarily with
minimum acceptable requirements for
standards to be applied to the
generation of CO concentrations.
Subsection 2.2 provides step-by-step
recommended calibration procedures
for a nondispersive infrared (NDIR) CO
analyzer, along with example
calculations. The data form (Figures
2.1 and 2.2) is to be used in the
documentation of calibration data.
Dynamic instrument calibration is
essential for quality control.
3. Operation and Procedure
Section 2.6.3 outlines the protocol
to be followed by the operator during
each site visit. To provide
documentation and accountability of
activities, the operator should compile
and fill out a checklist, similar to the
example in Figure 3.1 of Section
2.6.3, as each activity is completed.
Checks should include visual
inspection of the shelter, the sample
introduction system, the analyzer, and
the recorder. Level 1 zero and span
checks must be carried out at least
once every 2 weeks; Level 2 checks
should be conducted between the
Level 1 checks at a frequency
established by the user. Span
concentrations for both levels should
be between 70 and 90 percent of the
measurement range. A one-point
precision check should be made every
2 weeks at a CO concentration
between 8 and 10 ppm. Data forms
similar to Figures 3.2 and 3.3 of
Section 2.6.3 should be used to
document the analyzer performance
checks. Routinely scheduled checks to
verify the operational status of the
monitoring system are essential in a
quality assurance program.
4. Data Reduction, Validation, and
Reporting
Section 2.6.4 describes procedures
to be used for editing strip charts and
for data validation and reduction. Data
collected on strip charts serve no
useful function until they are
converted into meaningful units
(fjg/m3. ppm) applying to a specific
time period (e.g., hourly) through the
use of the calibration relationship.
These data must be transcribed into
an appropriate format such as that of
the SAROAD hourly data form.
5. Maintenance
Section 2.6.5 addresses the
recordkeeping and the scheduled
activities pertinent to preventive and
corrective maintenance. A sample
maintenance log is shown in Figure
5.1. Preventive and corrective
maintenance are necessary to
minimize loss of air quality data due
to analyzer malfunctions and out-of-
control conditions.
6. Assessment of Data for Accuracy
and Precision
Section 2.6.6 discusses procedures
and forms for system and
performance audits. Multipoint
performance audits to be used to
assess the accuracy of the data
collection are discussed in Subsection
6.1.1; audit procedures are given in
Subsection 6.1.2; a data reduction
audit is discussed in Subsection 6.1.3;
and a system audit is discussed in
Subsection 6.2. Figure 6.1 presents
examples of audit summary and audit
calculation forms. Figure 6.2 is an
example checklist to be used by the
auditor.
Section 2.6.7 describes the
techniques for assessment of data for
accuracy and precision.
7. Reference Information
Section 2.6.8 discusses the
traceability of standards to established
•standards of higher accuracy, a
prerequisite for obtaining accurate
data.
Sections 2.6.9 and 2.6.10 contain
the Reference Method and pertinent
references.
-------
Jan. 1983
Section 2.6.1
1.0 Procurement of Equipment and Supplies
Measurement of carbon monoxide
(CO) in ambient air requires basic
sampling equipment and peripheral
supplies; these include, but are not
limited to. the following:
1. Reference method CO analyzer
(NDIR) (Subsection 1.1 provides
information on obtaining an up-
to-date list of analyzers)
2. Strip chart recorder or data
logging system
3. Sampling lines
4. Sampling manifold
5. Calibration equipment
6. NBS-SRM or commercial CRM
calibration standard
7. Working calibration and audit
gases traceable to NBS or CRM
standard
8. Zero-air source
9. Spare parts and.expendable
supplies
10. Record forms
11. .Independent audit system.
The person responsible for
purchasing materials should maintain
a log to record vendor names, part
numbers, prices, dates, and other
pertinent information. An example log
is shown in Figure 1.1. The log will
serve as a reference for- future
procurement needs and as a tool for
planning budgets for future
monitoring programs. Quality
assurance activities for procurement
of equipment and supplies are
summarized in Table 1.2 at the end of
this section.
1.1 The CO Analyzer (NDIR)
As stated in the Code of Federal
Regulations,' each method for
measuring CO shall be either a
Reference or Equivalent Method when
the purpose .is to determine
compliance with the National Ambient
Air Quality Standards (NAAQS). For
carbon monoxide, the Reference
Method is Nondispersive Infrared
Photometry (NDIR).
Although the NDIR analyzers
currently available for measuring CO
in ambient air are competitively
priced, price differences become
apparent when options to the basic
package are ordered. The buyer
should consult the list of designated
Reference and Equivalent Methods for
lapproved options. An up-to-date list of
'analyzers designated as reference or
Equivalent methods for CO is
available by writing to:
U.S. Environmental Protection Agency
Environmental Monitoring Systems
Laboratory
Department E, MD-77
Research Triangle Park, North
Carolina 27711
Available options include automatic
zero and span systems and complete
telemetry systems for transmitting
daily zero and span checks and real-
• time data from the site to a central
location. For certain CO analyzers, the
automatic zero and span systems are
required to meet the EPA Reference '
Method designation. Although options
can add convenience and flexibility,
their necessity and desirability must
be dictated by the availability of field
personnel, accessibility of the site,
and limitations of the budget.
When purchasing, the buyer should
request that the manufacturer supply
documented proof that the specific
analyzer performs within
specifications (Table 4.1, Section
2.0.4). The best proof is a strip chart
recording showing the specific
analyzer's zero drift, span drift,
electronic noise, risetime, falltime,
and lagtime. Acceptance of the •
analyzer should be based on these
performance tests; once -accepted, the
Reference and Equivalent analyzers
are warranted by the manufacturer to
operate within the required
performance limits for 1 year. The
strip chart will also serve as a
reference to determine whether the
performance of the analyzer has
deteriorated at a later date. The user
should reverify the performance
characteristics either during the initial
calibration or by using abbreviated
forms of the test procedures in the
ambient air monitoring Reference and
Equivalent Methods Regulations.2
1.2 Strip Chart Recorder
Recorders are commercially
available at a wide variety of prices
and specifications. Factors to be
considered in the purchase of a
recorder are:
1. Compatibility with the output
signal of the analyzer
2. A minimum chart width of 15
cm (6 in.) for the desired
accuracy in data reduction
3. A minimum chart speed of at
least 2.5 cm/h (1 in./h)
4. Response time
5. Precision and reliability
6. Flexibility of operating variables
(speed, range)
7. Maintenance requirements.
1.3 Sampling Lines and
Manifold
Wherever possible, sampling lines
and manifolds should be constructed
of Teflon or glass to minimize
degradation of the sample; however,
because of the relative inertness of
CO, other types of materials
(polypropylene, stainless steel) will
suffice if only CO is being measured.
Sample residence time should be
minimized. The use of a particle filter
on the sample inlet line of an NDIR
CO analyzer is optional on some
'analyzers, and left to the discretion of
the-user or the manufacturer. Use of
the filter should depend on the
analyzer's susceptibility to
interference, malfunction, or damage
due to particles.
1.4 Calibration Equipment
and Standards
The two acceptable methods for
dynamic multipoint calibration of CO
analyzers are:3
1. The use of individual certified
standard cylinders of CO for each
concentration needed.
2. The use of one certified standard
cylinder of CO, diluted as necessary
with zero-air, to obtain the various
calibration concentrations needed.
Both methods require the
following:
1. Pressure regulator(s) for CO
cylinder(s)
2. Flow controller
3. Flow meter
4. Mixing chamber (dynamic .
dilution only)
5. Output manifold •
•6. Zero-air source
7. Calibration standard.
The equipment needed for calibration
can be purchased commercially, or it
can be assembled by the user. When
a calibrator or its components are
being purchased, certain factors must
be considered:
1. Traceability of the certified
calibration gases to an NBS-
SRM4 or an NBS/EPA-approved
commercially available Certified
Reference Material (CRM).
2. Accuracy of the flow-measuring
device (rotameter, mass flow
meter, bubble meter).
-------
Section 2.6.1
Jan. 1983
-------
Jan. 1983
Section 2.6.1
3. Maximum and minimum flows of
dilution air and calibration gases.
4. Ease of transporting the
calibration equipment from site
to site.
1.4.1 Pressure Regulator—
A pressure regulator will be
required for the CO calibration
standard cylinder. If individual
cylinders are to be used for individual
calibration points, it is advisable to
procure regulators for each cylinder.
Regulators must have a nonreactive
diaphragm and suitable delivery
pressure. A two-stage regulator with
inlet and delivery pressure gauges is
recommended. The .supplier from
which the CO cylinders are to be
obtained should be consulted as to
Ihe correct cylinder fitting size
required for the regulator.
1.4.2 Flow Controller —
The flow controller can be any
device (valve) capable of adjusting and
regulating the flow from the
calibration standard. If the dilution
method is to be used for calibration, a
second device will be required for the
zero-air. For dilution, the controllers
must be capable of regulating the flow
to ±1 percent.
1.4.3 Flow Meter —
A calibrated flow meter capable of •
. measuring and monitoring the
calibration standard flow rate will be
required. If the dilution method is
used, a second flow meter will be
required for the zero-air flow. For
dilution, the flow meters must be
capable of measuring the flow with an
accuracy of ±2 percent.
1.4.4 Mixing Chamber —
A mixing chamber is required only if
the calibrator concentrations are
generated by dynamic dilution of a CO
standard. The chamber should be
designed to provide thorough mixing
of CO and zero-air.
1.4.5 Output Manifold —
The output manifold should be of
sufficient diameter to insure an
insignificant pressure drop at the
analyzer connection. The system
must have a vent designed to insure
atmospheric pressure at the manifold
and to prevent ambient air from
entering the manifold.
1.4.6 Zero-Air Source —
A source of dry zero-air that is
verified to be'free of contaminants
that could cause detectable responses
from the CO analyzer will be needed.
Zero-air containing <0.1 ppm CO may
be purchased in high-pressure
cylinders or generated with
commercially available clean air
systems. The zero-air must contain
-------
Section 2.6.1
Jan. 1983
Table 1.2. Activity Matrix for Procurement of Equipment and Supplies
Equipment and
supplies
NDIR analyzer
Strip chart recorder
Sampling lines and manifold
Calibration gases
Audit gases
Zero-air
Acceptance limits
Performance according to
specifications in Table 4.1,
Sec. 2.0.4
Compatible with output
signal of analyzer: recom-
mended chart width of 15
cm (6 in.)
Constructed of Teflon or
glass
Traceable to an NBS-SRM
or a commercially available
CRM; ±2.0% of rated
concentration
Traceable to an fJBS-SRM
or commercially available
CRM: ±2.0% of rated
concentration
<0.1 ppm CO
Frequency and method
of measurement
Manufacturer strip chart
recording of analyzer's
performance
Visually observe upon
receipt
Visually observe upon
receipt
Upon receipt and monthly
thereafter for first 3 mo: if
concentration remains'
stable, verify every 6th
month
As above
Check against analyzer
internal zero or another
source of zero-air known to
to be CO-free
Action if
requirements
are not met
Have the manufacturer
adjust and rerun the per-
formance checks
Return to supplier
Other types of materials
may be acceptable for CO
sampling •
Return to supplier
As above
As above
-------
Jan. 1983
Section 2.6.2
2.0 Calibration of Equipment
The accuracy and validity of
measurement data recorded by air
monitoring equipment depend on the
quality assurance procedures used.
The primary procedure is dynamic
calibration, which determines the
relationship between the observed
and the actual values of the variable
being measured.
In dynamic multipoint calibration,
gas samples of known concentrations.
are introduced to an instrument to
derive a calibration relationship or to
adjust the instrument to a
predetermined sensitivity. The
relationship is derived from the
instrumental responses to the
successive samples of known
concentrations. A minimum of four
reference points and a zero point are
recommended to derive the
relationship. The "true" value of each
calibration gas must be traceable to
an NBS-SRM or a commercially
available CRM (Section 2.Q.7)..
Most present-day monitoring
systems are subject to drift and
variability o£ internal parameters, and
they cannot be expected to.maintain
calibrations over long periods of time.
Therefore, it is necessary that the
calibration relationship be dynamically
checked on a predetermined schedule.
Precision is determined by a one-point
check performed at least once every 2
weeks. Network accuracy is determined
by a three-point audit performed at
least once each quarter. Zero and
span checks must be made to
document in-control conditions; these
checks are also used in data reduction
and validation.
Table 2.1 at the end of this section
summarizes the quality assurance
activities for calibration procedures.
2.1 Calibration Gases
2.1.1 CO Standard —
The CO standards must be in air
unless the dilution method is used.
For dilution, CO in nitrogen may be
used if the zero-air dilution ratio is not
less than 100:1. All calibration gas
mixtures must be referenced against
an NBS-SRM or a commercially
available CRM (Section 2.0.7). The
steps required for comparing the
concentration of a commercial
working calibration standard to the
concentration of an NBS-SRM or a
CRM are described in Subsection 7.1
of Section 2.0.7. Subsections 7.1.4
and 7.1.5 describe the procedures for
verification and reanalysis of cylinder
gases. The CO gas cylinders should be
recertified every 6 months. The use of
aluminum cylinders will provide better
stability of CO standards.
2.1.2 Dilution Gases —
Zero-air, verified to be free of
contaminants that would cause
detectable responses in the CO
analyzer, may be purchased in high-
pressure cylinders or generated with
commercially available clean air
systems. Care must be exercised to
ensure that <0.1 ppm CO is present
in the zero air; some air-cylinders sold
as ultrapure may actually contain 1 to •
2 ppm CO. Any zero air source used
must be verified to contain <0.1 ppm
CO. The use of a catalytic oxidizing
agent such as Hopcalite on any zero-
air source would be prudent. Any zero
air passing through a catalytic oxidizer
must be free of water vapor.
2.2 Calibration
The procedure for dynamically
calibrating the NDIR analyzer may be
found in 40 CFR'50,3 and in the
manufacturer's manual. Essentially,
the procedure involves challenging
the analyzer with a minimum of four
CO concentrations and defining the
relationship between the
concentration and the analyzer
response. Forms for recording
operational and calculation data have
been developed to aid in the
documentation of calibrations and
quality assurance checks.
Documentation of all data on the
station, instrument, calibrator,
reference standard, and calibration
activity is of prime importance
because the validity of the data
collected by the monitor' depends on
its calibration.
2.2.1 Calibration Procedure —
The following calibration procedure
is based on dynamically diluting a
high CO concentration with zero-air.
An alternative procedure is to use
individual cylinders containing the
desired CO concentrations, which
eliminates the necessity of dilution.
Any dynamic dilution system used
for calibration must be capable of
measuring and controlling flow rates
to within ±2 percent of the required
flow. Flow meters must be calibrated
under the conditions of use against a
reliable standard, such as a soap
bubble meter or a wet test meter. All
volumetric flow rates should be
corrected to 25°C (77°F) and 760 mm
(29.92 in.) Hg. If both the CO and the
zero-air flow rates are measured with
the same device under the same
conditions of temperature and
pressure, the STP correction factor in
the calibration equations can be
disregarded.-
The following step-by-step
procedure uses a data form (Figure
2.1) to aid in the collection and
documentation of calibration data. The
calibration equations in Figure 2.1,
the CO calibration and linearity check
table, and the calibration relationship
plot in Figure 2.2 are given to
facilitate the systematic recording of
data derived during the calibration of
the NDIR CO analyzer. The user
should consult the manufacturer's
manual before beginning the
calibration because the zero and
calibration procedures and adjustments
differ from analyzer to analyzer.
1. Record the official name and
.address of the individual station. Note:
Where appropriate, the station name,
address, and SAROAD ID should be the
same as that on the hourly average
data form (Figure 4.1 of Section 2.6.4)
to help eliminate confusion on the
part of persons not familiar with the
station.
2. Identify the analyzer being -
calibrated by recording the
manufacturer's name, model, and
serial number.
3. Identify the person performing'
the calibratioo and give the date of
calibration.
4. Identify the calibrator or dilution
system used.'If the system was
purchased, record the manufacturer's
name, model, and serial number; if
the system was assembled by the
user, assign it an identification
number so that calibrations can be
referenced to that particular
apparatus.
5. Identify, by supplier and cylinder
number, the reference standard used;
record the concentration of calibration
gases determined by the user and the
cylinder pressure; provide a record of
NBS-SRM or CRM traceability for any
cylinder used in a calibration; and
include the date and the name of the
person who conducted the traceability
test. Note: Cylinders with pressures of
-------
Section 2.6.2
Jan. 1983
L Station
Calibration Summary
2. Analyzer
North
Model
3. Calibration by
4, Calibrator mfr.
Model
5. CO standard _
Date
II-/0-71
S/N
Verified against N8S-SRM
Concentration
CU MKlafir CC A^-T / Cylinder pressure 5OO PS f
9-
6. Flow-measuring device
7. Barometric pressure
Traceability
8, Analyzer's sample How rate
9, Zero knob setting
/
Shelter temperature
Span knob setting
Calibration Equations
Equation 2-1
Fo OfFcosF (STP correction factor]
Equation 2-2
STP Correction factor = Bf> x 29g
76O AT+273
Equation 2-3
fCGJoor * (COlrg*fw
Fo » Fco
Equation 2-4
% scale * [COlout x 10O * 2cQ
URL
Figure 2.1. Example of calibration data form.
F = uncorrected flow rate for dilution air or CO standard gas. l/min
F'o = flow rate of dilution air corrected to 25°C and 760 mm Hg. l/min
Fco = flow rate of CO standard corrected to 25°C and 760 mm Hg.
l/min
BP = barometric pressure, mm Hg
AT - temperature of gas being measured, °C
[COJour = concentration at the output manifold, ppm
[CO]sTo= concentration of the .undiluted standard, ppm
Zoo = recorder response to zero air
<200 psig should not be used for
calibration because gases in cylinders
may become unstable for some
concentrations at low pressures
(Section 2.0.7).
6, Identify the flow-measuring
device used, and document the
traceability of its accuracy.
7, Record the barometric pressure
and the shelter temperature before
the calibration.
8, Record the analyzer's sample
flow rate.
9, Record the zero and span knob
settings after the calibration so that
these settings can be used later to
determine changes in instrument
performance.
Figure 2.2 contains a CO calibration
and linearity check table and a graph to
facilitate the plotting of the calibration
data. The equations at the bottom of
Figure 2.1 are to be used to obtain the
entries in the table in Figure 2.2. The
detailed steps of the calibration
procedure are given below. Analyzer
responses in these steps refer to
recorder responses. The
manufacturer's instrument manual
should be consulted for analyzer-
specific calibration procedures.
1. Select the operating range of the
analyzer to be calibrated by referring
to the manufacturer's manual for the
ranges over which the analyzer is
considered to be a reference method.
2. Connect the recorder output
cable(s) of the analyzer to the input
terminals of the strip chart
recorder(s). All adjustments to the
analyzer should be based on the
appropriate strip chart readings. Note:
When data acquisition systems are
used to store and/or transmit data to
a base station, some provision must
be made to verify the accuracy of the
transmitted data. In these cases, a
voltmeter .or recorder can be used to
take readings and to make
adjustments onsite. A comparison
check must then be made between
signal outputs from the analyzer and
data received at the base locations.
3. Adjust the zero-air flow to the
-------
Jan. 1983
Section 2.6.2
Calibration
points
Zero
80% URL
1
2
3
1
Fco,
1/min
(Eg 2-1 &2-2I*
0.^00
0.500
0.500
0. 500
2
Fa
1/min
(Eq2-1 &2-2I
2. (eZ-5
3.^7
5.150
12.. 000
3
[CO]OUT.
ppm
(Eg 2-31
o
HO
30
ZO
IO
4
% scale
(Ed 2-4)
5*7*
•riS^o
t>5%
45ti
?J5%
'Equations 2-1 through 2-4 are given in Figure 2.1 and in the text.
100
Slope Ibl of calibration relationship
2..0
Intercept fat of calibration relationship
Figure 2.2. Example of calibration data form. (Linearity Check and .Calibration Relationship)
-------
Section 2.6.2
Jan. 1983
arwfyzer; the flow must exceed the
total demand of the analyzer
connected to the output manifold to
ensure that no ambient air is pulled
into the manifold vent.
4. Allow the analyzer to sample the
zero air until a stable response is
obtained; adjust the analyzer zero
control to within ±0.5 ppm of zero
base line; and record the stable zero-
air response (% scale) under column 4
of the calibration table in Figure 2.2.
/Vote: Offsetting the analyzer zero
adjustment to +5% of scale is
recommended to facilitate observing
n«ga«ive zero drift. On most analyzers,
rtiis should be done by offsetting the .
recorder zero,
5. Determine the 80 percent upper
range limit (URL) of the analyzer.
Example; For an analyzer with an
operating range of 0 to SO ppm, the
SO percent URL value would be 0.80
x SO. or 40 ppm.
6, Adjust the CO flow from the
standard CO cylinder to generate a
CO concentration of approximately 80
percent of the URL. Measure the CO
How, correct it to STP, and record
unefer column 1 (Fco), on the 80
percent URL line.
Fco s F x (STP correction factor)
Equation 2-1
STP correction factor = BP x 298
760 AT + 273
' Equation 2-2
where
Fco = flow rate of CO standard
corrected to STP, l/min
F = uncorrected flow rate, l/min
8P=barometric pressure, mm Hg
AT » temperature of gas being
measured, °C
e.- If wet test meter or bubble
meter is used for flow measurement,
fhe vapor pressure of water at the
temperature of the meter must be
subtracted from the barometric
pressure.
Measure the dilution air flow,
correct it to STP, and record under
column 2 (Fo).
Fo - F x (STP correction factor)
7 Calculate the CO concentration
[.Colour using Equation 2-3.
JCOlsTpxFro
(COlour = Fo +Fco
Equation 2-3
Record this value on the 80% URL
line under column 3.
8, Calculate the required recorder
response for span adjust (80% URL)
using Equation 2-4.
% scale = ([COlouT x 100 U Zco
\ URL /
Equation 2-4
Allow the analyzer to sample until the
response is stable; adjust the analyzer
span until the required response is
obtained, and record the CO recorder
response on 80 percent URL line
under column 4. Note: If substantial
adjustments of the span control are
necessary, recheck the zero and span
adjustments by repeating steps 4 and
8.
9. After the zero and 80 percent
URL points have been set, without
further adjusting the instrument,
generate three approximately evenly
spaced points between zero and 80
percent URL by increasing the dilution
flow (Fo,) or by decreasing the CO
flow (Fco). For each concentration
generated, calculate the CO
concentrations (using Equation 2-3)
and record the results for each point
under the appropriate column in the
table in Figure 2.2.
10. On the blank graph of Figure
2.2, plot the analyzer responses
expressed in percent scale at the
recorder (y-axis) versus the
corresponding calculated
concentrations (x-axis) to obtain the
calibration relationship. Determine the
straight line of best fit by the method
of least squares (Volume I, Appendix J
of this Handbook) using a
programmed calculator or the
calculation data form (Figure 2.3).
Note: Because manual calculations
(using the data form) require
considerably more time than the use
of a programmed calculator, it is
•suggested that the latter be used
when possible.
11; After determining the slope (b)
and the intercept (a) where the line
crosses the y-axis, draw the fitted line
as follows: On the y-axis, plot the y
intercept, a; use the equation Y = a +
bx to calculate the predicted Y value
using the 80 percent URL
concentration for the x value as the
second point on the graph. Draw a
straight line through these two points
to give a best-fit line, as shown in
Figure 2.4.
12. After drawing the best-fit line,
determine if the analyzer response is
linear, that is, no calibration point
varies from the best-fit line by more
than 2 percent of full scale. Make a
simple test for linearity by plotting a
point 2 percent of scale above and 2
percent of scale below the point
where the best-fit line crosses the 40-
ppm level and the 10-ppm level, and
then draw a straight line through the
+2 percent points and one through the
-2 percent points (Figure 2.4). The two
lines (above and below the best-fit
line) define the limits between which
the calibration points can fall for the
calibration curve to be considered
linear. Points outside these limits
should be repeated to check for
calibration point errors; if the repeated
points still fall outside the limits,
consult the manufacturer's manual
to determine and correct the problem.
2.2.2 Calibration Frequency —
To ensure accurate measurements
of the CO concentrations, calibrate the
analyzer at the time of installation,
and then recalibrate it as specified in
the instrument manual or:
1. No later than 3 months after the
most recent calibration or
performance audit. If
performance audit results are
satisfactory, recalibration must
be performed immediately.
2. After an interruption of more
. than a few days in analyzer
operation, after any repairs that
might affect its calibration, after
physical relocation of the
analyzer, or after any other
indication (including excessive
zero or span drift) of possible
significant inaccuracy of the
analyzer. Following any of these
activities, a Level 1 zero and
span check should be made to
determine if recalibration is
necessary. If the zero and span
drifts do not exceed the limits
(Table 9.1, Section 2.0.9,
Subsection 9.1.3), a calibration
need not be performed. If either
the zero or the span drift exceeds
its limit, investigate the cause of
the drift, take corrective action,
and calibrate the analyzer.
-------
Jan. 1983
Section 2.6.2
Calibration
point
Zero
80% URL
1
2
3
Concentration.
ppm
X
o
VO
30
2-0
/£
X2
0
fcOQ
900
WO
/£>O
Recorder
reading,
% scale
y
5
85
tf
45
Z.5
y2
25
72^5
40tfS
£0-25
£Z5
xy
o
31 oo
JJ5O
900
250
n - number of calibration points.
The eouation of the line fitted to the data is written as:
Y = Y * b(x-x) = (y-tixj + bx = a + bx
where Y = predicted mean response for corresponding x
b - slope of the fitted line
a = intercept where the line crosses the y-axis
a =y--
y = I///? = .
and
Figure 2.3. Calculation form for the method of least squares.
-------
Section 2.6.2
Jan. 1983
100
80
Limits for instrument
linearity check. ±2%
20 30
fCOJour. ppm
Figure 2.4. Example of a CO calibration relationship.
"V
Table 2.1. Activity Matrix tor Calibration Procedures
Calibration
activities
Acceptance limits
Frequency and method
of measurement
Action if
requirements
are not met
Dilution gas
Span gases
Multipoint^ calibration
Zero-air free of contami-
nants (Sec. 2.0.7, Subsec.
7.1)
Cylinder gases certified to
NBS or CRM standard;
cylinder pressure >200
psig .
According to calibration
procedure fSubsec. 2.2)
and data recorded (Figs 2.1
and 2.2)
Compare the new zero-air
against source known to be
free of contaminants
Assay against an NBS-
SRM or CRM semiannually
(Sec. 2.0.7)
Calibrate at least once.
quarterly;.anytime a Level
1 span check indicates dis-
crepancy; after mainte-
nance that may affect the
calibration (Subsec. 2.2)
Return to supplier, or take
corrective action with
generation system as
appropriate
Working gas standard un-
stable, and/or measurment
method out of control;
take corrective action,
e.g., obtain new span gases
Repeat the calibration
-------
Jan. 1983
Section 2.6.3
3.0 Operation and Procedure
A routinely scheduled series of
checks to verify the operational status
of the monitoring system is an
essential part of the quality
assurance program. The operator
should visit the site at least once each
week, and he/she must make a Level
1 zero and span check on the analyzer
at least once every 2 weeks. The user
may decide on the frequency of any
Level 2 zero and span checks. In
addition, an independent precision
check between 8.0 and 10.0 ppm
must be carried out at least once
every 2 weeks.
Table 3.1 at the end of this section
summarizes the quality assurance
activities for routine operations
discussed in the following subsections.
To provide documentation and
accountability of activities, the field
operator should compile and fill out a
checklist as each activity is completed;
Figure 3.1 is an example checklist.
In Subsections 3.1 and 3.2.
reference is made to the sampling
shelter and sample inlet system. The
design and-construction of these
.components of the sampling system
are not within the scope of this
document, but an in-depth study of
these is provided in Reference 5.
3.1 Shelter
The shelter's role in quality
assurance is to provide a
temperature-controlled environment
in which the sampling equipment can
operate at optimum levels of
performance. The mean shelter
temperature should be between 22°
and 28°C (72° and 82°F). A
thermograph should be installed at the
shelter so that daily temperature
fluctuations can be continuously
recorded. Fluctuations greater than
~2°C (4°F) may cause the electronic
components of the analyzer to drift
and introduce error into the data;
thus, fluctuations outside of the
specifications should be identified,
and the data for the affected time
period should be flagged to indicate-
possible discrepancies. Excess
vibrations will cause analyzer
fluctuations and should be minimized
where possible.
3.2 Sample Introduction
System
The sample introduction system
consists of an intake port, paniculate
and moisture traps, a sampling
manifold, a blower, and a sampling
line to the analyzer. As part of the
quality assurance program, the field
operator should inspect each of these
components for breakage, leaks, and
buildup of paniculate matter or other
foreign materials; check for moisture
depostion in the sampling line or
manifold; and check the connection
between the sampling line and the
manifold. Any component that is not
within tolerance should be cleaned or
- replaced immediately (Section 2.0.2).
3.3 Recorder
During each visit to the monitoring
site, the field operator should check
the recorder against the following list:
• 1. Legibility of the ink trace
2. Ink supply in the reservoir
3. Chart paper supply
4. Chart speed control setting
5. Signal input range setting
6. Time synchronization. Mark chart
with correct time and date.
Any operational parameter that is not
within tolerance must be corrected
immediately. "
3.4 Analyzer
The user should read thoroughly the
specific instructions, in the
manufacturer's manual before
attempting to operate the analyzer.
As part of the quality assurance
program, each site visit should include
a visual inspection of the external
parameters of the analyzer, the zero
and span checks, and a biweekly
precision point check.
3.4.1 Visual Inspect/on —
The field operator should inspect
the external operating parameters of
the analyzer; these will vary from
instrument to instrument, but they
generally will include the following:
1. Correct setting of flow meter and
regulators
2. Cycling of temperature control
indicators
3. Verification that the analyzer is
in the sampling mode rather than
in the zero or calibration modes
4. Zero and span potentiometers set
and locked at proper values.
3.4.2 Zero and Span Checks —
Interim zero and span checks on the
responses of the instrument to known
concentrations must be used to
document within-control conditions. If
a response is outside of the
prescribed limits, the analyzer is
considered out of control, and the
cause must be determined and
corrected. A quality control chart can
be used to check the analyzer visually
for within-control conditions.
Level 1 and Level 2 span checks
must be conducted in accordance with
the specific guidance given in
Subsection 9.1 of'Section 2.0.9. If
permitted by the associated operation
or instruction manual, a CO analyzer
may temporarily operate during the
zero and span checks at reduced vent
or purge flows, or the test atmosphere
may enter the analyzer at a point
other than the normal sample inlet if
the analyzer's response is not likely
to be altered by these deviations from
the normal operational mode. Because
variability information may not be
uncovered by checking only part of
the analyzer's sample-handling
system, however, it is' recommended
that these operational deviations be
used only for Level 2 checks.
Level 1 zero and span checks must
be conducted every 2. weeks; Level 2 .
checks should be conducted in
between the Level 1 checks at a
frequency decided on by the user.
Span concentrations for both levels
should be between 70 and 90 percent
of the measurement range. The data
should be recorded on a zero and
span checks form such as that shown"
in Figure 3.2.
Level .1 zero and span data are used
for the followmg:
1. To adjust the analyzer for zero
and span drifts
2. To decide when to calibrate the
analyzer
3. To decide when to invalidate
monitoring data.
Items 1 and 2 are detailed in
Subsection 9.1.3 of Section 2.0.9;
Item 3, in Subsection 9.1.4 of the
same section.
When the response from a span
check is outside of the control limits,
the cause for the extreme drift must
be determined and corrective action
taken. Some of the causes for drift are
listed below:
1. Lack of preventive maintenance
2. Fluctuations in electrical power
supply
3. Fluctuations in flow
4. Change in zero-air source
-------
Section 2.6.3
Jan. 1983
Site identification
Site location J.
Sue address -3***^.
nO(
Date
Technician
t. Inspect thermograph for temperature variations greater than ±2°C (4°F); identify time frame of any temperature level out of
tolerance
/£.(/€,!.<>
Comments: 1^VY)f. (d/fa
\S 2, Inspect sample introduction system for moisture, paniculate buildup, foreign material, breakage..leaks
•• Comments:
3. Is sample line connected to manifold?
Comments:
4. Inspect data recording system
Legibility of trace
Ink supply
Paper supply
Chart speed
Signal range
Time synchronization ,
Corrective
action taken
Comments:
^
^L
/
5. Inspect analyzer operational parameters
• Sample flow rate
• Oven temp light flashing
• Analyzer in sampling mode
• Zero and span potentiometers locked at correct settings
Comments,'
OK
Corrective
action taken
6 Zero the analyzer
7 Is unadjusted zero within tolerance?
Comments: ^&TO O
*4. ^
-------
Jan. 1983
Section 2,6.3
Site identification ^~ LJ IJ
Location
Address
Pollutant C O
Analyzer
AJorrti
Adjusted zero
Serial number
Adjusted span
/ /
/ J
Date
// ~/5~7^
Operator
^
Unadjusted
zero.
% chart
5-6
Span
concentration,
ppm
35>m
.
\
-~
i
' i
Unadjusted
analyzer
response. Difference.
% chart
757
ppm ppm
35 O
\
i
i
i i
i t
i
i
1 • . •
t
j
j ' •
!
I
Figure 3.2. Example of a Level / zero and span check data form.
-------
Section 2.6.3
Jan. 1983
5. Change in span gas
concentration
6. Degradation of detector
7. Electronic and physical
components not within
manufacturer's specifications.
Corrective actions for the above can
be found in the manufacturer's
instruction/operations manual.
3.4.3 Precision Check —
A periodic precision check is used
to assess the data. A one-point check
on each analyzer must be carried out
at least once every 2 weeks at a CO
concentration between 8 and 10 ppm.
The analyzer must be operated in its
normal sampling mode, and the
precision test gas must pass through
all filters, scrubbers, conditioners, and
other components used during normal
ambient sampling. If permitted by the
associated operation or instruction
manual, a CO analyzer may
temporarily operate during the
precision check at reduced vent or
purge flows, or the test atmosphere
may enter the analyzer at a point
other than the normal sample inlet if
the analyzer's response is not likely to
be altered by these deviations from
the normal operational mode. The
standards from which the precision
check test concentrations are obtained
must be traceable to an NBS-SRM or
a commercially available CRM; the
standards used for calibration may be
used for the precision check.
The precision check procedure is as
follows:
1. Connect the analyzer's sample
inlet line to a precision gas
source that has a concentration
between 8 and 10 ppm CO and
that is traceable to an NBS-SRM
or a CRM. If a precision check is
made in conjunction with a
zero/span check, it must be
made prior to any zero and span
adjustments.
2. Allow the analyzer to sample the
precision gas for at least 5 min
or until a stable recorder trace is
obtained.
3. Record this value on a precision
check data form (Figure 3.3), and
mark the chart as "unadjusted"
precision check.
The biweekly check generates data for
assessing the precision of the
monitoring data; Section 2.0.8 of this
volume of the Handbook presents
procedures for calculating and
reporting precision.
3.4,4 Special Instructions for
Precision Checks on Beckman Model
866 Ambient Carbon Monoxide
Analyzer — Because of the operational
nature of the Beckman Model 866 CO
analyzer, the following slightly
modified procedures for precision
checks and audits of this analyzer
model are generally necessary to
obtain accurate quality assessment of
the ambient readings.
The Model 866 uses a dynamic,
flowing reference cell as part of its
compensation for variable
environmental factors such as water
vapor and carbon dioxide (COz). This
mechanism responds rather slowly to
changes in water vapor concentration.
Although the syste.m is entirely
adequate to follow natural
environmental, moisture changes, it
does not respond instantly to rapid
changes in moisture level that occur
when the analyzer is switched from
ambient air to dry concentration
standards used for precision checks
and audits. Most concentration
standards obtained from compressed
gas cylinders or diluted from high-
concentration gas cylinders have a very
low moisture level, whereas ambient
air normally contains much higher
levels of water vapor. During the
period immediately following a switch
from ambient sampling to a
concentration standard, the analyzer
is operating in a nonequilibrated
mode, which causes a significant
offset (up to 1 to 2 ppm) in the
analyzer's readings. Accordingly, the
precision check or audit response will
be inaccurate unless suitable
compensatory measures are taken.
(This effect is accounted for in the
calibration and automatic
standardization procedures in the
operation manual; accurate-calibration
and .automatic standardization will be
obtained if these procedures are
followed explicitly.)
Either of two methods may be used
to avoid errors from this effect during
precision checks and audits. The first
is simply to allow sufficient time for
the analyzer to reestablish equilibrium
at the concentration-gas moisture
level. Equilibrium is established when
the analyzer response to this
concentration standard stabilizes at a
new reading somewhat different than
the original reading. (The original
reading may be stable for 10 to 20
minutes after introduction of the dry
gas before the offset occurs.)
Unfortunately, the analyzer may
require as much as 1 to 2 hours to
reach moisture equilibrium at the dry-
gas condition.
The second method takes advantage
of the temporary stable period
immediately after dry gas is
introduced, and it must be completed
before the offset occurs. Prior to the
precision check or audit, dry zero gas
is introduced into the analyzer just
long enough to establish a
temporary, nonequilibrated zero
baseline. The precision or audit
concentration standard(s) is then
introduced, and interpretation of the
reading(s) is based on the net
response referenced to this temporary
zero baseline rather than the
equilibrated zero baseline; i.e., the net
difference between the response to
the standard and the temporary
baseline is used with the calibration
curve to determine the response in
concentration units. Finally, dry zero
gas is reintroduced to verify that the
offset has not yet occurred and that
the temporary zero baseline has not
shifted. If the temporary zero baseline
has changed significantly, the second
method is not valid and the precision
check or audit must be repeated by
using the first method.
-------
Jan. 1983
Section 2.6.3
Site ID
Location _
Address /[7£>
Pollutant
Serial number
Date
I
Operator
i
Precision
test gas
concentration,
ppm
/O Of^i^\
i
Analyzer
response
% chart
"2—b
ppm
!
Difference.
ppm
Figure 3.3. Example of precision check form.
-------
Section 2.6.3
Jan. 1983
Table 3.1. Daily A ctivity Matrix
Characteristic
Acceptance limits
Frequency and method
of measurement
Action if
requirements
are not met
Shelter temperature
Sample introduction system
Recorder
Analyzer operational settings
Analyzer operational check
Precision checks
Mean between 22° and
28°C (72° and 82°F); daily
fluctuations not greater
than ±2°C (4°F)
No moisture, foreign
materials, leaks, or ob-
structions; sampling line
connected to manifold
Adequate supply of ink and
chart paper; legible ink
traces; correct setting of
chart speed and range
switches; and correct time
Flow and regulator indica-
tors at proper settings:
analyzer in sampling mode;
and zero and span controls
locked at proper settings
Zero and span within toler-
ance limits (Subsec 9.1.3,
Sec. 2.0.9)
Precision assessed
(Subsec. 3.4.3)
Edit thermograph chart
daily for variations <2°C
(4°F)
Weekly visual inspection
Weekly visual inspection
Weekly visual inspection
Level 1 zero and span
checks every 2 weeks:
Level 2 checks between
Level 1 checks at frequency
decided by user
Every 2 weeks {Subsec.
3.4.3)
Mark the strip chart for the
affected time period: repair
or adjust the temperature
control system.
Clean, repair, or replace as
needed.
Replenish the ink and chart
paper supplies: adjust the
recorder time to agree with
clock, and note the time on
on the chart.
Adjust or repair as needed.
Isolate the source of error,
arid then repair; after cor-
rective action, recalibrate
the analyzer
Calculate and report the
precision (Sec. 2.0.8)
-------
Jan. 1983
Section 2.6.4
4.0 Data Reduction, Validation, and Reporting
Quality assurance activities for data
reduction, validation, and reporting
are summarized in Table 4.1 at the
end of this section.
4.1 Data Reduction
Hourly average concentrations from
a strip chart record may be obtained
by the following procedure:
1. Make sure the strip chart record
has a zero-trace at the beginning
and end of the sampling period.
2. Fill in the identification data
called for at the top of the hourly
average data form (Figure 4.1).
3. Draw a line from the zero
baseline at the start of the
sampling period to the zero
baseline at the end of the
sampling period by using a
straight edge.
4. Read the zero baseline (% Chart)
at the midpoint of each hourly
interval, and record the value on
the data form.
5. Determine the hourly averages
by placing a transparent straight
edge parallel to the horizontal
chart division lines. Adjust the
straight edge between the lowest
and highest points of the trace in
the interval between two vertical
hour lines of interest so that the
area above the straight edge and
bounded by the trace and the
hour lines is approximately equal
to the area below the straight
edge and bounded by the trace
and hour lines, as shown below.
8. Convert reading values (% chart)
to concentrations (ppm) by using
the most recent calibration curve,
and record the CO
concentrations in the last column
of an hourly averages form such
as that shown in Figure 4.1.
An alternative method of converting
% chart to ppm is to eliminate steps 6,
• 7, and 8 and to use Equation 4-1:
YV
,-,-... - "i
Slope
Equation 4-1
where
Yz=zero baseline from step 4,
% scale
Y = recorder reading from step
5, % scale
Slope = slope of calibration
relationship from Section
2.6.2
4.2 Data Validation
Data of poor quality can be worse
than no data. Data validation to
screen for possible errors or.
anomalies is one activity of a quality
assurance program. Statistical
screening procedures should be
applied to identify gross anomalies in
air quality data.6 Subsections 4.2.1
and 4.2.2 recommend two data
validation checks.
4.2.1 Span Drift Check — The first
•level of data validation for accepting
or rejecting the monitoring data
should be based on routine periodic
50
4O
30
20
JO
0\
Straight edge
Area above line
Area below line
1200
13OO
J40O
150O
1600
Read the deflection (% chart) for all of
the hourly intervals for which data
have not been marked invalid, and
record all values on the hourly
average data form in the column
headed Reading - Original (Orig).
6. Subtract the zero baseline value
from the reading value, and
record the difference.
7. Add the percentage of zero
offset, <-5 percent, to each
difference.
checks of the analyzer. Results from
the Level 1 span checks (Section
2.6.3) should be used as the first
Level of data validation. Thus, up to 2
weeks of monitoring data may be
invalidated if the span drift for a
Level 1 span check is >25 percent."
For this reason, it may be desirable to
perform Level 1 checks more often
than the recommended 2-week
frequency.
4.2.2 Edit of Strip Chart — The strip
chart should be edited to detect signs
of monitoring-system malfunctions
that result in traces that do not
represent "real" data. In a review of a
• strip chart, typical, points to watch for
are:
1. A straight trace (other than
minimum detectable) for several
hours.
2. A wide solid trace indicating
excessive noise or spikes that are
sharper than is possible with the
normal instrument response time
and are indicative of erratic
behavior. Noisy outputs usually
result when analyzers are
- exposed to vibration sources.
3. A long, steady increase or
decrease in deflection.
4. A cyclic trace pattern within a
definite time period, which
indicates a sensitivity to changes
in temperature or parameters
other than CO concentration.
5. A trace that drops below the zero
baseline during certain periods; •
this may indicate a larger-than-
- normal drop in the ambient room
temperature or the power line
voltage. This may also indicate
CO in the zero-air.
Void any data for any time interval for
which a malfunction of the sampling
system is detected.
4.3 Data Reporting
Information and data from the
hourly average form should be
transcribed to a SAROAD hourly data
form (see Section 2.0.3 of this volume
of the Handbook for details and
instructions for filling out the
SAROAD). If the data are to be placed
in the National Aerometric Data Bank,
further instructions can be obtained
from the SAROAD Users Manual.7
-------
Section 2.6.4
Jan. 1983
£)a\Hrw\ ,
Calibration curve: Slope (bl *
Site number 3(?lbb£>C>/7
Pollutant
OO
B
Intercept (a) =
x = fy-aj/b
Date
b-15
fc-(5
Hour
00
01
--
Reading
Orig
&l
zz
Check
•
Zero baseline
Orig
t,
(,
Check
•
Difference
Orig
/5
17
Check
y. Add + 5
Orig
2.0
zz
Check
x, ppm
Orig
8
7
Check
Flgut* 4.1. Sample data form for recording hourly averages.
-------
Jan. 1983
Section 2.6.4
Table 4.1. Activity Matrix for Data Reduction
Activity
Acceptance limits
Frequency and method
of measurement
Action if
requirements
Data reduction
Span drift check
Editing of strip chart
Data reporting
Stepwise procedure for
data reduction (Subsec.
4.1}
Level 1 span check <25%
(Sec. 2.6.3)
No sign of malfunction
Data transcribed to
SAROAD hourly data form
Follow method Subsec. 4.1
for each strip chart.
Perform Level 1 check at
least every 2 weeks. (Sec.
2.6.31
Visually edit each strip
chart. (Subsec. 4.2)
VisuaJ checks
Review data reduction
procedure.
. Invalidate data; take
corrective action; increase
frequency of Level 1
checks until data are
acceptable.
Void data for time interval
for which malfunction of •
sampling system detected.
Review data transcription
-------
-------
Jan. 1983 1 Section 2.6.5
5.0 Maintenance
The quality assurance activities for
maintenance are described briefly.
5.1 Preventive Maintenance
Maintenance requirements vary
from instrument to instrument;
therefore, the supervisor should refer
to the manufacturer's manual for a
thorough discussion of maintenance
requirements for a specific analyzer.
After becoming familiar with the
requirements, the supervisor should
develop a suitable preventive
maintenance schedule.
5.2 Corrective Maintenance
Corrective maintenance is any
unscheduled maintenance activity that
becomes necessary because of system
malfunctions; for example,
replacement of a damaged pump
diaphragm, cleaning of a clogged
sampling line, or replacement of a
defective temperature control card.
The need for corrective maintenance
becomes apparent as the operator
performs the daily operations
described in Section 2.6.3 of this
Handbook;"when the need arises, the
operator should refer to the
manufacturer's manual for
troubleshooting procedures. A detailed
maintenance record should be kept on
file to identify recurring system
malfunctions. A sample maintenance
log is presented in Figure 5.1.
-------
Section 2.6.5
Jan. 1983
Site identification
Address
Pollutant
Instrument
Serial number
Date
Initiajs of
technician
fvent
initiating
maintenance
maintenance
activity
Comments
Dai
Figure S. J, Analyzer maintenance log.
-------
Jan. 1983
Section 2.6.6
6.0 Auditing Procedure
An audit is an independent
assessment of the accuracy of data
generated by an ambient air analyzer
or a network of analyzers.
Independence is achieved by having
the audit performed by an operator
other than the one conducting the
routine field measurements and by
using audit standards, reference
materials, and equipment different
from those routinely used in
monitoring.
The audit should be an assessment
of the measurement process under
normal operations-that is, without
any special preparation or adjustment
of the system. Routine quality
assurance checks (e.g., those in
Section 2.6.3) conducted by the
operator are necessary for obtaining
and reporting good quality data, but
they are not to be considered part of
the auditing procedure.
Three audits are recommended: two
performance audits and a system audit.
The performance audits are described
in detail in Subsection 6.1, and the
system aud.it is described in
Subsection 6.2. These audit activities
are summarized in Table 6.1 at the •
end of this section. (See Sections
2.0.11 and 2.0.12 for detailed
procedures for a system audit and a
performance audit, respectively.)
Proper implementation of an
auditing program will ensure the
integrity of the data and assess the
accuracy of the data. The technique '
for estimating'the accuracy of the
data is presented in Section 2.0.8 of
this volume of the Handbook.
6.1 Performance Audits
The following subsections describe
the recommended performance audits:
6.1.1 Calibration Audit —
A calibration audit consists of
challenging the continuous analyzer
with known concentrations of CO
within the measurement range of the
analyzer. Known concentrations of CO
can be generated by using individual
cylinders for each concentration or by
using one cylinder of a high CO
concentration and diluting it to the
desired levels with zero-air. In either
case, the gases used must be
traceable to an NBS-SRM or a
commercially available CRM (Section
2.6.2); acceptable protocol for
demonstrating traceability is
presented in Section 2.0.7. A dynamic
dilution system must be capable of
measuring and controlling flow rates
to within ±2 percent of the required
flow. Flow meters must be calibrated
under the conditions of use against a
reliable standard such as a soap
bubble meter or a wet test meter; all
volumetric flow rates should be
corrected to STP at 25°C (77°F) and
. 760 mm (29.92 in.) Hg, but if both the
CO and the zero air flow rates are
measured with the same type device
at the same temperature and
pressure, the STP correction factor in
the audit equations can be
disregarded. Note: If a wet test meter
or a bubble meter is used for flow
measurement, the vapor pressure of
water at the temperature of the meter
must be subtracted from the barometric
pressure.
The audit schedule depends on the
purpose for which the monitoring data
are being collected. For SLAMS monitor-
ing, each analyzer must be audited at
least once a year. Each agency should
audit 25 percent of the Reference or
Equivalent analyzers each quarter.8 If
an agency operates fewer'than four
analyzers, they should be randomly
selected for reauditing so that one
analyzer is audited each calendar
quarter and each analyzer audited at
least once a year. For PSD monitoring,
each Reference or Equivalent analyzer
must be audited at least once during a
sampling quarter.9
6.1.2 Calibration A udit
Procedures —
The analyzer should be challenged
with at least one audit gas of known
concentration from each of the
following concentrations within the
measurement range of the analyzer
being audited:
Audit point
1
2
3
4
CO concentration range.
ppm
3 to 8
15 to 2O
35 to 45
80 to 9O
The difference in CO concentration
(ppm) between the audit value and the
measured value is used to calculate
the accuracy (Section 2.0.8) of the
analyzer.
Information on the station,
analyzer, audit device, reference
materials, and audit procedures are of
prime importance because the validity
of the audit results depends on
accurate documentation (Figures 6.1
and 6.2). The following procedure has
been, developed to aid in conducting
the audit.
1. Record the station's number,
name, and address on the audit
summary report (Figure 6.1).
2. Identify the perso.n(s)
performing the audit and indicate the
date of the audit.
3. Record the type of audit device
used. If it was purchased, record the
manufacturer's name, model, and
serial number; if it was assembled by
the .user, assign an identification
number so that audits can be
referenced to that particular
apparatus.
4. Identify the CO cylinder(s) used
for auditing and the NBS-SRM or
commercially available CRM used to
verify the concentration. As required,
the CO cylinder(s) should be
reanalyzed every 6 months (Section
2.0.7).
5. Identify the device used to
measure flow rates, if applicable;
6. "Connect the audit system outlet
line to the inlet of the CO analyzer.
Analyzers must operate in the normal
sampling mode during the audit, and
the test atmosphere must pass
through all filters, scrubbers,
conditioners, and other components
used during normal ambient sampling
and through as much of the ambient
air inlet system as practicable. The
exception to this rule that is permitted
for certain CO analyzers during
precision and span checks does not
apply for audits.
7. Turn on the zero-air flow, and be
sure that the zero air output exceeds
the analyzer intake by at-least 10
percent.
8. Record the analyzer zero value on
the audit summary report.
9. Generate the first up-scale audit
point by challenging the analyzer with a
CO concentration within one of the
required concentration ranges; obtain a
stable trace, and record the audit value
and the analyzer response on the audit
summary report.
10. Determine the analyzer's
response (ppm) from the analyzer's
latest calibration relationship; if the
relationship is reported as slope and
-------
Section 2.6.6
Jan. 1983
Station
2, Analyzer mfr. .
Model
3. Audit performed by
4. Audit device mfr. .
S/N
Date
Model
5, CO standard used
Verified' a/jafnst NBS-SRM
By .
rn. c
-------
Jan. 1983
Section 2.6.6
Yes No
1. Zero and span checks performed at least biweekly
2. Temperature variations monitored
3. Flow meters routinely calibrated to ±2% accuracy against a reliable standard such as a soap bubble meter or
wet test meter
4. Flow rates monitored routinely
5. Excessive noise minimized
6. Data processing checks performed
7. Multipoint calibration performed routinely, and results of the calibrations recorded
8. Quality control charts maintained for zero and span checks
9. Maintenance performed routinely on pertinent components per manufacturer's manual
10. Calibration gases traceable to an NBS-SFtM
1J. Sample introduction system check made weekly
12. Paniculate filter (if used) changed per manufacturer's manual
13. Recording system checked and serviced before each sampling period
14. Recorded data checked for signs of system malfunction
15. Data quality records maintained — completeness, accuracy, precision, and representativeness
16. Calibration gases periodically assayed against an NBS-SRM
Comments: : :
Figure 6.2. Checklist for use by auditor. (Measurement of Continuous CO in Ambient Airj
intercept, use Equation 6-1 of Fiqure
6.1.
11. Repeat steps 9 and 10 for two
more audit points.
12. Calculate the percent difference
for each audit point by using Equations
6-2 and 6-3 of Figure 6.1 and record on
the audit summary report. Results of
the audit are used to estimate the
accuracy of ambient air'quality data (as
described in Section 2.0.8).
6.1.3 Data Reduction Audit — Data
reduction involves reading a strip
chart record, calculating an average,
and either transcribing or recording
the results on the SAROAD form. The
audit is an independent check of the
entire data reduction process, and
should be performed by an individual
other than the one who originally
reduced the data. Initially, the data
processing check should be performed
for 1 day out of every 2 weeks of data.
For two 1-hour periods within each
day audited, make independent
readings of the strip chart record and
continue through the actual
transcription of the data on the
SAROAD form. The 2 hours selected
during each day should be those for
which the trace is either most
dynamic (in terms of spikes), or for
which the average concentration is the
highest.
The data processing check is made
by calculating the difference:
d = [CO]B - [COJA
Equation 6-4
where
d = the difference between the
measured value and the
corresponding check value,
ppm
[CO]R=the recorded analyzer
response, ppm
[CO]A = the audit value of the CO
concentration, ppm
If d exceeds ±2 ppm, all of the
remaining data in the 2-week period
should be checked.
6.2 System Audit
A system audit is an onsite
inspection and review of the quality
assurance activities used for the total
measurement system (sample
collection, sample analysis, data
processing, etc.). System audits are
normally qualitative appraisals of
system quality conducted at the
startup of a new monitoring system
and periodically, as appropriate, to
audit significant changes in system
operation.
An example form for a system audit
is shown in Figure 6.2. The items on
this form should be checked for
applicability to the particular local.
State, or Federal agency.
See Sections 2.0.11 and 2.0.12 for
detailed procedures and forms for a
system audit and a performance audit.
respectively.
-------
Section 2.6.6
Jan. 1983
Table 6,1. Activity Matrix for A udit Procedure
Audit
Acceptance limits
Frequency of method
of measurement
Action if
requirements
are not met
Multipoint calibration audit
Data processing audit
System audit
The difference in concen-
trations between the
measured values and the
audit values is used as a
measure of accuracy.
(Sec. 2.0.8)
Adhere to stepwise
procedure for data reduc-
tion. Sec. 2.6.4; no
difference should exceed
±2 ppm.
Use method described in
this section of the Hand-
book.
Perform at least once per
quarter; see Subsec. 6.1.1
for procedure.
Perform independent data
processing check on a
sample of the recorded
data; e.g., check 1 day out
of every 2 weeks of data. 2
hours for each day.
Perform at the start-up
of a new monitoring sys-
tem, and periodically as
appropriate; observation
and checklist IFiq. 6.21.
If differences are outside
the agency acceptance
limits, locate the problem
and correct.
Check all remaining data
if one or more data reduc-
tion checks exceed ±2
ppm.
Initiate improved methods
and/or training programs.
-------
Jan. 1983 1 Section Z.6.7
7.0 Assessment of Monitoring Data for Precision and Accuracy
For continuous analyzers, perform a
check every two weeks to assess the
precision of the data. Use these data
to estimate single instrument
precision as described in Section
2.0.8 of this volume of the Handbook.
The precision check procedures
described in Section 2.6.3 are
consistent with those given in
References 8 and 9.
Estimates of single instrument
accuracy for ambient air quality
measurements from continuous
methods are calculated according to
the procedure in Section 2.0.8. The
audit procedure is described in
Section 2.6.6.
-------
-------
Jan. 1983
Section 2.6.3
8.0 Recommended Standards for Establishing Traceability
Two considerations are essential for
ensuring data of the desired quality:
1. The measurement process must
be in statistical control at the
time of the measurement.
2. The systematic errors, when
combined with the random
variation in the measurement
process, must result in an
acceptable uncertainty.
Evidence of good quality data
includes documentation of the quality
control checks and the independent
audits of the measurement process by
the recording of data on specific forms
or on a quality control chart and by
using materials, instruments and
measurement procedures that can be
traced to appropriate standards of
reference.
For traceability to be established,
. data must be obtained routinely by
repeat measurements of standard
reference samples (primary.
secondary, and/or working standards).
A condition of process control also
must be established. Working
calibration standards should be
traceable to standards of higher
accuracy.
The CO calibration standards must
be traceable to an NBS-SRM (as listed
in Table 8.1) or to a commercially
available CRM.
A list of gas manufacturers who
produce approved CRM is available by
writing to:
U.S. Environmental Protection
Agency
Environmental Monitoring Systems
Laboratory (MD-77)
Research Triangle Park, North
Carolina 27711 -•
ATTN: List of CRM Manufacturers
Tables. 1. NBS-SRM's for CO Monitors
SRM
168O
1681
2613
2614
Type
CO in nitrogen
CO in nitrogen
CO in air
CO in air
Vol/unit,
liters
at STP
870
870
870
870
Nominal CO
concentration,
ppm
500
7000
18. 1
43 0
-------
-------
Jan. 1983
Section 2.6.3
9.0 Reference Methods*
Appendix C—Measurement
Principle and Calibration
Procedure for the
Measurement of Carbon
Monoxide in the Atmosphere
(Non-Dispersive Infrared
Photometry)
Measurement Principle
1. Measurements are based on the
absorption of infrared radiation by
carbon monoxide (CO) in a non-
dispersive photometer. Infrared
energy from a source is passed
through a cell containing the gas
sample to be analyzed, and the
quantitative absorption of energy by
CO in the sample cell is measured
by .a suitable detector. The
photometer is sensitized to CO by
employing CO gas in either the
detector or in a filter cell in the
optical path, thereby limiting the
measured absorption to one or more
of the characteristic wavelengths at
which CO strongly absorbs. Optical
filters or otfier means may also be
used to limit sensitivity of the
_ photometer to a narrow band of
interest. Various schemes may be
used to provide a suitable zero
reference for the photometer. The
measured absorption is converted to
an electrical output signal, which-is
related to the concentration of CO
in the measurement cell.
2. An analyzer based on this
principle will be considered a
reference method only if it has been
designated as a reference method in
accordance with Part 53 of this
chapter.
3. Sampling considerations.
The use of a particle filter on the
sample inlet line of an NDIR CO
analyzer is optional and left to the
discretion of the user or the
manufacturer. Use of filter should
depend on the analyzer's'
susceptibility to interference,
malfunction, or damage due to
particles.
Calibration Procedure
1. Principle. Either of two methods
may be used for dynamic
multipoint calibration of CO
analyzers: (1) One method uses a
single certified standard cylinder of
CO, diluted as necessary with zero
air, to obtain the various calibration
concentrations needed. (2) The other
method uses individual certified
standard cylinders of CO for each
concentration needed. Additional
information on calibration may be
found in Section 2.0.9 of Reference
1.
2. Apparatus. The major
components and typical
configurations of the calibration
systems for the two calibration
methods are shown in Figures 1 and
: 2.
2.1 Flow controller(s). Device
capable of adjusting and regulating
flow rates. Flow rates for the
dilution method (Figure 1) must be
regulated to ±/%.
2.2 Flow meter(s). Calibrated flow
meter capable of measuring and
monitoring flow rates. Flow rates for
the dilution method (Figure 1) must be
measured with an accuracy of ± 2%
of the measured value.
2.3 Pressure regulator(s) for
standard CO cylinder(s). Regulator
must have nonreactive diaphragm and
internal parts and a suitable delivery
pressure.
2.4 Mixing chamber. A chamber
designed to provide thorough mixing
of CO and diluent air for the
dilution method.
2.5 Output manifold. The output
manifold should be of sufficient
diameter to insure an insignificant
pressure drop at the analyzer
connection. The system must have a
vent designed to insure atmospheric
pressure at the manifold and to
prevent ambient air from entering the
manifold.
3. Reagents.
3.1 CO concentration standard(s).
Cylinder(s) of CO in air containing
appropriate cbncentration(s) of CO
suitable for the selected operating
range of the analyzer under
'calibration; CO standards for the
dilution method may be contained in a
nitrogen matrix if the zero air dilution
ratio is not less than 100:1. The assay
of the cylinder(s) must be traceable
either to a National Bureau of
Standards (NBS) CO in air Standard
Reference Material (SRM) or to an
NBS/EPA-approved commercially
available Certified Reference Material
(CRM). CRM's are described in
Reference 2, and a list of CRM
sources is available from the address
shown for Reference 2. A
recommended protocol for certifying
Mixing
Chamber
CO
CO
Std
Output
Manifold
Vent
P
Extra Outlets Capped
When Not in Use
To Inlet of Analyzer
Under Calibration
•40 CFR 50 Appendix C (as amended 47 FR
54922. December 6. 1982)
Figure 1. Dilution method for calibration of CO analyzers.
-------
Section 2.6.9
Jan. 1983
fS t-1-*- Flow riowmetei 1
i i i ^ ^ ^ C°ntr°"er "*"'"''*
A
CO
Sid
n
CO
Std
A
CO
Stf
Ve
A
CO
Sfrf
A
Zero
Air
Output
Manifold
di tt III
t
Extra Outlets Capped
When Not in Use
Jo Inlet of Analyzer
Under Calibration
Flguti 2, Multiple cylinder method for calibration of CO analyzers.
CO gas cylinders against either a CO
SRM or a CRM is given in Reference
1, CO gas cylinders should be
recertified on a regular basis as
determined by the local quality control
program,
3.2 Dilution gas (zero air). Air, free
of contaminants which will cause a
detectable response on the CO
analyzer. The zero air should contain
<0.1 ppm CO. A procedure for
generating zero air is given in
Reference 1.
4. Procedure Using Dynamic
Dilution Method.
4.1 Assemble a dynamic calibration
system such as the one shown in
Figure 1, All calibration gases
including zero air must be introduced
into the sample inlet of the analyzer
system. For specific operating
instructions refer to the
manufacturer's manual.
4.2 insure that all flowmeters are
properly calibrated, under the
conditions of use. if appropriate,
against an authoritative standard
such as a soap-bubble meter or wet-
test meter, All volumetric flowrates
should be corrected to 25°C and 760
mm Hg (101 kPa). A discussion on
calibration of flowmeters is given in
Reference 1;
4.3 Select the operating range of
the CO analyzer to be calibrated.
4.4 Connect the signal output of the
CO analyzer to the input of the strip
chart recorder or other data collection
device. All adjustments to the
analyzer should be based on the
appropriate strip chart or data device
readings. References to analyzer
responses in the procedure given
below refer to recorder or data device
responses.
4.5 Adjust the calibration system to
deliver zero air to the output manifold.
The total air flow must exceed the
total demand of the analyzer(s)
connected to the output manifold to
insure that no ambient air is pulled
into the* manifold vent. Allow the
analyzer to sample zero air until a
stable response is obtained. After the
response has stabilized, adjust the
analyzer zero control. Offsetting the
analyzer zero adjustments to + 5
percent of scale is recommended to
facilitate observing negative zero drift.
Record the stable zero air response as
Zco.
4.6 Adjust the zero air flow and the
CO flow from the standard CO
cylinder to provide a diluted CO
concentration of approximately 80
percent of the upper range limit (URL)
of the operating range of the analyzer.
The total air flow must exceed the
total demand of the analyzer(s)
connected to the output manifold to
insure that no ambient air is pulled
into the manifold vent. The exact CO
concentration is calculated from:
[COlour = [COlsToxFco
FD + FD
Where:
[CO]ouT = diluted CO concentration
at the output manifold,
ppm;
(D
[CO]sTo = concentration of the
undiluted CO standard,
ppm;
FCo = flow rate of the CO
standard corrected to 25°C
and 760 mm Hg, (101 kPa),
L/min; and
Fo = flow rate of the dilution
air corrected to 25°C and
760 mm Hg, (101 kPa),
L/min.
Sample this CO concentration until a
stable response is obtained. Adjust
the analyzer span control to obtain a
recorder response as indicated below:
Recorder response (percent scale) =
[CO]ouTx100 + Zco
URL
(2)
Where:
URL = nominal upper range limit of
the analyzer's operating range,
and
Zco = analyzer response to zero air,
' % scale.
If substantial adjustment of the
analyzer span control is required, it
may be necessary to recheck the zero
and span adjustments by repeating
Steps 4.5 and 4.6. Record the CO
concentration and the analyzer's
response.
4.7 Generate several additional con-
centrations (at least three evenly spaced
points across the remaining scale are
suggested to verify linearity) by decreas-
ing Fco or increasing FD. Be sure the
total flow exceeds the analyzer's total
flow demand. For each concentration
generated, calculate the exact CO
concentration using Equation (1).
Record the concentration and the
analyzer's response for each concentra-
tion. Plot the analyzer responses versus
the corresponding CO concentrations
and draw or calculate the calibration
curve.
5. Procedure Using Multiple
Cylinder Method.
Use the procedure for the dynamic
dilution method with the following
changes:
5.1 Use a multi-cylinder system
such as the typical one shown in
Figure 2.
5.2 The flow meter need not be
accurately calibrated, provided the
flow in the output manifold exceeds
the analyzer's flow demand.
5.3 The various CO calibration
concentration required in Steps 4.6 and
4.7 are obtained without dilution by
selecting the appropriate certified
standard cylinder.
-------
Section 2.6.9
Jan. 1983
References
1. Quality Assurance Handbook for
Air Pollution Measurement Systems.
Volume II—Ambient Air Specific
Methods, EPA-600/4-77-027a, U.S.
Environmental Protection Agency,
Environmental Monitoring Systems
Laboratory, Research Triangle Park,
North Carolina 27711, 1977.
2. A Procedure for Establishing
Traceability of Gas Mixtures to Certain
National Bureau of Standards
Standard 'Reference Materials. EPA-
600/7-81-010, U.S. Environmental
Protection Agency, Environmental
Monitoring Systems Laboratory (MD-
77), Research Triangle Park, North
Carolina 27711, January 1981.
-------
-------
Jan-1983 1 Section 2.6.10
10.0 References
1. 40 CFR 50.8.
2. 40 CFR 53.
3. 40 CFR 50, Appendix C. (As
amended 47 FR 54922, December 6
1982).
4. U.S. Department of Commerce.
Catalog of NBS Standard Reference
Materials. NBS Special Publication
260, 1981-1983 Edition. National
Bureau of Standards, Washington, D.C.
November 1981.
5. U.S. Environmental Protection
Agency. Field Operations Guide for
Automatic Air Monitoring Equipment.
Office of Air Programs. Publication
Nos. APTD-0736, PB 202-249 and PB
204-650, October 1972.
6. U.S. Environmental Protection
Agency. Screening Procedures for
Ambient Air Quality Data. EPA-
450/2-78-037, July 1978.
7. U.S. Environmental Protection
Agency. Aeros Manual Series Volume-
II: Aeros User's Manual. EPA-450/2-
76-029, OAQPS No. 1.2-039,
December 1976.
8. 40 CFR 58, Appendix A.
9. 40 CFR 58, Appendix B. '
-------
4ft
-------
-------
-------
Section No. 2.8
Revision No. 0
Date December 30, 1981
Page 1 of 5
Section 2.8
REFERENCE METHOD FOR THE DETERMINATION OF LEAD IN
SUSPENDED PARTICULATE .MATTER COLLECTED FROM
AMBIENT AIR
OUTLINE
0^+- • Number of
bec-cion Documentation pages
SUMMARY oo
£. . O . J_
METHOD HIGHLIGHTS ' 2.8 3
METHOD DESCRIPTION
'• 1. PROCUREMENT OF EQUIPMENT- '
AND SUPPLIES 2.8.1 4
2. CALIBRATION OF EQUIPMENT ' 2.8.2 4
3. FILTER SELECTION AND
PREPARATION .2.8.3 1
4. SAMPLING PROCEDURE 2.8.4 1
5. ANALYSIS OF SAMPLES 2.8.5 14
6. CALCULATIONS AND DATA REPORTING 2.8.6 6
7. MAINTENANCE 2.8.7 ' 3'"
8. AUDITING PROCEDURE ' "2.8.8 12
9. ASSESSMENT OF MONITORING DATA
FOR PRECISION AND ACCURACY 2.8.9 \
10. RECOMMENDED STANDARDS FOR
ESTABLISHING TRACEABILITY 2.8.10 1
11. REFERENCE METHOD 2.8.11 6
12. REFERENCES 2.8.12 2
13. DATA FORMS 2.8^3
-------
Section No. 2.8
Revision No. 0
Date December 30, 1981
Page 2 of 5
SUMMARY
Ambient air is drawn through a glass fiber filter of a
hi-vol sampler to collect particulate material. The lead con-
centration in the suspended particulate matter is analyzed by
atomic absorption spectrophotometry.1
This method of sampling is applicable to measurement of the
mass concentration of suspended particulates in ambient air.
The size of the sample collected is usually adequate for other
analyses. When the sampler is operated 24 h at an average flow
rate of 1.70 m3/min (60.0 ft3/min) an adequate sample is ob-
tained, even in an atmosphere having a concentration of sus-
pended particulates as low as 1 pg/m3.
The typical range of the method is 0.07 to 7.5 pg Pb/m3
assuming an upper linear range of analysis of 15 pg/ml and an
air volume of 2400 m3. Typical sensitivities for a 1% change in
absorption (0.0044 absorbance units) are 0.2 and 0.5 pg Pb/ml
for the 217.0 and 283.3 nm lines, respectively. A typical lower
detectable limit (LDL) is 0.07 pg Pb/m3 when an air volume of
2400 m3 is assumed. The value quoted in the Federal Register1
(0.07 pg Pb/m3) was derived from instruments of different models
using the 283.3 and the 217.0 nm Pb lines.
Absolute values for individual laboratories will vary with
the type of instrument, the absorption wavelength, and the in-
strumental operating conditions.
The method description which follows is based on the pro-
mulgated Reference Method.1
-------
Section No. 2.8
Revision No. 0
Date December 30, 1981
Page 3 of 5
METHOD HIGHLIGHTS
This document is designed as a guideline for the develop-
ment of a quality assurance (QA) program as applied to the
reference method for measurement of ambient air particulate lead
concentrations. The description of the lead method is sub-
divided into categories, for easy referral to specific informa-
tion. Also at the end of each section is an activity matrix
which summarizes the QA activities and can be used for a quick
review of important information. Any of the sections, data
forms, or activity matrices can be easily removed from the rest
of the Handbook for making "working" copies for. convenient
reference. The sampling procedure is the same as the ambient
air hi"-vol method for total particulate described in Section 2.2
of Volume II of this Handbook. Therefore, for complete sampling
and analytical procedures for ambient air particulate lead it is
necessary to refer to the appropriate Section/Subsections of
Section 2.2. Following is a brief discussion of the material
covered in the method description.
1- Procurement of Equipment and Supplies
Section 2.8.1 describes the equipment and supplies for
monitoring ambient air particulate lead. It includes specifica-
tions, procurement log, acceptance limits, and recommended
action if acceptance limits are not met. Table 1.1 is an
activity matrix summarizing the procurement of equipment and
supplies.
2. Calibration of Equipment
Section 2.8.2 provides calibration procedures for the
hi-vol sampler, elapsed-time meter, orifice calibration unit,
and the atomic absorption spectrophotometer. Table 2.1 is an
activity matrix which summarizes the requirements for cali-
bration of the equipment.
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Section No. 2.8
Revision No. 0
Date December 30, 1981
Page 4 of 5 •
3. Filter Selection and Preparation
Section 2.8.3 briefly discusses filter selection.and prepa-
ration and refers the reader to Section 2.2.3 of Volume II of
this Handbook where the hi-vol method was previously discussed
in detail.
4. Sampling Procedure
Section 2."8.4 refers the reader to Section 2.2.4 of Volume
II of this Handbook where the hi-vol sampling method is dis-
cussed in detail. Sampling procedures 'for total suspended
particulate and ambient air particulate lead are identical.
5. Analysis of Samples
Section 2.8.5 contains a step-by-step procedure for the
analysis of ambient hi-vol filters for lead. The quality assur-
ance program includes sample documentation and inspection; it
discusses analytical equipment and supplies, analytical
reagents, and calibration of the analytical procedure. Table
5.1 is an activity matrix for the analysis and it summarizes
acceptance limits of specific activities involved with analysis
of samples.
6. Calculations and Data Reporting
Section 2.8.6 describes those.activities pertaining to data
calculation and reporting. An important part and final step in
this quality assurance program is the data calculation, review-
and standardized reporting format. Independent checks of the
data are recommended any time they are recorded or transcribed.
Example data forms are provided and an activity matrix at the
end of this section summarizes the activities for calculations
and data reporting.
7. Maintenance
Section 2.8.7 discusses periodic maintenance recommended
for sampling and analytical equipment. In order to maintain
optimum equipment performance, a preventive maintenance schedule
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Section No. 2.8
Revision No. 0
Date December 30, 1981
Page 5 of 5
should be established. Table 7.1 is an activity matrix for
maintenance of sampling and analytical equipment.
8. Auditing Procedure
Section 2.8.8 describes the recommended audit procedures
for maintaining a quality assurance program- for this method.
There are two types of audits discussed:
1. performance audit
2. system audit.
The data can be quantitatively evaluated by performance audits.
A system audit will assess the quality of the total measurement
system. Example control charts and control limits are provided.
Table 8.1 is an activity matrix which summarizes auditing proce-
dures .
9. Precision and Accuracy
Section 2.8.9 discusses data evaluation based on precision
and accuracy.
10. Recommended Standards
Section 2.8.10 discusses traceability of standards. .As
evidence in support of good quality data, it is necessary to
perform quality control checks and independent audits of the
measurement process, to document these data, and to use
materials, instruments, and measurement procedures that can be
traced to appropriate standards of reference. This section
describes these standards of reference which are applicable to
this method.
Section 2.8.11 is the reference method for measurement of
particulate lead in ambient air as promulgated by the EPA.
Section 2.8.12 lists the references.
Section 2.8.13 contains data forms applicable to this
method. They can be easily removed and copied for use with this
method.
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-------
Section No. 2.8.1
Revision No. 0
Date December 30, 1981
Page 1 of 4
METHOD DESCRIPTION
1.0 PROCUREMENT OF EQUIPMENT AND SUPPLIES
Specifications for the equipment and supplies for monitor-
ing ambient air for particulate lead (APPb) are in the Reference
Method, Section 2.8.11 and listed below.
Upon receipt of the sampling and the analytical equipment
and supplies, the procurement checks should be conducted. These
quality assurance checks are summarized in Table 1.1 at the end
of this section. These checks should be recorded in a procure-
ment log. An example of a log is Figure 1.1 and a blank copy of
the log is in Section 2.8.13 for the Handbook user. The procure-
ment^, log will serve as a permanent record for future procure-
ments, provide continuity of equipment and supplies, and provide
records for future program fiscal projections.
The following is a tabulation of equipment and supplies and
a reference to the subsections within this section or other
sections of Volume II of this Handbook containing pertinent
information. This will aid the user in finding specific infor-
mation regarding equipment and supplies necessary for this
method.
Reference to Handbook
Equipment and Supplies ' Section Subsection
Sampling
Hi-vol air sampler 2.2.7 7.1-7 6
Analysis equipment
Atomic absorption spectro-
photometer 2.8.5 5.3.1
Analytical support
Acetylene • 2.8.5 5.3.2
Air 285 coo
•£•0-0 5.3.3
-------
Section No. 2.8.1
Revision No. 0
Date December 30, 1961
Page 2 of 4
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(/> 4->
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-------
Section No. 2.8.1
Revision No. 0
Date December 30, 1981
Page 3 of 4
Reference to Handbook
Equipment and Supplies
Analytical support
Beakers
Volumetric flasks
Pipettes
Hot plate
Ultrasonic bath
Template
Pizza cutter
Watchglass
Polyethylene bottles
Parafilm "M"
Reagents
Cone HNO3
Cone HCl
Water
3M HN03
0.45M HNO3
2.6M HN03 + 0 to 0.9M HCl
0.40M HN03 + XM HCl
Pb(N03)2
Lead stock solution
(1000 |jg Pb/ml)
Section
2.8.5
2.8.5
.2.8.5
2.8.5
2.8.5
2.8.5
2.8.5
2.8.5
2.8.5
2.8.5
2.8.5
2.8.5
2.8.5
2.8.5
2.8.5
2.8.5
2.8.5
2.8.5
2.8.5
Subsection
5.3.4
5.3.4
. 5.3.4
5.3.5
5.3.6 -
5.3.7
5.3.8-
5.3.9 .
5.3.10
5.3.11
5.4.1
5.4.2
' • 5.4.3
' ' 5.4.4
5.4.6
5.4.7
5.4.8'
• 5.4.9
5.4.10, 5.5.11
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Section No. 2.8.1
Revision No. 0
Date December 30,
Page 4 of 4
1981
TABLE 1.1. ACTIVITY MATRIX FOR PROCUREMENT OF EQUIPMENT AND SUPPLIES
Equipment
Atomic absorp-
tion spectro-
photometer
Elapsed-time
meter
Orifice cali-
bration unit
Sampler
Acceptance limits
Equipped with lead hol-
low cathode lamp or
electrode!ess dis-
charge lamp
24 h ±2 min
Flow rate from manu-
facturer = actual flow
rate ±4%
Sampler complete;
no damage evident
Frequency and method
of measurements
On receipt, check
specifications and
parts
On receipt, check
against standard
timepiece of known
accuracy
On receipt, check
against flow rate
primary standard
Visually observe
Action if
requirements
are not met
Contact manu-
facturer or
supplier
Adjust or
replace
Adopt new
calibration
curve if no
evidence of
damage; re-
pi ace if
damaged
Repair or
replace
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Section No. 2.8.2
Revision No. 0
Date December 30, 1981
Page 1 of 4
2.0 CALIBRATION OF EQUIPMENT
Calibration of the equipment is one of the most important
functions for maintaining good data quality, therefore, the
sampling and analytical equipment must be calibrated regularly.
The calibration activities are summarized in Table 2.1, at
the end of this section. Many of these activities should be used
as initial procurement checks. All data and calculations in-
volved in the calibrations should be recorded in a calibration
log, which should have a separate section designated for each
apparatus and sampler.
2.1 Hi-Vol Sampler
The hi-vol air sampler shall be calibrated as specified in
Section 2.2.2 of Volume II of this Handbook.
2'1-1 Elapsed-Time Meter - The elapsed-time' meter (synchronous.
motor type, 60 Hz) should be checked upon receipt and again every
6 mo against a timepiece of known accuracy (Section 2.2.2).
2.1.2 On-off Timer - For those samplers that are equipped with
an on-off timer, the timer should be calibrated and adjusted
using a calibrated elapsed-time meter, upon receipt and every.3
mo thereafter. The calibration procedure is in Section 2.2.2.
2'1-3 Orifice Calibration Unit - "The orifice calibration unit
should be calibrated against a secondary standard (e.g., a
Rootsmeter), upon receipt and at 1-year intervals thereafter.
The calibration procedure is in Section 2.2.2.
2.1.4 Sampler - Samplers must be calibrated when first pur-
chased, after major maintenance (e.g., replacement of motor or
motor brushes), any time the flow rate measuring device (i.e.,
rotameter or recorder) has to be replaced or repaired, or any
time a one-point audit check (Section 2.2.8) deviates more than
±7% from the calibration curve. The calibration procedure for a
sampler is in Section 2.2.2.
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Section No. 2.8.2
Revision No. 0
Date December 30, 1981
Page 2 of 4
2.2 Atomic Absorption Spectrophotometer
Major repairs and adjustment of the atomic absorption spec-
trophotometer normally require the services of the manufacturer
or the manufacturer's representative. However, before operating
the spectrophotometer, instrument performance, such as sensitivi-
ty and reproducibility should be checked by using a standard
metal solution. The instrument sensitivity depends on- various
factors such as alignment of the hollow cathode lamp and burner
head, cleanness of optical systems and. burner head, and the level
of grating system calibration. An optimal sensitivity is recom-
mended by the manufacturer in the instrument manual. After this
sensitivity is achieved, check the reproducibility. Typical
sensitivities for a 1% change in absorption are 0.2 and 0.5 jjg
Pb/ml for wavelengths ,of 217.0 and 283.3 nm, respectively. An
instrument reproducibility change of ±5% is acceptable; repeat
the analysis until this limit is achieved. If the reproducibili-
ty varies by more than ±5%, the instrument should be checked by a
manufacturer's representative or a. qualified operator.
The following step-by-step reproducibility test procedure is
recomended:
1. Prepare a series of standard lead solutions containing
0.2, 1.6, and 10.0 |jg Pb/ml,- or 3 standard concentrations that
"bracket1! the normal sample concentration range, as described in
Section 2.8.5, Subsection 5.7.2.
2. Set the atomic absorption spectrophotometer for stan-
dard conditions, as described in Section 2.8.5, Subsection 5.6.
3. Take three or more _ readings for each standard metal
solution prepared in step 1. This can be done either sequential-
ly or by alternating the standards, however, calibration stan-
dards should be analyzed at random throughout the analysis to
check the calibration stability. See Section 2.8.5, Subsection
5.7.3.
4. Record the instrument response in absorbance'units. If
using a strip chart recorder, take the mid point of the noise as
baseline and measure the net difference between the baseline
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Section No. 2.8.2
Revision No. 0
Date December 30, 1981
Page 3 of 4
noise and the peak height. If the instrument has a digital read-
out and printer, there is no need to manually measure peaks and
absorbance units can be read directly.
5, Determine the instrument's reproducibility by subtract-
ing the lowest response from the highest response, then dividing
by. average response, and multiplying by 100. Correct these
values by subtracting the blank. For example, assume that' the
three response values derived from a 10.0 pg Pb/ml standard
solution are:
Absorbance Peak response minus blank
Blank = 0.005
1st peak = 0.100 , 0.095
2nd peak = 0.098. 0.093
3rd peak = 0.098 . 0.093
The average response value 'for these three analyses is
0.094, which represents the standard metal solution's concen-
tration (10.0 Mg Pb/ml). The maximum percentage absorbance
fluctuation is given by:
Percent fluctuation = 10° x (Q-095 - Q.Q93) _
0.094 ~ z/&-
The percent fluctuation should be <_5%; if not, have the instru- .
ment checked by a qualified service engineer.
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Section No. 2.8.2
Revision No. 0
Date December 30,
Page 4 of 4
1981
'TABLE 2.1. ACTIVITY MATRIX FOR CALIBRATION OF EQUIPMENT
Equipment
Acceptance limits
Frequency and method
of measurements
Action if
requirements
are not met-
Elapsed-ti'me
meter
±2 min/24 h
Check against stan-
dard timepiece (known
accuracy) on receipt
and at 6-mo intervals
Adjust, or
replace time
indicator
Timer
±15 min/24 h
Check at purchase
and quarterly against
elapsed-time meter
Adjust, and
repeat test
Orifice cali-
bration unit
Manufacturer's f1ow
rate = actual flow rate
±4%
Check flow rate
against primary stan-
dard at receipt and
at 1-year intervals
Adopt new
calibration
curve if no
evidence of
orifice dam-
age; replace
orifice unit
if damaged
Sampler
Q - Q
0 „ c x 100 < ±7%
Q = observed flow
Q = flow rate from
c calibration curve
Check against a
calibration orifice
unit on receipt and
after major mainte-
nance of sampler
Rerun points
outside the
limits until
acceptance
limits-are
attained
Atomic absorp-
tion sepctro-
photometer
Reproducibility within
±5%
Measure the instru-
ment's, reproducibility
(Subsec 2.2); at pur-
chase check instrument
specifications, align
the lamp and clean
the lamp and the
photometer window
Have the
manufacturer
or represen-
tative ser-
vice and ad-
just to in-
strument
specifica-
tions
-------
Section No. 2.8.3
Revision No. 0
Date December 30, 1981.
Page 1 of 1
3.0 FILTER SELECTION AND PREPARATION
Filter selection and preparation must be made carefully for
a good sample collection. The spectroguality grade filter,
which is commercially available and contains the least organic
binders and inorganic contaminants, is recommended, especially
when additional chemical analyses are anticipated. For more
information, see Section 2.2.3 of this Handbook.
-------
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Section No. 2.8.4
Revision No. 0
Date December 30, 1981
Page 1 of 1
4.0 SAMPLING PROCEDURE
All criteria for the collection of total suspended particu-
lates2 are equally applicable to the sampling procedure .for lead
(Section 2.2.4 of this Handbook).
-------
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Section No. 2.8.5
Revision No. 0
Date December 30, 1981
Page 1 of 14 .
5.0 ANALYSIS OF SAMPLES
Table 5.1 at the end of this section summarizes the major
quality assurance activities for sample analyses.
5.1 Sample Documentation and Inspection
1. Upon receipt of the sample from the field, remove the
filter folder from its shipping envelope and examine the hi-vol
field data form (Figure 3.2, Section 2.213 of this .Handbook.) to
determine whether all data needed to verify the- sample for
analysis and to calculate concentrations have been provided.
Void the sample if data are not only missing but also unobtaina-
ble upon inquiry to the field operator or if sampler malfunction
is evident (e.g., obvious faceplate gasket leakage).
2. Record the filter number on the hi-vol field data form
and on the laboratory, data log (Figure' 3.1, Section. 2.2.3).
3. Examine the shipping envelope for sample material that
may have become dislodged from the filter. If such material is
observed, recover as much as possible by brushing it from the
envelope to the deposit on the filter with a soft camel hair
brush.
4. Examine the filter for insects embedded in the sample
deposit; if any are found, remove them with Teflon-tipped tweez-
ers without disturbing any more of the sample deposit than is
necessary. If more than 10 insects are observed, refer the
sample to the supervisor for a determination whether to accept
or reject it.
5. Record (under remarks) any observations that may have
an impact on the validity of the sample.
5.2 General Analysis Description
In atomic absorption spectrophotometry, the element being
measured is aspirated into a flame or injected into a carbon arc
furnace and atomized. A light beam is directed through the
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Section No. 2.8.5
Revision No. 0
Date December 30, 1981
Page 2 of 14
flame, into a monochromator, and onto a detector that measures
the amount of light absorbed by the atomized element.
Because each metallic element has its own characteristic
absorption wavelength, a source lamp composed of that specific
element is used to minimize spectral or radiation interferences.
The amount of absorption of the characteristic wavelength is
proportional to the concentration of the element in the sample.
With the EPA method, at least two types of interferences
are possible: chemical and light scattering.3'4'5'6'7 Reports
on the absence of chemical interference far outnumber reports on
its presence; therefore, no correction for chemical interference
is given here. Non-atomic absorption as light scattering,
produced by high concentrations of dissolved solids in the sam-
ple, can produce a significant interference, especially at low
lead concentrations. The interference •is greater at the '
217.0-nm wavelength than at the 283.3-nm wavelength; in fact,
Scott, D.R., et al. have reported that no interference was
observed using the 283.3-nm wavelength.3
In this type of photometric analysis, the concentration of
the sample and particularly the concentration of reagent and
standard solutions, are of utmost importance to the accuracy of
the determination. Samples and standard metal solutions must be
carefully and accurately prepared.
5-3 Apparatus
5.3.1 Atomic Absorption Spectrophotometer - An atomic absorp-
tion spectrophotometer is required for determination of lead
content in suspended particulate matter, and must be equipped
with a lead hollow cathode lamp or electrodeless discharge lamp.
5.3.2 Acetylene - The grade recommended by the instrument manu-
facturer should be used as a fuel. Change cylinder when pres-
sure drops below 50 - 100 psig.
5.3.3 Air - Filtered clearn air (as free of particulates, oil
and water as possible) is needed as an oxidant.
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Section No. 2.8.5
Revision No. 0
Date December 30, 1981
Page 3 of 14
5.3.4 Glassware -
a. Beaker - Beakers, Borosilicate glass, including 30 ml
and 150 ml are needed to digest the sample. Phillips beakers
are useful for this purpose.
b. Volumetric flask - 100-ml volumetric flasks (Class A)
are required for analysis.
c. Pipette - Several volumetric pipettes (Class A), in-
cluding 1, 2, 4, 8, 15, 30, 50 ml should be available for the
analysis.
All glassware should be thoroughly cleaned with laboratory
detergent, rinsed, soaked for 4 h in 20% (w/w) HN03, rinsed 3
times with distilled deionized water, and dried in a dust free
manner.
5.3.5 Hot plate - Hot plates, 750 watts, 120 volt, having
enough plate surface area for several sample beakers, and cap-
able of heating to 370°C (698°F) are required for the hot ex-
traction of the sample.
5.3.6 Ultrasonication Bath Unheated - An ultrasonication bath
is required for the sample extraction when an ultrasonic extrac-
tion procedure is employed, and should provide the 'necessary
energy (>20,000 cycles per second). Commercially, available
baths of 450 watts or higher cleaning power have been found
satisfactory.
5:3.7 Template - Templates are needed to aid in sectioning the
glass fiber filter (Figure 5.1).
5.3.8 Pizza Cutter - A pizza cutter having a thin wheel (<1 mm
thickness) is needed to cut the filter. (Figure 5.2).
5.3.9 Watch glass - A watch glass is needed to cover the beaker
containing the sample.
5.3.10 Polyethylene Bottle - Linear polyethylene bottles are
needed to store the samples for subsequent analysis.
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Section No. 2.8.5
Revision No. 0
Date December 30, 1981
Page 4 of 14
30 cm
MANILA FOLDER - TO PREVENT
FILTER FROM STICKING TO
PLASTIC
GLASS FIBER FILTER FOLDED
(LENGTHWISE) IN HALF
12.7
WIDTH OF GROOVE/
1 cm
ALL GROOVES
2 mm DEEP
IGID PLASTIC
0.8 cm
JZZA CUTTER
25 mm
(1 in.) WIDE
IDTH OF GROOVE 8 mm
Figure 5.1. Sample preparation, filter sectioning 1.
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Section No. 2.8.5
Revision No. 0
Date December 30, 1981
Page 5 of 14
STRIP FOR
OTHER ANALYS
nim ' 203 T""
. 0 A.NALV; ,',
Figure 5.2. Sample preparation, filter sectioning 2.
-------
Section No. 2.8.5
Revision No; 0
Date December 30, 1981
Page 6 of 14 Jfth
5.3.11 Parafilm M Sealing Film - A pliable, selfsealing, mois-
ture proof, thermoplastic sheet material, substantially color-
less is recommended for use in sealing, the acidified sample
beakers. Commercially available Parafilm M satisfies this
requirement.
5.4 Reagents (Analysis) . • .
5.4.1 Nitric Acid (HNO3) Concentrated - A.C.S. reagent 'grade
HNO3 and commercially available redistilled HNO3 have been' found
to have sufficiently low lead concentration:
5.4.2 Hydrochloric Acid (HCl) Concentrated - A.C.S. reagent
grade. '
5.4.3 Water - The same source or batch of distilled deionized
water must be used for all purposes in the analysis.
5.4.4.. 3M HNOa - This solution is used in the hot extraction
procedure-. To prepare, add 192 ml of concentrated HNO3 to dis-
tilled deionized water in a 1-2 volumetric flask. Shake'well,
cool, and dilute to volume with distilled deionized water. Cau-
tion: Nitric acid fumes are toxic. Prepare in a well venti-
lated fume hood.
5.4.5. Glass Fiber Filter - Low lead content of the filter is
desirable. EPA typically obtains filters with a lead content of
«75 p.g/filter. Minimal variation in lead content from filter to
filter is also important.
5.4.6 0.45M HNOa - This solution is used as the matrix for
calibration standards when using the hot extraction procedure.
To prepare, add 29 ml of concentrated HNO3 to distilled deion-
ized water in a 1-2 volumetric flask. Shake well, cool, and
dilute to volume with distilled deionized water.
5.4.7 2.6M HNOa + (0 to 0.9M HCl) - This solution is used in
the ultrasonic extraction procedure and the concentration of HCl
can be varied from 0 to 0.9M. Directions for preparing a 2. 6M
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Section No. 2.8.5
Revision No. 0
Date December 30, 1981
- Page 7 of 14
HNO3 + 0.9M HCl solution are as follows: place 167 ml of concen-
trated HNO3 into a 1-2 volumetric flask and add 77 ml of concen-
trated HCl. Stir 4 to 6 h, dilute to nearly 1 e with, distilled
deionized water, 'cool to JLOOIII temperature, and dilute to 1
liter.
5.4.8 0.40M HNOr< + xM HC1 - This solution is used as the matrix
for calibration standards wnen using the ultrasonic extraction
procedure. To prepare, add 26 ml of concentrated HNO:;.. plus the
ml of HCl required (Equation 5-1), to a l-i! volumetric flask.
Dilute to nearly 1 8. with distilled deionized water, cool to
room temperature,.and dilute to 1 £. The amount of HCl required
can be determined from the following equation:
y • <77 mlj;<°M151 *
where. .
y = ml of concentrated HCl required, - /
x = molarity of HCl from Subsection"5.4.7, and "
0.15 = dilution factor from Subsection 5.5.2.
5.4.9 Lead Nitrate Pb(NQ:t).^ - A.C.S. reagent grade purity of
99.0%. Heat for 6 h at 120°C and cool in a desiccator.
5.4.10 Stock Lead Solution (100Q pg Pb/ml) in HNO:t - Dissolve
1.598 g of Pb(NO3)2 in 0.45M HNO3 contained in a 1-J> volumetric
flask and dilute to volume with 0.45M HNO3.
5,4.11 Stock Lead Solution. (1000 yq Pb/ml) in (HNOr,./HCl) - Pre-
pa,.e as in 5.4.10 except use the HNO3/HC1 solution from 5.4.84
Store standard in a linear polyethylene bottle. Commer-
cially available certified lead standard solutions may be used.
This stock solution may be stored up to 2 years. Label clearly
with contents, concentration, person who prepared the standard,
date prepared and expiration date. This date should be periodi-
cally checked and a fresh standard made as required.
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Section No. 2.8.5
Revision No. 0
Date December 30, 1981
Page 8 of 14
5.5 Sample Preparation for Atomic Absorption Spectrophotometry
5.5.1 Hot Extraction Procedure -
1. Gut a 1.9 cm x 20.3 cm (3/4 in. x 8 in.) strip from
the exposed filter using a template and a pizza cutter 'as de-
scribed in Figures 5.1 and 5.2. Other cutting procedures may be
used. Care should be taken to avoid cross-contamination from
one filter to another by wiping off any fibers which may adhere
to template or pizza cutter between samples. Note: Lead in
ambient particulate matter collected on glass fiber filters has
been shown to be uniformly distributed across the filter.3'5'8
Another study9 has shown that when sampling near a roadway,
strip position contributes• significantly to the overall varia-
bility associated with lead analysis. Therefore,, when sampling
near a roadway, additional strips should be analyzed to minimize
this-variability. .
2. Fold the sample in half twice and place. in a 150-ml
beaker. Add 15 ml of 3M HNO3 to completely cover the sample.
Cover the beaker with a watch glass. It is important to keep
the sample covered so that corrosion products (formed on fume
hood surface which may contain lead) are not deposited in the
extract.
3. Gently boil the sample in a beaker on a hot plate
under a fume hood for 30 min. Do riot let the sample evaporate
to dryness. Caution; Nitric acid fumes are toxic.
4. After 30 min, remove the beaker from the hot plate and
cool to near room temperature. Rinse watch glass and sides of
beaker with distilled deionized water.
5. Decant extract and rinsings into a 100-ml volumetric
flask, and add distilled deionized water to 40 ml mark on
beaker, cover with watch glass, and set aside for a minimum of
30 min. This is a critical step and cannot be omitted since it
allows the HNO3 trapped in the filter to diffuse into the rinse
water.
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Section No. 2.8.5
Revision No. 0
Date December 30, 1981
. ' Page 9 -of 14
6. Decant the water from the filter into the volumetric
flask and rinse filter and beaker twice with distilled deionized
water and add rinsings to volumetric flask until total volume is
80 to 85 ml.
7. Stopper flask and shake "vigorously, and set aside for
approximately 5 min or until foam has dissipated.
8. Bring solution to volume .with distilled deionized
water and mix thoroughly. Allow solution to settle for one hour
before proceeding with analysis. (Note: Do not filter the
extracted sample to remove.particulate matter because of-loss of
lead due to filtration. The final extract can be centrifuged at
2000 RPM for 30 min to remove any suspended solids.
9. If sample is to be stored for subsequent analysis,
transfer to a linear polyethylene'bottle, being carefu.' not to
disturb the settled solids.
5-5.2 Ultrasonic Extraction Procedure - . .
1. Cut a 1.9 cm x 20.3 cm (3/4 in. * 8 in.) stup, as de-
scribed in Subsection 5.5.1, step 1.
2. Fold the sample in half twice and place in a 30-mi
beaker. Add 15 ml of HNO;J/HC1 solution (see Subsection 5.4.7)
to completely cover the sample, and cover the beaker with
Parafilm. The Parafilm should be placed over the beaker such
that none of the Parafilm is in contact with water in the'ultra-
sonic bath. Otherwise, rinsing of the Parafilm in step 4 may
contaminate the sample. . " .
3. Place the beaker in the ultrasonication bath and
operate for 30 min.
4. Rinse Parafilm and sides of beaker with distilled
deionized water.
5. Decant the extract and rinsings into a 100-nrl volumet-
ric flask. Add 20 ml distilled deionized water to covet the
filter strip, cover with. Parafilm, and set asi-de for a miinuuiui
of 30 min. This is a critical step and cannot, be omit Led. The
sample is then processed as in Subsection b . s . 1, yteps {<.• )
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Section No. 2.8.5
Revision No. 0
Date December 30, 1981
Page 10 of 14
through (9). Samples prepared by hot extraction procedure are
now in 0.45M HN03 and samples prepared by ultrasonic extraction
procedure are now in 0.40M HNO3 + xM HC1.
5.6 Instrument Operation and Analysis
Because of the differences between makes and models of
atomic absorption spectrophotometers, it is difficult.to formu-
late detailed instructions applicable* to every instrument. Con-
sequently, it is recommended that the* user follow manufacturer's
operating instructions.
1. Set the atomic absorption spectrophotometer for the
standard conditions as follows: choose the correct hollow
cathode lamp or electrodeless discharge lamp for lead, install,
and align in the instrument; position the monochromator at 217.0-
nm or 283.3 nm; select the proper monochromator slit width; set
the light source current according to the manufacturer's recom- '
mendation; light the flame and regulate the flow of fuel and
oxidant; adjust the burner for-maximum absorption and stability;
and balance the photometer.
2. If using a chart recorder, set the chart speed at 8 cm
to 15 cm per minute and turn on the power, servo, and chart
drive switches. Adjust the chart pen to the 5% division line.
Also adjust instrument span using highest calibration standard.
While aspirating the standard sample, span instrument to desired
response.
3. The sample can be analyzed directly from the volu-
metric flask, or an appropriate amount of sample decanted into a
sample analysis tube. In either case, care should be taken not
to disturb the settled solids. At least the minimum sample
volume required by the instrument should be available for each
aspiration.
4. Aspirate samples, standards, and blank into the flame
and record the absorbance. If using a recorder wait for re-
sponse to stabilize before recording absorbance.
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Section No. 2.8.5
Revision No. 0
Date December 30, 1981
Page 11 of 14
5. Determine the average absorbance value for each known
concentration, and correct- all absorbance values by subtracting
the blank absorbance value. Determine the lead concentration in
pg Pb/ml from the calibration curve as presented in the follow-
ing subsection. Record these values on the Data Record Form
(Figure 6.1 of Section 2.8.6).
Note:
a. Samples that exceed the calibration range should be
diluted with acid of the same concentration and matrix as the
calibration standards and reanalyzed.
b. Check for drift of 'the zero point resulting from pos-
sible nebulizer clogging, especially when dealing with samples
of low absorbance.
5.7 Preparation of Calibration Curve
5.7.1 -Working Standard Solution (20 yg Pb/ml) - Prepare .by
diluting 2 ,ml of stock lead .solution .(Subsection' 5.4.10 if the
hot extraction was used or Subsection 5.4.11 if the ultrasonic
extraction procedure was used) to 100 ml with acid of the same
concentration and matrix as used in the stock lead solution.
•This standard should be prepared daily.
5.7.2 A Series of Calibration Standards - Prepare daily by-
diluting the working standard solution (Subsection 5.7.1) 'as
indicated below with the same acid matrix as used in the working
solution. Other lead concentrations may be used provided they
are in the linear range of the instrument.
Volume of 20 \iq/ml Final Concentration
working standard, ml volume, ml pg Pb/ml
0 • 100 0.0
1-0 . 200 0.1
2.0 200 0.2
2.0 100 0.4
4.0 100 0.8
8.0 . 100 1.6
15.0 100 3.0
30.0 100 6.0
50.0 100 10.0
100.0 ' 100 20.0
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Section No. 2.8.5
Revision No. 0
Date December 30, 1981
Page 12 of 14
5.7.3 Calibration Curve - Since the working range of analysis,
will vary depending on which wavelength Is used and the type of
instrument, no one set o'f instructions for preparation of a
calibration curve can be given.
Select at least three standards (plus the reagent blank) to
cover the linear range indicated by the instrument's manufac-
turer. Aspirate these standards and the blank and measure the
absorbance. Repeat until good agreement is obtained between re-
plicates. Plot absorbance (y-axis) versus concentration in pg
Pb/ml (x-axis) as shown in Figure 5.3. Draw a straight line
through the linear portion of the curve, and do not force the
calibration curve through zero. Note: To determine stability
of the calibration curve, analyze a control standard before the
first sample, after every subsequent 10th sample, and after the
last sample. Vary the control standard concentration by alter-
nating", in run sequence, a value less than 1 |jg Pb/ml, and a ,
value between 1 and 10 M9 Pb/ml. If either standard deviates by
more than 5% from the value predicted by the calibration curve,
take corrective action and repeat the previous 10 analyses.
-------
Section No. 2.8.5
Revision No. 0
Date December 30, 1981
Page 13 of 14
0-20
6 3 10 12 14
Concentration, ug Pb/ml
16'
18
Figure 5.3. Example of a calibration curve for absorbance
versus concentration of Pb standard.
-------
1
Section No. 2.8.5
Revision No. 0
Date December 30,
Page 14 of 14
1981
TABLE 5.1. ACTIVITY MATRIX FOR ANALYSIS OF SAMPLES
Activity
Verify documen-
tation and-
inspect sample
Atomic •absorp-
tion spectro-
photometer
Reayents
Glassware
FiIter strip
Hot extraction
Ultrasonic
fj/traction
V:»nplfj acid
concentration
I if/ration
.ur /<•
Acceptance limits
Complete documentation;
absence of evidence of
malfunction or sample
loss; ten or fewer
insects visible in
sample
Equipped with lead
hollow cathode lamp or
electrodeless dis-
charge lamp
Al1 reagents must be
A.C.S. reagent grade
Borosilicate glass and
Class A
Size = 1.9 cm x 20.3 cm
(3/4 in. x 8 in.)
Do not evaporate to
dryness and cover so
that, corrosion products
are not deposited in
the extract
Provide '20,,000 cycles
per second
0.45M HNO-.; or 0.40M
HNO- + xM HC1
ReprnducifoiIity is
Frequency and method
of measurement
Visual check
Upon receipt check
for specifications
or certification
Prepare fresh as
introduced in Sub-
sec 5.4
Upon receipt check
for stock number,
cracks, breaks, and
manufacturer flaws
Check its size
Frequently and
visually check the
level of evapora-
tion
Action if
requirements
are not met
Void sample
Upon receipt check
the label and per-
formance by comparing
to the hot extraction
procedure
Prepare fresh
Recalibrate and
repeat the analysis
Service by
manufacturer
Use new
reagents
Replace or
return to
supplier
Prepare new
strip
Void sample
Return to
supplier or
use a hot
extraction
procedure
Void sample
Check instru-
ment or pre-
pare a new
ca I ibration
curve
-------
Section No. 2.8.6
Revision No. 0
Date December 30, IvSI
Page 1 of 6 .
6.0 CALCULATIONS AND DATA REPORTING
A matrix summarizing the quality control activities for the
calculations and the data-reporting requirements is presented in
Table 6.1. •
6.1 Sample Air Volume
At standard temperature and pressure (STP) for samplers
equipped with rotameters:
(Qi + Qf)
V = ^ t - Equation 6-1
where
V = air volume sampled, m3,
9-i = initial air flow rate, m3/min at STP,
Qf = final air flow rate, m3/min at STP, and
t = sampling period (elapsed time), min.
For samplers equipped with flow recorders:
V = Qt Equation 6-2
where Q = average sampling rate, m3/min at STP.
Estimate the Q from the recorder chart. If the flow rate varies
less than 0.11 m3/min during the sampling period, read the flow
rate from the chart at 2-h intervals and take the average value
for Q.
Calculation for sample air volume is identical to the
hi-vol method'(Section 2.2.6 of the Handbook).
6.2 Lead Concentration
6.2.1 Estimation of Lead Concentration of the Blank Filter, \.tq -
1. For testing of the large batches of filters ("500 fil-
ters) select at random 20 to 30 filters from a given batch. For
small batches (<500 filters) a lesser number of filters may bt>
taken. Cut one 1.9 cm - 20.3 cm (3/4 in. x 8 in.) strip from
-------
Section No. 2.8.6
Revision No. 0
Date December 30, 1981 ^^
Page 2 of 6 {•»
each filter, anywhere in the filter.. Analyze all strips, sepa-
rately, according to the directions in Subsections 5.5 and 5.6
of Section 2.8.5.
2. Calculate total lead in each filter as
F = ua Pb/ml x 10° ml x 12 strips
Fb pg Pb/ml x strip x filter
where
F. = Amount of lead per 465 square cm (72 square
in. ) of blank filter, (jg,
pg Pb/ml = Lead concentration determined from Subsection
5.6 of Section 2.8.5,
100 ml/strip = Total sample volume,
12 strips/filter =
Useable filter area, 20 cm x 23 cm (8 in. x 9 in.) _ .
Exposed area of one strip, 1.9 cm x 20 cm (3/4 in. x 8 in.)
3. Calculate the mean, F^, and .the relative standard de-
viation (100 x standard deviation/mean).
n
Z
Equation 6-3
where .
F^ = average amount of lead per. 72 square inches of
filter, |jg
F^ • =. amount of lead per 72 square inches for each
1 filter, Mg
n = number of blank filters analyzed.
The standard deviation (SD) of the analyses for the blank fil-
ters is given by Equation 6-4,
SD =
n-l
1/2
Equation 6-4
The relative standard deviation (RSD) is the ratio
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Section No. 2.8.6
Revision No. 0
Date December 30, 1981
Page 3 of 6
RSD =
If the relative standard deviation is high enough so that in the
analyst's opinion subtraction of ?b may result in a significant
error in the jjg- Pb/m3, the batch should be rejected. For ac-
ceptable batches, use the value of Fb to correct all lead anal-
yses (Subsection 6.2.2) collected using that batch of filters.
If Fb is below the lower detectable limit (LDL), no correction
is necessary.
6.2.2 Calculation of Lead Concentration of the Exposed Filter -
Lead concentration in the air sample can be calculated from data
tabulated on data record form (Figure 6.1) as follows:
Pb/ml .x 100 ml/strip x 12 strips/filter) - F
'• 7 - :
where
C = Concentration, pg Pb/m3,
Mg Pb/ml = Lead concentration determined from Section
2.8.5, Subsection 5'. 6,
100 ml/strip = Total sample volume,
12 strips/filter =
_ Useable filter area, 20 cm x 23 cm (8 in. x 9 jn. ) _
Exposed area of one strip, 1.9 cm x 20 cm (3/4 in. x 8 in.)
Fb = Average lead concentration of blank filters,.
V = Air volume from Subsection 6.1.
6-2.3 Sample Calculation of Lead Concentration in Air Sample -
Data are tabulated on a data record form as shown in Figure 6.1.
The standard data are recorded and a standard curve is drawn
(Figure 6.2). The line of best fit is drawn through the points.
Average all standards analyzed throughout the run but do not
include the standards used as checks of the calibration stabil-
ity. These are check samples to be compared to the calibration
curve.
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Section No. 2.8.6
Revision No. 0
Date December 30, 1981
Page 4 of 6
r-oject
Simple location
Date
Ancilyst
Sample
number
/lfi£
Air volume
at STP, m3
A*1I
Avg
blank
V
US'
-^7jr
Absorbance
0. 0
-------
Section No. 2.8.6
Revision No. 0
Date December 30, 1981
Page 5 of 6
0.20
8 10 12 14 16 18 20
ug Pb/ml
Figure 6.2. Calibration curve.
-------
Section No. 2.8.6
Revision No. 0
Date December 30, 1981
Page 6 of 6
To calculate total Pb of a sample use equation from Subsec-
tion 6.2.2.
_ F(5.7 ug/ml)(100 ml/strip) (12 strip/filter)] - (0)
(2291 m )
C = 3.0 (jg Pb/m .
TABLE 6.1. ACTIVITY MATRIX FOR CALCULATION AND DATA REPORTING
Activity
Calculations
(1) sample
volume
(2) Fb, blank
(3) SO and RSD
of F. values
D
(4) sample
concentration
Analysis data
form
Documentation
and sample
verification
Documentation
of report
data
Acceptance limits
Al1 needed, data
available; relative
standard deviation of
F. is not high
All data and calcu-
lations are given
Documentation complete
for calculation of
concentration; all
sample and data
identification numbers
match; absence of evi-
dence of malfunction
or sample loss
All needed data
available
Frequency and method
of measurements
Visual check for each
sample; repeat all
calculations.
Visual check
Visual check for
each sample
Visual check for
each sample
Action if
requirements
are not met
Void sample;
indicate
errors and
make correc-
tions
Complete
missing data
values
Void sample
Void sample
-------
Section No. 2.8.7
Revision No. 0
Date December 30, 1981
Page 1 of 3
7.0 MAINTENANCE
Scheduled or preventive maintenance of the sampling equip-
ment and atomic absorption spectrophotomete_r will result in a
reduction- of downtime and remedial maintenance' requirements.
Table 7.1 at the end of this section summarizes the quality
assurance aspects of major maintenance checks. Record all main-
tenance activities in a maintenance log book. Normally, two to
three remedial maintenance activities are required per year.
The maintenance methods for a.sampler motor, faceplace gas-
ket, rotameter, sampling head, motor gaskets, and -flow trans-
ducer and recorder, are presented in Section 2.2.7-of Volume II
of this Handbook.
7-1 '-Atomic Absorption Spectrophotometer
As previously indicated, major maintenance and calibration
should be done by service engineers or qualified operators. The
following general maintenance procedures should be carried out
only after consulting the manufacturer's manual.
7-1-1 Light Source - When problems are concerned with a light
source, check the hollow cathode lamp-or electrodeless discharge
lamp mounting bracket, lamp connection, and make sure the in-
strument is plugged in, turned -on, and warmed up. If line
voltages are low, operate the power supply from a variac which
•is set to give maximum voltage. Lamp current meter fluctuation
can be reduced by using a constant voltage sine wave trans-
former.
7'1-2 No Absorbance Response - Make sure that the lamp is
lighted, properly aligned, and that the wavelength, slit, and
range controls are properly adjusted. if the meter cannot be
zeroed, (1) adjust the level of the burner head to avoid inter-
cepting the light beam, and (2) clean the lamp and window, or
photometer cover windows, with a dilute solution of a mild
-------
Section No. 2.8.7
Revision No. 0
Date December 30, 1981
Page 2 of 3
detergent and rinse several times with distilled water. Dirty
windows or lenses are a major problem when operating the instru-
ment below 2300 A° (23C nm).
7.1.3 Readout Noisy, Flame On - Check the lamp current setting,
fuel ,and oxidizer flow rates, the leviner to make sure it is
draining properly, the nebulizer for corrosion around the tip,
the adjustment of the nebulizer 'capillary, the burner head (it
may need cleaning with razor blade), the acetylene cylinder
pressure, the air pressure, and the air line filter.
7.1.4 Poor Sensitivity (Within 50% of That Suggested in the
Analytical Method Book) - Check the sensitivity obtainable for
several other elements to ascertain that the-low sensitivity is
not due to the lamp used. Check the slit width, wavelength,
range setting, the burner alignment, the , adjustment of the.
nebulizer capillary, the fuel/oxidant flow rate ratio to ascer-
tain that it is optimized for the element to be analyzed. Make
sure that the lamp current is not above the recommended value,
check the lamp alignment, and the concentration of the standard
solution used.
All other maintenance problems such as cleaning of mirrors
or gratings should be discussed with the manufacturer or service
representative. •
-------
Section No. 2.8.7
Revision No. 0
Date December 30, 1981
Page 3 of 3
TABLE 7.1. ACTIVITY MATRIX FOR MAINTENANCE
Equipment
Acceptance limits
Frequency and method
of measurements
Action if
requirements
are not met
Sampler motor
400 h operation of
motor; absence of
malfunction
Visually check upon
receipt and after
each 400 h of
operation
Replace motor
brushes;
other mainte-
nance as in-
dicated
Faceplace
gasket
Absence of leaks at
filter seal
Visually check after
each sampling period
Replace gas-
ket
Rotameter
Absence of foreign
materials; stable
operations
Visually check for
each sample
Clean; re-
place if
damaged
Motor gaskets
Leak tight fit
Visually check each
400 h of operation
Replace gas-
kets
Sampling head
Absence of leaks
Visually check each
200 h of operation
Replace samp-
ling head
Atomic absorp-
tion spectro-
photometer
Absence of dirt and/
or contamination in
light source systems;
absence of current
fluctuation; manu-
facturer's specifica-
tions on sensitivity
achieved
Clean up and adjust
trouble parts, vi-
sually check energy
meter needle; vi-
sually check gauge,
and adjust light
passing systems,
and clean up lamp
and window and
photometer cover
window; check for
possible troubled
parts as indicated
in Subsec 7.1.4
Replace dam-
aged parts;
use constant
voltage
transformer;
contact manu-
facturer
-------
-------
Section No. 2.8.8
Revision No. 0
Date December 30, 1981
Page 1 of 12
8.0 AUDITING PROCEDURE
An audit is an independent assessment of the quality of
data. Independence is achieved by having the audit made by an
operator other than the' one conducting the routine field mea-
surements and by using audit standards and equipment different
from those routinely used. Routine quality assurance checks
conducted by the operator are necessary for obtaining and re-
porting good'quality data, but they are not to be considered as
part of the auditing procedure.
Based on the results of the Reference Method Test10 for
lead analysis and Hi-Vol Sampling Method2, three performance
audits and a system audit are recommended and are described in
detail in the subsequent sections.
The basic purpose of an auditing program is to ensure.the
integrity of the data and to assess the data in terms of ac-
curacy. Techniques for estimating the accuracy of the data are
given in Section 2.0.8 of Volume II of this Handbook. '
8.1 Performance Audits
Performance audits are independent checks made by the
supervisor or auditor to evaluate the quality of data produced
by the total .measurement system (sample location, sample ana-
lysis and data processing). Performance audits are normally a
quantitative appraisal of quality.
Three performance audits of individual variables are recom-
mended: '
1. Audit of flow rate calibration
2. Audit of lead analysis
3. Audit of data processing.
8-1-1 Audit of Flow Rate Calibration - The frequency of the
audit of the flow rate depends on the use of the data (e.g., for
PSD air monitoring or for SLAMS). it is recommended that the
flow rate of each hi-vol sampler be audited each quarter.
-------
Section No. 2.8.8
Revision No. 0
Date December 30, 1981
Page 2 of 12
1. Conduct the flow rate audit using a reference flow
(ReF) device, a or a similar device.
2. Audit the flow rate at one flow rate. The ReF device
used for auditing must be different from the one used to cali-
brate the flow of the hi-vol sampler being audited.
3. Operate the hi-vol sampler at its normal flow rate
with the audit device in place.
4. Great care -must be used in auditing the hi-vol sam-
plers having flow regulators because "the introduction of resist-
ance plates in the audit device can cause abnormal flow patterns
at the point of flow sensing. For this reason, the orifice of
the flow audit device should be used with a normal glass fiber
filter in place and without resistance plates, in auditing flow
regulated hi-vol samplers, or other steps should be taken to
assure that flow patterns are not disturbed at the point of flow
sensin'g. ,
* ' •
5 . Use the known audit . flow measurement and the flow
measured by the sampler's normal flow indicator to calculate
percent difference (Equation 8-1), a measure of inaccuracy.
Both flows must be referenced to same temperature and pressure.
Let X. represent the known flow rate, Y. the measured flow rate,
th
and d. the percent difference for the i — audit:
Y. - X,
d. = — =7= - =• 100. ' Equation 8-1
i X±
Thus if Y. = 52 ft3/min and X. = 50 ft3/min,
> •flC!**' ^
then
di =
If d- is greater than ±7% for any one check, recalibrate before
resuming the sampling.
aUSEPA uses ReF device with five orifice plates that mount onto
the faceplate of the hi-vol adaptor; this device may be pur-
chased from Dexco; Co., Inc., 630 Chapel Hill Blvd., Burling-
ton, N. C. 27215.
-------
Section No. 2.8.8
Revision No. 0
Date December 30, 1981
Page 3 of 12
6. Report the Y^ the X^ and the .^ on an X-and-R.chart
Crigure 8.1) under "Measurement Result, Items 1 and 2." Record.
the d^ in the cells preceded by the "Range R." The d- can be
positive or negative, but the range is always positive; so
t/etain the sign -of the difference since it may Indicate trends
ctnd/or consistent biases. The steps in the construction of a
Duality control chart, and the interpretation of the results are
in Appendix H, Volume I of this Handbook.11
7. Repeat the above for each flow rate calibration audit;
plot all points on the chart; and connect the points by.drawing
a straight-line. Tentative limits are ±4.7% (warning lines) and
x?% (out-of-control lines). Out-of-control points indicate
possible problems in calibration errors or instrument• damage.
Recalibrate the sampler prior to further sampling when out of
control.- After 15 to 20 points are plotted, new control and
warning limits may be derived, as described in Appendix H of
Volume I of this Handbook.11 Do not increase the control and
warning limits, however, more stringent limits may be
established.
8-L-2 Audit of Lead Analysis - Each calendar quarter, audit the
leaa analysis using glass fiber filters containing a, known quan-
tity of lead. Audit samples are prepared by depositing a lead
solution Pb (N03)2, on 1.9 cm x 20 cm (3/4 in? by 8 in.) unex-
posed glass fiber filter strips, and allowing to dry thoroughly.
•It ij required that the audit samples be prepared using reagents
.-iitferent from those, used to generate the lead calibration curve
.in Section 2.8.5. If the routine network operators are used to
perform the audit, these, operators must not know the audit
values prior to the audit. This means another individual must
administer the audit program. Prepare blind audit samples in
the following concentration ranges:
-------
Section No. 2.8.8
Revision No. 0
Date December 30, 1981
Page 4 of 12
rcj
O
HI
S-
i
i-
o
M-
o
4->
!=
O
u
3
o-
co
d)
«_
a
en
0
-------
Section No. 2.8.8
Revision No. 0
Date December 30, 1981
Page 5 'of 12
Range Cone, ng Pb/strip Cone, pg Pb/m3*
1 100 to 300 0.5 to 1.5
2 600 to 1000 3.*0 to 5.0
*Calculation of lead concentration in ug/m3 is based on sampling
at 1.7 m3/min for 24 h on an 20 cm x 25 cm (8 in. x 10 in.)
glass fiber filter.
Analyze at least one audit sample in each of the two ranges
each day that samples are analyzed. If samples are analyzed
only once per quarter, analyze at least two audit samples in
each of the two' ranges. The percentage difference d between the
audit concentration (|jg Pb/strip) and the analyst's measured
concentration (ug Pb/strip) is used to calculate analysis inac-
curacy, (Equation 8-2),
- d = cPb(M) - cPb(A) x 100 : ion 8_2
• UPb(A)
where
d = Percentage difference,
CPb(M) = Concentrati°n measured by the lab analyst,
(jg Pb/ml, and
CPb(A) = Audited or known concentration of audit sample,
(jg Pb/ml.
Tabulate the percentage differences on an X and R chart
(optional). The upper and lower control lines and the upper and
lower warning lines should also be plotted (Figure 8.2) and used
as guidelines to determine when results are questionable and
corrective action needs to be taken. Record on the chart the
nature of the corrective action. Deta-ils for construction of a
quality control chart are given in Appendix H of Volume I of
this Handbook.ll
The recommended control limits for the two audit sample
ranges (0.5 to 1.5 and 3^ to 5 jjg Pb/m;! ) are the 90th percent!le
values for d based on the results of seven audits (8/77,. 1.. 78,
6/78, 1/79, 7/79, 1/80, and 7/80) performed by the Environmental
-------
Section No. 2.3.8
Revision No. 0
Date December 30, 1981
Page 6 of 12
•
-------
. Section No. 2.8.8
Revision No.. 0
Date December 30, 1981
Page 7 of 12
Monitoring Systems Laboratory, USEPA, Research Triangle Park,
North Carolina.12'13'14'15 By definition, 90% of the laboratory
participants in the audit obtained values of d less than the
values tabulated below. The control limits are expected to be
exceeded by 10% of the laboratories to be audited, based on
these seven audits over four years. The 90th percentile values
and the known audit concentrations are given below for each
audit concentration range.
Audit date
8/77
1/78
6/78
6/78
1/79
7/79
.1/80
7/80
0.5 to 1.5 |jg Pb/m3
Known audit
concentration, 90th
|jg. Pb/m3
1.8
0.6
0.4
1.5
1.5
1.2
0.9
0.6
3 to 5 ug Pb/m3
Known audit
concentration, 90th
pg Pb/m3
4.0
5.0
3.5
3.5
4.5
4.2
percentile
°/
/o
45
35
31
. 15
15
16
16
11
percentile
%
23
12
- • 14
13
20
9
for d,
.3
.1
.1
.7
for d,
.5
.5
.8 '
.9
.0
.8
Audit date
8/77
6/78-
1/79
7/79
1/80
7/80
Based on the results of these seven audits, the recommended 90th
percentile control limits for .audit samples are ±16% for both
the 0.5 to 1.5 |jg Pb/m3 and the 3.0 to 5.0 pg Pb/m:l concentra-
tion ranges. The control limits of ±16% are also recommended
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Section No. 2.8.8
Revision No. 0
Date December 30, 1981
Page 8 of 12
for the lower Pb concentrations range (0.5 to 1.5- ug Pb/m3) on
the assumption that the first three audits are not representa-
tive of current limits (last four audits).
The method user should take part in the EPA semi-annual
audit program for lead analysis. For more information on the
EPA lead audit program, see Section 2.0.10 of this Handbook.
8.1.3 Audit of Data Processing - A data processing audit allows
for correction of errors, after the original calculations have
been performed. The audit rate of seven measurements out of
every 100 is recommended. The audit is made starting with the
raw data on the data form. When the original and the audit
calculations do not agree, all calculations for the correspond-
ing audit period should be recalculated. The nature of the
error(s) should be clearly explained to the appropriate per-
sonnel in order to minimize their reoccurrence. Audit values
are recorded in the data log and reported to the supervisor for
review. These results can be used to check computer programs
and manual methods of data processing.
8.2 System Audit
A system audit is an on-site inspection and review of the
quality assurance system used for the total measurement system
(sample collection, sample analysis, data processing, etc.).
Whereas performance audits are a quantitative assessment, system
audits are normally a-qualitative appraisal.
A system audit should be conducted for a monitoring system.
The auditor should have sufficient experience with the method
and an extensive background with the characterization technique
that he is auditing. Figure 8.3 can be used as a preliminary
form for use in a system audit. These questions should be
checked for the applicability to the particular local, State, or
Federal agency. One should also refer to Section 2.0.11 of this
volume of the Handbook for further details on a system audit.
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Section No. 2.8.8
Revision No. 0
Date December 30, 1981
Page 9 of 12
I. What types of hi-vol samplers are utilized in the network?
flloMr Itinrfc mock! (4
2. How often are the samplers run? Ka)) daily, (b) once every six days,
(c) once every 12 days, (d) other — _ . _
3. What type and quality of filter and number of filters is being utilized?
fihts , Spec.'h'hftLL&lihj o
4. Are there any pre-exposure checks for pin holes or imperfections run on
the filters?
5. What is the collection efficiency for your filters?
6. What is the calibration procedure for the hi-vol sampler?
i Procedure flu-WiruH \n 5?CJVnn 3.3
7. Which statement most closely estimates the frequency of flow rate cali-
bration? (a) once when purchased- (b) once when purchased, then after
every sampler modification, or/c^once when purchased, then at regular
intervals thereafter
8. Are flow rates measured before and after sampling period? Yes y
No
9. If the answer to number 8 is yes using the equation below, what is the
estimated average percent of change in the flow rates?
100 (Q. - Qf)
s = percent change
4i
((a)3ess than 10%, (b) 10-20%, or (c) greater than 20% .
10. Is there a log book at each sampler to record flows and times?
Yes ix^ No
11. Is the atomic absorption spectrophotometer properly calibrated? U€S
If so, when? COilihf CL-Hnn tU/l/e r\LT\ W}±h tU-SfU Samle
12. Are all components of the atomic absorption spectrophotometer correctly
aligned? Yes \^ No _
13. Qualifications of atomic absorption spectrophotometer operator? /
14. Extraction procedure. (1) Hot extraction
(2) Ultrasonic extraction •
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Section No. 2.8.8
Revision No. 0
Date December 30, 1981
Page 10 of 12
15. Calibration curve check? OK
16. Calculation procedure check? QK
17. Are reagents, calibration standards, samples, etc., labeled clearly with
test numbers, dates, and all pertinent data?
Comments:
Figure 8.3. Checklist for use by auditor.
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Section No. 2.8.8
Revision No. 0
Date December 30, 1981
Page 11 of 12
The system audit should be performed at the beginning of
the monitoring program and annually thereafter unless problems
occur to require more frequent system audits.
8.3 Activity Matrix
Table 8.1 summarizes the quality assurance activities for
auditing procedures.
-------
Section No. 2.8.8
Revision No. 0
Date December 30,
Page 12 of 12
1981
TABLE 8.1. ACTIVITY MATRIX FOR AUDITING PROCEDURE
Audit
Flow rate
audit
Audit of analy-
sis process
using audit
samples
Data
processing
audit
System
audit
Acceptance limits
di
Yi
Xi
100
= routinely measured
flow rate, and
= audited flow rate
d should be within ±16%
for both the 0.5 to 1.5
ug Pb/m3 and the 3 to
5 ug Pb/m3 concentration
ranges (Subsec 8.1.2)
The reported value
should agree with the
audited value within
round-off error
Method described in
this.section of
Handbook
Frequency and method
of measurement
Audit each sampler
quarterly; same
method as for cali-
bration procedure
Analyze an audit
sample in each of
the two concen-
ranges at
least once each ana-
lysis day and at
least twice per
calendar quarter
that samples are
analyzed (Subsec
8.1.2)
1 in 14 samples or .
1/mo, whichever is
greater; independent
calculations from
raw data to final
recorded data
At the beginning of
a new monitoring
system, and period-
ical ly as appro-
priate; observation
of procedures and
use of a check 1ist
Action if
requirements
are not met
Corrective
action before
resuming sam-
pling; action
noted on X-
and- R chart
Calibration
curve
checked, if
necessary; a
new reference
sample
checked, and
if accepta-
ble, analysis
'resumed; data
accuracy cal-
culated per
Sec 2.0.8
Calculations
for all sam-
ples col-
lected since
previous
audit checked
and corrected
Improved
methods and/
or trainiiH)
programs
ini tiated
-------
Section No. 2.8.9
Revision No. 0
Date December 30, 1981
Page 1 of 1
9.0 ASSESSMENT OF MONITORING DATA FOR PRECISION AND ACCURACY
9.1 Precision
For each monitoring network, collocate an additional sam-
pler at a minimum of one site (two sites are required for
SLAMS).
1. Select a site with the highest expected geometric mean
concentrations.
2. Locate the two hi-vol samplers within 4 m of each
other, but at least 2 m apart to preclude air flow interference.
3. Identify one of the two samplers at the time of in-
stallation as the sampler for normal routine monitoring;
identify the other as the duplicate sampler.
4. Be sure that the calibration, sampling, and analysis
are the same for the collocated sampler as for all other sam-
plers in the network.
5. Operate collocated sampler whenever the routine sam-
pler is operated.
6. Use the differences in - the concentrations (ug Pb/m:: )
between the.routine and duplicate samplers to calculate the pre-
cision as 'described in Section 2.0.8 of this Handbook.
9.2 Accuracy -
The accuracy of the hi-vol method for measurement of Pb is
assessed by auditing a portion of the measurement process, as
described in Section 2.8.8. The calculation procedure for
single instrument accuracy is given 'in Sections 2:8.8 and 2.0.8
of th i .<•; volume of the Handbook.
-------
-------
Section No. .2.8.10
Revision No. 0
Date December 30, 1981
Page 1 of 1
10.0 RECOMMENDED STANDARDS FOR ESTABLISHING TRACEABILITY
To achieve data of desired quality, two essential considera-
tions are necessary: (1) the measurement process must be in a
state of statistical control at the time of the measurement and
(2) the systematic errors, when combined with the random varia-
tion (errors of measurement), must result in an acceptable level
of uncertainty. As evidence in support of good quality data it
is necessary to perform quality control checks and independent
audits of the measurement process, to document these data, and to
use materials, instruments, and measurement procedures that can
be traced to an appropriate standard of reference.
Repeat measurements of standard reference samples, (primary,
secondary and/or working standards) aid in establishing a condi-
tion ^ of process control. The working calibration standards
should be- traceable to standards of higher accuracy, such as
those given below.
1. A linearity test should be performed on the atomic
absorption spectrophotometer employing a series of standard metal
solutions. This should be done at regular intervals and when the
analyst suspects erroneous readings. Refer to Section 2.8.2,
Subsection 2.2 for details on instrument performance checkout.
2. A positive displacement rootsmeter is recommended for
calibrating the orifice used to calibrate the high volume sam-
pler. .See Section 2.2.2, Subsection 2.5 for details.
3. The elapsed time meter, checked against an accurate
.timepiece3 on a semi-annual basis, must be within ±2 min-per 24 h
time period. See Section 2.1.2, Subsection 2.4 for details on
elapsed time meter calibration.
4. Obtain a Pb (NO3)2 Standard Reference Material (SRM
928) from. National Bureau of Standards.16 Analyze this standard
at regular intervals .along with samples, and record accuracy as
described in Section 2.8.8, Subsection 8.1.2.
Atomic clock, Boulder, Colorado, (303) 499-7111.
-------
-------
-------
-------
3EPA
Sept. 1982
United States
Environmental Protection
Agency
Section 2.9.0
Environmental Monitoring Systems
Laboratory
Research Triangle Park NC 27711
Research and Development
EPA-600/4-77-027a
Test Method
Section 2.9
Equivalent Method for the
Determination of Sulfur
Dioxide in the Atmosphere
(Fluorescence)
Outline
Section
Summary
Method Highlights
Method Description
1. Procurement of Apparatus
and Supplies
2. Calibration of Equipment
3. Operation and Procedure
4. Data Reduction, Validation, and
Reporting
5. Maintenance
6. Audit Procedure
7. Assessment of Monitoring Data
for Precision and Accuracy
8. Recommended Standards for
.Establishing Traceability
9. Equivalent Method
10. References
11. Data Forms
Summary
The Reference Method for the
determination of sulfur dioxide in the
atmosphere (i.e., pararosaniline
method) is discussed in Section 2.1 of
this Handbook. Many organizations,
however, will find it advantageous to
conduct continuous monitoring of SO2
in ambient air by employing automated
monitoring techniques. For use in air
quality surveillance systems, state and
local agencies are required' to use
analyzers that are EPA designated
reference or equivalent methods.
Documentation
2.9.0
2.9.0
2.9.1
2.9.2
2.9.3
2.9.4
2.9.5
2.9.6
2.9.7
2.9.8
2.9.9-
2.9.10
2.9.11
Number
of Pages
1.
1
5
10
7
1
2
1
1
1
1
4
A current list of all designated
reference and equivalent methods is
maintained by EPA and updated
whenever a new method is
designated. This list may be obtained
from any EPA Regional Office or from
the Environmental Monitoring
Systems Laboratory, Department E,
MD-77, Research Triangle Park, North
Carolina 27711. Moreover, any
analyzer offered for sale as a reference
or equivalent method after April 1 6,
1 976, must bear a label or sticker '
indicating that the analyzer has been
-------
Section 2.9.1
Sept. 1982
removed from the sample gas stream
by an appropriate scrubber upstream
of the reaction chamber. The
scrubbers may operate at ambient or
elevated temperature. Certain
elevated-temperature scrubbers,
however, have the potential for
converting ambient hydrogen sulfide
'(which normally does not interfere
with the fluorescent technique) into
SOj. In these cases, the hydrocarbon
scrubber must be preceded by a
scrubber for H2S.
1.1.2 Specific Fluorescent
Analyzers • Currently, four (4)
instrument manufacturers have EPA
designated equivalent fluorescent SOz
analyzers. The manufacturers and
their respective designated equivalent
methods are: Thermo Electron
Corporation (TECO), EQSA-0276-009;3
Beckman. EQSA-0678-029;4 Monitor
Labs. Inc., EQSA-0779-039;S and
Mcloy (Columbia Scientific Industries
Corp.) EQSA-0580-046.'
The TECO Series 43 fluorescent SO2
monitor utilizes a pulsed UV light to
excite the S03 molecules. TECO states
six (6) major reasons for using a
pulsed UV lamp:3
1. Long bulb life
Z High intensity—improved signal to
noise ratio
3. Small bulb size
4, Low power requirements—less
than 1 watt
5. Long-term stability
6, Chopped signal processing—no
dark current drift
Before passing into the reaction
chamber the sample air passes
through a permeation dryer, to remove
water vapor, and an aromatic
hydrocarbon cutter (replace every 18
months of operation). The instrument
operates with a sample flow rate
between 472 and 1888 cmVmin.
The Beckman Model 953 fluorescent
SOz monitor uses a continuous UV
light source (deuterium lamp) but
mechanically chops the light signal
before it enters the reaction chamber.
The sample air passes through a
selective scrubber, for the removal of
rtiS and mercaptans (change every 12
months), and a heated temperature
controlled reactor which removes
pofynuclear aromatic compounds
{replace every 6 months). The sample
then passes into a heated,
temperature-controlled fluorescence
reaction chamber. The chamber is
heated to reduce condensation of
water vapor. The instrument operates
vinth a sample flow rate of 400 to 700
cmVmin.
The Monitor Labs Model 8850 uses
UV light from an arc tube to excite the
SO2 molecules. The UV light passes
through a mechanical chopp.er before
entering the reaction chamber. Sample
air passes through a five (5)-micron
teflon particulate filter and a catalyst
(replaced every 12 months) for removal
of aromatic hydrocarbons before
entering the heated (40°C) reaction
cell. The instrument operates with a
sample flow rate of 500 ± 50
cmVmin.
The Meloy Model SA700 fluorescent
SO2 analyzer operates with a
_ continuous wave of UV light from a
deuterium lamp. The instrument uses
a UV detector to monitor lamp
intensity in the reactor cell and
compensates and adjusts the UV
source as the source ages and as
contamination accumulates on optical
surfaces. The instrument uses no
optical or mechanical chopper. .
The sample air passes through a
membrane dryer to remove water
vapor and a hydrocarbon scrubber
must be replaced as part of scheduled
annual maintenance. The instrument
operates with a sample flow rate pf
200 to 500 cmVmin.
1.2 Strip Chart Recorder
Strip chart recorders are
commercially available with a wide
variety of prices and specifications.
Factors to be considered when
purchasing a recorder are:
1. Compatibility with the output
signal of the analyzer
2. Chart width (minimum of 15 cm is
recommended for desired
accuracy of data reduction)
3. Chart speed (>2.5 cm/h)
4. Response time
5. Precision and reliability
6. Flexibility of operating variables
(speed and range)
7. Maintenance requirements.
1.3 Sampling Lines and
Manifolds
Sampling lines and manifolds should
be Teflon or glass to minimize reaction
with and degradation of the SOz. The
residence time within the sampling
lines should be minimized to reduce
the possibility of interaction of the SOz
sample with interim surfaces. If
particulate filters are employed, they
should be of Teflon construction.
1.4 Calibration Equipment
The recommended calibration
procedure requires both a permeation
tube that is traceable to NBS standards
in a temperature-controlled
environment and a diluent airstream
free of SO2 (<0.001 ppm). A detailed
discussion of this calibration
procedure appears in Section 2.9.2.
Calibration may also be conducted by
diluting an SOz standard gas with zero
air.
The calibration system (purchased or
built) must meet the guidelines
outlined in the Federal Register.^
Calibration systems of the types
described are commercially available.
Several manufacturers of continuous
SOz analyzers either offer compatible
' calibration systems or can inform the
user on where to purchase such
systems. When purchasing a
calibration system, the following
factors should be considered:
1. The permeation tube must be
traceable to NBS standard
reference materials (NBS-SRM).
2. The method for measuring air flow
through the calibrator must be
accurate within ±2% of the actual
flow.
3. The temperature control module
must be capable of maintaining
the permeation tube at a
predetermined temperature within
±0.1 °C (0.2°F). The ability to make
an independent check of the
temperature within the
permeation tube chamber is
desirable.
4. The calibrator must be portable.if
it is to be.used at more than one
site.
5. Maintenance requirements should
be minimal.
Permeation tubes are commercially
available or may be prepared-in the
laboratory.2'7 The working permeation
tube must be traceable to an NBS-
SRM. If the permeation tube supplied
with the calibrator is not certified, or if
the user prepares his own tubes, the
user must conduct certification tests
and thus purchase an NBS-SRM. The
following permeation tubes are
available as NBS-SRM's:8
SRM
1625
1626
1627
S02
SO2
SO2
Type '
permeation
permeation
permeation
tube
tube
tube
Tube
length,
cm
10
5
2
Nominal
permeation
rate.
/ug/min at 25°
2.8
1..4
0.56
C
-------
Sept. 1982
Section 2.9.1
An acceptable protocol for
demonstrating the traceability of
commercial permeation tubes to NBS-
SRM's is described in Section 2.0.7 of
this volume of the Handbook.
The user will need a source of zero
air that is free of contaminants that
would cause any detectable response
with the SO2 analyzer. Zero-air is
commercially available in cylinders or
can be generated by the user. Because
fluorescent SOa analyzers may be
sensitive to the composition of
synthetically prepared zero-air, a clean
air system utilizing ambient air may be
more desirable to use for zero and
dilution purposes. If ambient air is not
used, the zero-air cylinder must
contain the major constituent gases
normally found in ambient air,
especially oxygen which is known to
quench the fluorescence response.
1.5 Spare Parts and
Expendable Supplies
In addition to the basic equipment
discussed above, it is necessary to
maintain an inventory of spare parts
and expendable supplies. The
manufacturer's manual specifies
which parts require periodic
replacement and the frequency of
replacement. Based on these
specifications, the management of the
monitoring network can determine
which parts and how many of each
should be available at all times. A
generalized list of spare parts and
expendable supplies is provided below
(for specific requirements, refer to the
manufacturer's manual):
1. Paniculate filters
2. Selective scrubbers for the
removal of aromatic .
hydrocarbons •
3. SampJing lines
4. Pump diaphragms
5. Drier columns
6. Activated charcoal
7. Recorder chart paper and ink or
pens
8. Calibration gas
9. Record forms
10. Spare fitjings.
schedules in Section 2.1.2 of this
Handbook.
1.7 Record Forms
Recordkeeping is critical for all
quality assurance programs. Standard
forms similar to those in this
Handbook should be developed for
individual programs. Three questions
to consider in the development and
storage of record forms are:
1. Does the form serve a necessary
function?
2. Is the documentation complete?
3. Will the forms be filed so that they
can be retrieved easily when
needed?
1.8 Audit System
An independent audit system is a
necessary part of the quality
assurance program. Two types of audit
systems may be used:
1. A system using an NBS traceable
permeation tube (Subsection 1.4),
or
2. A dynamic dilution system with a
tank of SO2 certified traceable to
an NBS-SRM or a commercially
available Certified Reference
Material (CRM) and a zero-air
supply (Section 2.5.6).
In either case, the system used for
auditing must not be the same as that
used to calibrate the analyzer. ,
1.6 Reanalysis of Calibration
Working Standards
All working standards for
calibrations should be reanalyzed at
least once every 6 mo. (Subsection
7.2.6 of Section 2.0.7 describes the
procedures for analysis and for
reanalysis of permeation devices).
Flow-measuring devices should be
reca-librated using the procedures and
-------
Section 2.9.1
Sept. 1982
.1
(3
Q
Q
O
^r
41
I
to
OQ
1
•§
5
e
a. o c
Oa
o.
a
,3.
1
Q
-------
Sept. 1982
Section 2.9.1
Table 1.1. Activity Matrix for Procurement of Equipment and Supplies
Equipment and
supplies
Acceptance limits
Frequency and method
of measurement
Action if
requirements
are not met
Fluorescence
SOz ana/yzer
Strip chart
recorder
Samp/ing fines
and manifolds
Calibration
devices
SOz permeation
tube
Zero -air -~
Record forms
Audit system
Performance according
to specifications in
Table 4.1, Sec 2.0.4
Compatible with output
signal of analyzer;
chart width of 1 5 cm
(6 in.) is recommended;
accurate chart speed
Constructed of Teflon
or glass
Must meet guidelines
of Reference 1
Traceable to NBS-SRM;
meets limits in trace-
ability protocol for
accuracy and stability
(Sec 2.O.7;
•Clean dry ambient air.
free of contaminants
that cause detectable
responses with the SOz
analyzer
Standard form
developed
Must not be the same
system as used for
calibration, either an
NBS traceable perme-_ ,
at/on tube or a dynamic
dilution system (Sub-
sec 1.8)
Have the manufacturer
provide a strip chart
recording of specific
analyzer's performance;
verify performance
specifications at
installation
Check upon receipt
As above
See Reference J
Analyze against an
NBS-SRM; protocol
in Sec 2.0.7
.See Sec 2.9.2 .
N/A
Check the system
against a known
standard
Have the
manufacturer
make proper
adjustments;
recheck the
performance
Return to
supplier
As above
As above
Obtain new
working stan-
dard; check
for traceability
. Obtain 'air
from another
• source or re-
generate
Revise forms
as appropriate
Locate problem;
correct, -or
return to
supplier
-------
-------
Sept. 1982
Section 2.9.2
2.0 Calibration of Equipment
The accuracy and precision of data
derived from the air monitoring
equipment are dependent on the
quality assurance procedures used,
primarily the dynamic instrument
calibration. Calibration determines the
relationship between the observed and
the true values of the variable being
measured. Table 2.2 at the end of this
section summarizes the quality
• assurance activities for calibration.
Dynamic calibration involves-
introducing gas samples of known
concentrations into an instrument in
order to adjust the instrument to a
predetermined sensitivity and to derive
a calibration relationship. This
- 'relationship is derived from the
instrument's responses to successive
samples of different known
concentrations. Introducing these
standard gas mixtures in decreasing
order of concentration will minimize
the response times. As a minimum,
three reference points and one zero
point are recommended to define this
relationship. Linearity of fluorescent
analyzers is'-also checked at this time.
The true value of the calibration gas.
must be traceable to NBS-SRM's
(Section 2.0.7).
Most currently available monitoring
instrument systems (e.g., the
fluorescent SOz analyzer) are subject
to drift and variation in internal
parameters, and thus cannot be
expected to maintain accurate
calibration over long periods of time.
Therefore, it is necessary to
dynamically check the calibration
relationship on a predetermined
schedule. Precision is determined by a
one-point check at least once every 2
weeks. Accuracy is determined by a
three-point audit once each quarter.
Zero and span checks (Subsection'
3.4.2) must be used to document.
within-control conditions; these
checks are also used in'data reduction
and validation.
2.1 Calibration Gases
The recommended method of
dynamically calibrating a fluorescent
SOz analyzer requires both a certified
permeation tube traceable to an NBS-
SRM in a temperature-controlled
environment (±0.1 °C) and diluent air
void of SO2 «0.001 ppm). To conduct
biweekly precision checks and Level 1
zero and span checks, the user will
need a supply of zero air, a cylinder of
SO2 (50 to 100 ppm) in nitrogen, and a
dynamic dilution system or a
calibration system with a permeation
tube capable of generating the
precision check point at 0.08 to 0.1
ppm and a span check point at 70 to
90 percent of the analyzer's
measurement range. To implement a
quality assurance program for
calibration, the user will therefore
need the following:
1. An SOz permeation tube or device
that is traceable to an NBS-SRM
2. Zero air
3. An SO2 span gas that is traceable
to an NBS-SRM or commercially
available CRM
4. A calibration system!
2.1.1 SO2 Permeation Tubes - The
NBS-SRM's provide a reference
against which all calibration gas
mixtures must be compared. See
Section 2.9.1 (Subsection 1.4) for an
address for obtaining a list of NBS-
SRM's which are available for S02
analyzers.
One function of NBS is to supply
standards, but they do not supply
working calibration gases. Therefore
the user is advised either to purchase
commercially available certified
permeation tubes that are traceable to
NBS standards or to make the tubes.2
In either case, the user is responsible
for the verification and reanaiysis of
working standards versus NBS-SRM's.
or CRM's. Procedures the user must
follow to verify working calibration
gases are outlined in Section 2.0.7. •
2.1.2 Dilution Air - Zero-air, free of
contaminants which could cause a
detectable response in the fluorescent
SO2 analyzer, must be used for the
calibration, the precision check, and
the Level 1 zero and span checks. This
air is used to establish the analyzer
zero base line and to dilute the SOz to
the required concentrations. Zero-air
may be supplied from cylinders or from
a clean air system.
Because the fluorescent reaction
has some degree of sensitivity to
aromatic hydrocarbons, COz levels.
and to the oxygen/nitrogen ratio,3 it is
recommended that a clean air system
be used. The air for this system must
be drawn from outside the station to
prevent excess CO2 levels. Water
vapor and aromatic hydrocarbons
should be removed from the zero air.
If compressed air cylinders are used,
the air.should have the following
properties for use with fluorescent
analyzers:
1. The same O2 and N2 percentage
composition as ambient air
(20.94% Qz. 78.08% N2).
2. A C02 content similar to that of
ambient air (between 300 and 400
ppm).
3. Less than 0.1 ppm aromatic
hydrocarbons.
2.1.3. SOzPrecision and Span
Cases - Aluminum or steel cylinders
containing 50 to 100 ppm S02 in N2
are available from most specialty gas
suppliers. Aluminum cylinders have
been demonstrated by NBS to have
superior stability for storing SO2
mixtures, and they are preferred
whenever possible. These gases can
be diluted to the desired concentration
by using zero-air and a dynamic
dilution system. The cylinder gas
concentration should be certified to
NBS-SRM or commercially available
CRM (Certified Reference Materials)
using EPA Traceability Protocol No. 2
(Section 2.0.7). NBS-SRM'or
commercially available CRM at 50 and
100 ppm SO2 in N2 should be used for
the traceability analysis. A CRM may
be used directly for precision or span
checks. However, due to the limited
supply of NBS-SRM, an SRM should
not be used directly for routine
precision or span checks. A list of gas
manufacturers who have approved
CRM's is available by writing to:
U.S. Environmental Protection
Agency
Environmental Monitoring Systems
Laboratory (MD-77)
Research Triangle Park, North
Carolina 27711
ATTN: List of CRM Manufacturers
(Note: CRM's are cylinder gases
prepared by gas manufacturers
according to an NBS-EPA procedure to
within ±1% of existing SRM
concentrations. Each CRM lot of 10 to
50 cylinders is audited by EPA. Each
lot receives written approval from NBS
and this approval must accompany any
CRM sold.)
Precision and span gases may also
be generated by a calibrator using an
SOz permeation tube traceable to an
NBS-SRM.
-------
Section 2.9.2
Sept. 1982
2.2 Calibration System
The calibration system consists of
two primary parts.
1. The temperature controlled
permeation device
2. A dynamic dilution system.
2.2.1 Temperature Controlled
Permeation System • The purpose of a
permeation system is to generate a
low SOj concentration at a constant
rate. This is done by holding a
permeation tube at a constant
temperature (±0.1 °C) for which the
permeation rate is known. The SO2
permeating from this tube is carried
away by a low flow of gas (usually
clean dry air or N2) to a mixing
chamber where it is accurately diluted
with zero air to the concentration
desired.
2.2.2 Dynamic Dilution System - A
dynamic dilution system is required to
dilute the SOj output from either the
temperature-controlled permeation
system or an 80s gas cylinder to the
desired concentration. All parts in
contact with the SO2 output must be
glass or Teflon. The system must be
capable of controlling and measuring
flow rates to within ±2% of stated
flow.
2.3 Dynamic Multipoint
Calibration Principles
Dynamic calibration involves
introducing gas samples of known
concentrations to an instrument in
order to adjust the instrument to a
predetermined sensitivity and to derive
a calibration relationship. A minimum
of three reference points and one zero
point uniformly spaced covering 0 to
80 percent of the operating range are
recommended to define this
relationship.
The recommended method of
dynamically calibrating an SO2
analyzer requires a certified
permeation tube traceable to an NBS-
SRM in a temperature controlled
environment (±0.1 °C) and diluent air
that is free of SO2 «0.001 ppm).
Temperature must be verified with an
NBS traceable thermometer prior to
calibration.
The permeation tube is held at a
constant temperature for a minimum
ol 24 hours to allow the SO2 to diffuse
from the tube at a known rate. The low
How of zero air that is passed over the
permeation tube serves as a carrier for
the SOa. This purged air is then diluted
wuh different quantities of zero air to
generate the desired concentrations.
The analyzer's recorded response is
compared with the known
concentration to derive the calibration
relationship. This relationship is used
to convert the analyzer's responses
during sampling into ppm's of SO2.
The recorded response may be either
voltage output or percent chart (%
chart) as long as it is consistent with
that used to determine the calibration
relationship.
Biweekly precision checks are used
to calculate the variability of the
calibration relationship over a period of
. time. Three-point audits conducted
quarterly are used to check the
analyzer's accuracy. These precision
checks and the 3 (or 4) point audits are
used to generate precision/accuracy
data for the reporting organization.
They are not intended for use in
reducing or validating data since they
are performed infrequently. Level 1
zero and span checks must be used to
'document within-control conditions
and to validate the collected data.
2.4 Calibration Procedures
The procedures for multipoint
calibration of an SO2 analyzer by an
SO2 permeation system are specified
- in the.Federal Register.' To facilitate
these procedures, operational and
calculation data forms have been
developed as aids in conducting
calibrations and quality assurance
checks. Detailed descriptions of the
calibration theory and procedures for
SO2 permeation systems are in the
Federal Register.'
Documentations of all data on the
station, instrument, calibrator,
reference standard, and calibration
procedures are of prime importance
since the validity of the data collected
by the instrument is dependent on the
quality of the calibration. Calibration
must be performed with a calibrator
that meets all conditions specified in
Subsection 2.2.
2.4.1 General Calibration
Recommendations - It is important that
the fluorescent analyzer be operated
during calibration under conditions
identical to those during normal
ambient air sampling. No modifications
or alterations shall be made to the
analyzer's components, flow system,
prescribed flow rate, or other
parameters. Concentrations of SO2
intended for calibration must be
generated continuously by means
entirely independent of the analyzer.
The flow rate of the calibration gas
must exceed the sample flow rate of
the analyzer. The calibration gas
should flow through a manifold, and
the analyzer should draw its sample
through the regular ambient air
sampling line, which is attached to a
port of the vented calibration manifold.
2.4.2 Calibration Procedure for SOz •
The procedure for multipoint
calibration of a fluorescent analyzer is
necessarily general. That given here is
for fluorescent analyzers equipped
with a linearized output. Where
analyzer-specific explanations are
necessary, the reader is referred to the
manufacturer's instruction manual.
The following procedure using the
forms shown in Figures 2.1 and 2.2, is
given to aid in the collection and
documentation of calibration data.
1. Record the official name and
address of the station on the
form; where appropriate, the
name and address should be the
same as that appearing on the
SAROAD site identification form-
to eliminate any confusion by
persons not familiar with the
station.
2. Identify the analyzer being
calibrated by the manufacturer's
name, model, and serial number.
3. Identify the person performing
the calibration and the date of
calibration.
4. Identify the calibrator used. If
the calibrator was purchased,
record the manufacturer's name, .
model and se'rial number.
Calibrators assembled by the
user should be assigned an
identification number so that
calibrations can be referenced to
that particular apparatus.
5. Identify, by supplier and tube
number, the reference standard
to be used. Provide a record of
NBS traceability for any tube
used in a calibration and include
the data of verification and the
name of the person who verified
the reference standard.
6. Identify the device used to
measure the flow of the dilution
air.
7. Record the barometric pressure
and the.shelter temperature.
8. Record the analyzer sample air
flow.
9. Record the zero and span knob
settings after the calibration is
completed. (These settings can
be used as a basis of comparison
when changes are later
determined in the instrument
performance.)
10. Record the temperature at which
the permeation tube is
maintained during calibration
and use the recorded
-------
Section 2.9.2
Sept. 1982
span drift exceeds its respective
limit, investigate the cause of the
drift, take corrective action, and
calibrate the analyzer. Individual
agencies may wish to use limits
which are tighter than those in
Table 9.1.
-------
Section 2.9.2
Sept. 1982
Calibration Data Forms
2.
5r
"7 ' " O cL
4, Calibrator used
5. SO) standard _
ur 60 *.
Ti//ag
verified against NBS-SRM
BV Tom
f (ff 2.W T\J&£ /C.Q
Date
e,
7, Barometric pressure
AvA&LF
f&i-
mm Hg Shelter temperature
8, Anafyter sample flow readings
9, Zero knob setting _:
Span knob setting
10, Permeation equilibrium temperature .
A
2.5". O
Permeation rate (PR)
fjg/min
1}, Temperature at which air flow rate was 'measured (A T)
12. Vapor pressure of water at temperature (A T)
*• '• '
Equation 2-1
238
BP*VP
STP correction factor = - X
760 AT T 273
Equation 2-2
Ft » F X STP correction factor
5Q
mm Hg
PR MV
- X -
Ft M
Squatton 2-3
.__ ,
ppm ISOiJ out
equation 24
Response (% scale, = fS°j£ur X ,00 - Zso,
Calibration Equations
BP = barometric pressure, mm Hg
VP = vapor pressure of water, mm Hg at AT (Table 2. 1)
AT = temperature at which air flow rate was measured. °C
'
F = uncorrected flow rate
F T = total air flow rate, corrected to 25°C'and 760 mm Hg. L/min
PR = permeation rate at equilibrium temperature, fjg/min
MV = molecular volume of SO2 at 25°C and 760 mm Hg 24.45 L/molj
Q2 (64 g/mol)
_„,.,-. /n
— O.382 L/g
M = molecular weight
V _ 24.45 L/mol
Figure 2, 1, Example of a calibration data form.
..
M 64 g/mol
URL = upper range limit of analyzer
Zso, - recorder response to zero air
-------
Sept. 1382
Section 2.3.2
SO2 Calibration and linearity check.
Calibration
points
Zero
80% URL
1-
2
1
F.
L/min
f.5~
-------
Section 2.9.2
Sept. 1982
Calibration
point
Zero
80% URL
1
2
: 3
4
X
O-OOO
O-VOO
0.00,2
o.ov^
X2
o-ooo
OJbQ
O.OY/
O.OO2.
y
• S".O
8S.O
ViT^
M.O
y*
JS
-I**.*
AObl
t*(i
xy
o.o
J+0
9.2
O'b
x * concentration, ppm y = recorder reading. % scale
^=0.203 *v=
7/>e equation of the tine fitted to the data is written as
Y = y + bfx - x} = (V - bx) = bx = a + bx
where
Y — the predicted mean response for the corresponding i.
b = the slope of the fitted line.
a « the y-intercept.
n = the number of calibration points.
l£*l (Tvl
txy -
Figure 2.3. Calculation form for the method of least squares.
-------
Sept. 1982
Section 2.9.2
1
O
5-
-------
Section 2.9.2
10
Sept. 1982
Table 2. 1,
Temp.
°C
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
3O
31
32
33
34
' 35
Tabla 2.2.
Calibration
activities
Saturation Vapor Pressure Over Water (°C. mm. HgJ
0.0
12.788
13.634
14.530
15.477
16.477
17.535
18.65O
19.827
21.068
22.377
23.756
25.209
26.739
28.349
30.043
31.824
33.695
35.663
37.729
39.898
42.175
0.2
12.953
13.809
14.715
15.673
16.685
17.753
18.880
20.070
21.324
22.648
24.039
25.509
27.055
28.680
3O.392
32.191
34.082
36.068
38. 155
4O.344
42.644.
Activity Matrix for Calibration
0.4
13.121
13.987
14.903
15.871
16.894
17.974
19.113
20.316
21.583
22.922
24.326
25.812
27.374
29.015
30. 745
32.561
34.471
36.477
38.584
4O.796
43.117
Procedures
Acceptance limits
0.6
13.290
14.166
15.092
16.071
17.105
18.197
19.349
20.565
21.845-
' 23.198
24.617
26.117
27.696
29.354
31.102
32.934
34.864
36.891
39.018
, 41.251
43.595
0.8
13.461
14.347
15.284
16.272
17.319
18.422
19.587
20.815
22.110
23.476
' 24.912
26.426
28.021
29.697
31.461
33.312
35.261
37.308
39.457
41.71O
44.078
Action if
Frequency and method requirements
of measurement are not met
Permeation
tube
Dilution gas •
Span gases
Multipoint
calibration
Traceable to NBS stand-
ards
Zero-air free of con-
taminants; Sec 2.0.7,
Subsec 7. 1. and TAD10
Cylinder gases cer-
tified to NBS-SRM or
commercial CRM cylin-
der gas or to an NBS-
SRM permeation tube
Cases generated by
calibrator using an
SOz permeation tube
Calibration proce-
dure in Subsec 2.2.
and the Federal
Register,1 completed
Figs 2.1 and 2.2
Subsec 2.0.7 for
frequency and method
TAD10
Assay against an
NBS-SRM semi-annually;
Sec 2.0.7
Perform at least
once every quarter,
or anytime a level
span check indicates
a discrepancy, or
after maintenance
which may affect the
calibration; Subsec
2.5
Return to
supplier, or
make another
permeation tube
Return to
supplier, or take
corrective action
with generation
system
Working as
standard is
unstable and/ or
measurement
method is out
of control; take
corrective action
(e.g., obtain new
span gases)
Repeat the
calibration
-------
Sept 1982
Section 2.9.3
3.0 Operation and Procedure
Essential to quality assurance are
scheduled checks for verifying the
operational status of the monitoring
system. At least once each week the
operator should visit the site. Every
two weeks. Level 1 zero and span
checks must be made on the analyzer.
Level 2 zero and span checks should
be conducted at a frequency desired by
the user. Level 1 and 2 checks,are
described in-depth in Section 2.0.9 of
this Handbook.
At least once every two weeks, an
independent precision check at a
concentration between 0.08 and 0.10
ppm SC>2 must be conducted. Table 3.1
at the end of this section summarizes
the quality assurance activities for the
routine operations discussed in the
following sections.
For documentation and
accountability of activities, a checklist
should be compiled and then filled out
by the field operator as each activity is
completed. A simplified example
checklist.js given in Figure 3.1. A more
comprehensive check list should be
developed for specific sampling
stations. - " -
In Subsections 3.1 and 3.2,
reference is made to the sampling
shelter and the sample inlet system,
but the design and construction of
these components are not within the
scope of this Handbook. For more
information refer to an in-depth study
of these in Reference 11.
3.1 Shelter
The shelter's role in quality
assurance is to provide a temperature-
controlled environment in which the
sampling equipment'can operate at its
optimum. The mean shelter
temp.erature should be between 22°
and 28°C (72° and 82°F). A
thermograph should be installed at.the
shelter to continuously record daily
fluctuations in temperature.
Fluctuations greater than ±2°C (±4°F)
may cause the electronic components
of the analyzer to drift and may
introduce error into the data.
Fluctuations outside of these limits
should be identified, and the data for
the affected time period should be
flagged to indicate possible
discrepancies.
3.2 Sample Introduction
System
The sample introduction system
consists of an intake port, the
paniculate and moisture traps, the
sampling manifold and blower, and the
sampling line to the analyzer. The field
operator, as part of the quality
assurance program, should inspect
each of these components for
breakage, leaks, and buildup of
paniculate matter or other foreign
objects; check for moisture deposition
in the sample line or manifold; see that
the sample line is connected to the
manifold; see that any component of
the sample introduction system that is
not within tolerance is either cleaned
or replaced immediately. See Section
2.0.2 for more details.
3.3 Recorder
During each weekly visit to the
monitoring site, the field operator
should use the following list to check
the recorder for proper operation:
1. Ink trace for legibility
2. Ink level in reservoir •
3. Chart paper for supply
4. Chart speed control setting
5. Signal input range switch
6. Time synchronization.
Any operational parameter that is not
within tolerance must be corrected
immediately.
3.4 Analyzer
'Specific instructions in the
manufacturer's manual should be read
thoroughly before attempting to
operate the analyzer. As part of the
quality assurance program, each site
visit should include a visual inspection
of the external parameters of the
analyzer; the zero and span checks;
and a biweekly precision check when
applicable.
3.4.1 Visual Inspection - The field
operator should inspect the external
operating parameters of the analyzer;
these will vary from instrument to
instrument, but in general they will
include the following:
1. Correct settings of flow meters
and regulators.
2. Cycling of temperature control
indicators.
3. Temperature level, if equipped
with a pyrometer.
4. Verification that the analyzer is in
the sampling mode rather than the
zero or the calibration mode.
5. Zero and span potentiometers
locked and set at proper values.
3.4.2 Zero and Span Checks - Zero
and span checks must be used to
document within-control conditions
and to provide interim checks on the
response of the instrument to known
concentrations. A quality control chart
can be used to provide a visual check
to determine if the analyzer is within
control conditions. If a response is
outside of the prescribed limits, the
analyzer is out of control and the
cause must be determined and
corrected. A zero check should be
conducted at the same time that the
span check is performed.
Level 1 and Level 2 zero and span
checks are recommended and must be
conducted i'n accordance with
Subsection 9.1 of Section 2.0.9. Level
1 zero and span checks must be
conducted every two weeks. Level 2
checks should be conducted between
the-Level 1 checks at a frequency
desired by the user. Span
concentrations for either Level 1 or 2
checks should be between 70% and
90% of the measurement range. The
data should be recorded on the zero
and span check form, Figure 3.2.
Zero and span checks are used to
provide:
1. Data to allow analyzer adjustment
for zero and span drift
2. A decision point for calibrating the
analyzer
3. A decision point for invalidating
the monitoring data.
Items 1 and 2 are described in detail in
Subsection 9.1.3 of Section 2.0.9 and
item 3 is described in Subsection 9.1.4
of the same section.
. When the response from a span
check is outside of the control limits,
the cause for the extreme drift should
be determined, and corrective action
should be taken. Some of the causes
for drift are:
1. Lack of preventive maintenance
2. Fluctuations in electrical power
supply
3. Major fluctuations in sample flow
4. Change in zero air source
5. Change in span gas concentration
6. Degradation of photomultiplier
tube
-------
Section 2.9.3
Sept. 1982
7. Degradation of UV light source
8, Electronic and physical
components not within
manufacturer's specifications.
Corrective actions for the above can be
found in the manufacturer's
instruction/operations manual.
3.4.3 Precision Check - For
continuous analyzers, periodic checks
are used to assess the data for
precision. A one-point precision check
must be carried out at least once every
2 weeks on each analyzer at an SO2
concentration between 0.08 and 0.10
ppm. The analyzer must be operated in
its normal sampling mode, and the
precision test gas must pass through
all filters, scrubbers, conditioners, and
other components used during normal
ambient sampling. The standards from
which precision check test
concentrations are obtained must be
traceable to NBS-SRM's or NBS/EPA-
approved commercially available
Certified Reference Material (CRM).
Direct use of a CRM as a working
standard is acceptable, but direct use
of an NBS-SRM as a working standard
is discouraged because of the limited
supply and expense of SRM's.
Standards used for calibration may
also be used. The precision check
procedure is as follows:
1. Connect the* analyzer to a
precision gas that has a
concentration between 0.08 and
0.10 ppm. An SO2 precision gas
may be generated by an SO2
permeation tube or by dilution of a
high concentration (50 to 100
ppm) SO2 standard gas. If a
precision check is made with a
zero and span check, it must be
made prior to any zero or span
adjustments.
2, Allow the analyzer to sample the
precision gas until a stable trace is
obtained at the recorder.
3. Record this value on the precision
check data form (Figure 3.3), and
mark the chart as "unadjusted
precision check." Information from
the check procedure is used to
assess the precision of the
monitoring data; see Section 2.0.8
for procedures for calculating and
reporting precision.
-------
Sept. 1982
Section 2.9.3
Site ID .
ool
Site name
1. Inspect thermograph for temperature variations greater than ±2°C (4°FJ. Identify time frame of any temperature level
2. Inspect sample introduction system for moisture, particulate buildup, foreign objects, breakage, and leaks.
Comments:. J-C&f/M t/^sfr?/)*/ OP
. 3. Check to see if sample line connected to manifold.
Comments:
4. Inspect data recording system.
• Legibility of trace
• Ink supply
• Paper supply
• Chart speed selector
• Signal input range switch
• Time synchronization
Comments:
OK
Corrective
action taken
5. Inspect analyzer's operational parameters
• Sample flow rate
• Oven temperature light flashing
• Analyzer in sample mode
• Zero and span potentiometers locked at
correct setting
Comments: .
OK
Corrective
action taken
6. Zero the analyzer
7. Check to see if unadjusted zero is within tolerance.
Comments: ZSgQ OKAV A.T
-------
Section 2.9.3 4 Sept. 1982
12, Record cylinder pressure of zero and span tanks.
Zero air /&*> F5/
, 13, Close valves on zero and span tanks.
Signature of technician
Figure 3,1. • Example of an operational checklist (backside).
-------
Sept. 1382
Section 2.9.3
Site ID
OOI
Location,
Address
Adjusted zero.
Pollutant
50;
Analyzer
_ Serial number _
.Adjusted spa/7.
V7/O. O
OF
Date
Time
.Operator
Unadjusted
zero,
% chart
Span
concentration,
ppm
Unadjusted
span,
% chart
Z-l-So
&4C.
8V
Figure 3.2. Example of a Level 1 zero and span check data form.
-------
Section 2.9.3
Sept. 1982
Site ID
001
Location
J336»
_ Pollutant _
Analyzer
A/g. Serial number W/Q. O
Date
2-/-£o
Time
/O30
Operator
4&C.
Precision
test gas
concentration,
ppm
O.IO
-
Analyzer
response.
% chart
H
ppm
o-ol?
Difference",
ppm
-0.005"
'Difference » analyzer response - test gas concentration.
figure 3,3. Example of precision check form.
-------
Sept. 1982
Section 2.9.3
Table 3.1. Daily A ctivity Matrix
Characteristic
Acceptance limits
Frequency and method
of measurement
Action if
requirements
are not met
Shelter temper-
ature
Sample intro-
duction system
Recorder
Analyzer oper-
ational set-
tings
Analyzer oper-
ational check
Precision
check
Mean temperature be-
tween 22° and 28°C
(72° and 82°F). daily
fluctuations not
greater than ±2°C (4°Fj
No moisture, foreign
material, leaks, or ob-
structions; sample line
connected to manifold
Adequate ink and chart
paper; legible ink
traces; correct
settings of chart
speed and range
switches; correct
time
Flow and regulator
indicators at proper
settings; temperature
indicators cycling or
at proper levels;
analyzer set in •
sample mode; zero and
span controls locked
Zero and span within
tolerance limits;
Subsec 9. 1.3 of Sec
2.0.9
Precision assessed as
described in Sec 2.0.8
and Subsec 3.4.3'
Edit thermograph
chart daily for
variations greater
than ±2°C (4°F)
Visually inspect
weekly
Visually inspect
weekly
Visually inspect
weekly-
Check level J zero
and span every 2
weeks; check Level 2
between Level 1
checks at frequency
desired by user
Check every 2 weeks.
Subsec 3.4.3
Mark strip chart
for the affected
time period;
repair or adjust
temperature
control system
Clean, repair.
or replace
as needed
Replenish ink
and chart paper;
adjust recorder
time to agree
with clock;
note on chart
Adjust or repair
as needed
Isolate source
of error, and
repair; then
recalibrate
the analyzer
Calculate;
report precision;
Sec 2.0.8
-------
-------
Sept. 1982
Section 2.9.4
4.0 Data Reduction, Validation, and Reporting
This section is the same as that of
Section 2.5.4. Table 4.1 summarizes
the quality assurance activities for the
data reduction, validation, and
reporting.
Table 4.1. Activity Matrix for Data Reduction, Validation, and Reporting
Activity
Acceptance limits
Frequency and method
of measurement
Action if
requirements
are not met
Data reduction
Data validation
Span drift
check
Strip chart
edit
Data reporting
Stepwise procedure,
Subsec 4.1
Level 1 span drift
check <25%, Sec
2.0.9
No sign of malfunc-
tion
Data transcribed to
SAROAD hourly data
form; Re f 13
Follow the method
in Subsec 4.1
Check at least every
2 weeks; Sec 2.5.3;
Ref 12 recommends
screening procedures
to identify gross
anomalies
Visually edit each
strip chart; Subsec
4.2
Visually check
Review the
reduction
procedure
Invalidate data;
take corrective
action; increase
frequency of
Level 1 checks
until data
are acceptable
Void data for
time interval
for which
malfunction
detected
Review the
data transcribing
procedure
-------
-------
Sept. 1982 1 Section 2.9.5
5.1 Preventive Maintenance
Because maintenance requirements
vary from instrument to instrument,
the supervisor should refer to the
manufacturer's manual for a specific
analyzer. After becoming familiar with
these requirements, the supervisor
should develop a suitable preventive
maintenance schedule.
5.2 Corrective Maintenance
Corrective maintenance is defined
as nonscheduled activities that
become necessary due to system
malfunctions. A few examples of
corrective maintenance are: replacing
a damaged pump diaphragm; cleaning
a clogged sampling line; and replacing
the selective scrubber for aromatic
hydrocarbons. The need for corrective
maintenance becomes apparent as the
operator performs the operations
described in Section 2.9.3. When the
need for corrective maintenance
arises, the operator should refer to the
owner's manual for troubleshooting
procedures. A detailed record of
corrective maintenance activities
should be kept on file for each analyzer
at the site to identify recurring
malfunctions; maintenance log
appears in Figure 5.1.
Catyf/on: When replacing, aligning-,
and otherwise servicing the deuterium
source lamp, always wear UV-
absorbing glasses to protect the eyes
from the ultraviolet radiation produced.
Ordinary prescription spectacles with
glass lenses are suitable. Plastic
lenses may not provide adequate
protection.
5.0 Maintenance
-------
Section 2.9.5
Sept. 1982
OOl
Sue number
Sit* location /TWcififtf
a.***, 333fa JeFre*5o^
- Pollutant
.Instrument
ACME. Fluorescence.
. Serial number
288-70*1^-5
Date
Technician
Event
initiating
maintenance
Maintenance
activity
Comments
2-/-80
Loss erf-
d/iArf def/<2. ef /ort
UV
•ft.ll
UV
source.
Figure 5.1, Analyzer maintenance log.
-------
Sept. 1982
Section 2.9.6
6.0 Auditing Procedure
Table 6.1 summarizes the quality
assurance activities for audits. This
section is the same as Section 2.5.6.
See References 14 and 15 for the
frequency and brief descriptions of
audit procedures.
Table 6.1. A ctivity Matrix for A udit Procedure
Audit
Acceptance limits
Frequency of method
of-measurement
Action if
requirements
are not met
Multipoint
calibration
audit
Data reduction
audit
Systems audit
Difference between
measured and audit.
values is used as mea-
sure of accuracy: Sec
2.0.8
Step wise procedures for
data reduction. Subsec
6.2; no audit dif-
ference exceeding
±0.02 ppm
Method in this sec-
tion of the Handbook
Perform at least once
a quarter; Subsec
6.1.3 for procedure
Perform independent
data processing check
on a sample of the
recorded data; check
1 day of every 2
weeks of data, 2
hours each day
At startup of new
monitoring system,
and periodically
observe as appropri-
ate; checklist.
Fig 6. 4
Recalibrate
the analyzer
Check all re-
maining data
if one or
more data re-
duction checks
exceed ±0.02
ppm
Initiate
improved
methods and/
or training •
programs
-------
-------
Sept. 1982 1 Section 2.9.7
7.0 Assessment of Monitoring Data for Precision and Accuracy
For continuous analyzers, in
SLAMS, NAMS, or PSD networks a
biweekly check is performed to
determine if the measurement process
is within control and to assess the data
for precision. These data can be used
to calculate estimates of single
instrument precision, and reporting
organization precision as prescribed in
Section 2.0.8 of this volume of the
Handbook. The precision check ' . .
procedures described in Section 2.9.3, ' -
Subsection 3.4.3 are consistent with
those in References 14 and 15.
Estimates of single instrument
accuracy as well as reporting
organization accuracy for ambient air
quality measurements from
continuous methods are based on the
results of the in-depth accuracy audit
and are calculated according to the
procedure in Section 2.0.8. The audit
is described in Section 2.9.6.
-------
-------
Sept. 1982 1 Section 2.9.8
8.0 Recommended Standards for Establishing Traceability
Tp achieve data of desired quality,
two considerations are essential:
1. The measurement process must
be in statistical control at the time
of the measurement, and
2. The systematic errors, when
combined with the random
variation in the measurement
process, must result in an
acceptable uncertainty.
As evidence in support of good quality
data, it is necessary to perform quality
control checks and independent audits .
of the measurement process; to
document these data (e.g., by means of
specific data forms or a quality control
chart); and to use materials,
instruments, and measurement
procedures that can be traced to
appropriate standards of reference.
Data must be routinely obtained by
repeat measurements of standard
reference samples (primary, secondary,
and/or working standards), and a
condition of process control must be
established. The working standards
must be traceable to either NBS-
SRM's or commercially available
CRM's, such-as those listed below:
NBS-SRM's Available for Use in Establishing Traceability of Permeation Tubes8
SRM
1625
1626
1627
Type
SOz permeation tube
SOa permeation tube
SO2 permeation tube
Tube
length,
cm
10
5
2
Nominal
permeation
rate.
fjg/min af25°C
2.8
1.4
0.56
NBS-SRM's Available for Use in Establishing Traceability of Compressed
Cylinder Gases
Nominal
bHM _ ; _ Type concentration
o S02inN2 " s
1694 _ SQ2inN2 _ IQOppm
A list of gas manufacturers who
have approved CRM is available by
writing to:
U.S. Environmental Protection
Agency
Environmental Monitoring Systems
Laboratory (MD-77)
Research Triangle Park, North
Carolina 2771 1
ATTN: List of CRM Manufacturers
-------
-------
Sept. 1982 1 Section 2.9.9
9.0 Equivalent Method
A method description is not given
herein. The concepts of equivalent
analyzers are discussed in Section
2.0.4 of this volume.of the Handbook.
The analyzer must also comply with
the performance specifications in
Table 4.1 of Section 2.0.4. An
instruction manual including the
calibration procedure must accompany
the analyzer when- it is delivered to the
purchaser. This instruction manual
. has been reviewed and approved by
EPA as part of the equivalency test
program. The user of the analyzer
should use the method description in
this section of the Handbook and the
instruction manual.
A list of equivalent methods may be
obtained from any EPA regional office
or from the EnvironmentalMonitoring
Systems Laboratory, Department E,
MD-77, Research Triangle Park, N.C.
27711. Any analyzer offered for sale
as an equivalent method after April 16,
1976, must bear a label indicating this
designation by EPA.
-------
-------
Sept. 1982
Section 2.9.10
1. Code of Federal Regulations 40.
Protection of the Environment.
Parts 50 to 69. Revised July 1,
1977.
2. Summary of Performance Test
Results and Comparative Data
for Designated Equivalent
Methods for S02, EPA Document
No. QAD/M-79.12.
3. Thermo Electron Corporation,
Environmental Instruments
Division. Instruction Manual
Model 43 Pulsed Fluorescent
SO2 Analyses Equipped with .an
Aromatic Hydrocarbon Cutter.
TE5405-112-77, Revision C.
Hopkinton, Massachusetts.
4. Beckman Instruments, Inc.
Beckman Model 953 Fluorescent
Ambient Sulfur Dioxide
' Analyzer. Fullerton, CA. May
1979.
5. Monitor Labs, Inc. Monitor Labs,
Inc. Model 8850 Fluorescent
SOz Analyzer Instruction
Manual. Document 8850 Rev. D.
San Diego, CA. September
197,9.
6. Columbia Scientific Industries
Corp. Fluorescent Sulfur Dioxide
Analyzer Model SA700
Operation, Maintenance, and
Parts Manual.. Meloy
Laboratories, Inc. Springfield,
Virginia. 1980 and 1981.
7. Scaringelli, F. P., O'Keefe, A. E.,
Rosenberg, E. and Bell, J. P.,
"Preparation of Known
Concentrations of Gases and
Vapors with Permeation Devices
Calibrated Gravimetrically",
Analytical Chemistry, 42 871
(1970).
. 8. Catalog of NBS Standard
Reference Materials. NBS
Special Publication 260. 1981 -
83 Edition. U.S. Department of
Commerce, NBS, Washington,
' D.C. November 1981.'
9. Quality Assurance Handbook for
Air Pollution Measurement
Systems. Vol. I. EPA-600/9-76-
005. March 1976.
10. Use of the Flame Photometric
Detector Method for
Measurement of Sulfur Dioxide
in Ambient Air, A Technical
Assistance Document, EPA-
600/4-78-024, May 1978.
11. Field Operations Guide for
Automatic Air Monitoring
Equipment. U.S. Environmental
10.0 References
Protection Agency, Office of Arr
Programs; October 1972.
Publication No. APTD-0736, PB
202-249, and PB 204-650.
12. U.S. Environmental Protection
Agency, Sreening Procedures for
Ambient Air Quality Data. EPA-
450/2-78-037, July 1978.
13. AEROS Manual Series, Volume
II: AEROS Users Manual, U.S.
Environmental Protection
Agency, Research Triangle Park,
N.C., EPA-450/2-76-029,
OAQPS No. 1.2 - 039, December
1976.
14. Appendix A - Quality Assurance
Requirements for State and
Local Air Monitoring Stations
(SLAMS); Federal Register. Vol.
44, No. 92, pp. 27574-27582,
May 1979.
1 5. Appendix B - Quality Assurance
Requirements for Prevention of
Significant Deterioration (PSD)
Air Monitoring, Federal Register,
Vol. 44, No. 92, pp. 27582
27584, May 1979.
-------
-------
-------
-------
Addendum to Section 2.10
Reference Method for the Determination of Participate Matter as PM10
in the Atmosphere (Dichotomous Sampler Method)
This section is up-to-date. The blank data forms that are mentioned have
been removed.
-------
T,
-------
Section No.: 2.10.0
Date: April 11, 1990
Page: 1
SECTION 2.10
Reference Method for the Determination of Particulate Matter as PM10 in the Atrnos-
pnere (Dichotomous Sampler Method)
Subsection
0
1
2
3
• 4
5
6
7
8
10
11
12
Title
Introduction
Procurement of Equipment and
Supplies
Calibration Procedures
Field Operations
Filter Preparation and Analysis
Calculations, Validations, and
Reporting of PM10 Data
Maintenance
Auditing Procedures
Assessment of'Monitoring Data for
Precision and Accuracy
Recommended Standards for
Establishing Traceability
Reference Method
References
Data Forms
Full Section
Number
2.10.0
2.10.1
2.10.2
2.10.3
2.10.4
2.10.5
2.10.6
2.10.7
2.10.8
2.10.9
2.10.10
2.10.11
2.10.12
No. of
pages
7
17
14
10
7
6
12
1
5
1
10
C Printed on Recycled Paper
-------
Section No.: 2.10.0
Date: April 11, 1990
Page: 2
2.10.0 INTRODUCTION
As described in 40 CFR 50, Appendix J, the reference method for PM10 sampling
(i.e., sampling particulate matter with an aerodynamic diameter less than or equal
to a nominal 10 /im), a PM10 sampler draws a measured quantity of ambient air at a
constant flow rate through a specially designed particle size discrimination inlet.
Particles in the PM10 size range are then collected on one or more filters during
the specified 24-hour sampling period. Each sample filter is weighed before and
after sampling to determine the net weight" (mass) gain of the collected PM10
sample. ,
The total volume of air sampled is determined from the measured volumetric
flow rate and the sampling time. The concentration of PM10 in the ambient air is
computed as the total mass of collected particles in the PM10 size range divided by
the volume of air sampled. This sampled volume must be corrected to EPA reference
conditions (25 *C, 760 mm Hg or 101 kPa), and PM10 data are expressed as micrograms
per standard cubic meter (//g/std. m3). The particle size discrimination character-
istics (sampling effectiveness) of the sampler inlet over the PM10 size range, and
particularly the particle size at which the sampling effectiveness is 50%, are
functional specifications tested in accordance with explicit procedures prescribed
in 40 CFR 53. Sampling methods for PM10 that meet all requirements in both Parts
50 and 53 are designated as PM10 reference methods for use in SLAMS and PSD moni-
toring. These designated methods are usually identified by the name of the manu-
facturer and by the model of the sampler.
Two types of samplers that meet designation requirements are the high volume
PM10 sampler (HV PM10) and the dichotomous sampler. Only the dichotomous sampler
is discussed in this section of the Handbook; the HV PM10 sampler is discussed in
Section 2.11.
The most common commercially available dichotomous samplers are low flow rate
(16.7-L/rain) samplers that collect particles with an aerodynamic diameter up to a
nominal size of 10 /»m. (Note: In reference to PM10 samplers, all particle sizes
are specified by their aerodynamic rather than physical diameter.) Dichotomous
samplers further divide the sample into fine (0- to 2.5-^m) and coarse (2.5- to
W-ftm) fractions, which are collected on separate filters.
Particles with aerodynamic diameters greater .than 10 /tm are removed from the
air sample by inertial separation tn a specially designed fractionating in.let such
as the one illustrated in Figure 0.1. Particle-laden air is drawn into the inlet
and deflected downwards into the acceleration jet of an impactor. Because of their
greater inertia, particles larger than 10 /
-------
Section No.: < 2.10.0
Date: April 11, 1990
Page: 3
AMBIENT AIR FLOW
Vent Jet
Upper Plenum
Upper Flange
Screen
Lower Flange
Deflective Cone
Acceleration Jet
Middle Plenum
Lower Plenum
FLOW TO VIRTUAL IMPACTOR
Figure 0.1. Example of a PM10 dichotomous sampler Inlet head.
-------
Section No,: 2.10.0
Date: April Jl, 1990
Page: 4
From Aerosol Inlet
FIn« Particles,
<2.5>im
Coarse Particles,
Fitter Cassette
Fine
Particle
Fitter
inlet Tube
Virtual
Impactor
Nozzle
Virtual
Impactor
Receiver Tube
Fitter
Cassette
Coarse
Particle
Fitter
High Velocity
Air Row
To Control Module
Low Velocity
Air Flow
Figure 0.2. Principle of the secondary (2.5 ^m) particle size separation
In a dlchotomous sampler by virtual impactlon.
-------
Section No.: 2.10.0
Date: April 11, 1990
Page: 5
collected on the coarse particle filter, a correction must be made when fine and
coarse particle concentrations are calculated.
Method Highlights
The procedures provided in this document are designed to serve as guidelines
for the development of quality assurance (QA) programs associated with the opera-
tion of dichotomous samplers. Since recordkeeping is a critical part of QA activi-
ties, several data forms are included to aid in the documentation of necessary
data. The blank data forms (Subsection 12) may be used, as they are, or they may
serve as guidelines for preparing forms more specific to the needs of the indi-
vidual monitoring agency. Partially filled-in forms are included at appropriate
places in the text to illustrate their uses.
Tables at the end of some sections summarize the material covered in the text
subsections. The material covered in the various subsections of this section is
summarized here:
1. Subsection 1, Procurement of Equipment and Supplies, describes recom-
mended procurement procedures, equipment selection criteria, and minimum
accuracy requirements. It also provides an example of a permanent
procurement record.
2. Subsection 2, Calibration Procedures, provides detailed calibration .
procedures for the dichotomous sampler; References are provided for
calibration procedures for the flow-rate transfer standards and other
monitoring equipment. A table is provided at the end of this subsection
that summarizes the acceptance .limits for calibration.
3. Subsection 3, Field Operations, details procedures for filter installa-
tion, performance of operational quality control (QC) checks, sample
handling, and data documentation. Complete documentation of background
information during sampling is one of several QA activities that are
important to future data validation; particularly important are any
unusual conditions existing during collection of the sample. Such
conditions should be noted.
.4. Subsection 4> Filter Preparation and Analysis, presents important consid-
erations for the handling, integrity, equilibration, and weighing of
filters. A high qua-lity filter is recommended for use when additional
chemical analyses are expected. Subsection 2.10.4 also briefly describes
minimum laboratory QC procedures. The analytical balance must be cali-
brated annually, and the filters must be equilibrated in a controlled
environment.
5. Subsection 5, Calculations, Validations, and Reporting of PMIO Data
presents calculations for determining PMIO mass concentrations and mini-
mum data validation requirements. The final data review and validation
including standardized reporting procedures, are all important parts of'a
QA program. Independent checks of the data and calculations are required
to ensure that the reported data are both accurate and precise
-------
Section No.:
Date: April
Page: 6
2.10.0
11, 1990
6. Subsection 6, Maintenance, recommends periodic maintenance schedules to
ensure that the equipment is capable of performing as specified. Minimum
maintenance requirements and procedures are outlined. The objective of a
routine maintenance program is to increase measurement system reliabil-
ity.,
7. Subsection 7, Auditing Procedures, presents independent audit activities
and laboratory evaluations that provide performance checks of flow-rate
measurements and data processing. Filter weighing procedures and balance
operation evaluations and a system audit checklist are also provided.
Independent audits evaluate data validity.
8. Subsection 8, Assessment of Monitoring Data for Precision and Accuracy,
describes the assessment procedures for determining the accuracy and
precision, of the data. The precision check is performed by using collo-
cated samplers.
9. Subsection 9, Recommended Standards for Establishing Traceability, dis-
cusses the traceability of monitoring equipment to establish standards of
higher accuracy, a necessary prerequisite for obtaining accurate data.
10. Subsections 10 and 11 contain the PM10 Reference .Method and pertinent '
references, respectively, used to prepare this document. Subsection 12
provides blank data forms for the convenience of the user.
-------
Section No.: 2.10.1
Date: April 11, 1990
Page: 1
2.10.1 PROCUREMENT OF EQUIPMENT AND SUPPLIES
The establishment of an ambient PM10 air monitoring network requires the pro-
curement of specialized equipment and supplies for field operations'and subsequent
filter analysis. Information in this section has been provided to assist the
agency in selecting the proper equipment. Subsection 1.1 presents minimum sampling
equipment necessary to conduct field operations. Recommended laboratory instrumen-
tation is presented in Subsection 1.2. '
In addition to field operations and laboratory equipment, a data handling
system (including forms, logs, files, and reporting procedures) must be developed
and implemented. . K
It is recommended that each agency establish minimum monitoring equipment
requirements and budgetary limits before the procurement procedures are initiated.
UE°nireEeipt ?f th! samPlin9 equipment and supplies, appropriate procurement checks
should be conducted to determine their acceptability, and whether they are accepted
or rejected should'be recorded in a procurement log. Figure 1.1 is an example, of
such a log. This log will serve as a permanent record for procurements and provide
fiscal projections for future programs. It will also help to provide the continu-
ity of equipment and supplies. Table 1.1, at end of the subsection lists the
major equipment needed, how it should be tested, suggested acceptance limits and
actions to be taken if acceptance limits are not met.
1.1 Procurement Prerequisites—Field Operations • '
1.1.1 Dichotomous Samplers - -
The individual sampler must meet U.S. EPA operational standards and be a model
designated as a reference or equivalent method. A complete listing of minimum
sampler requirements (i.e., 40 CFR 50, Appendix J) is contained in the reference
method reproduced in Subsection 10. Dichotomous samplers not designated as refer-
mlln? nJ fSU1wa]ent 1"eAh^S maV not be used for Deporting data to determine attain-
ment of the National Ambient Air Quality Standard (NAAQS) for particulate matter.
Cost for dichotomous samplers will vary with the manufacturer and the sophistica-
tion of the sampler. Basic considerations include the flow control and measurement
system, maintenance requirements, reliability, and ease of operation.
Using only one model of sampler in a network will minimize the variety of '
spare parts required to keep the network in operation. An in-house inventory of '
general maintenance supplies and replacement parts is recommended. These include
various -hand tools general all-purpose cleaner, penetrating oil, distilled water
Kimwipes (or equivalent), soft brush, and cotton swabs. Spare parts for the
sampler may be supplied by the manufacturer or many may be purchased locally.
1-1.2 Calibration Equipment -
ha <«a)1-brati?n activUies require specialized equipment that will not necessarily
be used in routine monitoring. At a minimum, the following equipment is required:
-------
Section No.: 2.10.1
Date: April 11, 1990
Page: 2
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-------
Section No.: 2.10.1
Date: April 11, 1990
Page: 3
abJe °f a"urate1y measurin9 ambient temperatures to the
Technolnn /N eferen"d *° a National Institute of Standards and
Technology (N ST or an American Society for Testing Materials (ASTM)
thermometer within ,2'C (NIST is the former National Bureau of Standards
°f acc"rate1y measuring' barometric pressure over a
a^Hg (66i?° 106 kPa) t0 the nearest -"ill^e? of Hg
r ? Jeast annual]y to a standard of known accuracy within
h™ • °r 1aboratory measurements, a Fortin-type, mercury-coTumn
barometer is appropriate. For field measurements, a portable aneroid
barometer (e.g., a climber's or engineer's altimeter) is appropHate
^ transfe>:istanda'"ds capable of accurately measuring the total
and coarse flow rates of a dichotomous sampler. Tables 21 and 2 2
aLK
~
^^^
^
An adapter of the correct dimensions that will connect the transfer
1.1.3 QC Flow-Check Device
A, a
-------
Section No.:
Date: April
Page: 4
2.10.1
11, 1990
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-------
Section No.: 2.10.1
Date: April 11, 1990
Page: 5
1.1.4 Audit Equipment -
The equipment needed for auditing is similar to the calibration equipment-
however the audit orifice transfer standard MUST be a different device from the
one that is used for routine calibration and flow checks.
!-2 Procurement Prerequisites— Laboratory Operations
1.2.1 Filter Media -
No commercially -available filter is ideal in all respects. The samolino
Program should determine the relative importance of certa?n filter HZ o
criteria (e.g., physical and chemical characteristics, ease of handling cost)
'
lnlegriiy " !5 ^9/m3 (a5s"min9 sampler's nominal 24-h air sample volume)
measured as the concentration equivalent corresponding to the difference
h±?6H thj initia a"5 find1 W6ights of the fi"ter w^en weighed and
handled under simulated sampling conditions (equilibration initial
<™ -'s-Pler, re-
"/eSS th*n 0-005-mil1iequivalents/gram of filter as measured
' Re0ference 13 of the reference method (Subsec-
' and
Iilters may not be suitable for use with all samplers
1-2.2 Filter Protection -
'
-------
Section No.: 2.10.1
Date: April 11, 1990
Page: 6
comparable size (large enough to allow easy removal of the filtert_yet small enough
to prevent excess movement within the petri dish) and have a tight-fitting lid to
prohibit damage or loss of particles during transportation to the analytical labor-
atory. A label can be affixed to the dish to allow proper documentation when
sampling. A sufficient number of petri dishes must be available to provide (1)
protection for the filter in transportation to and from the monitoring 'location,
and (2) storage of an exposed filter for subsequent gravimetric or chemical
analysis.
1.2.3 Laboratory Equipment - " •
The analytical balance must be suitable for weighing the type and size of the
dichotomous filters used. The range and sensitivity are dependent upon routine
tare weights and expected loadings. A minimum sensitivity of ±1 /
-------
Section No.: 2.10.1
Date: April 11, -1990
Page: 7
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-------
-------
Section No.: 2.10.2
Date: April 11, 1990
Page: 1
2.10.2 CALIBRATION PROCEDURES
This subsection presents the folio-ing aspects of calibration procedures:
Basic calibration procedures, calculations, and rotameter "set nnint"
adjustments for the dichotomous sampler (Subsection 2 2)[
Recommended transfer standards and calibration equipment (Tables 2.1 and
Sampler calibration frequency requirements (Subsection 2.3).
requirements and calibration proce-
F1ow-Rate Measurement anrl
r consists of .... „_ UU01U
-------
Section No.: 2.10.2
Date: April 11, 1990
Page: 2
bration of
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Section No.: 2.10.2
Date: April II, 1990
Page: 3
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-------
Section No.:
Date: April
Page: 4
2.10.2
11, 1990
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-------
Section No.: 2.10.2
Date: April 11, 1990
Page: 5
As indicated above, the true or actual flow through the sampler inlet must be
known and controlled to ensure that only those particles nominally less than 10 w
are being collected. A common source of error in a PM10 monitoring program is
confusion between various air measurement units. Although the sampler must operate
in terms of actual flow rate (Qa) , flow rates must be corrected to EPA standard
h^hn10nS^°o ^mP?rature and Pressure (Qstd) before data can be submitted. Thus
both Qa and Qstd flow rates are used for PM10 measurements. Before calibration
procedures are initiated, the operating agency personnel should- review the
following flow-rate designations:
Qa: Actual volumetric air flow rates that are measured and expressed at
existing conditions of temperature and pressure are denoted by Qa
(Qactual). Typical units are L/min and m3/min. Inlet design flow rates
are always given in actual volumetric flow units.
Qstd: Air flow rates that have been corrected to EPA standard conditions
of temperature and pressure (25'C or 298 K, and 760 'mm Hg or 101 kPa) are
denoted by Qstd (Qstandard). Typical units are std. L/min and std
iii-Vim n. Standard volume flow rates are often used by engineers and
scientists and are equivalent to mass flow units. Standard volumes
(derived- from standard volume flow rates) are also required to be used in
the calculation of mass concentration (^g/std. m3j in reportina PM10
measurements. ,
These Qa and Qstd measurement units must not be confused or interchanged The
^/ate,units can be Converted as follows, provided the existing temperature and
periodT arerknown?me "^ * 3Verage temPerat^e and Pressure o?er a'sam^ing
Qstd = Qa(Pa7Pstd)(Tstd/Ta) (Eq. jj
Qstd = Qa(Pav/Pstd) (Tstd/Tav) (Eq. la)
. • • Qa = Qstd(Ta/Pa)(Pstd/Tstd) - (Eq. 2)
where:
Qstd = standard volume flow rate, std. m3/min
Qa = actual volume flow rate, actual m3/min
Pa = ambient barometric pressure, mm Hg (or kPa)
Pstd = EPA standard barometric pressure, 760 mm Hg (or 101 kPa)
Tstd = EPA standard temperature, 298 K
Ta = ambient temperature, K (K = °C + 273)
QTtd - average standard volume flow rate for the sample period, std. m3/min
Qa = average -actual volume flow rate for the sample period m3/min
Pav = average ambient barometric pressure during the sample'period, mm Hg (or
Tav = average ambient temperature during the sample period, K.
-------
Section No.:
Date: April
Page: 6
2.10.2
11, 1990
2.2 Sampler Calibration
This subsection presents flow-rate calibration procedures for the most common,
commercially available dichotomous samplers. Calibration procedures may have to be
adapted for other sampler models.
The dichotomous sampler operates at a total actual flow rate of 16.7 L/min.
To ensure correct fractionation of particles at the inlet, this flow rate must be
maintained within *10% of 16.7 L/min. The coarse flow rate is approximately 10% of
the total, or 1.67 actual L/min. it must also be maintained to ensure correct
fractionation within the sampler's secondary separation system.
Accurate calibration data for each dichotomous sampler are essential for the
following:
1. To determine sampler flow rate set points.
2. To establish sampler flow rate control limits.
3.. To calculate sampler flow rate during routine QC field flow checks and QA
performance audits.
4. . To calculate to.tal sample volume for the computation of PM10 mass
" concentrations.
Calibration of the sampler rotameters must be traceable to NIST standards. A
primary standard is used to calibrate a transfer standard, which in turn is used to
calibrate the sampler rotameters.
Several commercially available transfer standards can be used in calibrations.
Tables 2.1 and 2.2 list recommended standards, their applicable flow ranges, refer-
ences for transfer standard calibration procedures, and the equipment necessary to
perform sampler calibrations. The following are essential considerations in choos-
ing a transfer standard for subsequent rotameter calibrations.
1. The transfer standard must be traceable to NIST through the calibration
procedures referenced.
2. The transfer standard must be calibrated in the appropriate flow range.
A minimum range of 12 to 19 L/min (total) and 1.4 to 1.9 L/min (coarse)
is recommended.
Note; If the transfer standard has been calibrated in terms of EPA
reference conditions, indicated flow rates 'for each rotameter setting
must be corrected to actual flow rates (Qa) to determine the sampler's
set point.
As indicated in Tables 2.1 and 2.2, each transfer standard has a certain
value. The operating agency should carefully choose the method that best utilizes
equipment on hand and minimizes difficulties in establishing traceabi1ity.
-------
Section No.: 2.10.2
Date: April 11, 1990
Page: 7
Regardless of the transfer standard employed, a leak-tight adaptive device
must be used to connect the transfer standard to the sampler inlet". Figure 2.1
illustrates such an adapter. These may be purchased comrnercially or fabricated
in-house. Obviously, the corresponding outlet on the transfer standard will
determine whether a pipe thread or tube fitting will be attached.
Tables 2.1 and 2.2 present only the basic apparatus necessary to perform
calibrations. In addition to those listed, the operator will need a few miscellan-
eous supplies. _These include a 9.53-mm (3/8-in.) Swagelok cap, 6.35-mm (1/4-in )
Swagelok cap, and hand tools.
A station log book or calibration data sheet must be used to document
calibration information. This information includes, but is not limited to
instrument and transfer standard model and serial numbers, transfer standard
traceability and calibration information, ambient temperature and pressure
conditions, and the collected calibration data (rotameter units versus indicated
flow rate).
2.2.1 Precalibration System Check -
Procedures for the precalibration system check are as follows:
1. Place a pair of filters into the dichotomous sampler filter holders
Filters used for flow rate calibrations should not be used for subsequent
sampling. . . ^
2. Remove the sampler's inlet. Turn on the sampler and allow it to warm up
to full operating temperature (at least 5 min).
3. While the sampler is energized, slowly close off the inlet tube with a
rubber stopper or duct tape and observe the total vacuum gauge. If the
sampler is equipped with an overload feature, it should shut down the
system when approximately 15 in. of vacuum is reached.
4. If the sampler is equipped with the overload feature, disconnect Next
perform a system leak check by opening both rotameters completely and ' '
sealing the inlet tube with a rubber stopper or duct tape. When a maxi-
mum indication on.the total vacuum gauge is reached, shut off power to
tne unit record the maximum reading on a data sheet, and observe the
rate of decline in the readings of the vacuum gauges.
Note: Leak-free systems should indicate a vacuum of 10 to 15 in or
more, and the rate of decline to 0 in. indication should require 60 s or
more. If these conditions are not met and the control module was
•successfully leak-tested previously, a leak exists either in the inter-
connecting tubing or in the sample module.
5. If applicable, reconnect the overload feature. Conduct a pump perform-
ance check. Open the inlet tube and apply power to the unit P When
stable flow is achieved, adjust, both rotameter control valve to 90% of
the rotameter scale. Observe the total vacuum gauge indication.
-------
Section No.: 2.10.2
Date: April 11, 1990
Page: 8
O-RIng
Transfer Standard
Noncrimp Tubing
9.53 mm (3/8 in) NPT to
Barb Connector
•Place Teflon tape here
32mm —>j
38 mm •
To Inlet Tube
.Stainless Steel
or Aluminum
Figure 2.1. Inlet adapter that may be used to connect the
transfer standard to the sampler's inlet tut*.
-------
Section No. : 2.10.2
Date: April 11, 1990
Page: 9
Note: Consult manufacturer's instruction manual for minimum vacuum
indication. Readings lower than specified vacuum readings indicate
possible pump diaphragm or reedvalve problems, which should be
investigated and corrected before continuing with the calibration.
2.2.2 Total Rotameter Calibration -
Procedures for calibrating the total rotameter are as follows:
1. Set up calibration system as illustrated in Figure 2.2. The inlet of the
transfer standard is open to the ambient air; the outlet of the transfer
standard is connected to the inlet tube of the dichotomous sampler.
2. Turn on the sampler and allow it to warm up to normal operating tempera-
ture (at least 5 min). If an electronic transfer standard is used it
must also equilibrate before proceeding with the calibration.
3. Adjust the total flow control valve to approximately 90% of the rotameter
of 167 L/min °°arSe f1°W C0ntro1 valve to indi«te a nominal flow
4. Read the following parameters and record them on a data form (Fiaure 2 3)
or in a log book: 3 '
• Ambient temperature (Ta) , K • .
Barometric pressure (Pa), mm Hg or kPa
Transfer standard readings (TS) , volts, AH20, timings, etc.
Sampler total rotameter indication (I), arbitrary units.
pr°5e5n.re !°r rotameter settings representing flow rates of 75
°f establd operating range (12 to 19 L/min) For
'
each
' "—ponding
2-2.3 Coarse Rotameter Calibration -
1' I?/S ?fVhe^Sa?p.1er- disconnect the fine flow vacuum line [9.53-mm
3/Sin' ?:!L i!ej; 3?d Ca?-lhC fyVlow outlet-port with a 9.53-mm
in?"™™ tn th P ^^ Fl9Ure 2'4)' Thl'S St6P ke6PS the fine ^°«
f if0^Ph0 ?+ ! vacuum pump. It is recommended that a particle-free
filter be attached to the detached fine flow line to prevent particles
sCnd^d 9 ^ SyStem' In5td11 the C°arse f1ow ra'e transfer
2' h^h9?6 the samP1er and the transfer standard (if electronic) Allow
both to warm up again to full operating temperature.
-------
Section No.:
Date: April
Page: 10
2.10.2
11, 1990
Calibration
Adaptive •
Device
Chosen
Transfer
Standard
Coarse Flow
0 0
Coarse
Flow
Rotameter
Total
Row
Rotameter
Figure 2.2. Calibration assembly and dlchotomous sampler
with transfer standard connected.
-------
Dlchotomous Sampler Calibration Data Sheet
Section No.: 2.10.2
Date: April 11, 1990
Page: 11
Station Location Kalet'^k, , NC n^te *?[
Sampler Model 'Z'f'f £" -<$/N £,(Cj
Pa ^4? mmHq Ps ^l mm Hg
Leak check, maximum vacuum (^ in.
Total Trans. Std. Model M.FM S/N 2.113
Qa Cal. relationship m. 6-142 b. 0-oo
Coarse Trans. Std. Model SFFf^\ s/N V/<1
Qa Cal. relationship m . '• ° b - O
Cal. Indication Flow Rate
Point (TS) Cv
^ V* 0:1*1-3 \.bO
/3 3 -
2-0 '(. O.3-I2. /.*fo <2 £- 6" Z^?'
>^^^^^^^«^^i»^^Bi*H^HBBl^HMi^HiHi^ll^
Sampler Cal. Relationship (Qa, x-axis; corrected recorder response, AC, y-axis)
Total:
TFR
CFR
Coarse: m « I
X-^_ CSP
' " ^^^™» ^^ III ^^mHB^Bo.
TFR = 16.7 (Ps/Pa)(TayTs) CFR = 1.67 (Ps/Pa)(TaATs)
TSP, CSP - {[m (TFR, CFR) + b] [(Pa/Ta)'*]}
Operator _
Figure 2.3. Example dlchotomous sampler calibration data sheet.
-------
Section No.:
Date: April
Page: 12
2.10.2
11, 1990
Calibration
Adaptive •
Device
Chosen
Transfer
Standard
Fine Flow
Coarse Flow
Disconnect 9.53 mm (3/8 In)
O.D. tubing and install
Swageiok cap
Paniculate filter
Installed on
9.53 mm (3/8 In)
O.D. tubing
0 0
Coarse
Flow
Rotameter
Total
Flow
Rotameter
Figure 2.4. Calibration assembly and dichotomous sampler
set up to calibrate the coarse flow rotameter.
-------
Section No.: 2.10.2
Date: April 11, 1990
Page: 13
3. Adjust the coarse rotameter flow-control valve to an approximate value of
90% of the rotameter scale. Adjust the total flow control valve to
indicate a nominal flow of 16.7 L/min.
4. Read the following parameters and record them on a data form (Figure 2.3)
or in a log book:
• .Ambient temperature (Ta) if variation has occurred, K
. • Barometric pressure (Pa) if variation has occurred, mm Hg or kPa
Transfer standard readings (TS), volts, AI^O, timings, etc'.
• Sampler coarse rotameter indication (I), arbitrary units..
5. Repeat procedure for rotameter settings representing flow rates of 75,
60, 40, and 20% of the established operating range (1.4 to 1.9 L/min)!
For each calibration point, record the rotameter indication and corre-
sponding transfer standard output.
6. Turn off sampler, and reconnect the fine flow line and the sampler's
inlet. v
2-2.4 '"Calibration Calculations -
Gather together all the calibration data, including the transfer standard
calibration information and the dichotomous sampler calibration data sheet The
following calibration calculation procedures are recommended.
Note: These calculations should be done at the time of the calibration
rather than later. This approach will allow additional calibration points to be
taken if questions arise about the data that have already been obtained.
'1. Verify that the transfer standard calibration equation is current and
traceable to an acceptable primary standard.
• 2. Calculate Qa for each calibration point as determined by the transfer
standard calibration equation.
• Note: It may be necessary to correct the indicated transfer standard
flow rates from Qstd to Qa. This can be accomplished by Equation 1.
Qa = Qstd(Ta/Pa)(Pstd/Tstd) ' -(£q. 2)
where
Qa = flow rate at actual conditions L/min
Ta = ambient temperature, K (K = °C + 273)
Pa = ambient barometric pressure, mm Hg or kPa •
Pstd, Tstd = standard barometric pressure and temperature, respectively.
-------
Section No.: 2.10.2
Date: April 11, 1990
Page: 14
3. Calculate and record the total and coarse rotameter actual corrections
(AC) for each calibration point as:
AC = I(Ta/Pa)l/2 (Eq. 3)
where ,
AC s actual correction
I s rotameter response, arbitrary units
Ta s ambient temperature, K
Pa s ambient barometric pressure, mm Hg or kPa.
4. On a sheet of graph paper, plot the sampler corrected total rotameter
units (y-axis) versus the corresponding calculated transfer standard
total flow rates (x-axis) to obtain the dichotomous sampler total flow-
rate calibration relationship.
5. Repeat Step 4, plotting corrected coarse rotameter units vs. the corre-
sponding calculated coarse flow rates.
Because the determination of the sampler's average operational flow rate (Qa)
during a sample period depends on the ambient average temperature and pressure, use
of a graphic plot of the calibration relationship is not recommended for subsequent
data reduction. This plot is used only to visually assess the calibration points |Bk
to see if any should be rerun. • ^P'
Plot the regression line on the same graph paper as the calibration data. For
the regression model y = mx + b, let y = AC = I(Ta/Pa)l/2 and x = Qa so that the
model is given by:
AC = m[Qa(transfer standard)] + b (Eq. 4)
Using a programmable calculator or a calculation data form, determine the
linear regression slope (m), intercept (b), and correlation coefficient (r) and
record them on the data sheet. A five-point calibration should yield a regression
equation with a correlation coefficient of r > 0.990, with no point deviating more
than 0.5 L/min for total or 0.05 L/min for coarse rotameter calibrations from the
value predicted by the regression equation. Plot the regression line on the same
graph paper that has the individual calibration points.
• 6. For subsequent sample periods, the sampler's average actual operational •
flow rate TQa or CQa is calculated from the calibration slope and
intercept using Equation 5: • .
TQa or CQa = l/m[T(Tav/Pav)1/2 . 5] (Eq. 5)
-------
Section No.: 2.10.2
Date: April 11, 1990
Page:- 15
where
TQa, CQa = sampler total or coarse average flow rate, actual L/min
I = average total or coarse rotameter response, arbitrary units
Tav - average ambient temperature for the .run day, K
Pav = average ambient barometric pressure for the run day, mm Hg or kPa
m = slope of the total or coarse flow-rate calibration relationship
b = intercept of the total or coarse flow-rate calibration relation-
ship.
Note; The expression [T(Tav/Pav).l/2] is the "y" term of linear regres-
sion equation: y = mx + b, or x = (y-b)/m.
Note: Tav and Pav readings may be recorded on-site or from a nearby U.S.
National Weather Service station or airport weather station. Barometric
pressure readings obtained from remote sources must be at station pres-
sure (not corrected to sea level), and they may have to be corrected for
differences between the elevation of the monitoring site and that of the
airport. If ambient temperature and pressure readings are not available,
seasonal average temperature (Ts) and barometric pressure (Ps) can also
be used. Care must be taken, however, that the actual conditions at the
site.can be reasonably represented by such averages. It is therefore
recommended that seasonal values represent actual values within 20 °C and
40 mm Hg.
2.2.5 Rotameter Set Point Adjustment Procedure -
1. Calculate and record on the calibration data sheet the total and coarse
seasonal flow rates. These values will be used to determine the seasonal
set points for both rotameters.
TFR = 16.7(Ps/Pa)(Ta/Ts) (Eq. 6)
where
TFR = total flow rate for adjustment of the sampler total rotameter
16.7 = design flow rate as specified by the manufacturer, L/min
Ps, Pa = seasonal average and ambient barometric pressure, respectively mm Ha
. or kPa .
Ts, Ta = seasonal average and ambient temperature, respectively, K.
CFR = 1.67(Ps/Pa)(Ta/Ts) (Eq. 7)
where
CFR = coarse flow rate for adjustment of the sampler coarse rotameter
1.67 = design flow rate as specified by the manufacturer, L/min
Ps, Pa = seasonal average or ambient barometric pressure, respectively, mm Hg
Or Kr3
Ts, Ta = seasonal average or ambient temperature, respectively, K.
-------
Section No.: 2.10.2
Date: April 11, 1990
•Page: 16
2. Calculate and record on the sampler's calibration data sheet the set
point rotameter responses that correspond to TFR and CFR" calculated in
Step 1.
TSP = {[m(TFR) + b](Pa/Ta)1/2} (Eq. 8)
where
TSP s total rotameten set point, arbitrary units
TFR s total flow rate, L/min
Pa s ambient barometric pressure, mm Hg or kPa
Ta s ambient temperature, K
m - slope of the total flow-rate calibration relationship
b s intercept of the total flow-rate calibration relationship.
"CSP = {[m(CFR) + b](Pa/Ta)1/2} (Eq. 9)
where
CSP = coarse rotameter set point, arbitrary units .
CFR s coarse flow rate, L/min
Pa - ambient barometric pressure, mm Hg or kPa
Ta = ambient temperature, K
nr-s slope of the coarse flow-rate calibration relationship .
b * intercept of the'coarse flow-rate calibration relationship.
Adjusting the sampler rotameter to seasonal average conditions will help
minimize data loss caused by exceeding the manufacturer's design condition
specifications.
1. Energize the sampler and allow it to warm up to operating temperature (3
to 5 min).
2. Following the manufacturer's instructions, adjust the total rotameter
until the sampler response indicates the total flow-rate set point (TSR)
as calculated in Step 2 above.
3. Following the manufacturer's instructions, adjust the coarse rotameter
until the sampler response indicates the coarse flow-rate set point (CSP)
as calculated in Step 2 above.
4. Verify'that the sampler will maintain these flow rates for at least 10
min. Turn off the sampler.
5. The sampler can now be prepared for the next sample run day.
2.3 Sampler Calibration Frequency
To ensure accurate measurement of the PM10 concentrations, calibrate the samp-
ler upon installation and then recalibrate it as follows:
-------
Section No.: 2.10.2
Date: April 11, 1990
Page: 17
1. At least annually.
2. After any repairs that might affect sampler calibration.
3. If the field calibration flow check results exceed QC limits (+10% from
the sampler's required design condition flow rate or ±7% from the
sampler's indicated flow rate).
4. Whenever an audit indicates that the sampler is out of calibration (±105
from the sampler's required design condition flow rate or ±7% from the
sampler's indicated flow rate).
-------
-------
Section No.: 2.10.3
Date: April 11, 1990
Page: 1
2.10.3 FIELD OPERATIONS
3.1 Siting Requirements
As with any type of air monitoring study in which sample data are used to draw
conclusions about a general population, the validity of the conclusions depends on
the representativeness of the sample data. Therefore, the primary goal of a PM10
monitoring project is to select a site where the collected sample mass is repre-
sentative of the monitoring area. .
.Spatial' and temporal scale considerations are important in dichotomous sampler
siting. .Spatial scales may range from a small (0.1- to 0.5-square kilometer) area
to large regional areas exceeding tens of hundreds of square kilometers. Whether
the potential impact of particulate pollution is generated by a local or qeneral
source category will affect the decision on the size of the spatial monitoring
™?i *' ! ?S !?"' e S1'i1f)9 Of the samPlers W1'thin a monitoring .network should
reflect whether the expected impact will be limited to a small area (a few city
blocks) or extend to larger areas (metropolitan or rural).
.With regard to the temporal scale, interest focuses on either an annual geo-
metric mean concentration or a 24-h average concentration. Because siting of a
dichotomous sampler requires that consideration be given to prevailing wind direc-
tion, a sampler sited for monitoring trends in air quality over a period of a vear
of l^r^r^n6 JdeaT *>r ^asuring 24-h concentrations. Thus, the choice
of temporal scale will also affect the.sampler location.
Although spatial and temporal scales must be considered in site selection the
following guidelines should be observed regardless of the scale: cie"lon, me
1. The dichotomous sampler must have unobstructed air flow for a minimum of
2 m m all directions.
2. The sampler inlet should be .placed at a height of 2 to 15 m above ground
3. If a dichotomous sampler is collocated with any other particulate sam-
pler, the minimum spacing between sampler inlets must be 2 m and the
maximum spacing must be 4m. All inlet heights should be within 1
vertical meter of one another.
Complete siting requirements are outlined in 40 CFR 58, Appendix E.
win £IdHt1?nayaCJ!!rS mustnbe considered in determining where the actual sampler
ab ifv ofPl2n ;t h?SV"0 Ude acceS51'bili*y under all weather conditions aJa^
ability of adequate electricity, and security of the monitoring equipment.
A dichotomous sampler used for routine sampling must be situated where thP
operator can reach it safely regardless of weather Editions! if the sampler is
located on a rooftop, care should be taken that the operator'^ personal safety is
-------
Section No.: 2.10.3
Date: April 11, 1990
Page: 2
uwb jcupuiuitcu uj u ji.p^ij i «w i Ju, ,uv.v. uw. ,..y . ..w . w...w.... ,.^-w..w. . ».„...,.«_.-
tions also should be given to the fact that routine operation (i.e~., calibrations,
sample installation and recovery, flow checks, and audits) involves transporting
supplies and equipment to and from the monitoring site.
A dichotomous sampler will require a minimum continuous operating current of 3
to 5 A (120 V a.c., 60 Hz) and may require a higher startup current, which necessi-
tates a slow-blow fuse. Although most dichotomous samplers are equipped with
timers, there is often no recording device provided to indicate short-term power
interruptions. This lack necessitates a stable power source for the monitoring
site.
The security of the sampler itself depends largely on its location. Rooftop
sites with locked access and ground-level sites with fences are common. In all
cases, the security of the operating personnel as well as the sampler should be
considered.
3.2 Sampler Installation Procedures
1. On receipt of a dichotomous sampler from the manufacturer, visually
inspect the sampler to ensure that all components are accounted for.
Compare equipment delivered with the enclosed packing slip. Notify the
manufacturer immediately of any missing or damaged 'equipment.
2. Before transporting the sampler to the field site, perform a quick labor-
atory check'to determine if the sampler i.s operational. • Energize the
sampler and observe rotameter responses, vacuum gauges, and pump perform-
ance.
3. Carefully transport the sampler to the monitoring site.
4. Bolt down the sampling module to a secure mounting surface.
5. Install the control module. This module can be bolted down adjacent to
the sampling module (no closer than 2m), or it can be located remotely
(e.g., inside a monitoring station). It is recommended that the control
module be no more than 10 to 15 m away from the sampling module to avoid
a pressure drop along the flow lines.
6. Connect the vacuum lines between the sampling module and the control
module. First, hand-tighten the nuts on the tube connectors as much as
possible, and then wrench-tighten them 1-1/4 revolutions. Be careful not
to cross-thread the fittings.
7. Check all tubing for crimps, cracks, or breaks,
8. Plug the power cord into a line voltage outlet. The use of waterproof
interlocking electrical connectors is recommended to ensure operator
safety and to avoid shorts and/or power interruptions. Do not allow any
-------
Section No.: 2.10.3
Date: April 11, 1990
Page: 3
electrical connections to be submerged during periods of inclement
weather.
9. Perform a multipoint flow-rate calibration as described in Subsection 2.
3.3 Samp 1 i nq Operat i ons
Sampling operations provided here are specific to one type of commercially
available dichotomous sampler. Because operational procedures may vary among samp
ler models, the manufacturer's instrument manual should be consulted before the
sampler is put into operation. Sampling procedure checks are summarized in Table
J » i •
3.3.1 Filter Installation
,rp -in^rr-136 ^kel! t0 enSUre *?at Clean f i^ers are not damaged before they
are installed in a dichotomous sampler. Filter cassettes should be kept in their
protective petri dishes (see Figure 4.1), and any damaged filters must be
discarded.
Thr Pr°5?dhr? US6d t0 Tta11 fi1ters in a dichotomous sampler is presented
ch ?5 dichotomous sampler is equipped with two filter holders, and the petri
nn h Hmari?dKt0 ind,i"te which filter will be used for coarse particle
andh;ne sam^nYrun tll^* '""«<*"»"<*• the filter ^sampler ID
1. Switch mechanical or digital timer to "OFF."
2. The coarse-particle filter holder is the one with the 5,35-mm. (1/4-in.)
o.d. tubing and the Tine-particle filter holder is the one with the
erfrZ iun~in'H-°; S%\ As*hown in Fl"9ure 3.1, the filter hold-
ers can also be distinguished by the fact that the coarse-particle filter
holder is on the center line of the virtual impactor head and aerosol
l*n%'£ ^r635/^ fine-particle filter holder is offset. Unscrew (by
a^eLlJ6 k"urje
-------
Section No.:
Date: April
Page: 4
2.10.3
11, 1990
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-------
Section No.: 2.10.3
Date: April 11, 1990
Page: 5
Coarse Filter Holder
Fine Filter Holder
9.53 mm (3/8 in) Tubing
6.35 mm (1/4 In) Tubing
Figure 3.1. Location of the filter holders on the sampling module.
-------
Section No.: 2.10.3
Date: April 11, 1990
Page: 6
DIchotomous Sampler Field Data Sheet
Station Location t-AV'ti > ™ C. Run ^ate 12. [ |
Sampler Model 1# 4 £" S/N & ' 1
2 ^ SAROAD Number 332 3 b. ~£- 0
'•/ r. 0. W CFR /.4fc Umin
Vacuum Gauge Indications: Total Initial (^ Total Final I-!* Coarse Initial &
Coarse Final p
Rotameter Responses:
TSP* 13.*5 Final Total / 3 . 5" Ave. Total (T) ' '•
CSP' 'O.o? Final Coarse ^O.O Ave. Coarse (T) U
Elapsed Time Sampled /^^5" min
^ T5a ./f,i&^ , L/rni"
>.o Cr^i /• fr* Umin
TQa, CQa - 1 /m [T (Tav/Pav)1/z - b]
Total Act. Volume (TVa)- TQa X min sampled- ^ 5'*^ Umin FQa- /5". /^- i_/mjn
Coarse Act. Volume (CVa) « CQa X min sampled » 2
Comments: £}rfi.ss -n^c. i»^. ad(^a.c*^t -pf<
"* t^lOLOIK^ f^ i i,\fs * ^ "T™Y"aW\ ****\rn^_ ^^
•4/3 Umin FQa . TQa — CQa
/c( ; A. (oi" "»F Smofei,
^A*_pU^. o^-ite. o^-s-i-k.
•—*•""'
Operator CC^A. lAia.lv
Laboratory Calculations
Std. Volumes (Vstd): TVstd "2-3. S11) m3
TVstd, CVstd - (Va)CIO-3) [(Pav/Tav) (298/760)]
FVstd 2.1. 5X m3
FVstd « TVstd - CVstd
Filter Weights:
Fine: Gross Weight (Wg) loo . I3L mg
Tare Weight (Wt) '^.P-'l mg
Net Weight (Mf) 0- 92.5" ^
PM 10 Concentration ^ • ^ iiq/m3 nq/n
'Total or coarse set points, initial rotameter response.
CVstd "2 • 3T- m3
Coarse: Gross Weight (Wg) /OS. ^^mg
Tare Weight (Wt) Io4 . <4l 3 mg
Net Weight (Me) (?• ^S*/ mg
I3 -{Mf+Mc)(103)/TVstd
Figure 3.2. Example dlchotomous sampler field data sheet
-------
3.
Section No.: 2.10.3
Date: April 11, 1990
Page: 7
Open the front cover of the control module by turning the knob lat.'h
counterclockwise. The cover is released by turning the "indicator one-
quarter turn counterclockwise, and 'it is locked by reversina this
process. • 3
4. Switch the mechanical or digital timer to "ON." If the sampler has a
m,™ tal,*imer/Pr°9rammer equipped with a POWER switch, turn on the vacuum
pump. Allow the pump to run for at least 5 min. to establish operating
pp[e fCO"dltl°nS- While th* Ampler equilibrates, record on the
!! Cation documentary information (i.e., location, SAROAD desig-
samp er model, and S/N) and the run date of the sample The
ndVS 1Srat!Snhrelatio!ls!lips and the tota1 and coars* set p°ints
in Subsection 2 recorded. Set point calculations are presented
5" «!i the nKta1 flow/ate by adjusting the rotameter'to the calculated TSP
value. Observe and record the total vacuum gauge indication The vacuum
fife? PreSSUre '^ (AP) °f aPPr'°ximately 1 ?° 2 ]n Hg ?or
value** SbservP^nd "*" ^ adJustin9 the rotameter to the calculated CSP
value. Observe and. record the coarse vacuum gauge indication- it should
read approximately zero. Turn off the sampler. Incncai1on' u should
7' Ihl ™nPieV'S ri?W ^eady t0 Samp1e- Set the master timer (according to
the manufacturer's instructions to energize the sampler for the next
sampling period. Reset the elapsed time indicator to zero?
8. Close the front cover of .the control module and visually inspect the
SS'con^l51*; ^ensure that a11 ""-Pling components (sampling nlet
and control module) are in readiness for the next run day.
3-3.2 Filter Recovery Procedure -
' lf slmDler^lnn' *T°rd ^ e]aPsed-time indicator value and energize the
record the Jn^ltnt^mplHr t0 Wam "P t0 0Perati"9 temperature and
record the final total and coarse rotameter readings and the final total
a£ coarse vacuum gauge indications on the data shief. Turn the sampler
neall0n Procedure and remove each filter one at a
d shes JeHfv Jha?rf •??' T? 1nhtheir Or1g1nal marked P1astic Petri '
dishes, verify that filter ID numbers match numbers recorded on the data
3. Calculate and record the total and coarse average rotameter readings as:
T - (TSP or CSP +'IF)/2 (Eq. 10)
-------
Section No.: 2.10.3
Date: April 11, 1990
Page: 8
where
I - average total or coarse rotameter response, arbitrary units
TSP, CSP s total or coarse rotameter set points, arbitrary units
IF - indicated final total or coarse rotameter response, arbitrary
units.
4. Record the average ambient temperature [Tav (K)] and barometric .pressure
[Pav (mm Hg or kPa)] for the run day on the field data sheet.
5. Calculate and record the total and coarse average actual flow rates (TQa
and CQa), as determined by the sampler's calibration relationships.
TQa or CQa = l/m[T(Tav/Pav)l/2 - b] (Eq. 5)
where
TQa, CQa ~ sampler total or coarse average flow rate, actual L/min
I = average total or coarse rotameter response, arbitrary units
Tav s average ambient temperature for the run day, K
Pav = average ambient pressure for the run day, mm Hg or kPa
m s slope of the dichotomous sampler total or coarse calibration
relationship
b - intercept of the dichotomous sampler total or coarse calibration
relationship.
Note: Refer to Subsection 5 for a description of Tav and Pav measurements.
6. Calculate the actual fine flow rate by subtracting the calculated Qa
coarse from the Qa total, and record.
7. Observe conditions around the monitoring site; note any activities that
may affect filter particle loading (paving, mowing, fire) and record this
information on the field data sheet.
3.3.3 .Sample Validation -
Validation Criteria - The following criteria have been established to assist the
operator in determining whether or not a sample is valid.
1. Timing:
• All samplers must turn ON and OFF within 1/2 h of midnight.
• All samplers must operate for at least 23 but not more than 25 h
(1,330 to 1,500 min). ' ~
-------
Section No.: 2.10.3
Date: April 11, 1990
Page: 9
2. Flow Rates:
The average flow rates must be within 7% of 16.7 L/min (total) and 1.67
L/min (coarse) at actual conditions. If these limits are exceeded
investigate the cause. Use the following criteria as a basis for sample
invalidation:
Decreases in flow rate during sampling (due to mechanical failure)
of more than 7% from the initial set point require a field calibra-
tion check (Subsection 3.4). If the sampler's calibration check
indicates that the sampler flow was not Within ±7% of the designed
flow, the sampler should be invalidated.
If the sampler flow rate decreases because of heavy particulate
loading on the filter, a post-sampling check of the vacuum gauges
will indicate increased vacuum. These filters should not be invali-
dated because they may indicate an episodic situation.
Changes in flow-rate calibration of more than 7%, as determined by a
field calibration check, will invalidate all samples collected back
to the last acceptable flow-rate check.. Recalibrate the sampler.
3. Filter Quality: .
Any filter that is obviously damaged . (i .e. , is torn, frayed, or has
pin holes) should be invalidated.
3.3.4 Sample Handling - • •
Handling of a Valid Sample -
' C°arse' and fine f1ow rates arrd complete the data
2. Promptly deliver the filter cassettes in their protective petri dish
accompanied by the completed data sheet, to the analytical laboratory.
Handling of an Invalid Sample -
1. Complete as much of the data sheet as possible and explain any omissions'.
2. Mark "VOID" on the data sheet accompanying the filter and record in the
site log book.
3- Do not discard the filter.
shee?^ '" f]e Cassettes in their P^ri dish and the data
shee K
vanity wniaS^adea1 lab°rat°r^ where * «""' ^cision on sample
-------
Section No.: 2.10.3
Date: April 11 1990
Page: 10
Handling of a Questionable Sample -
If uncertain whether or not a sample should be voided:
1. Complete as much of the data sheet as possible and explain any factors
that may affect the sample validity.
2. Put a question mark in the upper right corner of the data sheet.
3. Record as "Questionable" in the site log book.
4. Promptly deliver the filter cassettes"in their petri dish and the data
sheet to the analytical laboratory, where a final decision on sample
validity will be made.
3.4 Operator's QC Field-Calibration-Check Procedure ,
For dichotomous samplers, a field calibration check of the total and coarse
flow rates is recommended after each month of operation. The purpose of this check
is to track the sampler calibration stability. Control charts presenting flow-
check data (indicated vs. observed) should be maintained. These charts provide a
quick reference of instrument flow-rate drift patterns and will indicate when flow
limits (±7% variation from the indicated or design condition flow rate) have been
exceeded. - The"field check is made by installing a measuring device (which is
traceable to NIST and is calibrated within the .range of the total ,or coarse flow
rate) on the inlet of the sampler. Calibration procedures for the measurement
device are referenced in Table 2.1.
Calibration checks of the sampler flow rate require that the instrument be
running. The following- flow-check procedures are specific to an orifice device. A
variety of transfer standards may be used with this same procedure; however, neces-
sary apparatus and subsequent calculations to determine the sampler's flow rates
will vary.
3.4.1 Ffeld-Check Apparatus -
The following equipment is required for a field calibration check:
• • A thermometer capable of accurately measuring temperature to. the nearest
±1°C and referenced to an NIST or ASTM thermometer within ±2°C at least
annually.
• A barometer capable of accurately measuring ambient barometric pressure
to the nearest ±1 mm Hg and referenced to an NIST or ASTM barometer
within ±5 mm Hg at least annually.
• Two calibrated orifice devices and calibration relationships (one for
total and one for coarse).
• The sampler's calibration information..
-------
Section No.: 2.10.3
Date: April 11, 1990
Page: 11
Two clean flow-check filters.
Dichotomous sampler flow-check data sheet (Figure 3.3) or log book.
3-4.2 Procedure for Field-Calibration Check -
1. Insert clean filters (designated "flow-check filters") into both the fine
and coarse filter holders of the sampler as described in the operating
procedure in Subsection 3.3.1. Flow-check filters should never be used
for subsequent sampling, as particles larger than 10 urn can impact on the
filter when the inlet is removed and bias the sample.
2. Turn on the sampler and allow it to warm up to operating temperature
(approximately 5 min).
3. Read and record the following parameters on the sampler flow check data-
sheet (Figure 3.3):
Ambient temperature (Ta), °C and K
Ambient barometric pressure (Pa), mm Hg or kPa
Sampler S/N and model • .
Orifice S/Ns and calibration relationships
- • Date, location, and operator's signature
rrop1rc rotameter's calculated flow rates and set points: TFR, TSP-
CFR, CSP. '
4. Adjust both the total and coarse rotameters to their respective
calculated set points (TSP, CSP).
5. Remove the inlet from the sampler, replace it with the flow-check orifice
device, and recheck the rotameter set points. unnce
6' 2eflec?ione^?2?haCh°t%S th%tojal flow orifi« ^ reading the manometer
inn fin
-------
Section No.: 2.10.3
Date: April 11, 1990
Page: 12
Dlchotomous Sampler Flow Check Data Sheet
Station Location.
Sampler Model .
.Pa 14 "Z- mm Hg Ta
Date.
S/N
SAROAD Number 17 2^01 Eft
EPA Number
K
Unusual Conditions
.Orifice S/N ll"7
Orifice S/N "Si b (t»+ne^ Orifice Calibration Date.
Orifice Qa (Total) Calibration Relationship:
Orifice Qa (Coarse) Calibration Relationship:
Sampler Total Calibration Relationship:
, TFR
Sampler Coarse Calibration Relationship:
L/min,
L/min,
TSP
CSP.
Flow
Rate
' Description
AH.O
(In.)
Orifice Flow
Rate*
(L/mln)
Sampler"
TQa or CQa
(L/mln)
Difference
L/mln
Total
Flow
Design
Cond.'
16.7
Coarse
Flow
Design
Cond."
1.67
* TQa or CQa « m[(AP) (Ta/Pa)]1/2 + b
."TQa or CQa » 1/m [(TSI? or CSP) (Ta/Pa)"2 - b]
QC % Difference - (TQa or CQa) - Orifice Flow Rate ' (1 00)
-Design condition % Difference
Operator
Orifice Flow Rate
Row Rate - (16.7 or 1.67) (100) '
(16.7 or 1.67)
Figure 3.3. Example dlchotomous sampler flow-check data sheet.
-------
Section No,: 2.10.3
Date: April 11, 1990
Page: 13
8. Observe the AH20 across the coarse orifice by reading the manometer
deflection and determine the corresponding flow rate from the orifice
calibration data. Record both values on the flow-check data sheet
Using the sampler's calibration relationship, calculate indicated coarse
actual flow rate (CQa) and record.
9. Using the above information, calculate the QC percentage difference as:
% Difference = (TQa or CQa) - Orifice flow rate Mnn. ,_ .
Orifice flow rate (-L(J(J) (Eq. 11)
10. Determine the percentage difference between the sampler design flow rate
(16.7 L/min or 1.67 L/min) and the orifice determined flow rate as:
= Office flow rate - (16.7 or l.fi?) ,.n_. . '
i 16.7 or 1.67 ~ (10°). (Eq- 12)
* 3s within 93 to 107% of'the 16.7 L/min or 1.67
T"? th(at a-tUal conditions). the sampler is operating
™l,n ?5eSe imUS 3re exceeded' investigate and correct any
resumeS necessary' ^calibrate the sampler before sampling is
12. Turn off the sampler, remove the orifice device, replace the inlet and
reconnect the fine flow vacuum line. . '
13. Remove the filters from both fine and coarse filter holders.
3.5 Documentation
3-5-1 Operator Who Starts the Sample -
Mark on the filter petri dish:
1. Sampler ID number.
2. Fi 1 ter number.
3. Sample date.
4. Designation [e.g., whether it is a coarse (C) or fine (F) filter].
Mark on the field data sheet and record in the log book:
-------
Section No.: 2.10.3
Date: April 11; 1990
Page: 14
1. Site designation and location.
2. Sampler ID number.
3. Filter ID number.
4. Sample date.
5. Initial flow rates and rotameter readings. Initial temperature and
barometric pressure, if required.
6. Unusual conditions that may affect the results (e.g., subjective evalua
tion of pollution that day, construction activity, weather conditions).
7. Signature.
3.5.2 Operator Who Removes the Samples -
Mark on the field data sheet and record in the log book:
1. Elapsed time of the sample run.
2. Final flow rates and rotameter readings. Final temperature and baro-
jietric pressure, if required.
3. Existing conditions that may affect the results.
4. Explanations for voided or questionable samples.
5. Signature.
-------
Section No.: 2.10.4
Date: April 11, 1990
Page: 1
2.10.4 FILTER PREPARATION AND ANALYSIS
^n • y*Z a ™i;.sa?P '"S Program depends on several factors. A primary
th™ ?h the analytical laboratory staff's attention to detail and balance
coercion', J iL?eCi;°n °fferS Sidelines to enhance the accuracy of laboratory
operation and hence the mass concentration determinations of PM10L
i's1on' calibration requirements, and recommended filter
f
4.1 Filter Handlin
4.2 Filter Integrity Check
Specific defects to look for are:
apPeTng (a) as a ^stinct and obvious bright
2 lack of seal between the fmer and
3- aff °r nashinq--An.y extra attached residual material on the reinforc
- "
-------
Section No.: 2.10.4
Date: April 11, 1990
Page: 2
50-mm Diameter
Plastic Petri Dish
with Tight-Fitting
Lid
37-mrnDlameter
TeflorFFilter
with Polyolefln Ring,
in Cassette
Rgure 4.1. Dlchotomous filter cassette and petri dish.
-------
Section No.: 2.10.4
Date: April 11, 1990
Page: 3
4. Loose material-Any extra loose material or dirt particles on the filter
that require removal by brushing prior to weighing. "ner
5' ofSa0contaam?nan^y °bV1'°US VlSible dl'scoloration that might be evidence
'6. Filter nonuniforaity-.Any obvious visible nonunifomity in the appearance
of the filter when viewed over a light table or black surface that mioht
indicate gradations in porosity across the face of the filter. 9
7. Other-A filter with any imperfection not described above such as irren
UTIr-surfaces or other results of poor workmanship. 9"
4.3 Filter Equilibration
Filters must be equilibrated in a conditioning environment for at least ?&. h
valuerebetwee9nW|d9,heHd-^?ela^hVe """^I* (RH) shoufd bi KlTJSnstln? aJ fLw
chnn?H h t U S 45-s, with a variability of not more than ±5%. Temoerature
o? not more' haS°*n3Sorant ?lth.a mea"^lue between 15 and 30'C, with r^riaMmy
t®2^&r~Z32S^&&s
4-4 Initial Weighing Procedures (Tare Weight)
NOTE: Make sure that the balance has been calibrated (at least .ni.u.11,,1
ma,nta,ned according to manufacturer's recoraendations I? out of
"™ HaV "cording tS
-------
Section No.: 2.10.4
Date: April 11, 1990
Page: 4
2. Zero the balance according to manufacturer's directions.
3. Have the QC supervisor perform the "standard" filter QC check (Subsection
4.5.2) to increase the validity of subsequent tare weight values.
4. If filters must be weighed outside the conditioning chamber, use caution
to avoid interference with ambient hydroscopic particles .and begin the
weighing procedure within 30 s. Weigh the filter according to manufac-
turer's directions, making sure a stable reading is obtained.
5. Place the tared filter, with the reinforcing ring side up, in a
comparably sized petri dish.
6. It is recommended that each balance be assigned a block of filter numbers
to be used sequentially. Assign a filter ID number and take extreme care
to avoid duplication or missed numbers.
7. Legibly record the assigned filter number on the petri dish, leaving
sufficient room for one more letter designating size fraction [(F) for
fine or (C) for coarse] to be written following the number.
Suggestion; The operator may decide to include three additional digits
on the petri dish label to represent the tare weight of the filter (e.g.,
101, 99, 105, etc.). -
8. Record the balance number, the assigned filter number, and the tare
weight on the data/coding form (Figure 4.2). Number each form sequen-
tially in the upper right-hand corner.
9. Perform regular QC checks as detailed in Subsection 4.5.
10. Install the filter into a cassette, and return the filter/cassette
assembly to its. individual petri dish.
4.5 Internal QC
4.5.1 Operator QC -
After every fifth weighing, the operator should recheck the zero and calibra-
tion of the balance and record these check values on the Laboratory Internal
Quality Control Log (Figure 4.3). (The zero and 10-mg weight checks are internal
standards of the analytical balance.) Zero QC checks within 4 /*g of true zero and
calibration QC checks within 2 fig of 10 mg are acceptable. Larger discrepancies
should be corrected immediately. When QC checks are unacceptable, the previous
five filters must be reweighed. Any filter weight outside of the normal range of
80 to 110 mg must be investigated immediately.
Note; An electrostatic charge will prevent a microbalance from operating
properly. Static charge is the accumulation of electrical charges on the surface
-------
Section No.:
Date: April
Page: 5
2.10.4
11, 1990
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21
-------
Section No.: 2.10.4
Date: April 11, 1990
Page: 6
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-------
Section No.: 2.10.4
Date: April 11, 1990
Page: 7
of a non-conductive material. Common symptoms of this problem include noisy read-
out, drift, and sudden read-out shifts. To reduce static charge within the
ofn?""'^1 may- !?e necessary *° Place a radioactive ionizing unit (i.e., Polonium
210) in the weighing chamber. It may also be necessary to pass the filters over an
ionizing unit before they are weighed. For more information about static and how
to minimize its effects, see the.Technical Note, "Static Control for Balances "
prepared by Cahn Instruments, Inc.
4.5.2 Supervisory QC Procedures - .
1. Keep a bound QC notebook. These notebooks must contain all QC data
including the balance calibration and maintenance information, internal
routine QC checks, and independent audits. It is recommended that con-
trol charts be maintained on each balance and included in this notebook.
These charts may indicate any excess drift that could flag an instrument
malfunction.
all QC data on the Quality Control
fhp1™®91""1'!!9"-0?-^—1'9!!1'"? day' after the 0Perator has completed
the zeroing and calibration checks of the balances, tare weigh one
arbitrarily selected filter from a set of "standard" filters (10% of the
total number of filters to be weighed). Because these f Uteri represent
LSB J QC check do not use them for subsequent sampling. Thlse
weights must be repeatable for each balance to within 20 ug of the
original value. If not, the balance performance is unacceptable-
troubleshoot and reweigh the filters as necessary. If more than one
Jhi?n!£tI™-neSVhake -a-e ?hat the (iUer 1s we^hed on the same
that determined the original tare value. Unless this procedure is
adhered to, many samples may have to be invalidated.
Reweigh five to seven exposed and unexposed filters per balance each dav
of operation Weights should be within *20 /.g of origina? values? if
.not, troubleshoot and reweigh. Because of the loss of volatile
''
hv ?° I1'1"]'1? a1 -Set for exP°sed filters. Record all data on
the Quality Control Log Form and in the QC notebook.
5" th^ilL3^6^1']1^ 2t fl'iter wei9hts and data completeness daily on
the laboratory data/coding forms and initial. When bound these serve as
a laboratory notebook. Sign each completed form. -
4-5 Post-Sampling Documentation and Inspection
this p?ocedr!re:'Pt °f ^ Sample ^ the field< the Samp1e c^todian should follow
1. Examine the field data sheet. Determine whether all data needed to ver-
-------
Section No.: 2.10.4
Date: April 11, 1990
Page: 8
2. If the exposed filter was packaged for shipment, remove the filter from
its protective pertri dish and examine the petri dish. If sample mate-
rial has been dislodged from a filter, recover as much as possible by
brushing it from the petri dish onto the deposit on the filter with a
soft camel's-hair brush.
3. Match the filter ID number with the correct laboratory data/coding form
on which the original bal-ance ID number, filter ID number, filter tare
weight, and other information are inscribed. The sample custodian should
group filters according to their .recorded.balance ID numbers. Initial
separation of filters by balance ID number will decrease the probability
of a balance error that could result from the use of different balances
for tare and gross weights.
4. Remove the .filter from both the petri dish and the filter cassette. The
filters must be handled with clean, nonserrated forceps; they must not be
touched by the hands. Inspect the filters for any damage that may have
occurred during sampling. Reject the filter for mass concentration
determination or any additional analysis if defects are found.
5. Return filters with no defects to their original petri dish and forward
to the laboratory. File the data sheets for subsequent mass concentra-
tion calculations.
6. Return defective filters with the type of defect (or combination of de-
fects) to their original petri dish, labeled by defect type(s), and
submit to laboratory supervisor for final approval of filter validity.
4.7 Final Weighing Procedure (Gross Weight)
1. Group filters according to their recorded balance numbers. (Filters
should be separated initially by balance ID number; this will lower the
incidence of balance error that would occur if different balances were
used for tare arid gross weights.) Reweigh each filter on the same bal-
ance on which its tare weight was obtained.
2. . In an environmentally controlled area, open the petri dish, making cer-
tain that the lid (with the filter ID inscribed) is placed beneath the
bottom and that no mix-up occurs.
3. Cover the open petri dish with a clean laboratory paper towel and place
it in the conditioning environment. Allow the filter to equilibrate
according to procedures outlined in Subsection 4.3.
4. Repeat Steps 1 through 5 of the dichotomous filter tare weighing proce-
dure (Subsection 4.4).
5. Perform the internal QC checks described in Subsection 4.5 to ensure
validity of reweighing.
6. Record the indicated gross weight on the laboratory data/coding form.
-------
Section No.: 2.10.4
Date: April 11, 1990
Page: 9
7. If the dichotomous filter is not to receive additional analysis, place it
back into the corresponding petri dish. Deliver weighed filters to the
sample custodian for archiving.
8. If the filter is to receive further analysis, return it to the petri dish
and note on the petri dish what additional analyses are required. Place
an asterisk after the gross weight column on the laboratory data/coding
form to indicate that the filter requires additional analysis. Carefully
place each filter thus packaged in a box, and deliver to the sample
custodian who will forward it to the laboratory responsible for the
additional analysis.
4.8 Calculation of Net Mass Filter Loading
The gross weight minus the tare weight of a dichotomous filter is the net mass
of the particulate for that filter. Each calculation of this process must be inde-
pendently validated. Refer to Subsection 5 for information regarding the calcula-
tion of PM10 mass concentration.
-------
Section No.:
Date: April
Page: 10
2.10.4
11, 1990
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-------
Section No.: 2.10.5
Date: April 11, 1990
Page: 1
2.10.5 CALCULATIONS, VALIDATIONS, AND REPORTING OF PM10 DATA
Measurements of PM10 mass concentration in the atmosphere that are used to
determine attainment of the National Ambient Air Quality Standards for particulate
matter must be expressed in units of micrograms per standard cubic meter (ag/std
mJJ of air. For these measurements, "standard" means EPA-standard conditions of
temperature and pressure, which are 25 °C (298 K) and 760 mm Hg (101 kPa) respec-
K- y: J?IS sectlon Presents the calculations required to compute and report
ambient PM10 concentrations. A summary of all calculation formulas and associated
symbols presented in Section 2.10 is given in Table 5.1.
Particle size discrimination by inertia! separation requires that specific air
velocities be maintained in the sampler's air inlet system. These design veloc-
ities are obtained when a specified "design flow rate" is maintained. The design
flow rate is specified as an actual flow rate (TQa and CQa) , measured at existina
conditions of temperature (Ta) and pressure (Pa). *"urea ai existing
The sampler's operational flow rate (i.e., the actual flow rate when the
sampler is operating normally to collect a PM10 sample) should, of course be very
° '110" ' ^ ^?]er3 hav? Some means for
o erat on now ' * ^?er3 av? Some means for ^asuring the
?!? „ ?? h f ' J"J-t5a3,flow rate measurement system must be calibrated .
ically with a certified flow rate transfer standard. Usually measurements
. s
nt. temperature and b*™metric pressure are requred to gel
f n indication of the operational flow rate. . For determining the average
er flow rate .over a sample period, use of average temperature (Tav) and a-ver-
Pmnprr?m^rlCHPreSSUre (Pa^ °vr the Samp1e Period is recommended If averagf
elch samoH npHSH65^"6 Va1U6S (°P !Teasonab1e estimates) cannot be .obtained for
D?essureP PO fnr ;H. rr> ^^l 3Verage temPerature (Ts) and barometric
pressure (Ps) for the site may be substituted.
fmm ?V *"% ?f,\ reftd " '"9S ?** be recorded on-site or estimated from data obtained
station £? U^--Natlona1 Weather Service Forecast Office or airport weather
be It J;at?Sn n C pr?SSUre readin9S obtained from airports or other sources must
Ur
u
f (1'!-' "Ot corrected to- ^a level), and they may have to b
**"
corrtP n f ,
theliroort ?} {ndT^ ¥?**" 5"? elevat-ion of th* monitoring siteand that of
period and sea^nnll II » f "jj P'V readin9s cann°t be obtained for each sample
?aken that ?K Srf ?vjr 96S . the,S,!te are routinely substituted, care must be
taken that the actual temperature and barometric pressure at the site can be
may £ substituted for Tav, and Ps may be substituted for^ ?n Equations l] I,
-------
Section No.:
Date: April
Page: 2
2.10.5
11, 1990
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-------
Section No.: 2.10.5
Date: April 11, 1990
Page: 3
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-------
Section No.: 2.10.5
Date: April 11, 1990
Page: 4
5.1 Calculations
5.1.1 Flow-Rate Calculations -
The total and coarse flow rates are calculated by first averaging the
sampler's initial rotameter set points (TSP or CSP) and final indicated rotameter
responses (IF).
I = (TSP or CSP + IF)/2
(Eq. 10)
where
I s average total or coarse rotameter response, arbitrary units
TSP, CSP. = total or coarse rotameter set points, arbitrary units
IF * indicated final total.or coarse rotameter response, arbitrary
units. . J
These values are then applied to the sampler's total or coarse calibration rela-
tionship.
TQa or CQa = l/m[I(Tav/Pav)l/2 .
(Eq/5)
where
TQa, CQa = sampler total or coarse average flow rate, actual L/min
I - average total or coarse rotameter response, arbitrary units
Tav - average ambient temperature for the run day, K
Pav = average ambient pressure for the run day, mm Hg or kPa
slope of the total or coarse flow-rate calibration relationship
intercept of the total or coarse flow-rate calibration relation-
ship.
m
b
The average flow rates are then corrected to EPA reference standard conditions
by using Equation 13. Note: For the subsequent calculation of PM10 concentra-
tions, only the TQstd flow rate is considered.
TQstd or CQstd = [(TQa or CQa).(lQ-3)(Pav/Tav)(fstd/Pstd)] (Eq. 13)
where
TQstd or CQstd =
TQa or CQa =
10-3 s
Pav, Tav =
Tstd, Pstd =
total or coarse flow rate corrected to standard conditions
std. iTH/min
s.ampler total or coarse flow rate, actual L/min
conversion factor for L/min to m3/min
ambient barometric pressure, mm Hg, kPa; temperature K
standard temperature and pressure 25°C, 298 K, 760 mm Hg, or
1U1 kPd•
-------
Section No.:
Date: April
Page: 5
2.10.5
11, 1990
5.1.2 PM10 Concentrations Calculation -
The reporting of total PM10 mass concentration data requires the calculation
of the total volume of air sampled (Equation 14) and the computation for total mass
concentration (Equation 15).
V = (TQstd)t
(Eq. 14)
where
V =
TQstd =
t =
PM10 =
total sample volume in standard volume units, m3
total flow rate corrected to standard conditions (see Equation 13)
std. nwmin '
elapsed total sampling time, minutes.
(Mf + Mc)(lQ3)
TV)
(Eq. 15)
where
PM10 = mass concentration of PM10, /
-------
Section No.: 2.10.5
Date: April 11, 1990
Page: 6
2. Compute the total mass concentration of PM10 for seven samples per 100
(minimum of four per lot) as specified in Subsection 5. Y.I or 5.1.2.
These suggested starting frequencies may be altered, based on experience
and data quality. Decrease the frequency if past experience indicates
that data are of good quality, or increase it if data are of poor qual-
ity. It is more important to be sure that the validation check is repre-
sentative of the various conditions that may influence data quality than
to adhere to a fixed frequency. If calculation errors are found all
values in that sample lot should be recalculated.
3. Scan all total mass concentration values, note those that appear exces-
sively high or low, and investigate. Repeat Step 2 for these samples.
Compare validated PM10 concentration to the originally reported value.
Correct any errors that are found, initial them, and indicate the date of
correction.
4. If all mass concentration computations appear correct and questionably
high or low value(s) still exist, review all raw data (i.e., sample time
average actual total flow rate and 'its subsequent correction to standard'
conditions, and total net particle mass for coarse and fine filters) for
completeness and correctness.
5.3 Data Reporting
The primary standards for paniculate matter in the ambient air are based on
the measured mass concentration of -PM10. ' Information on reporting and interprets-'
Jrt°?rS BJ 9 data with respect to the-attainment of these standards is covered in
40 CFR 50, Appendix K.
5.4 Additional Calculations
This section outlines the procedures and computations necessary to calculate
c^n?fSS concentration for the fine and coarse particle fractions of a dichotomous
sample. The following calculations are not required to determine attainment of the
*ec?njar* standards; rather, they are supplemental and may not be neces-
- otomous sampler is designed to fractionate a total PM10 sample" into
?nS12e hra:9eS [Iine Par^cles <1ess tha" 2.5 jun) and coarse particles
r*ia- ? ^ ' ?f 9reater than 2.5 ^m)]. Note: A correction is required for
illustrated^ ^ P3rtl'CleS ComEted 0" the "'™ fil?er<
by Equation Concentrat1on of the fine part id e fraction as calculated
- Mf(lQ3)
'
-------
Section No.: 2.10.5
Date: April 11, 1990
Page: 7
where
[F] = mass concentration of fine particles, /
-------
-------
Section No.: 2.10.6
Date: April 11, 1990
Page: 1
2.10.6 MAINTENANCE
Preventive maintenance is defined as a program of positive actions aimed
toward preventing failure of monitoring and analytical systems. The overall objec-
tive of a routine preventive maintenance program is to increase measurement system
reliability and to provide for more complete data acquisition.
This subsection outlines general maintenance procedures for a specific commer-
cially available dichotomous sampler. For more complete information on a particu-
lar sampler, or on laboratory equipment maintenance, refer to the manufacturer's
instruction manual for the individual instrument.
Records should be maintained for the maintenance schedule of each dichotomous
sampler. Files should reflect the history of maintenance, including all replace-
ment parts, suppliers, cost- expenditures, and an inventory of on-hand spare equip-
ment for each sampler. H M F
6.1 Maintenance Procedures
6.1.1 Recommended Supplies for Maintenance Procedures -
An alcohol-based general -purpose cleaner, cotton swabs, a smaH soft-bristle
brush, paper towels, distilled water, and miscellaneous handtools are required
maintenance supplies for dichotomous samplers. A compressed-air source is recom-
mended-, but not .required.
6.1.2 Sampl ing Module - " - •
The sampling module of the dichotomous sampler consists of the sampler inlet
and the virtual imp-action assembly. Figure 6.1 shows, a disassembled sampling
sealed with "O^rin ll1ustrates the virtual impactor assembly. All parts are
NOT BE DISHANTLED- CHECK
To dismantle the sampler inlet:
Mark each assembly point of the samp-ler inlet with pen or pencil to pro-
vide "match marks" during reassembly.
• ' Disassemble the unit in accordance with manufacturer's instructions
taking care to retain all "0" rings and miscellaneous parts.
N£le: If the assembly screws, appear frozen, the application of penetrat
ing oil or commercial lubricant will make removal easier.
Clean all interior surfaces with the general-purpose cleaner or
• compressed-air source, paying particular attention to small openinqs and
crevices. Cotton swabs and/or a small brush would be most helpful in
these areas. Completely dry all components.
-------
Bug Screen
Lower Plate
with Rain
Deflector
Collector
Assembly
Section No.: 2.10.6
Date: April 11, 1990
Page: 2
Top Plate with
Deflector Cone
Pan Head Screw
Spacer
Acceleration
Assembly
O-Rings
Figure 6.1. Dichotomous sampler inlet.
-------
Section No.: 2.10.6
Date: April 11, 1990
Page: 3
Receiver
Nozzle Assembly
Coarse Tube
Fine Tube
Filter Cartridge
Fine Filter Holder
Bracket
O-Rlngs
Inlet Tube
Accelerator
Nozzle
0-Rings
Coarse Filter
Holder
Figure 6.2. Dlchotomous sampler virtual impactlon assembly.
-------
Section No.: 2.10.6
Date: April 11, 1990
Page: 4
• Reassemble the unit in accordance with the previously scribed match
marks. Take particular care to ensure that all "0" ring seals are
properly sealed and that all screws are uniformly tightened.
The "0" rings in the aerosol inlet should be removed periodically and
conditioned with vacuum grease. This will inhibit breakdown and fraying of the "0"
ring caused by friction on the inlet tube. The bug screen protecting the aerosol
sampler inlet should be cleaned periodically during the summer months. The bug
screen is exposed for cleaning by pulling the sampler inlet.off the receiver tube
assembly. An "0" ring in the sampler inlet acts as the seal. Many samplers are
equipped with an inlet that also has a primary water trap on the exterior of the
unit. If this trap is glass, care should be taken not to crack or break it, as the
sampler will not maintain adequate vacuum during operation. The glass -trap may
either be replaced with a plastic jar or wrapped with insulating tape to minimize
the danger of accidental breakage.
Virtual Impactor Assembly - Internal particulate deposits accumulate primarily on
the outer and inner surfaces of the tip (closest to sampler inlet) of the inlet
tube. Thus, the inlet tube should be inspected periodically for such particulate
deposits and cleaned as required. An inlet tube cleaning schedule of every 3 to 4.
months is typical; the remaining inner surfaces should be cleaned every 6 to 12
months. Use alcohol or water and a soft-bristle brush for cleaning.
' Examine sample module vacuum tubing periodically for crimps, cracks, or breaks
and replace as necessary. Examine connecting fittings for cross-threading, and
replace fittings if necessary.
6.1.3 Control Module
CAUTION: UNPLUG THE POWER CORD FROM ITS RECEPTACLE BEFORE REMOVING OR OPENING THE
FRONT PANEL OF THE DICHOTOMOUS CONTROL MODULE.
Control Module Cleaning Procedures -
1. Remove or open the front panel and blow out loose dust and dirt if com-
pressed air is available. Wipe down all surfaces with the general-pur-
pose cleaner and towels.
2. Make note of any obvious problems in the unit and take action to correct
them before completion of cleaning. Refer to the manufacturer's instruc-
tion manual.
3. Check rotameters for cleanliness. If they are dirty and/or contain
water, they must be removed and cleaned. (If water is found, the inter-
ior of the vacuum pump may be damaged. It should be opened for inspec-
tion and possible repair.) To clean the rotameters, take the following
steps:
-------
Section No.: 2.10.6
Date: April 11, 1990
Page: 5
• Remove the tubing from the total rotameter output port and any
other connecting tubing that may prove too inflexible to allow
removal of the rotameters.
Remove the screws securing the rotameter assembly to the front
panel. .
• Slip the assembly back from the front panel enough to gain
access to the Allen screws in the top of each rotameter and
remove the protective cover,
While holding the glass rotameter with one hand, loosen the
Allen screws just enough to allow removal of each of the gradu-
ated glass tubes.
Clean the two rotameters with an alcohol-based cleaner and
rinse thoroughly in distilled water. For proper cleaning of
the unit, the float and its retainers also' should be removed
The retainers are easily removed with the aid of a wire hook
fashioned from a paper clip.
Allow the tubes to' dry thoroughly and reassemble. •
4.. Remove and clean all filter jars. Check each for possible cracks
and replace if. necessary. Should a filter jar become cracked or '-
loosened, the dichptomous sampler will not maintain an adequate
vacuum during system leak tests. Be certain that each filter jar is
tightened and sealed properly. Clean or replace any dirty filter
elements. These elements may become dirty in routine operation or
• ™« samP'er 1S inadvertently energized without sample filters
installed.
5. Clean the cooling fan's blades an.d housing with compressed air or a
sma.ll brush. Check the housing for any dirt that could cause the
fan to lock up.
6. Clean exterior surfaces of the vacuum pump; be sure that all cooling
rhlrl 3n °Pen:- Tat6 Care that f1uids do not run inside the P"«np.
Check all mounting brackets to ensure that they are tight and in
good condition. . •
Vacuum Pump - It is recommended that the diaphragm and the flapper valves of
? rep1aC6d routine1y
-------
Section No.: 2.10.6
Date: April 11, 1990
Page: 6
the procedure, making sure that the screw clearance cavity in the.plate is
lined up under the intake valve screw heads. All head screws must be tight-
ened evenly. Diaphragms are often available through local suppliers or they
may be purchased through the manufacturer.
When all cleaning and routine maintenance operations have been 'completed,
close the control module, reassemble and connect the sample module, and recal-
ibrate the instrument (if necessary). Refer to Subsection 2 for calibration
procedures.
6.2 Refurbishment of Dichotompus Samplers
Dichotomous samplers that have been operated in the field for extended
periods may require major repairs or complete refurbishment. In these cases,
the manufacturer's instrument manual must be referred to before work is under-
taken. A dichotomous sampler that has been subject to major repairs or refur-
bishment must be leak-checked and calibrated prior to sample collection.
-------
Section No.: 2.10.7
Date: April 11, 1990
Page: 1
2.10.7 AUDITING PROCEDURES
The operating agency must perform QA audits and process evaluations to
determine the accuracy of the PM10 monitoring system and, hence, the data it
produces. The primary goal of an auditing program is to identify system errors
that may result in suspect or invalid data. The efficiency of the monitoring
system (i.e. labor input vs. valid data output) is contingent upon effective QA
activmes: This true assessment of the accuracy and efficiency of the PM10
guide'hnes: ** "" °"ly ^ achieved b* conducting an audit under the following
• Without special preparation or adjustment of the system to be audited.
By an individual with a thorough knowledge of the instrument or process
being evaluated, but not by the routine operator. process
rnmnt- . NIST-traceable transfer standards that are
completely independent of those used for routine calibration and QC flow
With complete documentation of audit information for submission to- the
operating agency. The audit -information includes, but is not limited to
nd 11'* tr™**r standards instrument rnoSe and '
t™"b'"ty,. calibration inflation,
estimates™?^ K??S£?ad"CHb?i in thi$ subsection produce two quantitative
estimates of a PM10 sampler's performance: the audit flow rate oercentaoe
oercenlace6 Tiffl^W f1°W rat* Percentage difference. ThI KdU flow rate
percentage, difference determines the accuracy of 'the sampler's indicated flow ratP
by comparing it with a flow rate from the audit transfer standard The des?on ??
SieiS?rJe3ta?e difference determines how closely t^sample^s ?iow rate mltche
the inlet design flow rate under normal operating conditions. matches
An independent observer should be present for the audit oreferablv thP
tSfJntecrufo0? ll^u^l^ ««uiP-?nt- This Practice not^nly'coni? utes to
he -6 *
Poscsso
discrepancies between audit-standard values and the lamPHngPequ!pmen"values[
di:fferences in flow rate (between audit flow and sampler
ling equipment malfunction or operator technique an
'
Flow-rate performance audit.
System audit of data processing.
-------
Section No.: 2.10.7
Date: April 11, 1990
Page: 2
Analytical process system evaluation.
These audits and evaluations are summarized in a table at the end of this
subsection (Table 7.1). Refer to Section 2.0.11 of this volume for detailed proce-
dures for systems audits.
Proper implementation of an auditing program serves a twofold purpose: to
ensure the integrity'of the data and to assess the accuracy of the data. Addition-
al information on assessing the accuracy of the data is given in Section 2.0.8 of
this volume of the Handbook.
7.1 Flow-Rate Performance Audit
The following subsection presents audit procedures specific to commercially
available dichotomous samplers which operate at an actual total flow of 16.7 L/min
and a coarse flow of 1.67 L/min. Audit techniques may vary between different
models of samplers due to differences in required flow rates and the sampler's
sampling configuration.
The dichotomous sampler flow rate audit method involves using two transfer
standards. One is calibrated in the flow range of the total and fine flow rates
and the second is calibrated within the range of the coarse flow rate. This
enables the auditor to measure the critical flow rates directly without compounding
transfer ..standard error through subtraction. Obviously, the optimum audit method
would incorporate one transfer standard calibrated over the entire range of the
sampler's accepted flow limits (1.5 L/min to 18.4 L/min). Accuracy over this flow
range is difficult to achieve within acceptable limits. Consequently, it is
recommended to conduct audits using transfer standards withrn -specific ranges to
measure the sampler's indicated flow rates. .
Since the accurate measurement of PM10 mass concentration is dependent upon
flow rates under actual conditions, the auditor must also audit in terms of actual
conditions. If the audit transfer standard's calibration data have been corrected
to EPA reference conditions (298 K, 760 mm Hg or 101 kPa), a conversion must be
calculated to adjust the standard L/min flow rate (Qstd) to an actual L/min flow
rate (Qa).
7.1.1 Audit Apparatus -
Any type of flow-rate transfer device acceptable for use in calibration of
dichotomous samplers may be used as the audit flow-rate reference standard; how-
ever, the audit standard must be a different device from the one used to calibrate
the sampler. The audit standard must be calibrated against a primary standard
traceable to the MIST. Refer to Subsection 2, Tables 2.1 and 2.2, which reference
flow-rate transfer standard calibration procedures. Assemble the audit apparatus
as indicated in Figures 7.1 through 7.3. In addition to that which is presented in
the tables, a few miscellaneous supplies are required. These include a 9.53-mm
(3/8-in.) Swagelok cap, 6.35-mm (1/4-in.) Swagelok cap, hand tools, and an adapter
to connect the transfer standard outlet to the sampler inlet.
-------
Section No.: 2.10.7
Date: April 11, 1990
Page: 3
Audit
Adaptive
Devic*
Chosen
Transfer
Standard
Coarse Row
0 0
Coarse
Flow
Rotameter
Total
Flow
Rotameter
Figure 7.1. Audit assembly and dlchotomous sampler
set up to audit total flow (TQa).
-------
Section No.:
Date: April
Page: 4
2.10.7
11, 1990
Audit
Adaptive •
Device
Chosen
Transfer
Standard
Coarse Flow
Disconnect 6.35 mm (1/4 In) O.D.
tubing and install Swagelok cap
Paniculate filter installed on
6.35 mm (1/4 In) O.D. tubing
= 00
Coarse
Flow
Rotameter
Total
Flow
Rotarneter
Figure 7.2. Audit assembly and dichotomous sampler
set up to audit fine flow (FQa).
-------
Section No.: 2.10.7
Date: April 11, 1990
Page: 5
Audit
Adaptive •
Device
Chosen
Transfer
Standard
Fine Row
Coarse Flow
Disconnect 9.53 mm (3/8 in) O.D,
tubing and install Swagelok cap
Paniculate filter installed on
9.53 mm (3/8) O.D. tubing
0 0
nrm
Coarse
Row
Rotameter
q Total
Row
Rotameter
Figure 7.3. Audit assembly and dichotomous sampler
set up to audit coarse flow (CQa).
-------
Section No.: 2.10.7
Date: April 11, 1990
Page: 6
An audit data sheet similar to Figure 7.4 must be used to document audit
information. This information includes, but is not limited to, sampler and audit
transfer standard type, model and serial numbers, transfer standard traceability
and calibration information, ambient temperature and pressure conditions, and
collected audit data.
7.1.2 Total Flow-Rate Audit Procedures -
1. Instruct the operator to install new filters .in both the fine and coarse
filter holders and energize the sampler. Filters used for flow rate
audits should not be used for sampling.
2. Instruct the operator to adjust the rotameter flow-control valves to set
the total and coarse rotameters to their operational set points for rou-
tine sampling. These set points should correspond to the calculated set
points (TSP, CSP) determined, by the sampler's calibration relationship.
3. Allow- the sampler to warm up for a minimum of 5 min while maintaining the
proper total and coarse rotameter set points.
4. Complete the top half of the data sheet with the required information,
including ambient temperature (Ta) and ambient barometric pressure (Pa).
Record both the TSP and CSP values and the corresponding flow rates.
5. Remove the sampler inlet and replace with the transfer standard adaptive
device (see Figure 2.1).
6. Connect the adapter to the transfer standard outlet with flexible tubing,
being careful not to crimp the tubing. If the transfer standard is elec-
tronic, it must equilibrate to operating conditions. A warmup time of at
least 5 min is recommended.
7. Recheck rotameter settings; if different from designated .set points,
record new value and the-corresponding flow rate as determined by the
sampler's calibration relationship.
8. Record on the audit data sheet the transfer standard (TS) readings
(volts, AH20, timings, etc.).
7.1.3 Fine Flow Rate Audit Procedures -
1. Turn the sampler off and disconnect the coarse-flow 6.53-mm (1/4-in.)
line. Cap the coarse-flow outlet port located beneath the dichotomous
sampler filter holder with a 6.53-mm (1/4-in.) Swagelok cap. This opens
the coarse line to the vacuum pump. To prevent particle entrapment
within the system, it is recommended that a particle-free filter be
attached to the line.
-------
Section No.: 2.10.7
Date: April 11, 1990
Page: 7
Dlcnotomous Sampler Audit Data Sheet
Station Location L&^f /L/£L natft ^ /// /£*? q * no A n M, ,mh nr *1 ^ ^ ^1-1 <&
Station Address /O / /O. f/5
3^
Transfer Standards Calibration Relationships:
Total and Rne: m . 23.
-------
Section No.: 2; 10-.7
Date: April 11, 1990
Page: 8
2. Turn the sampler on and check the rotameter set points. If variation has
occurred since the total flow rate audit, record the to'tal and coarse
rotameter units and their corresponding flow rate values determined from
the sampler's calibration. A small flow imbalance occurs when the coarse
line is disconnected; this may cause rotameter fluctuations.
3. Record on the audit data sheet the transfer standard (TS) readings
(volts, AH20, timings, etc.).
7.1.4 Coarse Flow Rate Audit Procedures -
1. Turn the sampler off and exchange the total and fine flow rate transfer
standard for the coarse flow transfer standard. If necessary, allow this
transfer standard to equilibrate to ambient conditions (at least 5 min).
2. Reconnect the coarse flow line and disconnect the fine flow 9.53-mm (3/8-
in.) line. Cap the fine flow outlet port located beneath the dichotomous
sampler filter holders with a 9.53-mm (3/8-in.) Swage'lok cap. This opens
the fine line to the vacuum pump. To prevent particle entrapment within
the system, it is recommended that a particle-free filter be attached to
the line.
3. Turn the sampler on and check rotameter set points. If variation has
-occurred since'the total flow rate audit, record the total and coarse
rotameter units and their corresponding flow rate.values determined from
the sampler's calibration. A small flow imbalance occurs when the fine
line is disconnected; this may cause rotameter fluctuations.
4. Record on the audit data sheet the transfer standard (TS) readings
(volts, AH20, timings, etc.).
7.1.5 Audit Data Calculations -
1. Calculate and record the audit total, fine, and coarse flow rates by.
using the calibration curve accompanying the transfer standard. Record
these values to the nearest 0.01 L/min (e.g., 1.67 L/min) on the audit
data sheet.
Note; It may be necessary to correct audit flow rates to actual condi-
tions1. If a1 soap film flowmeter has been used to determine the coarse
flow rate, no water .vapor corrections are necessary for this audit flow.
Qa = Qstd(Ta/Pa) (Pstd/Tstd)
(Eq: 1)
where
Pstd,
Qa
Qstd
Ta
Pa
Tstd
flow rate at actual conditions, L/min
flow rate corrected to standard temperature and pressure (25
298 K; 760 mm Hg or 101 kPa), L/min
ambient temperature, K
ambient barometric pressure, mm Hg or kPa
standard barometric pressure and temperature, respectively.
'C,
-------
Section No.: 2.10.7
Date: April 11, 1990
Page: 9
2. Instruct the operator to calculate (using the sampler's calibration rela-
tionship) the corresponding sampler flow rates and record.
3. Determine the percentage difference between the sampler-indicated flow
rates and the audit-measured flow rates as:
% Difference = ^^(Ldi?) ^-1 (100) (Eq. 18)
b*tween the sa*Pler <«'*» flow rates
% Difference = Qa (audit) - Design flow rate
Design flow rate (EQ- 19)
T?T?:| /m?n I"?** C^m?c ^'fhotomous samplers, the design flow rates are
conditions. ' /min ( ine)> and K67 L/min (coarse) at actual
5' ^°rJhSerCenf diff?r;nce: If the deference is less than or equal to
rp ,Slrr,oali •KatJr. the audit should be
7-1-5 Performance Audit Frequency -
7.2 Systems Audit
procedures to evaluate data processing anS labo^tory operations " SyStem$ 3Udlt
-------
Section No.: 2.10.7
Date: April 11, 1990
Page: 10
Subsections 2.0.11 and 2.0.12 of this volume provide detailed procedures and
forms for systems audits and performance audits, respectively.
7.2.1 Systems Audit of Data Processing -
It is recommended that data processing be audited soon after the original
calculations have been performed. This allows corrections to be made immediately
and also allows for possible retrieval of additional explanatory data from field
personnel when necessary. A minimum frequency of seven samples per 100 (minimum of
four per lot) is recommended. The procedure is as follows:
1. Use the operational flow rates as reported on the-sample data sheets.
2. Beginning with the raw data on the dichotomous sample data sheet and the
filter net- and tare weights, independently compute the concentration
(^g/std. m3) and compare it with the corresponding concentration origin-
ally reported. If the mass concentration computed by the audit check
(/jg/std. m^) does not agree with the original value within round-off
error, recheck all samples in the lot.
3. Record the audit values on a data sheet, and report them, along with the
original values, to the supervisor for review. The audit value is always
..given as the correct value based on the assumption that a discrepancy
between the two values is always double-checked by the auditor.
7.2.2 Analytical Process System Evaluation - .
A performance audit of the microbalances used to weigh dichotomous filters
would require the use of ASTH Class 1 standard weights. Since microbalances are
extremely delicate instruments and should not be operated by inexperienced person-
nel, it is recommended that the performance evaluation of the filter weighing proc-
ess be done in the following manner:
1. Review the maintenance and calibration log for each balance. Routine
balance maintenance and calibrations must be performed by the manufactur-
er's service representative at manufacturer-specified scheduled inter-
vals. In no case should the interval between calibrations exceed 1 year.
2. Review QC data records for the filter-weighing process. Ensure that the
following QC activities have been performed and documented:
• Zero and calibration checks after every five filter weighings.
• Standard filter weighing every day of the balance operation.
• Duplicate filter weighing for every five to seven filters.
If QC checks were out of limits, note what action was taken.
-------
Section No.: 2.10.7
Date: April 11, 1990
Page: 11
Select randomly and have the balance operator reweigh four equili-
brated filters out of every group of 50 or less. For groups of 50
to 100, reweigh 7 from each group. It is of primary Importance to
be sure that the sample is representative of the various conditions
that may influence data quality.
Record the original values and the audit weights on the audit form.
, Calculate the weight difference for each filter as follows:
Difference = Original weight (mg) - Audit weight (mg)
For unexposed filters, the difference should be less than ±20 itg (0.020
h?b,:t< JrreTSed/fl ter-' *?? P°tentl'a1 loss °f volatile particles pro-
Sltl to .H Pf KCe/rejeCt1°n limits to be established. Forward the aSdit
data to the laboratory supervisor for review.
-------
Section No.: 2.10.7
Date: April 11, 1990
Page: 12
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-------
Section No.: 2.10.8
Date: April 11, 1990
Page: 1
2.10.8 ASSESSMENT OF MONITORING DATA FOR PRECISION AND ACCURACY
8.1 Precision
One or more monitoring sites within the reporting organization are selected
tor duplicate collocated sampling as follows: for a network of 1 to 5 sites 1
site is selected; for a network of 6 to 20 sites, 2 sites are selected; and for a
network of more than 20 sites, 3 sites are selected. Where possible, additional-
collocated sampling is encouraged. Annual mean particulate matter concentrations
of the selected sites should be among the highest 25% of the annual mean PM10
concentrations for all the sites in the network. If such sites are impractical
however, alternate sites approved by the Regional Administrator may be selected!
aii K0l12CaJed PM1° samPlers bein9 "sed for assessment of precision should gener-
ally be of the same type. That is, they should have similar flow rates (e q
c^iJ^r"1' orj°?!' similar inlet types (e.g., impaction or cyclonic), and'
—"i- flow controller types (e.g., MFC or rotameters). Where a PM10 network
anar+Tl!e tw° Allocated samplers must be within 4 m of each other, but at least 2 m
bS tL LJTS dK f;r f ?W intrference' Calibration, sampling, and analysis must
on. nf K 01- b°Jh C? 10Cated samP1ers and all other samplers in the network.
wh?c£ «JSuEai-i?fhCOll°Saied 5amplerS is desi9nated as the primary sampler from
SJ2 If?^8/'1] ! US6d ?° rep°rt ai> qualit>' for the site; the other is desig-
nated as the duplicate sampler. Each duplicate sampler must be operated concur-
^^1^5 ^ associated routine sampler at least once a week. The operation
the tlr !n2 ^tJ61?^6*1 S0,that the ™m?]^ **** *™ distributed evenly oJer
the year and over the 7 days .of the week. The every-6th-day schedule used by many
Si o? J3 a9en^es is recommended. The measurements from both samplers at each *
• rP-lin9 l^* *£ reP°rted. An example precision data reporting form is
? hTre 8;J- Jhe P?^centa9e differences in measured concentrations
8.2 Accuracy
asseJJrf h!;C^MH5t<0f l^ dl'c5otomous sampler method in the measurement of PM10 is
assessed by auditing .the performance of the sampler (at its. specified flow rate) as
flow'ate are'renortlS" ' ?1 ^ ^ 3Udit ^-"te and the corresponding samp er
F cure 8 2 Thfnlrrit, H^6 accuracy data reporting form is presented in
c u acyT 6i \f ^ll
-------
Section No.:
Date: April
Page: 2
2.10.8
11, 1990
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Section No.: 2.10.8
Date: April 11, 1990
Page: 3
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-------
Section No.: 2.10.9
Date: April 11, 1990
Page: 1
2.10.9 RECOMMENDED STANDARDS FOR ESTABLISHING TRACEABILITY
Two factors are essential for attainment of data of the desired quality:
(1) the measurement process must be under statistical control at the time of the
measurement, and (2 the combination of systematic errors and random variation
^measurement errors) must yield a suitably small uncertainty. Evidence of qood
quality data requires the performance of QC checks, independent audits of the meas-
urement process, careful documentation of data, and the use of equipment and
instrumentation that can be traced to an appropriate primary standlrd
The following standards are recommended for establishing tr-aceability:
ASTtt Class 1 weights are recommended for the laboratory microbalance
checks3 ' Subsection 4.5 for details on balance calibration
2. A positive-displacement primary"standard or laminar flow element is
recomi;,endedflfoLcalibrating_the_f;ow-rate transfer standard that is used
?hS tit <~ flacement primary standard is recommended for calibrating
the transfer standard used to audit the dichotomous flow-rate calibra-
- ' audits. Subsectlon 7A for details on the flow-rate performance
4. The elapsed-time meter should be checked semiannuaHy against an accurate
timepiece, and it must be accurate within 15 min/day. accurate
5' barometeVf^toV^^ (i'6" then?onieterf•
and against standards of known accuracy and traceable toVsT.
3
-------
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-------
Addendum to Section 2.11
Reference Method for the Determination of Paniculate Matter as PM10
in the Atmosphere (High-Volume PM10 Sampler Method)
This section is up-to-date except that brushless motors are now available
for high-volume PM10 samplers. According to their vendors, these
motors have a maintenance-free operational life of 20,000 hours. Also,
the blank data forms that are mentioned in. this section have been
removed.
-------
-------
SECTION 2.11
Part1cuute Hatter
pmo
Sub-
section
0
0
2
3
4
5
6
7
8
10
11
12
Outline
Title
Introduction
Method Highlights
Procurement of Equipment and
Supplies
Calibration Procedures
'Field Operations
Filter Preparation and Analysis
Calculations, Validations, and
Reporting of PM10 Data
Maintenance
Auditing Procedures
Assessment of Monitoring Data
for Precision and Accuracy
Recommended Standards for
Establishing Traceability
Reference Method
References
Data Forms
Full Section
Number
2.11.0
2.11.0
2.11.1
2.11.2
2.11.3
2.11.4
2.11.5
2.11.6
2.11.7
2.11.8
2.11.9
2.11.10
2.11.11
2.11.12
No. of
pages
6
2
5
30
31
10
10
5
19
1
5
1
16
Printed on Recycled Paper
-------
-------
Section No.: 2.11.0
Date: January 1990
Page: 1
2.11.0. INTRODUCTION
ao™H PM10.1S *he designation for particulate matter in the atmosphere that has an
aerodynamic diameter of 10 micrometers (H or less. A high-volume (HV) PM10 sam-
^"t-^5-3!^0^/^""16 uf ambient air at a constant flow rate through a size-
selective inlet and through one or more filters. Particles in the PM10 size ranae
?£h SJlS^u"1 °" th- ri*ris) dun'ng the 5Pecif^d 24-hour samp ?ng peri o?9
Each samp e filter is weighed before and after sampling to determine the net weioht
(mass) gain of the collected PM10 sample. The referent method™? PM10 slmpTinq
nFqUlatinnS(4° CFR 5° Aendi 11"9
.ii,
computed as the total mass of collected particles in the PM10 size ?angfdiv ded bv
s isrs
tiveness) of the sampler inlet over the PM10 size range. Of particularP moortlnce
is the^particle size at which the sampler effectiveness is 50 percent (i e ?he
SS inS «S1Ze SUt|?01nt)- Methods for PM1° that »eet all requirements n'both
50 and 53 are designated as PM10 reference methods for use in State and Lorll
Monitoring System (SLAMS) and Prevention of Significant olterioraJion (PSD) m
f^urer I^lhf^f ol T^ ™
are discussed in this section; dichotomous sampled are discussed in Section
-------
Section No.: 2.11.0
Date: January 1990
Page: 2
Impaction Inlet
Figure 0.1 is a schematic drawing showing the basic elements of an impaction
HV PM10 inlet. The symmetrical design of the inlet insures wind-direction insensi-
tivity. Ambient air that is drawn into the inlet is evacuated from the buffer
chamber through nine acceleration nozzles into the first impaction chamber, where
"Initial particle separation occurs. The air is then accelerated through an addi-
.tional 16 jets into a second impaction chamber. The acceleration jets have criti-
cal diameters calculated by the manufacturer to provide the necessary changes in
velocity to effect correct particle size fractionation within the impaction cham-
bers. The air flow finally exits the inlet through nine vent tubes onto a sample
fiHer. Because air velocities are critical to maintain the correct particle size
cutpoint within the inlet, maintaining the correct design flow rate through the
inlet is important. This design flow rate is specified by the manufacturer in the
instruction manual. For example, the design flow rate for one popular impaction
inlet is 1.13 m3/min. <
Cyclonic Inlet
Figure 0.2 is a schematic drawing of a cyclonic HV PM10 inlet. The omnidirec-
tional cyclone used for fractionation in this inlet allows particles to enter from
a>TT angles of approach. Ah angular velocity component is imparted to the sample
aitr stream and the particles contained in it by a series of evenly spaced vanes.
Lsirger particle removal occurs in an inner collection tube. This tube incorporates
a "'perfect absorber"--an oil-coated surface to eliminate particle bounce and reen-
trainment. The sample flow (with the unremoved smaller particles) then enters an
frrtermediate tube, where the trajectory is altered to an upward direction. An
additional turn is then made to alter the flow to a downward trajectory to allow
the remaining particles (i.e., PM10 fraction) ultimately to deposit on a filter for
subsequent analysis. As with the impaction inlet, control of air velocities in the
cyclonic inlet is critical to maintain the correct particle size cutpoint. Main-
taining the correct design volumetric flow rate through the inlet is important.
"WHs design flow rate is specified by the manufacturer in the instruction manual.
For example, as in the case of the impaction inlet, a popular cyclonic inlet also
Iras, a design flow rate of 1.13 m^/min.
Wass-Flow-Control'(MFC) System
The flow rate in a MFC system is actively sensed and controlled at some prede-
termined set point. Air is .pulled through the filter into the intake of a blower
and? subsequently exits the sampler through an exit orifice, which facilitates meas-
urement of the flow with a manometer or pressure recorder. The flow rate is con-
troTled by an electronic mass-flow controller, which uses a flow sensor installed
below the filter holder to monitor the mass flow rate and to control the speed of
the-motor accordingly. The controlled flow rate can be changed by an adjustment
knob on the flow controller.
Vtolumetric-Flow-Control (VFC) System
A VFC system maintains a constant volumetric flow rate (given a fixed tempera-
ture) through the inlet, rather than a constant mass flow rate as in the MFC
-------
Section No.: 2.11.0
Date: January 1990
Page: 3
Buffer Chamber
Air Flow
Acceleration Nozzle
Impaction Chamber
Acceleration Nozzle
Impaction Chamber
Vent Tubes
Filter Cassette
Fitter
Rlter Support Screen
Motor Inlet
Figure 0.1. Schematic diagram of an impaction inlet.
-------
Section No.: 2.11.0
Date: January 1990
Page: 4
Maintenance Access Port
Perfect
Absorber
No-Bounce
Surface
Housing-Deflector
Spacing
Vanes
Wane
Assembly
Base
Insect
Screen
Protective
Housing
Aerodynamic
Inlet
Pathway
Aerodynamic Flow
Deflector
Outer Tube
Figure 0.2. Schematic diagram of a cyclonic inlet.
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Section No.: 2.11.0
Date: January 1990
Page: 5
system. In a popular commercial VFC system, a choked-flow venturi is operated such
that the air attains sonic velocity in the throat of the device. In this "choked"
mode, the flow rate is unaffected by downstream conditions such as motor speed or
exit pressure, and is a predictable function of upstream conditions, such as the
stagnation pressure ratio and temperature. Thus, the volumetric flow is controlled
without any moving parts or electronic components. In this type of flow control
system, ,no means is provided for adjusting the controlled flow rate.
-------
Section No.: 2.11.0
Date: January 1990
Page: 6
METHOD HIGHLIGHTS
The procedures set forth in this document are designed to serve as guidelines
for the development of quality assurance (QA) programs associated with the opera-
tion of an HV PM10 sampler. Because recordkeeping is a critical part of QA activi-
ties, several data forms are included to aid in the .documentation of data. The
blank data forms (see Subsection 12) may be used as they are, or they may serve as
guidelines for preparing forms more specific to the needs of the individual moni-
toring agency. Partially filled-in forms are included at appropriate places in the
discussion of the procedures to illustrate their uses.
Tables at the end of some subsections summarize the material covered in those
subsections. The material covered in the various subsections of this section is
summarized here:
1. Subsection 1, Procurement of Equipment.and Supplies, includes recommended
procurement procedures, equipment selection criteria, and minimum accu-
racy requirements. It also provides an example of a permanent pro-
curement record.
2. Subsection 2, Calibration Procedures, provides detailed calibration
procedures for the HV PM10 sampler. A table at the end of this subsec-
tion summarizes acceptance limits and gives references for the calibra-
tion procedures of associated monitoring equipment used in a PM10 sam-
pling program.
3. Subsection 3, Field Operations, provides detailed procedures for filter
installation and recovery, sample handling, and data documentation. It
also includes procedures for the field flow-rate calibration check.
Complete documentation of background information during sampling is one
of several QA activities important to future data validation; particular-
ly important information are any unusual conditions that existed during
sample collection. Such conditions should be noted.
4. Subsection 4, Filter Preparation and Analysis, presents important consid-
erations for the handling, .integrity, identification, equilibration, and
weighing of filters. A high-quality microquartz filter is recommended.
Subsection 4 also briefly describes minimum laboratory quality control
(QC) procedures. "The analytical balance must be calibrated annually and
the filters must be equilibrated in a controlled environment.
5. Subsection 5, Calculations, Validations, and Reporting of PM10 Data
presents calculations for determining PM10 mass concentrations and mini-
mum data validation requirements. The final data review and validation
including standardized reporting procedures, are all important parts of'a
QA program. Independent checks of the data and calculations are required
to ensure that the reported data are both accurate and precise.
6. Subsection 6, Maintenance, recommends periodic maintenance schedules to
ensure that the equipment is capable of performing as specified The
objective of a routine maintenance program is to increase measurement
system reliability.
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Section No.: 2.11.0
Date: January 1990
Page: 7
7. Subsection 7, Auditing Procedures, presents independent audit activities
that provide performance checks of flow-rate measurements and data pro-
cessing. An analytical process evaluation and a system audit checklist
are also provided. Independent audits evaluate data validity.
8. Subsection 8, Assessment of Monitoring Data for Precision and Accuracy
describes the assessment procedures for determining the accuracy and
precision of the data. The precision check is performed by using collo-
cated samplers. . y
9. Subsection 9, Recommended Standards for Establishing Traceability dis-
CxSu<:Vthe traceability of calibration equipment to established standards
of higher accuracy. Such traceability is a prerequisite for obtainina
accurate data. s
10.. Subsections 10 and 11 contain the PM10 Reference Method and pertinent
references used to prepare this document. Subsection 12 provides blank
data forms for the convenience of the user.
-------
-------
Section No.: 2.11.1
Date: January 1990
Page:. 1
2.11.1 PROCUREMENT OF EQUIPMENT AND SUPPLIES
The establishment of an ambient PM10 air monitoring network requires the pro-
curement of specialized equipment and supplies for field operations and subsequent
filter analysis. Information in this section has been provided to assist the agen-
cy in selecting the proper equipment. Subsection ,1.1 presents minimum sampling
equipment necessary to conduct field operations. Recommended laboratory instrumen-
tation is presented in Subsection 1.2.
In addition to field operations and laboratory equipment, a data-handling
system (including forms, logs, files, and reporting procedures) must be developed
and implemented. Sample blank data sheets are presented in Subsection 12.
It is recommended that each agency establish minimum monitoring equipment
requirements and budgetary limits before the procurement procedures are initiated.
Upon receipt of the sampling equipment and supplies, appropriate procurement checks
should be conducted.to determine their acceptability, and whether they are accepted
or rejected should be recorded in a procurement log. Figure 1.1, which is an exam-
ple of such a log, will serve as a permanent record for procurements and provide
fiscal projections for future programs. It will also help to provide a continuity
of equipment and supplies. Table 1.1, at the end of the subsection, lists the
major equipment needed, how it should be tested, suggested acceptance limits, and
actions to be taken if acceptance limits are not met;
1-1 Procurement Prerequisites—Field Operations
I'l.l HV PM1Q Samplers - An individual sampler must meet U.S. EPA operational
standards and be a model designated as a reference or equivalent method. A com-
plete listing of minimum sampler requirements (i.e., 40 CFR 50, Appendix J) is
reproduced in Subsection 10. Those HV PM10 samplers not designated as reference or
equivalent methods may not be used for reporting data to determine attainment of
the National Ambient Air Quality Standards (NAAQS) for particulate matter. The
cost of HV PM10 samplers will vary by manufacturer and the options chosen (i.e.
continuous flow recorder, timer).
An in-house inventory of general maintenance supplies and replacement parts is
recommended. These include various handtools; faceplate, motor, and filter cas-
sette gaskets; genera.l all-purpose cleaner; penetrating oil;-distilled water- Kim-
wipes (or equivalent); soft brush; and cotton swabs. Spare parts for the sampler
may be supplied by the manufacturer/ or many of them may be purchased locally.
1-1-2 Calibration Equipment - Calibration activities require specialized equipment
that will not necessarily be used in routine monitoring. At a minimum, the follow-
ing equipment is required.
A thermometer capable of accurately measuring ambient temperatures to the
nearest ±1°C and referenced to a National Institute of Standards and
Technology (MIST) or an American Society for Testing Materials (ASTM)
thermometer within ±2°C (NIST is the former National Bureau of Standards
[NBSJ) .
-------
Section No.: 2.11.1
Date: January 1990
Page: 2
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-------
Section No.: 2.11.1
Date: January 1990
Page: 3
A barometer capable of accurately measuring barometric pressure over a
range of 500 to 800 mm Hg (66 to 106 kPa) to the nearest millimeter of Hg
and referenced at least annually to a standard of known accuracy within
±5 mm Hg. For laboratory measurements, a Fort in- type, mercury-column
barometer is appropriate. For field measurements, a portable, aneroid
barometer (e.g., a climber's, or engineer's altimeter) is appropriate.
pFH«« s*andard (e;9" toP'hat orifice, variable orifice, or
!n n5 Si™* capable of accurately measuring the operational flow rate of
an HV PM10 sampler at actual conditions. The transfer standard calibra-
^°nw^T r°nSh^? mus* be refere"ced annually and be within ±2 percent of
the NIST-traceable .primary standard.. n^v-cnt
Water or oil manometer(s). with a 0- to 400-mm H20 (0- to 16-in ) ranae
ta±an™nTm Sca1e.div^°n of 2 mm (0.1 in.)/ The VFC sampler calfbra-
fonn K6oUlrn T'"™6- a ue£?nd oil or water "noneter with a 0- to
J ™"?S ?2° (?~ t0 36"in' H20) range and with a minimum scale division of
* ecorderrrmf,rrpnrtS fKth^SaTp1er is ^^^ "ith a continuous-flow
recorder), miscellaneous handtools, and 51 -mm (2-in.) duct tape.
lio^of^he^y'pm^J6'!'06 " A ^flow-check device is required for routine opera-
tion of the HV PMio sampler; a calibrated orifice transfer standard is recommended.
tionshio andfhp6r^naMfer/tandarJ TUSt have an NIST-traceable calibration rela-
1 24 m3/n,?S ?hS ?!r h^i ^.accur?^!y measuring volumetric flows between 1.02 and
n *2 percent of the N?^? lr* re^tlon!hlP must ^ referenced annually and be with-
'
r* w-
ThiS °-'fi« transfer stand-
1.1.4 Audit Equipment - The equipment needed for auditing is similar to the cali-
^"frsriiEni %^^x
l'2 Procurement Prerequisites— Laboratory Operation';
ter type selected! reSenS aS1C Cnteria that muSt be met gardless of he fil-
-------
Section No.: 2.11.1
Date: January 1990
Page: 4
1.2.2 Filter Protection - Post-sampling particle loss and filter damage will occur
if proper handling procedures are not followed. Filter cassettes are recommended
for sampling with most HV PM10 samplers. These may be purchased through the HV
PM10 sampler's manufacturer. A sufficient number of cassettes must be purchased to
allow insertion and removal of the filters in the laboratory. For storage of
exposed filters, however, cassettes may prove to be expensive and unwieldy.
For assurance of the integrity of the exposed filter during handling and stor-
age, some type of protective covering is required; a manila folder in a protective
envelope is recommended. The folder and envelope should be of comparable size
(large enough to allow easy removal of the filter, yet small enough to prevent
excess movement within the envelope) and be sealed to preclude damage or loss of
particles during transportation to the analytical laboratory. The folder can be
printed to serve as a data sheet for proper documentation during sampling. A suf-
ficient number of protective envelopes must be available to provide protection for
the filters during transportation to and from the monitoring location and for stor-
age of the exposed filters for subsequent gravimetric or chemical analysis.
1.2.3 Laboratory Equipment - The analytical balance must be suitable for weighing
the type and size of HV PM10 filters used. The range and sensitivity depend on
routine tare weights and expected loadings. The balance must be calibrated at
installation and recalibrated at least once a year, as specified by the manufac-
turer.
Prior, to their weighing, filters must be conditioned in an environment where
the mean relative humidity (RH) is between 20 and 45 percent and controlled within
±5 percent, and mean temperature is between 15' and 30°C and controlled within
±3'C. Temperature and RH readings must be recorded daily, either manually or by
hygrothermograph. Among the options available to ensure compliance with the refer-
ence nethod specifications are a sling psychrometer and a calibrated precision
thermometer (capable of measuring temperatures over a range of 10° to 30°C [283 to
303 K] to the nearest ±1°C) that has been checked against an NIST or ASTM thermome-
ter to within ±2*C.
It is impossible to present a complete procurement package that would provide
for unexpected contingencies in any monitoring network. Each agency must determine
the extent of its in-house inventory and the items that should be ordered before
sampling can begin. The agency must also be prepared to order any additional
equipment required over and above that outlined in this subsection.
-------
Section No.: 2.11.1
Date: January 1990
Page: 5
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Section No.: 2.11.2
Date: January 1990
Page: 1
2.11.2 CALIBRATION PROCEDURES
Before a PM10 monitoring program commences, it is essential to properly cali
brate all sampling and laboratory equipment. Calibration is defined as the rela-
tionship between an instrumental output and the input of a known reference stand-
ard. Data that .are traceable to common reference standards are more uniform in
character and more readily comparable than data that are not traceable. Because
PM10 concentration standards are not available for determining calibration rela-
tionships, individual components of the sampling method must be calibrated to
ensure the integrity of -reported data.
"Like a TSP sampler, an HV PM10 sampler is essentially a device that pulls a
sample of ambient air through a filter during a measured time period and collects
particulate mass on the filter. Thus, to establish ambient PM10 concentrations
three independent determinations are made: air volume flow rate, sampling time
and particulate mass. The objective of this subsection is to provide technically
sound flow-rate calibration procedures for both the MFC and VFC HV PM10 samplers.
Note: Calibration procedures for samplers that have been designated as reference
methods will also be provided by the manufacturer in the operation or instruction
manual. These manufacturer-provided calibration procedures are likely to be more
specific and detailed than the more generic procedures presented herein. Also
minimum calibration requirements for the determination of particulate mass and'
sample- time are presented in a table at the end of this subsection (Table 2.1).
Although it concerns TSP samplers rather than HV PM10 samplers, Reference 3
provides useful information concerning flow-rate-calibration procedures that is
applicable to PM10 samplers. Reference 4 provides useful information concerning
positive-displacement, standard volume meters (e.g., RootsR Meters).
The following aspects of PM10 monitoring are discussed in this subsection:
2.1 A discussion of volumetric and mass flow measurements and their applic
ability in a PM10 monitoring program. ,
2.2 A certification procedure for an orifice flow-rate transfer standard.
2.3 Basic calibration procedure specific to an MFC HV PM10 sampler.
2.4 Basic calibration procedure specific to a VFC HV PM10 sampler.
2.5 Calibration frequency requirements.
2'1' aVh! en
-------
Section No.: 2.11.2
Date: January 1990
Page: 2
(but do not mix the two units). Take care to avoid calibrating a PM10.sampler
using one set of units and then performing sample calculations using another set of
units.
2.1 Discussion of Flow-Rate Measurement and General Aspects
of PM10 Sampler Calibration
An HV PM10 sampler consists of two basic components: a specially designed
jnlet and a flow-rate controlling system. The particle size discrimination charac-
teristics of both the impaction and cyclonic type inlets depend critically on main-
taining certain air velocities within the inlet; a change in velocity will result
'in a change in the nominal particle size collected. For this reason, it is impera-
tive that the flow rate through the inlet be maintained at a constant value that is
as close as possible to the inlet's design flow rate. The design flow rate for a
given sampler is specified in the sampler's instruction manual. The manual may
also provide tolerance limits (or upper and lower limits) within which the sampler
flow must be maintained. If the tolerance is not specified by the manufacturer, it
should be assumed to be ±10 percent. For example, if the design flow rate is spec-
ified as 1.13 m^/min with no tolerance given, the acceptable flow-rate range would
be 1.02 to 1.24 m3/min.
As indicated above, the true or" actual flow rate through the sampler inlet
must be known and controlled to ensure that only those particles nominally less
than 10 /p-are being collected. A common source of error in a PM10 monitoring
program is confusion of various atr volume flow-rate measurement units. Although
the sampler's operational flow rate must be monitored in terms of actual volume
flow rate units (Qa), sampler flow rates must be corrected to standard volume flow
rate units (Qstd) at EPA standard conditions of temperature and pressure to calcu-
late PH10 concentrations as required by EPA. Thus", both Qa and Qstd flow rates are
used for PM10 measurements. Before calibration procedures are initiated, the oper-
ating agency personnel should review the following flow-rate measurement designa-
tions:
• Qa; Actual volumetric air flow rates, measured and expressed at existing
conditions of temperature and pressure and denoted by Qa (Qactual).
Typical units are L/min and m3/min. Inlet design flow rates are always •
given in actual volumetric flow rate units.
• Qstd: Air flow rates that have been corrected to equivalent standard
volume flow rates at EPA standard conditions of temperature and pressure
(25 °C or 298 K and 760 mm Hg or 101 kPa) and denoted by Qstd (Qstand-
ard). Typical units are std. L/min and std. m3/min. Standard volume
flow-rate units are often used by engineers and scientists because they
are equivalent to mass flow units. Standard volumes (derived from stand-
ard volume flow rates) are required for the calculation of PM10 mass
concentration (/*g/std. m3) in reporting PM10 measurements.
These Qa and Qstd measurement units must not be confused or interchanged. The
flow rate units can be converted as follows, provided the existing temperature and
pressure (or in some cases the average temperature and pressure over a sampling
period) are known:
-------
Section No.: 2.11.2
Date: January 1990
Page: 3
Qstd = Qa(Pa/Pstd)(Tstd/Ta) (Eq< ^
Qstd = Qa(Pav/Pstd)(Tstd/Tav) (Eq. la)
Qa = Qstd(Pstd/Pa)(Ta/Tstd) (Eq< 2)
where:
= standard volume flow rate, std. m3/min
= actual volume flow rate, actual m3/min
= ambient barometric pressure, mm Hg (or kPa)
= cnA sfan
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Section No.: 2.11.2
Date: January 1990
Page: 4
•
set of fixed resistance plates (e.g., a reference flow [ReF] device or a top-hat
orifice), and the other with an externally variable resistance valve. The series
of plates normally provided by the orifice manufacturer includes an 18-, 13-, 10-,
7-, and 5-hole plate. Unfortunately, the 5-hole plate provides too low a flow rate
to be useful for HV PM10 calibration, and other plates may produce flow rates sub-
stantially outside the design flow-rate range of the commercially available HV PM10
inlets. Agencies may opt to fabricate or procure a different series of resistance
plates that will provide more flow rates within the sampler's .design flow-rate
range or use the variable-resi'stance type orifice device.
2.2.1 Orifice Calibration Procedure -
1. Assemble the following equipment:
• Orifice transfer standard (i.e., top-hat orifice, variable orifice,
or ReF device) to be calibrated.
• Water or oil manometer with a 0- to 400-mm (0- to 16-in.) range and
minimum scale divisions of 2 mm (0.1 in.). This manometer should be
permanently associated with the orifice transfer standard.
• Variable voltage transformer (or a set of resistance plates, if a
variable voltage transformer is not available).
'*• Calibrated positive displacement, standard volume meter (such as a
Roots'* Meter) traceable to the National Institute of Standards and
Technology (NIST).
Note: As they are sold, standard volume meters may not be traceable
to NIST. Traceability can be established directly through NIST or
indirectly through the meter manufacturer's repair department. Peri-
odic recertification is not normally required under clean service
conditions unless the meter has been damaged and must be repaired.
In general, damage will be indicated by a substantial (e.g., 50-per-
cent) increase in the pressure drop across the meter. The meter's .
traceability certificate should contain a graph of the pressure drop
as a function of flow rate. See Reference 4 for additional informa-
tion concerning standard volume meters.
• High-volume air mover (e.g., a blower motor from a HV sampler).
• Accurate stopwatch.
• Mercury manometer, with a 0- to 200-mm (0- to 8-in.) range and
minimum scale divisions of 2 mm (0.1 in.).
• Thermometer, capable of accurately measuring temperatures over the
range of 0 to 50 8C (273 to 323 K) to the nearest ±1 °C and referenc-
ed.to an NIST or American Society for Testing and Materials (ASTM)
thermometer within ±2 °C at least annually. .
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Section No.: 2.11.2
Date: January 1990
Page: 5
Barometer, capable of accurately measuring ambient barometric ores-
r " °f 500. to 800 mm Hg (66 to 106 kPa) to Jhe'nl r-
°f
«»"«•" in
2' Sir °n -5* "rt^ication worksheet the .standard volume meter's serial
number; orifice transfer standard's type, model, and serial numb'er- 5-
person performing the certification; and the date. numoer, tne
3. Observe the barometric pressure and record it as Pa.
8.
,.
O. v.iici_* Lndr rnp <;r amiar-ri v/ninina ,„«*_- faklp •?«• 1 i j j •
7' fl"d (os'Jtd SnrtJKr;C1»fij51.nA£'!ll,™?-t"- !1»« «0 avoid
for-!?n9er than 30 s at a time with
eceockehi,n -
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Section No.: 2.11.2
Date: January 1990
Page: 6
ORIFICE TRANSFER STANDARD CERTIFICATION WORKSHEET
Date: 7/ZZ./ ^^ Roots meter S/N: 7Y6V3/ £ Ta: 2.2. l M/m}' Qa = IUH2O (Ta/Pa)l": - b! i1/m!
•NOTE For PM10 monitoring, a calibration curve corrected to standard conditions is optional
Figure 2.1. Example Orifice Transfer Standard Certification Worksheet.
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Section No.: 2.11.2
Date: January 1990
Page: 7
7pm v and mercury.^nometers by sliding their scales so that their
zero hnes are even with the bottom of the meniscuses.
variable resistance valve t ach eve 'the appro
10. After setting a flow rate, allow the system to run for at least 1 min tn
'"0-- •
'
^lume meter (AVol.) using
AVol. = Final Volume - Initial Volume (Eq. 3)
14. Correct- this volume to ambient atmospheric pressure.
Va =. AVol. (Pa - AHg)/Pa (Eq> 4)
where:
V°]Ume at ambient barometric pressure m3
a ambiet"? Z T^^ by the Standard ^™* ^ter, m3
ambient barometric pressure during calibration, mm iig .(or
AHg = differential pressure at inlet to volume meter, mm Hg (or
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Section No.: 2.11.2
Date: January 1990
Page: 8
15. Calculate the actual volumetric flow rate (m3/min).
Qa - Va/ATime (Eq. 5)
where:
Qa = actual volumetric flow rate through the orifice, m3/min
\ya = artnai vnlump at ambient barometric oressure, nH
Va s actual volume at ambient barometric pressure,
ATime s elapsed time, min. •• - •
16. Repeat Steps-9 through 15 for at least four additional flow rates within
the approximate range of 0.9 to 1.3 m3/min (32 to 46 ft*/min). At least
five evenly distributed different flow rates are required, and at least
three flow rates must be in the specified inlet flow-rate interval [1.02
to 1.24 m3/min (36 to 44 ft3/nrin)J. Better calibration precision may be
obtained by running additional flow rates or repeating the flow rates.
17. For each flow, compute [(AH20)(Ta/Pa)]1/2, and plot these values against
the corresponding values of Qa. Draw the orifice transfer standard's
certification curve. For the model [(AH2<))(Ta/Pa)]l/^ = m(Qa) + b, cal-
culate the linear least squares regression's slope (m), intercept (b),
and correlation coefficient (r) of the certification relationship. Plot
the regression line on the same graph as the calibration data. A certi-
fication graph should be readable to 0.02 m3/min.
v
18. If any calibration point does not fall within ±2 percent of the line,
rerun that point, recalculate, and replot.
19. For subsequent use of the orifice transfer standard, calculate Qa from
the calibration-relationship as:
Qa(orifice) - {[(AH20)(Ta/Pa)]l/2 . b} {1/m} (Eq. 6)
where:
Qa(orifice) = actual' volumetric flow rate as indicated by the orifice
transfer standard, m3/min
AH20 = pressure drop across the orifice, mm (or in.) H?0
Ta = ambient temperature during use, K (K = °C + 273)
Pa = ambient barometric pressure during, use, mm Hg (or kPa)
b = intercept of the orifice calibration relationship
m = slope of the orifice calibration relationship.
2.2.2 Orifice Transfer Standard Calibration Frequency -
Upon receipt and at 1-yr intervals, the calibration of the orifice transfer
Standard should be certified with a standard volume meter (such as a RootsR Meter)
traceable to NIST. An orifice transfer standard should be visually inspected for
signs of damage before each use, and should be recalibrated if the. inspection re-
veals any nicks or dents.
-------
Section No.: 2.11.2
Date: January 1990
Page: 9
2-3 Basic Calibration Procedure for a Mass-Flow-Controlled
. (MFC) Sampler Using an Orifice Transfer Standard
The MFC sampler calibration procedure presented in this subsection relates
arpW3ptP^n^eh t0 the Pressure in the exit orifice plenum. The known flow rates
are determined by an orifice transfer standard that has been certified according to
>resented in Section ? 9 1 THQ ovi+ -,_<*,•„„ ..i . ... 3
2'2'1' The ex1t orifice P^num is the area
wthn hpmt.- ''' e Pnum s e area
within the motor housing (below the motor unit) that contains the air flow just
° a" "
exit orifice. It is recom-
wter^r^iT^nnSiJ1 '"H" ^""u PreSSure 6e measured W1"th a 25,cm (10-in??
ifl Ln H^- man°meter- I* 1S further recommended that each sampler should have
HLi*r hone?! nianometer, which can be conveniently mounted to the side of the
?heS have romn?;,h?ther types of Pressure measurement devices may be used provided
they have comparable accuracy. However, the 4-in. continuous pressure (flow)
accurate ^ °1 ten,suPP1ied ^th HV PM10 samplers are generally not suffi-
*nt Th ff recommended for quantitative sampler pressure or flow
Thft^?he fl°W !?as aPPrpxinjately constant and uninterrupted over the sarnie
The flow recorder may be connected in parallel with the manometer or othpr
pressure measuring device, using a tee or »Y» tSbing connection man°meter Or other
Not§; Because 'flow recorders are still in wide use for Quantitative finw
iE1?^£iTrSSS%^^^
For this MFC calibration procedure, the following conditions are assumed:
samp
The sampler flow rate is measured by measuring the exit orifice plenum
pressure, using a water or oil manometer [or, if necessary a coEtfnuous-
flow recording device using square-root-scale chart paperj! C0ntinuou$-
r^tP n-f i n
-------
Section No.: 2.11.2
Date: January 1990
Page: 10 g^
2.3.1 Calibration Equipment -
1. Orifice transfer standard with calibration traceable to NIST (see Subsec-
tion 2.2).
Note; The predrilled resistance plates that are supplied with the ori-
TTce transfer standard may have to be modified for the calibration of
PM10 samplers. The holes in the plates may have to be enlarged or addi-
tional holes may have to be drilled to obtain flow rates within the
acceptable range. Alternately, new resistance plates could be purchased
if they are available.
2. An associated water or oil manometer, with a 0- to 400-mrn (0- to 16-in.)
range and a minimum scale division of 2 mm (0.1 in.).
3. A water or oil manometer, with a 0- to 200-mrn (0- to 8-in.) range and a
minimum scale division of 2 mm (0.1 in.) for measurement of the sampler
exit orifice plenum pressure. This manometer should be associated with
the sampler.
Note: Manometers used for field calibration may be subject to damage or
malfunction and should thus be checked frequently.
4. 'Thermometer, capable of accurately measuring temperature over the range
of 0 to 50 °C (273 to 323 K) to the nearest ±1 °C and referenced to an
NIST or ASTM thermometer within ±2 °C at least annually.
5. A portable aneroid barometer (e.g., a climber's or engineer's altimeter)
capable of accurately measuring ambient barometric pressure over the
range of 500 to 800 mm Hg (66 to 106 kPa) to the nearest mm Hg and refer-
enced within ±5 mm Hg of a barometer of known accuracy at least annually.
6. Miscellaneous handtools, calibration data sheets or station log book, and
51-mm (2-in.) duct tape.
2.3.2 Multipoint Flow-Rate Calibration Procedure - MFC Sampler -
The procedure presented here is basic and generic, given the assumptions list-'
ed in Subsection 2.3. There may be more detailed calibration procedures, varia-
tions, or alternative calibration procedures presented in the manufacturer's in- .
struction manual^. It is recommended that the manual be reviewed carefully-and that
the various calibration variations or alternative procedures be evaluated. In-
house equipment and personnel, procedural simplicity and uniformity, and subsequent
data applications should be considered in establishing the specific, detailed cali-
bration procedure to be implemented.
Caution; Do not attempt to calibrate the MFC sampler under windy conditions.
Short-term wind velocity fluctuations will produce variable pressure readings by
the orifice transfer standard's manometer. The calibration will be less precise
because of the pressure variations. -
-------
3.
Section No.: 2.11.2
Date: January 1990-
Page: 11
• 2*2 iflllj^ji^ri^Vr*? " reSommended fay the manufacturer. Figure
- i.2 illustrates th
stalledP
2. into a
22 il . u
i.2 illustrates the calibration configuration of a typical MFC samoler
P 3re Calibrated without a filter or filte? cassette in-
Disconnect the motor from the flow controller and plug it directly i
stable line voltage source (.i.e., the sampler's on-off timer if so
equipped, or other source of the line vojtage).
Install the orifice transfer standard and its adapter faceolate on th*
sampler. Check all gaskets .and replace any questionable oKes .
Caution: Tighten the faceplate nuts evenly on alternate corners to
perTyjlign and seat the gaskets. The nuts should be onlj hand-t^
because too much compression can damage the sealing gasket. ll9
5f]?cl'th? f!r!t Ca1i5ration fl°w rate and install the appropriate
resistance plate or adjust the variable orifice valve. At least four
flow, rates are required to define the calibration relationship
fl°W r/teS Sh°uld be within (°r near1y within) the accent
^ •?"""•£ - ™ -- «« a^:T£
fceple re in Pla" and ^riflce is not cross-threaded on the
' La '' ] ^ '" ™th * 1ar9e-diameter rubber stopper wide
" '
^6 Samp1fr for.;°n9er than 30 s at a time with
-------
Section No.: 2.11.2
Date: January 1990
Page: 12
a.
o-
«
_o
S
.a
"5
u
"a.
a
m
03
-------
Section No.: 2.11.2
Date: January 1990
Page: 13
6. Inspect the connecting tubing of both manometers for crimps or cracks.
Open the manometer valves (if present) and blow gently through the tub-
ing, watching for the free flow of the fluid.
Adjust the manometers' sliding scales so that their zero lines are at the
bottom of the meniscuses. Connect the orifice transfer standard manome-
ter to the orifice transfer standard. Connect the sampler's exit orifice
manometer [and the continuous-flow recorder, if used] to the exit orifice
plenum port. Ensure that one side of each manometer is open to atmos-
- pheric pressure. Make sure that the tubing fits snugly on the pressure
ports and on the manometer.
7. [If a continuous flow recorder is to be used quantitatively in lieu of a
manometer, record the site location, sampler S/N, date, and the opera-
tor s initials on the blank side of a clean recorder chart. Make sure
the chart has a square-root scale. Open the front door of the sampler
and install the clean recorder chart.]
8. Read and record the following parameters on the HV PM10 data sheet.
Figure 2.3 presents an example calibration data sheet'for the MFC sampler
(blank forms appear in Subsection 12).
Date, location, and operator's signature.
Sampler S/N and model. , . •
Ambient barometric pressure (Pa), mm Hg or kPa.
Ambient temperature (Ta), K (K = °C + 273).
Orifice S/N and calibration relationship.
Note: Consistency of temperature and barometric pressure units is
required. It is recommended that all temperatures be expressed in kelvin
in » t + Ml). It is also recommended that all barometric pressures be
expressed in either mm Hg or kPa (but do not mix the two units) Take
care to avoid calibrating a PM1.0 sampler using one set of units and then
performing sample calculations using another set of units.
Note: Ideally, the temperature of the air in the exit orifice plenum
should be measured because it will be somewhat higher than ambient tem-
5Sra-rS*K H°!^er\an adec*uate approximation of this temperature may be
obtained by adding 30 K to the ambient temperature. This addition is
incorporated in the calculations given in Subsection 2.3.3.
9. Turn on the sampler and allow it to warm up to operating temperature (3 •
!°A^!;.,I?en:,,r"land..r!"rd the orifice transfer standard's manome-
rs manome-
deflPrt nn*1^' A?2° £"• H20)' and the "^Ponding sampler's manometer
deflection, APex [or flow recorder chart reading, I]!
may ^ Partia11y l«*red over the orifice
prtH>
orov ded) !£rj M ^ VS 3 ^ Shield (if a Shield 1s not otherwise
provTded). Use a block to provTde at least 2 in. of clearance at the
bottom for air flow and for the manometer tubing. tiearance tne
-------
Section No.: 2.11.2
Date: January 1990
Page: 14
MFC SAMPLER CALIBRATION DATA SHEET
Station Loa
Sampler Me
Pa _76,
Orifice S/N
Orifice calib
Plate
Number
/
*•
Z-
3
<-f-
5
*tinn /ty /£.
vtel ^^
^fnmHg, 1
' mm Hg, T
-2L.
ration relations
Total AH2O
(In.)
?.3-7-_.7C/^,.. , , _ _,_.
s* * » / °C .,*?(•;• / K, ('seafional average Ta and Pa)
Orifice Calibration Date 7/2-2^/
1 ' ' f Sampler so* point (SSP) ^t- ^ ^—<
SSP » [Pa/CTa + 30)] [m(SFR) + b]2
or SSP « [Pa/(Ta + SO)]'* [m(SFR) + b] for flow
recorders
Figure 2.3. Example MFC sampler calibration data sheet.
-------
Section No.: 2.11.2
Date: January 1990
Page: 15
10. Install the other resistance plates or adjust the variable orifice value
to obtain each of the other calibration flow rates and repeat Step 9 for
each. At least four calibration flow rates are required, with at least
three in- the acceptable flow-rate range (i.e., 1.02 to 1.24 m3/min).
11. Plot the calibration data on a sheet of graph paper as specified in
'Step 4 of the next subsection.
Note,5 .The data should be plotted in. the fie.ld as the calibration is
occurring, rather than afterwards back at the laboratory.
Step V?r any data that are questionable on the plot. Running
additional calibration points at differing flow rates or repeating the
calibration points at the same flow rates is encouraged to improve the
precision of the calibration.
12. Turn off the sampler and remove the orifice transfer standard.
13. Reconnect the sampler motor to the flow controller.
14. Perform the calibration calculations presented in the following subsec-
- KMh^J-6 f! 9enerated V111 be used to set the mass flow controller
h*~H nn ?£ ] *? 3 V3lue that wil1 reSMlt in °Ptim-al volumetric flow
Dased on the seasonal average temperature and barometric pressure at the
monitoring site.
2.3.3 Calibration Calculations -
jf^^ f11 the cal ibration data, including the orifice calibration
the sampler calibration data sheet, [and, if used the flow recorder
chart, which should graphically display the various calibration flow rates]
rather^n I!?!6 Ca^u1ations should be done at the time of the calibration,
t^.n -f ?• • ™1S aPProach wl11 allow additional calibration points to be
taken if questions arise about the data that have already been obtained
l' rnrilnt^^ ?* °riVCe transfer standard calibrati-on relationship is
current and traceable to an acceptable primary standard.
th...Hf1c.-c.H-
Qa(orifice) = {[4H20(Ta/Pa)]l/2 . b} {1/m} ' (Eq. 6)
where:
Qa(orifice) = actual volumetric flow rate as indicated by the trans-
fer standard, orifice, nP/min
-------
Section No.: 2.11.2
Date: January 1990
Page: 16
AH^O = pressure drop across the orifice, mm (or in.) H?0
Ta = ambient temperature during use, K (K « °C + 273J
Pa - ambient barometric pressure during use, mm Hg (or kPa)
b - intercept of the orifice calibration relationship
m - slope of the orifice calibration relationship.
3. Calculate and record the quantity APext for each calibration point as:
APext = [APex(Ta+30)/Pa]!/2 (Eq.. 7)
where: •
APext s transformed manometer reading
APex = sampler manometer reading, mm (or in.) H20
Ta = ambient temperature, K (K = °C + 273)
Pa = ambient barometric pressure, mm Hg (or kPa).
[If a continuous-flow recorder is used quantitatively, calculate and
record the quantity It as follows:
It = I[(Ta+30)/Pa]l/2 (Eq. 7a)
where:
It = transformed flow recorder chart reading
I ~ flow recorder chart reading, arbitrary units on square root
scale.]
Note; If recorder charts with linear scales are used, substitute (1)1/2
for I in Equation 7a.
4. On a sheet of graph paper, plot the calculated Qa(orifice) flow rates on
the x-axis vs. the transformed sampler manometer response, APext [or the
transformed flow recorder reading, It] on the y-axis.
Because the determination of the sampler's average operational flow rate
(Qa) during a sample period depends on the ambient average temperature
and pressure, use of a graphic plot of the calibration relationship is
not recommended for subsequent data reduct-ion. This plot is used only to
visually assess the calibration points to see if any should be rerun.
Plot the regression line on the same graph paper as the calibration data.
For the regression model y = mx + b, let y = APext and x = Qa(orifice-) so
that the model is given by:
APext = m[Qa(orifice)] + b (Eq. 8)
[For the flow recorder,"the model is:
It-= m[Qa(orifice)] + b (Eq. 8a)]
-------
Section No.: 2,11.2
Date: January 1990
Page: 17
Using a programmable calculator or a calculation data form, determine the
i? JlHre9reS51;!! Sl°Pe '-intercePt (b), and correlation coefficient
(r) and record them on the data sheet. A five-point calibration should
yield a regression equation with a correlation coefficient of r > 0 990
with no point deviating more than ±0.04 m3/min from the value predicted
S^eth2rEr?Le9IJI*1^- iP1°Mthe Cession line on .the sS£ grjph
paper that has the individual calibration points.
5' nl^^fr* -amp1? Pfriods- the sampler's average actual operational
us'nglquat?^ 9? ^ *"" *"* Ca1ibration *^* ™* Intercept*1
Qi = {[APe7(Tav+30)/Pav]1/2 -. b) {1/m} (Eq. 9)
where:
= the sampler's average actual .flow rate, m3/min
= ^P^Vlo^'wl1 and final sampler manometer readings,
(APexi + APexf)/2, mm (or in.) H20
= |verage ambient temperature for the sample period, K (K = «C +
Pav = average ambient pressure for the sample period mm Ha (or kPa)
b = intercept of the sampler calibration relationshiT
m = slope of the sampler calibration relationship. '•
[For the flow recorder, ' ' - '
Qi = {T[(Tav+30)/PaV]1/2-.b} {1/m} (Eq. 9a)
where:
• I - average flow recorder reading for the sample period..]
2'3'4 Hass Flow Controller Adjustment Procedure -
'
seasonal aveVa/^e^^'^^ ^ V£s j??^ «% "»P«t to the
!^ta? ^ir&*] ™ »^ "°^TII
t (* » .
volumetric flow rate his at ?s and Js "aSS """ "te " the inlet desi9"
-------
Section No.: 2.11.2
Date: January 1990
Page: 18
Note; The correct SFR thus may be different from day to day and may be some-
what higher or lower than the inlet design flow rate on any particular day.
Set the mass flow controller as follows:
1. Determine the seasonal average temperature (Ts) and seasonal average
pressure (Ps) at the site and record them on the calibration data sheet.
(Determination of the number of "seasons," i.e., the number of different
seasonal average temperatures needed for the year, is left to the
discretion of the local agency.)
2. Calculate SFR and record on the calibration data sheet:
SFR = (1.13) (Ps/.Pa)(Ta/Ts) (Eq. 10)
where:
SFR = set-point actual volumetric flow rate for adjustment of the
mass .flow controller, based on seasonal average temperature
and average pressure at site, m^/min
1.13 = inlet design flow rate (as specified by the manufacturer),
nH/min
Ps, Pa = seasonal average and current ambient barometric pressure at
the site, respectively, mm Hg (or kPa)
Ts, Ta = seasonal average and current ambient temperature, respec-
tively, K (K = °C + 273). . '
3. Calculate arid record on the sampler's calibration data sheet the sampler-
set-point manometer reading [or flow recorder reading] that corresponds
to the SFR calculated in Step 2.
SSP = [Pa/(Ta + 30)][m(SFR) + b]2 (Eq. 11)
where:
SSP = sampler set-point manometer reading, mm (or in.) H20
Pa = ambient barometric pressure, mm Hg (or kPa)
Ta = ambient temperature, K (K = °C + 273)
m = slope of the sampler's calibration relationship
SFR = set-point flow rate from Equation 10, -m^/nrin
b = intercept of the sampler's calibration relationship.
[For the flow recorder,
SSP = [m(SFR) + b] [Pa/(Ta+30)]l/2 (Eq. lla)]
4. Visually check to make sure the motor is connected to the mass flow con-
troller and the manometer is properly connected.
5. Install a clean filter (in a filter cassette) in the sampler according to
'the manufacturer's instructions.
-------
Section No.: 2.11.2
Date: January 1990
Page: 19
[If the continuous flow recorder is used quantitatively, install a clean
chart and verify that the recorder is zeroed (i.e., the pen rests on the
innermost circle of the chart).]
6. Turn on the sampler and allow it to warm up to operating temperature (3
to 5 min).
7. Following the manufacturer's instructions, adjust the mass flow control-
ler until the manometer reading [or flow recorder response] indicates th<=
sampler.set point (SSP) as calculated in Step 3.
8.. Verify..that the flow controller will maintain this flow rate for at least
10 mm. Turn off the sampler.
9. The sampler can now be prepared for the next sample run day.
2-4 Basic Calibration Procedure for a Volumetric-Flow-Controlled
(VFC) Sampler Using an Orifice Device~
The VFC sampler calibration procedure presented in "this subsection relates
known flow rates (Qa, as determined by an orifice transfer standard) to the ratio
of the stagnation pressure to the ambient barometric pressure (Pi/Pa). The stagna-
tion pressure (PI) is the air pressure inside the sampler in the area just under
ine Ti-ner. VFC samplers have a stagnation pressure tap or port throuqh" which the
stagnation pressure'can. be measured. A VFC sampler may also have an exit orifice
r!t»Wrn ?HmKt0r S1mil*r *« th?s* in MFC samplers. In this case, the sampler flow
rate could be measured and calibrated using the exit orifice plenum pressure as
described in Subsection 2.3. However, the use of the stagnation pressurl generally
provides a more accurate indication of sampler flow rate. Additionally, a cSnfinu-
ous-flow recorder may.be connected to the exit orifice pressure tap for nonquanti-
samjle perioT" ^ fl°W rate W3S constant and uninterrupted over the
innn Jt /n reco!Fmeride-d that the stagnation pressure be measured with a 0- to
manrWo ?" ?+ • 2*'*?11 Or water manometer (to avoid the hazards of a mercury
manometer). It is further recommended that each sampler have its own dedicated
Other Jvn;,WnfCnrLan conveniently mounted to the side of the sampler housing.
Utner types of pressure measurement instruments, may be used provided thev have
comparable accuracy. However, the 4-in. continuous pressure (T.I flow) recorders
often s-upplied with HV PM10 samplers are generally not sufficientW accurate and
are not recommended for quantitative sampler pressure or flow memlasurements ..
nror,Ihe VFC seer's flow control system is a choked-flow venturi. It must be
precisely sized for a given average annual temperature and pressure because no
puarchasinqPrace cl L^not^f *?„adjustfthe operational flow'rate Ih^refore, the
J^nif 3-?? y " °tlfy the man"facturer of the operational location of the
the monjtorinali?rmlv rpf?ratUre a"d Pressure between the shipping address and
MFC samoler it wi?! h. n In f" ^ncorrect operational flow rate! As with the
MFC sampler, it will be necessary to determine or estimate both the ambient
-------
Section No.: 2.11.2
Date: January 1990
Page: 20
temperature and barometric pressure readings during the sample period for the
subsequent calculation of total sample volume in standard volume units.
For this VFC calibration procedure, the following conditions are assumed:
• The VFC sampler uses a choked-flow venturi to control the actual volumet-
ric flow rate.
• The sampler flow rate is measured by measuring the stagnation pressure
ratio, and the sampler is not equipped with a continuous flow recorder.
• The sampler inlet is designed to operate at a constant actual volumetric
flow rate of 1.13 m^/min, and the acceptable flow-rate range is ±10 per-
cent of this value.
• The transfer standard for the flow-rate calibration is an orifice device
equipped with either a series-of resistance plates or an integral
variable-resistance valve. The pressure drop across the orifice is meas-
ured by an associated water or oil manometer.
• The sampler will be calibrated in actual volumetric flow-rate units (Qa),
and the orifice transfer standard is also calibrated in Qa, as specified
in Subsection 2.2;
2.4.1 Calibration Equipment -
1. Orifice transfer .standard with proper calibration traceable to NIST (see
Subsection 2.2).
Note; The predrilled resistance plates that are supplied with the ori-
fice transfer standard may have to be modified for the calibration of
PM10 samplers. The holes in the plates may have to-be enlarged or addi-
tional holes may have to be drilled to obtain flow rates within the
acceptable range. Alternatively, new resistance plates could be pur-
chased if they are available.
2. An associated water or oil manometer, with a 0- to 400-mm (0- to 16-in.)
range and minimum scale divisions of 2 mm (0.1 in.) for measurement of
transfer standard pressure.
3. An oil or water manometer, -with a 0- to 1000-mm (0- to 36-in.) range and
minimum scale divisions of 2 mm (0/1 in.) or other pressure measurement
device for measurement of the sampler stagnation pressure. Ideally, this
manometer (or other pressure instrument) should be associated with the
sampler.
Note: Manometers used for field calibration may be subject to damage or
malfunction and should thus be checked frequently.
4. Thermometer, capable of accurately measuring temperature over the range
of 0 to 50 °C (273 to 323 K) to the nearest ±1 °C and referenced to an
NIST or ASTM thermometer within ±2 °C at least annually.
-------
Section No.: 2.11.2
Date: January 1990
Page: 21
5. A Portable aneroid barometer (e.g., a climber's or engineer's altime-
ter), capable of accurately measuring ambient barometric pressure over
±H°f >£° t0c8°° r HQ (65 t0 106 kPa) to the near*st ™ Hg and
mm 9 t0 3 barometer of known accuracy at least
b°°k and S1'm (2-in.)-wide
7. A clean filter.
2'4-2 Mu^Point Flow-Rate Calibration Procedure - VFC Sampler - '
, or alternative calibration procedures sted in the
iS rec°^ndedP that
-procedure to be implemented
blower motors that are intended for use in HV TSP samplers
reSommended by the manufacturer. Figure
n
Step 8 ' ler may e aPPr°P^'ate, as discussed in
----- - -^
only, too much compression can damage the sealing gasket.
-------
Section No.: 2.11.1
Date: January 1990
Page: 22
(MOO mm H2O
Manometer
(0-16 in.)
Resistance Plates
18 13 10 7
0-1000 mm H2O
Manometer
{0-36 in.)
APstg
JL
Stagnation
Pressure
Port
Calibration Orifice
Orifice Adaptor Plate
Rlter Paper
Cartridge/Cassette
Figure 2.4. Calibration assembly of the VFC sampler.
-------
Section No.: 2.11.2
Date: January 1990
Page: 23
3. Select a calibration flow rate and install the appropriate resistance
plate (or no plate) or adjust the variable resistance valve. At least
four flow rates are required to define the calibration relationship. At
least three flow rates should be within the acceptable flow-rate range
(i.e., 1.02 to 1.24 nP/min) for the sampler inlet. For resistance plate
orifices, make sure the orifice and resistance plate gaskets are in place
and the orifice is not cross-threaded on the faceplate.
4. .Leak Test: Block the orifice with a large-diameter rubber stopper wide
duct tape, or other suitable means. Seal both orifice and stagnation
pressure ports with rubber caps or similar devices. Turn on the sampler.
Cautjon: Avoid running the sampler for longer than 30 s at a time with
the orifice blocked. This precaution will reduce the chance that the
motor will be overheated due to the lack of cooling air. Such overheat-
ing can shorten the motor's lifetime. It can raise temperatures to the
point of defeating the electrical insulation, which could result in fire
or electric shock to the -user.
Gently rock the orifice transfer standard and listen for a whistling
sound that would indicate a leak in the system. Leaks are usually caused
H e^ La ^ama9?d or ^ssing gasket between the orifice transfer stand-
^H nn*I % ? ?te or bycrossthreading of the orifice transfer stand-
•^ ^ taueplate' A11 leaks must be eliminated before proceeding
with the calibration. When the system is determined to be leak-free
turn, off the sampler and unblock the orifice.
Note: The leak test procedure that is described above is one of many
alternate procedures which may be used. Operating agencies may develop-
their own procedures. p
5. Aspect the connecting tubing of the manometers for crimps or cracks
Open the manometer valves (if present) and blow gently through the tub-
• ing, watching for the free flow of the fluid:
bottnm ^e.J|anometers' sliding scales so that their zero lines are at the
transfer sSndW 5TJS' fCt the transfer standard manometer to the
;™c standard and the sampler stagnation- pressure manometer (or other
?fde of Mrh Snt! t0-the Sta9nation Pressure port. Ensure that one
tubina fifJ '« T *JS °Pen t0 atmc?5Pheric Pressure. Make sure the.
tubing fits snugly on the pressure ports and on the manometers.
6" n eC°rd te followin? Parameters on the VFC Sampler Data Sheet.
Date, location, and operator's signature
Sampler S/N and model.
-------
Section No.: 2.11.2
Date: January 1990
Page: 24
VFC SAMPLER CALIBRATION DATA SHEET
Station Location Gr-t-
•
\
(
I
Sampler M
Pa 7^
Orifice S/N
Orifice Cat
Plate
,No.
Notf£\
/^
'3
/&
odel W6.
— • « / ^^ ^% ^^ ^^ ^^ ^j ^ ™^i III ^r^^ ^*» ^^ ' ^?** .^^^\»^
*=. A/J' O K.Ti , v_ rl Date v / / / « / Time J~-' -3O " *rj
J»D/A^
~ S~mm Ha. Ta *i->. 7^
bration Rela
AH2O
(In.)
^75-
^./
^•f
^-5
"
Operational Row Rate
^«
tionship: m « _
APstg
(mm Hg)a
^3.3t/
*/7-,P£
^J.Vfi
&o.-)
-------
Section No.: 2.11.2
Date: January 1990
Page: 25
• Ambient barometric pressure (Pa), mm Hg (or kPa) .
Ambient temperature (Ta) , °C and K (K = °C + 273).
Orifice S/N and calibration relationship.
Note: Consistency of temperature and barometric pressure units is
required. It is recommended that all temperatures be expressed in kelvin
(K = °C + 273). It is also recommended that all barometric pressures be
expressed in either mm Hg or kPa (but do not mix the two units). Take
care to avoid calibrating a PM10 sampler using one set of units and then
performing sample calculations using another set of units.
7. Turn on the sampler and allow it to warm up to operating temperature (3
to o in i n j •
Note: The sampler inlet may be partially lowered over the orifice
transfer standard to act as a draft shield (if a shield is not otherwise
provided). Use a block to provide at least 2 in. of clearance at the
bottom for air flow and for the manometer tubing).
Then, read and record the orifice transfer standard's manometer reading
AH20, and the corresponding sampler relative stagnation" pressure
manometer reading, APstg, on the data sheet. (Relative stagnation
pressure is a negative pressure [i.e., a vacuum] relative to atmospheric
.^pressure as measured by a manometer with one leg open to 'the atmosphere.) '
Note: Be sure to convert APstg to mm Hg using Equation 12 before record-
ing the reading- on the calibration data sheet:
mm Hg = 25.4(in. H20/13.6) (Eq. 12)
8. Install the other resistance plates or adjust the variable orifice value
to obtain each of the other calibration flow rates and repeat Step 7 for
each. At least four calibration flow rates are required, with at least
three in the acceptable flow-rate range (i.e., 1.02 to 1.24 m3/min).
r m*Lbe en"untered in obtaining flow rates in the acceptable
range Even with modified resistance plates (or with no plates)
lr?th 5 UU may ^impossible to obtain three acceptable flow rates
rll a (i;te[.mounted on the sampler.. In this case, either lower flow-
olatpS3 nSnaJh°n P°in? K?USt be USed and the ca1 ib™tion must be extrap-
olated into the acceptable range, or .additional calibration points must
W1 °Ut * J] ] ter Jnst^ ^d in the sampler. If additional calibra-
"6 °bta,;ned wlthout a ™ter, they should be examined care-
su£MheVre consistent with the calibration points
6r le all the
9. Plot
Step
-------
-------
Section No.: 2.11.2
Date: January 1990
Page: 26
Note: The data should be plotted in. the field as the calibration is
occurring, rather than afterwards back at the laboratory.
Repeat Step 7 for any data that are questionable on the plot. Running
additional calibration points at differing flow rates or repeating the
calibration points at the same flow rates is encouraged to improve the
precision of the calibration.
Turn off the sampler and remove the orifice transfer standard.
11. Install a clean filter on the sampler in the normal sampling mode (use a
filter cassette if one is normally used). Turn on the sampler and allow
it to warm up to operating temperature.
12. Read the relative stagnation pressure as in Step 7 and record it on the
data sheet in the row for the operational flow rate.
13. Perform the calibration calculations presented in the following subsec-
tion. . 3
2.4.3 Calibration Calculations -
10,
e+a HGai*?er Aether all the calibration data, including the orifice transfer
standard -s calibration .information and the sampler calibration data sheet.
Jhese calculations should be done at the time of the calibration
rather than later. This approach will allow additional calibration poTnt ?i be
taken if questions arise about the data that have already been obtained.
1.
2,
Verify that the orifice transfer standard calibration relationship is
current and traceable to an acceptable primary standard.
Calculate and record Qa(orifice) for each calibration point from the
orifice calibration information and Equation 6:
Qa(orifice) = {[AH20(Ta/Pa)]l/2 . b} {1/m} . (Eq. 6)
where:
Qa(orifice) = actual volumetric flow rate as indicated by the trans-
fer standard orifice, m3/min
AH20 = pressure drop across the orifice, mm (or in.) H?0
Ta = ambient temperature during use, K (K = °C + 273)
Pa = ambient barometric pressure during use, mm Hg (or kPa)
b = intercept of the orifice transfer standard's calibra-
tion relationship
m = slope of the orifice transfer standard's calibration
relationship.
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-------
Section No.: 2.11.2
Date: January 1990
Page: 27
PI - Pa - APstg (Eq. 13)
where:
PI = absolute stagnation pressure, mm Hg
Pa-= ambient barometric pressure, mm Hg
APstg = relative stagnation pressure, mm Hg.
4. Calculate and record the stagnation pressure ratio:
- Stagnation pressure ratio = Pi/Pa (Eq. 14)
5. On a sheet of graph paper, plot the calculated orifice transfer stand-
ard's flow rates, Qa(orifice), on the x-axis vs. the corresponding stag-
nation pressure ratios, Pi/Pa, on the y-axis. Draw a smooth curve
through the plotted data. If necessary, extrapolate the curve to include
the acceptable flow-rate range. '
6. If the sampler manufacturer has provided a factory calibration table
. (i.e., the lookup table) for the sampler, compare Qa(orifice) for several
points on the calibration.plot with Qa(sampler) determined from the
factory Calibration at Ta. Calculate the percentage difference between
Qa(orifice) and Qa(sampl.er) using Equation 17:
± mff^r,^ , [Qa(sampler) - Qa(oriflce)] [1QQ]
IQa(orifice)J tlu°J . (Eq«-17)
i
If the agreement is within a few (i.e., 3 or 4) percent, the factory
calibration is validated and may be used for subsequent sample periods
Proceed to Subsection 2.4.5. -
7. If the agreement is not within a few percent, recheck the accuracy of the
orifice transfer standard and recheck the calibration procedure. Look
for leaks, manometer reading errors, incorrect temperature or pressure
data, or miscalculations. Also check for abnormally low line voltaqe at
the site (it should be at least 110 VAC), for the correct blower motor,
and for the presence of a gasket between the motor and the choked-flow
ventun A factory calibration is not likely to be substantially incor-
rect, and any discrepancy of more than a few percent is probably due to
some problem with the sampler or with the calibration procedure How-
ever if no errors or problems with the sampler or with the calibration
can be found, or if no factory calibration is provided by the manufactur-
er, proceed as described in Subsection 2.4.4.
2-4-4 Generation of Calibration Relationship - VFC Sampler -
1- For each calibration point, calculate and record the quantity,
Qa(orifice)/[Ta]l/2
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-------
Section No.: 2.11.2
Date: January 1990
Page: 28
where:
Qa(orifice) = actual volumetric flow rate as indicated by the
transfer standard orifice, m3/min
Ta = ambient temperature during sampler calibration K
(K = °C + 273)
2. For the general linear regression model, y = mx + b, let v = Pi/Pa and
let.x = Qa(orifice)/[Ta]l/2, sucn that the model is given by:
Pi/Pa = m[Qa(orifice)]/[Ta] 1/2 + 5 . '(Eq. 15)
re9ression s1ope ^ • Intercept (b) , and correlation
the
'he plotted call'bratl'on curve to determine whether any of
points that are substantially outside of the acceptable
-need t0 be e!imi?ated so tha' they do not cause an
linear regression line.
3. For subsequent sample periods the sampler's average actual operating
, is calculated from the calibration slope and intercept
n 16: •
ng
' ' . Qa(sampler) = {[(Pl./Pav).b][Tav]l/2}{.i/m} (Eq." 16.)
where:
Qa(sampler) = the sampler's average actual flow rate, m3/min
Pl/Pav = average stagnation pressure ratio for the sampling
period r y
Tav = average ambient temperature for the sampling period, K
\K ~ C •+• 273)
b = intercept of the sampler calibration relationship
m = slope of the sampler calibration relationship.
Note: The average value for PI should be calculated from staanation
pressure measurements taken before .and after the sampliSJ peHod Sav
should be estimated from barometric pressure for the sampling Seriod
See also Subsection 3.3 for additional information Samplin9 peno-d'
!I'Hn^1lbrati°n (lookVp) table is desired,'evaluate Equation 16 for
various aoDrnnn^to u^inae «-f 01/n, —i T. . . ,. . >-H«ai-'uu iu iui
Note: A calibration table based on Equation 16 may not match the
ffl!^r--~ •?•
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-------
Section No.: 2.11.2
Date: January 1990
Page: 29
2-4.5 Single-Point Operational Flow-Rate Verification -
This procedure compares the VFC sampler's normal operating flow rate to the
desTgn flow rate of the inlet (e.g., 1.13 m3/min).
1. Determine the value of Pi/Pa for the operational flow rate obtained with
only the filter cassette installed (Steps 11 and 12 of Subsection 2.4.2)
2. Determine the sampler's operational flow rate, Qa(sampler) that corre-
sponds to this value of Pi/Pa. Use the manufacturer's calibration table
if it has been validated in Step 6 of Subsection 2.4.3; otherwise use
euation 16.
equation 16.
' rate
Design flow rate % difference = [Qa(sampler) - 1.13jf100J ^ lg)
This design flow rate percentage difference must be less than the'
allowable flow rate tolerance (i.e., ±10, if~HoT otherwise specified by
the manufacturer). However, this value should be well within ±7 to allow
for some variation with ambient temperatUTe— If this value is not within
±7, recheck the calibration procedure and data for errors. Check the
" 5JS «r Sh 1 n b?d m?t0r b™she*' missing gaskets, incorrect motor
ld?«t!JiJ ^ III 10W I1"6 V°1ta9e- Because the VFC flow rate is not
adjustable, the VFC manufacturer must be consulted to resolve cases of
substantially incorrect VFC flow rates. «u,ve cases OT
2-5 Sampler Calibration Frequency
c^nJ0 ensure.accurfte measurement of the PM10 concentrations, calibrate HV PM10
samplers upon installation and recalibrate as follows: "MDrate Hv PMIU
. 1. At least quarterly or annually according to the state's quality assurance
Se4R5AendiX A ^ 3 -""
affeCt ^er calibration (e.g., replacing
3. After relocation of the sampler to a different site.
4. If the results of a field flow-check exceed quality control limits (e a
greater than *7 percent from the sampler's indicated flow rate?!
5. Whenever a field flow-check or performance audit indicates that
acceptabie
-------
-------
Section No.: 2.11.2
Date: January 1990
Page: 30
Note: Multipoint flow-rate calibrations should be distinguished from
single-point, quality control flow checks (see Subsection 3.5). The
latter are done more frequently than calibrations and are intended to
check if the sampler flow rate, Qa(sampler), or the calibration relation-
ship have changed significantly since the last calibration.
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-------
Section No.: 2.11.2
Date: January 1990
Page: 31
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-------
Section No.: 2.11.3
Date: January 1990
Page: 1
2.11.3 FIELD OPERATIONS
This section presents information pertinent to the routine operation of a PM10
monitoring site using an HV PM10 sampler. It covers an array of topics, ranging
from initial site selection to final data documentation. The procedures herein are
intended to serve as guidelines for the development of a monitoring programlhat
will accurately reflect trends in local or regional air quality. The effectiveness
or the monitoring program depends on responsible day-to-day operation of the moni
>nnnS^!"caTh? operatoCs who conduct sampling activities offer a unique perspec-
-" data thSleL? Eth 0rmanCK' ?nd their awareness and attention to detail-SiU
fataJh:!^aL^!r!!l!Lbe 125t- -Jt must be stress*d. however, that 'You-
operator provides cohesiveness in a
3.1 Siting Requirements
As with any type of air monitoring study in which sample data are used to draw
conclusions about a general population, the validity of the conclusions depends on
±Uo?re-entatlTeSS °f ^sample data. Therefore, the pHrnary goal
monitoring project is to select a site or sites where the collected par
mass is representative of the monitored area. d
^mnil^b1^:1 Prese"ts basic S1'tin9 criteria for the placement of the HV PM10
sampler. This TS not a complete listing of sitina requirements- instead it s
^cation35 c'Lnf fne-^ ^ °Peratl'ng a^ t0 determinfa samp er'fopt mum
ion cn - erop
} < C°m? 6te S1tin? criteria are presented in 40 CFR 58, Appendix E Addi-
" °" °timUm ^"^ '
Reerence site exposurecrtr is given in
n0i s?eci!ied in the CFR must be considered in detenrnnina
e ^P10*6^ ™ese include accessibility under all weather
°f ad^ate.^^ricity, and security Jf the ^Jto^InT
The sampler must be situated where the operator can reach it
&sx
i SeaudPfta f1?" <;•«•. "librations, filter installation and recovery, flow
orin s? } transporting supplies and equipment to and from the"
monitoing ste
sites with inrJX Sa?1er it5elf depends most1y on its location Rooftop
sites with locked access and ground-level sites with fences are common. In In
personnel as well as the sampler should be
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-------
Section No.: 2.11.3
Date: January 1990
Page: 2
TABLE 3.1. MINIMUM HV PMl'O SAMPLER SITING CRITERIA
Scale
Height
above
ground,
meters
Distance from support-
ing structure, meters
Vertical Horizontal3
Other spacing criteria
Micro
Middle, neigh--
borhood, urban,
and regional
scale
2 to 7
2 to 15
>2 1. Should be >20 meters from
trees.
>2 2. Distance from sampler to
obstacle, such as build-
ings, must be twice the
height that the obstacle
protrudes above the
sampler.
3. Must have unrestricted air
flow 270 degrees around
the sampler inlet.
4. No furnace or incineration
flues should be .nearby.b
5. Spacing from roads varies
with traffic (see 40 CFR
58, Appendix E).
6. Sampler inlet is at least
2 m but not greater than 4
m from any collocated PM10
sampler. (See 40 CFR 58,
Appendix A.) -
Un or\ r00ft°?' tnis separation distance is in reference to
walls, parapets, or penthouses located on the roof.
bDistance depends on the height of furnace or incineration flues, type of fuel or
waste burned, and quality of fuel (sulfur, ash, or lead content . This is to
avoid undue influences from minor pollutant sources
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Section No.: 2.11.3
Date: January 1990
Page: 3
3-2 Sampler Installation Procedures
J 'al'or«°ry "=!;«!; '» determine if the sampler fs operational
' motor ' ™
» instructions
6: Check'all tubing and power cords for crimps, cracks, or breaks.
of inclement
8.
9. Perform a multipoint flow-rate calibration, as described in Section
3 - 3. Sampl ing Operations
operation. Significant difLrencerexi5t ?n th J0^/""1"9 the samPler ^°
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-------
Section No.: 2.11.3
Date: January 1990
Page: 4
• The flow rate through a PM10 sampler that is equipped with a mass-flow
controller is indicated by the exit orifice plenum pressure. This pres-
sure is measured with a manometer [or a flow recorder].
• The flow rate through a PM10 sampler that is equipped with a volumetric-
flow controller is indicated by the stagnation pressure. This pressure
is measured with a manometer.
• The sampler has been calibrated according to procedures presented in
Subsection 2.
Sampling procedure checks are summarized in Table 3.2 at the end of this
section.
The average actual flow rate for MFC samplers is calculated by determining
(a) the average of the initial and final manometer readings of the exit orifice
plenum pressure [or the average flow recorder reading], (b) the average ambient
temperature (Tav)', and (c) the average ambient barometric pressure (Pav) during the
sampling period. These values are then applied to the sampler's calibration rela-
tionship. The 4-in. pressure (flow) recorders of the type often supplied with
HV PM10 samplers are generally not sufficiently accurate and are not recommended
for quantitative sampler pressure or flow rate measurements. These flow recorders
should be used only for nonquantitative determination that the flow was approxi-
mately constant and uninterrupted over the sampling period. The flow recorder may
be connected in parallel with the manometer or other pressure measuring device,
using a tee or "Y" tubing connector.
Note: Because flow record'ers are still in wide use for quantitative flow rate
measurements, the procedures in this section include specific instructions for the
use of a flow-recorder. These flow recorder instructions are enclosed in brackets
The average actual flow rate for VFC samplers is calculated by determining
(a) the average of the initial and final relative stagnation pressures (APstg),
(b) the average ambient temperature (Tav), and (c) the average barometric pressure
(Pav) during the sampling period and then by applying these values to the calibra-
tion relationship.
Note: Consistency of temperature and barometric pressure units is required.
It is recommended that all temperatures be expressed in kelvin (K = °C + 273). it
is also recommended that' all barometric pressures be expressed in either mm Hg or
kPa (but. do not -mix the two units). Take care to avoid, calibrating a PM10 sampler
using one set of units and then performing sample calculations using another set of
units.
3'-3-! Presamplinq Filter Preparation Procedures - Most HV PM10 samplers have been
designed to accept filter cassettes. Loading these cassettes in the laboratory
will minimize damage; however, if extreme care is exercised, they can be loaded at
the site when ambient conditions permit. Workers should wear protective gloves
when handling filters to avoid contaminating the filters with body oils and mois-
ture. The filters should b.e kept in protective folders or boxes. Unexposed
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-------
Section No.: 2.11.3
Date: January 1990
Page: 5
wnen
niter that has been labeled on its "down" side i
3-3-2 Sampling Procedures— MFC Sampler -
at the
of a cean
have
are sed
fro. th.,r curr,™"?^
' If cllarts
"
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-------
Section No.: 2.11.3
Date: January 1990
Page: 6
[While installing the chart, do not bend the pen arm beyond its limits of
travel. Raise the pen head by pushing on the very top of the pen arm (or
by using the pen lift). Be sure that the chart tab is centered on the
slotted drive to ensure full 360-degree rotation in 24 h. Make sure that
the chart edges are properly located beneath the retainers. Lower the
pen arm and tap the recorder face lightly to make certain that the pen is
free.]
[Note; During periods of inclement weather, the chart tends to stick to
the recorder face. Two charts can be installed simultaneously to enable
the sample (top, annotated) chart to rotate freely.]
5. [Using a coin or slotted screwdriver, advance the chart and check to see
that the pen rests on zero—the smallest circle diameter. If necessary,
adjust the zero set screw while gently tapping on the side of the flow
recorder. If a chart with a linear-function scale is used, some positive
zero offset may be desirable to allow for normal variations in.the zero
readings.]
6. Turn on the sampler and allow it to equilibrate to operating temperature
(3 to 5 min),
7. While the sampler is equilibrating, record the following parameters on
the MFC Sampler Field Data Sheet (Figure 3.1):
Site location.
Sample date.
Filter ID number.
Sampler model and S/N.
Operator's initials.
8. Inspect the manometer for crimps or cracks in" its connecting tubing.
Open the valves and blow gently through the tubing of the manometer while
watching for the free flow of the fluid. Adjust the manometer's sliding
scale.so that its zero line is at the bottom of the meniscuses.
9. Measure the initial exit orifice plenum pressure (APex) using an oil or
water manometer, with a 0- to 200-mm (0- to 8-in.) range and a minimum '
scale division of 2 mm (0.1 in.). Record the initial APex on the MFC
Sampler Field Data Sheet. If APex is substantially different than for
• previous samples or otherwise appears abnormal, carry out a QC -flow check
as described in Subsection 3.5.1.
10. [Verify that the flow recorder (if used) is operational and that the pen
is inking. Note the flow recorder reading. If it is substantially
different than for previous samples or otherwise appears abnormal, carry"
out a QC flow-check as described in Subsection 3.5.1.]
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Section No.: 2.11.3
Date: January 1990
Page: 7
MFC SAMPLER FIELD DATA SHEET
Station
Location
fV c.
Date
SAROAD*
Sampler Mode!
Filter ID No.
/M
S/N
2.?
/
. mm Hg, Tav
t &.
Final APex
Sampler Manometer Readings Flow Recorder Readings
in. H2O Mean I
in. H2O
Mean APex
V. 0
*/• /
. in. H2O
Sampler Calibration Relationship: m = O ,
Q3 - l-ld-2--
O ,
Elapsed Time /
Qa « {[meanAPexfTav + X)/Pavj'^ - b} {1/rn}
Qa - {mean I [fTav + 30)/Pavl* - b} {1/m} for flow recorders
Operator
Comments:
Laboratory Calculations:
Qstd =» Qa (Pav/Pstd) (Tstd/Tav)
Vstd
Vstd =. (Qstd) (elapsed time)
. std m3/min
stdm3
Gross weight (Wg) _ "^ • t
Tare weight (Wt) 3>,<
Net Weight (Wn) O . d 4 & 7
PM10 Concentration 3 9 . d
PM10 Concentration « (Wn) (106)/Vtetd
K
O , 'y^ 7 9
mjn
Q
'9
— g
. ^g/std m3
Figure 3.1. Example MFC sampler field data sheet.
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-------
Section No.: 2.11.3
Date: January 1990
Page: 8
11. Turn the sampler off.
12. [Check the time indicated by the time-set pointer on the flow recorder.
If it i.s in error, rotate the chart clockwise by inserting a screwdriver
or coin in the slotted drive in the center of the chart face until the
correct time is indicated.]
13. Reset the elapsed time meter to 0000 min and the sampler timer for the
next run day. Close the sampler door, taking care not to crimp the
vacuum tubing or any power cords. The sampler is now ready to sample
ambient air. ' . -
Filter Recovery Procedure - As soon as possible after sampling, the operator should
return to the monitoring site to retrieve the exposed filter. Particle loss or
filter damage will result if the filter is left in the sampler for extended peri-
ods. .
1. Turn on'the sampler and allow it to equilibrate to operating temperature
(3 to 5 min).
2. Measure the final APex and record it on the MFC Sampler Field Data Sheet.
3. Turn off the sampler.
4. [Open the door of the sampler, remove the flow recorder chart, and exam-.
ine the recorder trace. If the trace indicates extensive flow fluctua-
tions, investigate and correct before the next sampling day.]
5. Record the .following parameters on the MFC Sampler Field Data Sheet:
• Elapsed time of the sampling period, min.
• Average recorder response, arbitrary units.
• Average .ambient temperature for the run day (Tav), K (K = °C + 273).
• Average ambient barometric pressure for the run day (Pav), mm Hg or
kPa.
Note; The calculations presented in this subsection assume that the
sampler has been calibrated in terms o-f actual temperature and barometric
pressure. Average sampler flow rate for a sample period is determined
from the average exit orifice plenum pressure (APex) and the average
ambient temperature (Tav) and average ambient pressure (Pav) for the
sample period. Tav and Pav readings may be recorded or estimated on-site
or may.be obtained from a nearby U.S. National Weather Service Forecast
Office or airport weather station. Barometric pressure readings obtained
from remote sources must be at station pressure (not corrected to sea
level), and they may have to be corrected for differences between the
elevation of the monitoring site and that of the airport.
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4.
Section No.: 2.11.3
Date: January 1990
Page: 9
fjote: Jf specific Tav or Pav values for the sample period cannot be
tutPd"^; ?rS°nai avera9e temperature for the site (Ts) may be substi-
tuted for Tav, and average barometric pressure for the sit? fPO m*u L
uX&'ZiS'*' ^V^ "? t&^' h°weve°' t^Y^L' afcb dV
tions at the site during the sample period can be reasonably reoresented
by such averages It is therefore recommended that seasonal valuef be
used to represent actual.values only within 20«C and 40 mm Hg!
6' .fln?1^6 an?.j;ecord the .average actual flow rate (as determined bv the
™dPner h Call?rar°[! re!ati°nship) on the MFC Sampler Fie fd Sat a Sheet
and on the back of the chart. Attach the chart to the data sheet.
{[APe7 (Tav + 30)/Pa]1/2 - b} {1/m} (Eq- g)
or for the flow recorder,
9a)
where
-_2i = average sampler flow rate, actual. m3/min
APex = average exit orifice plenum pressure, mm Hg or kPa'
[I = average flow recorder response, arbitrary Qnitsl
Tav = average ambient temperature for the run day K
Pav = average ambient pressure for the run day, mm Ha or kPa
b = intercept of the MFC sampler calibration relationship
m = slope of the MFC samnler ral ihr-at,-«n ^i,*j'_.u7 5nip
..-_.—r- -• -•>- i'.v. jamHici uaijoration re ationsi
m = slope of the MFC sampler calibration relationship!
N£te: If charts with linear-function scales are used, substitute
(I) '* for T.
Sayear??ect0ndfilterSDaart0?H ^ •?nit?Hn9 SUe; "°te ^ activities'that
mm-A Zu- 'ier Ro'ticie loading (e.g., paving, mowino fire^ and
record.this information on the MFC Sampler Field Data Sheet }
5' -cilil?*n^l?r..!nl!* *nlle!!1?ve the f1Jter cassette.
6. The sampler may now be readied for the next run day
7
jamplinq Procedures--VFC Sampler -
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-------
Section No.: 2.11.3
Date: January 1990
Page: 10
1. Following the manufacturer's instructions, loosen the nuts that secure
the inlet to the base and gently tjlt back the inlet to allow access to
the filter support screen.
2. Examine the filter support screen. If the screen appears dirty, wipe it
clean. If the filter cassette is equipped with a protective cover, re-
move it and place the loaded cassette in position on the sampler support
screen. Tighten the thumb nuts sufficiently to hold the filter cassette
securely. Check that the gasket is in good condition and has not deteri-
. orated.
Caution.- Tighten the thumb nuts evenly on alternate corners to properly
align and seat the gasket. The nuts should be only hand-tightened
because too much compression can damage the sealing gasket.
3. Lower the sample inlet and secure it to the sampler base. For impaction
inlets, inspect the sample inlet to make sure that it is resting on the
filter cassette and not on the PM10 sampler's frame. Secure the sampler
inlet to the sampler base.
4. Turn on the sampler and allow it to reach a stable operating temperature
(3 to 5 min). •
5.-- While the sampler is warming up, record the following, parameters on the
VFC Sampler Field Data Sheet (Figure 3.2):
• Site location.
• Sample date.
Filter ID number.
• Sampler model and S/N.
• Operator's initials. .
6. Bring an oil or water manometer to the side of the sampler. This manom-
eter should have a range of 0 to 1000 mm (0 to 36 in.) and a minimum
scale division of 2 mm (0.1 in.).
Inspect the manometer for crimps or cracks in its connecting tubing.
Open the valves and blow gently through the tubing of the manometer
while watching for the free flow of the fluid.
Adjust the manometer's sliding scale so that its. zero line is at the
bottom of the meniscuses.
7. Remove the vacuum cap from the stagnation pressure port located on the
side of the sampler base. Using the connecting tubing, attach one side
of the manometer to the port. Leave the other side of the manometer open
to atmospheric pressure. Make sure the tubing snugly fits the port and
the manometer. ,
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-------
Section No.: 2.11.3
Date: January 1990
Page: 11
VFC SAMPLER FIELD DATA SHEET
Station
Location
, CA
Date
5/7/37
Sampler Model \jJ^DD)tiG-
Filter ID No. £77 J *•/ p-v ISO
SAROAD* OV./?/?V9
s/N
mm Hg, Tav
3O/-6
Relative Stagnation Pressure Readings
Initial APstg
Final
Average
2 __ mm Hg .Pi
L—_ mm Hg Pi
. mm Hg
Average Stagnation Pressure Ratio (Pl/Pav) O-
Average Flowrate (Qa)' 1-17*% n_ ;i
•Obtained from manufacturer's lookup table (pr
from alternate calibration relationship)
Absolute Stagnation Pressure
7ZO. 3
mm Hg
Pav -
Average .iPstg
Elapsed Time
. mm
Laboratory Calculations:
Qsid
Qsta » Qa (Pav/Pstd) (TstdHav)
. Std m3/min
/
Vstd
Vsta » (Qsid) (Elapsed Time)
. std m3
Gross Weight (Wg)
Tare Weight (Wt) _
Net Weight (Wn) _
'. 3^02.
O. 07/7
PMlO Concentration 55.
• 9
• 9
g
PM10 Concentration m (Wn) (106)/Vstd
wg/st£j
Figure 3.2. Example VFC sampler field data sheet.
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-------
Section No.: 2.11.3
Date: January 1990
Page: 12
8. Measure the initial relative stagnation pressure (APstg) and record this
reading on the VFC Sampler Field Data Sheet.
Note: Be sure to convert the manometer reading to mm Hg using Equation
12 before recording the reading on the VFC Sampler Field Data Sheet.
mm Hg = (25.4) (in.,H20/13.6) (Eq. 12)
9. Turn off the sampler, disconnect the manometer, and replace the vacuum
cap on the stagnation pressure port.
10. Reset the elapsed-time meter to 0000 min and the sampler timer for the
next run day.
11. The sampler is now ready to sample ambient air.
Filter Recovery Procedure - As soon as possible after sampling, the operator should
return to the monitoring site to retrieve the exposed filter. Particle loss or
filter damage will result if the filter is left in the sampler for extended peri-
ods.-
1. Turn on the sampler and allow it to warm up to operating temperature (3
--. to 5 min).
2. While the sampler is equilibrating, record the following parameters on
the VFC Sampler Field Data Sheet:
• Elapsed time of the sampling period, min.
• Average ambient temperature for the run day (Tav), °C and K.
• Average ambient barometric pressure for the run day (Pav), mm Hg or
kPa.
• Note: Tav and Pav readings may be recorded or estimated on site or may
be obtained from a nearby U.S. National Weather Service Forecast Office ,
or airport weather station. Barometric pressure readings obtained from
remote sources must be at station pressure (not corrected to sea level),
and they may have to be corrected for differences between the elevation
of the monitoring site and that of the airport. If Tav and Pav readings
are not available, seasonal average temperature (Ts) and barometric pres-
sure (Ps) can be substituted. Care must be taken, however, that the
actual conditions at the site can be reasonably represented by such aver-
ages. It is therefore recommended that s'easonal values represent actual
values within 20°C and 40 mm Hg.
3. Inspect the manometer for crimps or cracks in its connecting tubing.
Open the valves and blow gently through the tubing of the manometer,
while watching for the free flow of the fluid. Adjust the manometer
sliding scale so that its zero line is at the bottom of the meniscuses..
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-------
Section No.: 2.11.3
Date: January 1990
Page: 13
4. Remove the vacuum cap from the stagnation pressure port located on the
side of the sampler base. Using the connecting tubing, attach one side
of the manometer to the port. Make sure that the tubing snugly fits the
port and the manometer. Leave the other side open to atmospheric pres-
5. Record the final APstg on the VFC Sampler Field Data Sheet. Turn off the
sampler and replace the vacuum cap.
Note: Be sure to convert the manometer reading to mm Hg using Equation
12 before recording the reading on the data sheet.
mm Hg =25.4 (in. H20/13,6) (Eq. 12)
6. Calculate the average relative stagnation pressure (APltg) and record it
on tne data she'et.
7. Calculate the average absolute stagnation pressure (Pi) for the sample
run day and record it on the data sheet. - ^mpie
, "• ' P1 = Pav - AFstg - . .(Eq. 13)
where • • . - .
PI = average absolute stagnation pressure, mm Hg or kPa.
Hav = average ambient barometric pressure for the run day (not the
' retrieval day), mm Hg or kPa.
APstg = average stagnation pressure drop, mm Hg or kPa.
8. Calculate and record the average stagnation pressure ratio:
where
Pav
9.
Average stagnation •5T/D
pressure ratio ~ P1/Kav (Eq. 14a)
PI = average absolute stagnation .pressure, mm Hg or kPa
aV = ane^9!Dambient barometn'c Pressure on the sample run day, mm
• *yOiKiQ»
Using the manufacturer's lookup table (or an alternate calibration
relationship as described in Subsection 2.4.4), locale the column and
row corresponding to Pl/Pav and_the Tav value for the sample run dav
Read and record the indicated Qa value. sampie run aay.
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-------
Section No.: 2.11.3
Date: January 1990
Page: 14
10. Observe conditions around the monitoring site; note any activities that
may affect filter particle loading (paving, mowing, fire) and record this
information on the VFC Sampler Field Data Sheet.
11. Raise the sampler inlet and remove the filter cassette. Replace the
cassette protective cover (if so equipped). To avoid particle loss, be
, care/ul to keep the cassette as level as possible.
12. The sampler may now be readied for the next sampling period.
13. Keeping the filter cassette level, carefully transport it and the data
sheet to the laboratory sample custodian.
3-3.4 Post-Sampling Filter Handling Procedures .- If a sample will not be analyzed
immediately, the sample custodian should store the filter within a protective cov-
ering to minimize the loss of volatile particles. Because filter cassettes often
prove too expensive and unwieldy for storage purposes, the use of a manila folder '
and a protective envelope of comparable size to that of the filter is recommended
Laboratory personnel should adhere to the following procedure:
1. Following the manufacturer's instructions, remove the top frame of the
. filter cassette.
2. Conduct, a secondary check of a sample's validity as presented in "Labora-
tory Validation Criteria" (Subsection 3.4).
3. Carefully slip a manila folder underneath the edge of the exposed filter.
The filter may stick in the cassette because of overcompressi-on of the
filter cassette gasket. Be extremely careful to avoid damaqe to the
brittle quartz filter.
4. Center the filter on the folder. If the filter must be touched, do not
touch or jar the deposit. Fold the man.ila folder lengthwise at the .
middle with the exposed side of the filter in. If the collected sample
is not centered on the filter (i.e., the unexposed border is not uniform
around the f i Her) , fold it so that only deposit touches deposit. Do not
crease the folder—the sample filter may tear; If the filter shears or
breaks, ensure that all pieces of the filter are included within the
folder.
5. Insert the folder into the protective envelope.
6. Deliver the filter, in its protective folder and envelope, accompanied by
the completed data sheet, to the analytical laboratory.
Analysis and Calculation of PM10 Concentrations - Post-samp 1 inq fil-
analysis is discussed in Subsections 4.6 and 4.7. The calculation of PM10
concentrations is discussed in Subsection 5.1.2.
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-------
Section No.: 2.11.3
Date: January 1990
Page: 15
Sample Validation and Documentation -
-0^?* : The follow1'n9 criteria have been established to
lefail tn h Ini-*a1 y d!terminin9 wnetner a sample is valid. If a sam-
Sbserved thJt ^ thes^cntena- do,nOt dl*scard the filter. Document any factors
?n^ 5*1 I y resu1t in a Samp1e s invalidation oh the sample data sheet and
t£p ?&? H data Sheet and the fl'lter to the laboratory supervisor who wfll make
the final decision regarding the sample's validity.
1. - Timing:
All samplers must be turned ON and OFF within 1/2 h of midnight.
^ at 1east ^ but ^™ than 2§ h
2. Flow Rates:
nd ng period, calculate the percentage difference between
and the design flow rate (1.13 m3/min) using the following formuTaT
Difference. 100 'jZj .' (£q> lfl)
^^lgate P°tential err^ sources in^ediftely T he followina
should be used as the basis for determining a sample's Validity?
Decreases in flow rate during sampling (due to mechanical nrohlpm^
of more than 10 percent from the initial set poTnt result in simp 1
!!!:; «e"llbrat? t«e sampler. A saSple flow rate maJS so
due to heavy filter loading. If a hiqh PM10 concentratinn
' '
Sh°Uld inicate thisn feld data
gardng ^ «" ^ ^ ^ *^™ re-
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Section No.: 2.11.3
Date: January 1990
Page: 16
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-------
Section No.: 2.11.3
Date: January 1990
.Page: 17
1. Check the filter for signs of air leakage. Leakage may result from a
?or*tP,r i?Pr?per1^ Insta11ed faceplate gasket. A gasket general"? dlter-
orates slowly. The custodian should be able to decide well in advance
(by the increased fuzziness of the sample outline) when to chanae t£
gasket before total gasket failure resets. If s gns Sf leakage are
- ^served,, void the sample, determine the cause, and instruct th9e operator
to take .corrective actions before starting another sampling perfoS
inorafternnn- dama9e that «* have occurred dur
da?e [he Hinif PJ ?i ?hysicai dama9e after sampling would not invali
e I? '0 f
is ,or?lqu,>ede.U5e °f '°9 6°0kS " PM1° ™°'t°'-™
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-------
Section No.: 2.11.3
Date: January 1990
Page: 18
5. Initial APex for MFC or initial APstg for VFC (DS)(LB).
6. Unusual conditions that may affect the results (e.g., subjective evalua-
tion of pollution that day, construction activity, weather conditions)
(DS)(LB).
7. Operator's initials (DS).
8. Signature (LB).
Operator Who Removes the Samples -, '
1. Elapsed time of the sample run (DS) (RC) (LB). . _
2. Final APex [or mean I] for MFC or final APstg, PI, and Pl/Pav for VFC
(DS)(LB)[RC].
3. The calculated standard average flow rate (Qstd) in std. m3/min (DS)(LB).
4. .The percentage difference between the actual and design flow rates (CC).
.5. Average ambient temperature and barometric pressure on the sample run day
(DS)(LB). • ^
6. Seasonal average temperature and pressure, if needed (DS/LB). This
information needs to be recorded in the logbook once, at the change of
each season.
7. Existing conditions that may affect the results (DS)(LB).
8. Explanations for voided or questionable samples (DS)(LB).
9. Operator's initials (OS).
10. Signature (LB).
3-5 Field QC Procedure - For. HV PM.10 samplers, a field-calfbratiori check of the
operational flow rate is recommended at least once per month. The purpose of this
check is to track the sampler's calibration stability. A control chart (e.g;,
Figure 3.4) presenting the percentage difference between a PM10 sampler's indicated
and- measured flow rates should be maintained. This chart provides a quick refer-
ence of instrument flow-rate drift problems and is useful for'tracking the perform-
ance of the sampler. Either the sampler log book or a data sheet must be used to
document flow-check information. This information includes, but is not limited to
instrument and transfer standard model and serial numbers, ambient temperature and'
pressure conditions, and collected flow-check data.
In this subsection, the following is assumed:
The flow rate through a PM10 sampler that'is equipped with a mass-flow
controller is indicated by the exit orifice plenum pressure. This pres-
sure is measured with a manometer [or a flow recorder].
The flow rate through a PM10 sampler that is equipped with a volumetric-
•flow controller is indicated by the stagnation pressure. This pressure
is measured with a manometer.
Both sampler models are designed to operate at an actual flow rate of
1.13 m-Vmin. with an acceptable flow-rate fluctuation range of 10 percent
of this value.
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-------
Section No.: 2.11.3
Date: January 1990
Page: 19
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-------
Section No.: 2.11.3
Date: January 1990
Page: 20
• The transfer standard will be an orifice device equipped with a water or
oil manometer.
• The orifice transfer standard's calibration relationship is in terms of
the actual volumetric flow rate (Qa).
3.5.1 QC Flow-Check Procedure—MFC Sampler -
', * • '
The indicated flow rate (Qa (sampler)) for MFC samplers is calculated by
determining (a) the manometer reading of the exit orifice plenum pressure [or the
flow recorder reading], (b) the ambient temperature (Ta), and (c) the barometric
pressure (Pa) during the flow check. These values are then applied to the sam-
pler's calibration relationship. The 4-in. pressure (flow) recorders of the type
often supplied with HV PM10 samplers are generally not sufficiently accurate and
are not recommended for quantitative sampler pressure or flow measurements. The
flow recorder may be connected in parallel with the manometer'or other pressure
measuring device,- using a tee or "Y" tubing connector.
Note: Do not attempt to conduct a flow check of PM10 samplers under windy
conditions. Short-term wind velocity fluctuations will produce variable pressure
readings by the orifice transfer standard's manometer. The flow check will be less
precise because of the pressure variations.
An alternate QC flow-check procedure may be presented in the manufacturer's
instruction manual: It is recommended that the manual be reviewed and the various
methods be evaluated. In-house equipment and procedural simplicity should be con-
sidered in determining which method to use.
1.
Collect the following equipment and transport it to the monitoring sta-
tion. This equipment may be the same equipment as used for calibrations.
A water or oil manometer with a 0- to 200-mm (0- to 8-in.) range- and
a minimum scale division of 2 mm (0.1 in.), for measurement of the
sampler's exit orifice plenum pressure. This manometer should be'
the same as is used routinely for sampler flow rate measurements.
An orifice transfer standard and its calibration relationship.
An associated water or oil manometer with a 0- to 400-mm (0- to 16-
in.) range and a minimum scale division of 2 mm (0.1 in.) for
measurement of the orifice transfer standard.
• • A thermometer capable of accurately measuring temperature over the
range of 0° to 50°C (273 to 323 K) to the nearest ±1'C and refer-
enced to an NIST or ASTM thermometer within ±2°C at least annually.
A portable aneroid barometer (e.g., a climber's or engineer's altim-
eter) capable of accurately measuring ambient pressure over the
range of 500 to 800.mm Hg (66 to 106 kPa) to the nearest millimeter
Hg and referenced within ±5 mm Hg of a barometer of known accuracy
at least annually. J
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-------
Section No.: 2.11.3
Date: January 1990
Page: 21
• The sampler's calibration information.
• Spare- recorder charts and a clean flow-check filter.
MFC Sampler Flow-Check Data Sheet (Figure 3.5) or site log book.
2. [Record the site location, sampler S/N, and date on the back of a clean
chart and install it in the flow recorder. While installing the chart
do not bend the pen arm beyond its limits of travel. Raise the pen head
"* " 1?ft>
that
4' t[h!tn?ha coin,or slotted screwdriver,, advance the chart and check to see
Il?i«5l pen.hea? ^StS °" 2er° (*•«••• the smallest diameter circle). If
necessary adjust the zero-set .screw while gently tapping on the side of
the recorder. A quarter turn of the set screw usually results in arqe
offsets; adjust the set screw carefully.] . 9
5. Set up the flow-check system as previously illustrated in Figure 2.2
MFC samplers are normally flow-checked with a filter in line (i e
- f?u!r-th*H°r1fiC? trar»fer standard and the motor). Instal a clean
f ufr lr "if16"; Pla« thc filter directly upon the sampler's -
IlJ'iJhi S'f "K* USe a filter ca.ssette- A flow-check filter should
never be used for subsequent s.ampling because particles larger than 10 m
can be collected on the filter while the inlet'is raised. The sample ^
result of using a fiiter for both • fi
6. Install the orifice transfer standard and its faceplate on the samoler
Do not restr ct the flow rate through the orifice (e bv usinq f xed
• resistance plates or closing the variable-resistance vaivej. •
HnrrSiirJl9!!1?" th€ faceP1ate nuts on alternate corners first to elimi-
HnT^fn J t0 unSUre even ^flhtening. The nuts should be hand-
tightened; too much compression can damage the sealing gasket. Make sure
the orifice transfer standard gasket is in place and the orifice transfer
standard is not cross-threaded on the faceplate. oritice transfer
7. Connect the orifice manometer to the pressure port of the orifice trans
s:-sss.r" -^S1 L"
r> '
connecti"9
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-------
Section No.: 2.11.3
Date: January 1990
Page: 22
MFC SAMPLER FLOW CHECK DATA SHEET
Station *j
Location /W/LFOZQ, flC Date //// /33 Time /£>• 3Q
Sampler Model GMU S/N _/2-T7____ Operator D
^ 7^3 mmHg. Ta 2T7. O QQ 3OO.Q K< Unusual Conditions
0rificeS/N /O3<^7 Orifice Calibration Date
Orifice Calibration Relationship: m - /. ZV3O b , — O. OO6Z. r m £). ef'J" 0/J - bj {1/mJ
For calculation of sampler flow rates:
Qa (sampler) . {(QPex/Pa) (Ta + 30)1'^ - b} (i/m|
CQC o/o Difference = [ °* (sampler) - Qa (or.fice) 1 r -j
L Qa (orifice) J I w^ere Qa (sampler) is measured with the
J orifice installed
dQa (corrected sampler) = Qa (sampler) f 1°° " QC % ^wce 1
M L TOO e Qa (sarr>Pler) is measured
J
r is mea
without the orifice installed.
eDes.gn Flow Rate o/0 Difference = I" Qa
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-------
Section No.: 2.11.3
Date: January 1990
Page: 23
8. Turn on the sampler and allow it to warm up to operating temperature (3
to. 5 min) .
Note: The sampler, inlet may be partially lowered over the orifice trans-
fer standard to act as a draft shield (if a shield is not otherwise pro-
vided). Use a block to provide at least 2 in. of clearance at the bottom
for air flow and for the manometer tubing.
9. Read and record the following parameters on the MFC Sampler Flow-Check
Data Sheet:
Sampler location and date.
Sampler model and S/N
Ambient temperature (Ta) , °C and K.
Ambient barometric pressure (Pa), mm Hg or kPa.
Unusual weather conditions. :
Orifice transfer standard S/N and calibration relationship.
Operator's signature.
10. Observe the AH20 across the orifice by reading the manometer deflection.
Section 2.2 of this volume, .Figure 2.6, illustrates the correct way to
read a water or oil manometer. Record the manometer deflection on the •
MFC Sampler Flow-Check Data Sheet.
11. Measure the exit orifice plenum pressure "(APex) by reading the manometer
deflection-. Record the manometer deflection on the MFC Sampler Flow-
Check Data Sheet.
12. [Using a coin or small screwdriver, advance the recorder chart to read
the sampler's corresponding response (I) and record on the data sheet A
gentle tap on the recorder face is often necessary to ensure that the oen
is not sticking to the chart.]
13. Jurn off the sampler and remove the orifice transfer standard, but not
the filter. Turn on the sampler and repeat Step 11 [or 12] to check the
flow rate under normal operating conditions. Turn off the sampler and
remove the filter.
14. Calculate'and record Qa(orifice) at actual conditions using the following
equation: . ' a
where
Qa(orifice) =.{[(AH20)(Ta/Pa)]1/2 . b} {1/m} ' (Eq. .6)
Qa(orifice) = actual volumetric flow rate as indicated by the ori-
fice transfer standard, m3/min
AH20 = pressure drop across the orifice, mm (or in.) HoO
Ta = ambient temperature, K
Pa = ambient barometric pressure, mm Hg or kPa
b = intercept of the orifice calibration relationship
m = slope of the orifice calibration relationship
-------
Section No.: 2.11.3
Date: January 1990
Page: 24
15. Calculate and record the corresponding sampler flow rate at actual condi-
tions and record.
Qa(sampler) = {[APex (Ta + 30)/Pa]l/2 . b} {1/m} (Eq. 9)
or if a flow recorder is being used to measure the exit orifice plenum
pressure,
Qa(sampler) = {I[(Ta + 30)/Pa]l/2 - b} {1/m} (Eq. 9a)
where
Qa(sampler) = sampler flow rate, actual m^/min
APex = exit orifice plenum pressure, mm (or in.)
I - recorder response, arbitrary units
Ta ~ ambient temperature during the flow check, K (K = °C +
273)'
Pa - ambient barometric pressure during the flow check, mm
Hg or kPa
b =- intercept of the MFC sampler calibration relationship
m = slope of the MFC sampler calibration relationship.
Note; If charts with linear-function scales are used, substitute (1)1/2
for I. - •
16. Using this information and the formulas provided on the MFC Sampler Flow-
• Check Data Sheet, calculate the QC check percentage differences.
QC-check % difference = [Qalsampler^-^orifice)] [10Q] (Eq>
where Qa(sampler) is measured with the orifice transfer standard being
installed.
Record this value on the MFC Sampler Flow-Check Data Sheet and plot on
the QC control chart. If the sampler flow rate is within 93 to 107 per-
cent (±7 percent difference) of the calculated Qa(orifice) flow rate (in
actual volumetric units), the sampler calibration is acceptable. If
these limits are exceeded, investigate and correct any malfunction.
Recalibrate the sampler before sampling is resumed. Differences exceed-
ing ±10 percent may result in the invalidation of all data collected
subsequent to the last calibration or valid flow check. Before invali-
dating any data, double-check, the orifice transfer standard's calibration
and all calculations.
17. Calculate the corrected sampler flow rate, Qa(corr. sampler) usinq Equa-
tion 23:
Qa(corr. sampler) = [Qa(sampler)] [(10° " ^difference) j (Eq> 23)
-------
Section No.: 2:11.3
Date: January 1990
Page: 25
where Qa(sampler) is measured without the orifice transfer standard being
installed and where the QC-check percentage difference was obtained from
Equation 17 above.
Note; Take care to use the correct sign (i.e., positive or negative) for
the -% difference when it is used in Equation 23.
18. Calculate and record on the MFC Sampler Flow-Check. Data Sheet the per-
centage difference between the inlet's design flow rate (e.g., '1.13
iiH/min) and the corrected sampler flow rate as:
Design flow rate % difference = [Qa(corr- sampler) - 1.131 f10()J (Eq>
It is assumed in this subsection that the inlet' is designed to operate at
a flow rate of 1.13 actual nH/min. If the design flow rate percentage
difference is less than or equal to ±7 percent, the sampler calibration
is acceptable. If the difference is greater than ±7 percent, investigate
potential error sources and correct any malfunction. Recalibrate the
sampler before sampling is resumed. Differences exceeding ±10 percent
may result in the invalidation of all data collected subsequent to the
last calibration or valid flow check. Before invalidating any data
double-check the sampler's calibration, the' orifice transfer standard's
certification, and all calculations.
Note: Deviations from the. design flow rate may be caused in part -by
deviations in the site temperature and pressure from the seasonal average
conditions. Recalculate the optimum set-point flow rate (SFR) according
to Equation 10 in Subsection 2.3 to determine if the flow controller
should be adjusted.
19. Set up the sampler for the next sampling period according to the operat-
ing procedure in Subsection 3.3.
3.5.2 'QC Flow-Check Procedure— VFC Sampler - •
The indicated flow rate (Qa (sampler)) for VFC samplers is calculated by
^rpTTTVaV?e^elKtive !ta9nation Pressure (APstg) , (b) the ambient tempera-
ture (Ta) • and (c the barometric pressure (Pa) during the flow check. These val-
ues are then applied to the sampler's calibration relationship.
Dp not attempt to conduct a flow check, of PM10 .samplers under windy.
conditions. Short-term wind velocity fluctuations will provide variable pressure
orPc^pShpr, <6 TtH" transfer standard's manometer. The flow check will be less
precise because of the pressure variations.
Note:. An alternative QC flow-check procedure may be presented in the manufac-
turer's instruction manual. It is recommended that the manual be reviewed and the
bfron^r^5 5H raluated' Jn-house equipment and procedural simp cty hould
be considered in determining which method to use.
the fonowing equiPment and transport it to the monitoring sta-
-------
Section No.: 2.11.3
Date: January 1990
Page: 26
• A orifice transfer standard and its calibration relationship in
actual volumetric flow units (Qa).
• An associated oil or water manometer, with a 0- to 400-mrn (0- to
16-in.) range and minimum scale divisions of 2 mm (0.1 in.)-
• An oil or water manometer, with a 0- to 1000-mm (0- to ,36-in.) range
and minimum scale divisions of 2 mm (0.1 in.) or other pressure
measurement device for measurement of the sampler stagnation
pressure. Ideally, this manometer (or other pressure measurement
device) should be associated with the sampler.
Note; Manometers used for QC flow-checks may be subject to damage
or malfunction and thus should be checked frequently.
• A thermometer capable of accurately measuring temperature over the
. range of 0° to 50°C (273 to 323 K) to the nearest ±1°C and refer-
enced to an NIST or ASTM thermometer within 2°C at least annually.
To calculate the orifice flow rates, it will be necessary to convert
°C to K. '
• A portable aneroid barometer (e.g., a climber's or engineer's altim-
eter) capable of accurately measuring ambient barometric pressure
over the range of 500 to 800 mm Hg (66 to 106 kPa) to the nearest •
millimeter Hg and referenced within 5 mm Hg of a barometer of known
accuracy at least annually. . .
• The sampler's calibration relationship (i.e., lookup table or alter-
native calibration relationship).
• A clean flow-check filter loaded into a filter cassette.
• A VFC Sampler Flow-Check Data Sheet (Figure 3.6) or a site log book.
2. Set up the flow-check system, as previously illustrated in Figure 2.4.
VFC samplers are normally flow-checked with a loaded filter cassette in
line (i.e., between the orifice transfer .standard and the motor). The
orifice transfer standard should be installed without fixed resistance
plates or with the adjustable resistance value fully open.
A. flow-check filter should never be used for subsequent sampling because
particles- larger than 10 /*m can be collected on the filter while the
inlet is raised. The sample mass will be biased as a result of using a
filter for both a flow check and subsequent sampling.
Caution; Tighten the faceplate nuts on alternate corners first to elimi-
nate leaks and to ensure even tightening. The fittings should be hand-
tightened; too much compression can damage the sealing gasket. Make sure
the orifice gasket is in place and the orifice transfer standard is not
cross-threaded on the faceplate.
-------
Section No.: 2.11.3
Date: January 1990
Page: 27
3. Turn on the sampler and allow the sampler to warm up to operating temper-
ature (3 to 5 min).
Note: The sampler inlet may be partially lowered over the orifice trans-
fer standard to act as a draft shield (if a shield is not otherwise pro-
vided). Use a block to provide at least 2 in. of clearance at the bottom
for air flow and for the manometer tubing.
4. Read and record the following parameters on the VFC Sampler Flow-Check
Data Sheet (Figure 3.6):
Sampler location and date.
Sampler S/N arid model.
Ambient temperature (Ta), °C and K.
Ambient barometric pressure (Pa), mm Hg or kPa.
Unusual weather conditions.
Orifice transfer standard S/N and calibration relationship.
Operator's signature.
5. Inspect the manometers for crimps or cracks in the connecting tubing
Open the valves and blow gently through the tubing, watching for the free
flow of the fluid.
Adjust,the manometers' sliding scales so that the zero lines are at the
... bottom.of the meniscuses. ' - - •
61 Connect the orifice manometer to the orifice transfer standard, and the
sampler manometer to the sampler stagnation pressure port located on the
side of the sampler base. Ensure that one side of each manometer is open
to atmospheric pressure. Be sure that the connecting tubing snuqlv fits
the pressure ports and the manometers.
7. Read the pressure drop as indicated by the orifice manometer (AH?0) and
record on the VFC Sampler Flow-Check Data Sheet. Read the stagnation
pressure drop and record as APstg (mm Hg) on the data sheet.
Note: Be sure to convert APstg to mm Hg using Equation 12 before
recording the reading on the data sheet.
mm Hg =. 25.4(in. H20/1.3.6) ' (Eq. 12)
8. Turn off the sampler and remove the orifice transfer standard.
9. With only a loaded filter cassette in line, turn on the sampler and allow
it to warm up to operating temperature.
10. Read and record the stagnation pressure drop (APstg) for the normal oper-
ating flow rate. Turn off the sampler. Replace the vacuum cap on the
stagnation pressure port.
-------
Section No.: 2.11.3
Date: January 1990
Page: 28
VFC SAMPLER FLOW CHECK DATA SHEET
I .ration £\JEJJDQ2A, CA Date f m3/min /• /^V m3/min
QC — Check Percentage Differenced ' • ^ _ • _ q/0
Oa (corrected sampler)6 _ / • / / Cx _ m3/min
Design Row Rate Percentage Difference' ~ '* / __
-------
Section No.: 2.11.3
Date: January 1990
Page: 29
11. Calculate and record Qa(orifice) flow rate for the flow-check point as
in Equation (6) , reproduced below: '
Qa(orifice) - {[(AH20)(Ta/Pa)]l/2 - b} {1/m} (Eq. 6)
where
Qa(orifice) = actual volumetric flow rate as indicated by the
. transfer standard orifice, m3/min
AH20 = pressure drop across the orifice, mm (or in.) HpO
Ta-= ambient temperature, K (K = °C + 273)
Pa = ambient barometric pressure, mm Hg or kPa
b = intercept, of the orifice calibration relationship
m = slope of the orifice calibration relationship.
12. Calculate and record the value of PI .(mm Hg) for the measurements with
and without the orifice installed.
PI = Pa - APstg .(Eq. 13)
where
PI = stagnation pressure, mm Hg or kPa
Pa' = ambient barometric pressure, mm Hg or kPa
APstg = stagnation pressure drop, mm Hg or "kPa.
13' w?!hU]nieJ?h/?C?£d thVta9nation pressure' ratio for the measurements "
with and without the orifice installed.
Stagnation pressure ratio = Pi/Pa (Eq. 14)
where
PI = stagnation pressure, mm Hg or kPa.
Pa = ambient barometric pressure, mm Hg or kPa.
14. Refer to the instrument manufacturer's lookup table (or alternative cali-
• bration re atjonship as described in Subsection 2.4.4) and determine the
Qa sampler) fow rates (n.3/min) for the measurements with and wUhout the
ature In'"? PP^ *H J"dicate? for the r^io of Pi/Pa and ambient ?emPer-
' sJe U6S °n the VFC samP1er fl°w check data
15. Using Qa(orifice) and Qa(sampler) for the measurements with the orifice
installed, calculate the QC-check percentage difference as: oriTlce
QC-check % difference = [Qa(sampler) - Qa(prificen f ]
I Qa(orifice) \ [100J (Eq. 17)
?he°contthro? chlrt ?o 'nr JfC ^ ]eJ Flow-Check °'ta Sheet and plot it on
the control chart for QC flow checks. If the QC-check percentage differ-
-------
Section No.: 2.11.3
Date: .January 1990
Page: 30
ence is less than or equal to ±7 percent, the sampler calibration is
acceptable. Those differences exceeding ±7 percent will require recali-
bration. Differences exceeding slO percent may result in the invalida-
tion of all data collected subsequent to the last calibration or valid
flow check. Before invalidating any data, double-check the sampler's
calibration, the orifice transfer standard's certification, and all cali-
brations.
16. Using this percentage difference and Qa (sampler) from the measurements
without the. orifice installed (i.e., for the normal operating flow rate),
calculate the corrected sampler flow rate as:
Qa (corr. sampler) = [Qa (sampler)] [10° " ^fferencej (Eq> 23)
Record Qa (corr. sampler) on the VFC Sampler Flow-Check Data Sheet.
17. Determine the design flow rate percentage difference between the inlet
design flow rate (e.g., 1.13 m3/min) and Qa (corr. sampler) as:
Design flow rate % difference = [Qa (corr.^sampler) - 1.13J (£q> lg)
Record this design flow rate percentage difference o,n the VFC Sampler
-Flow-Check Data Sheet and plot it on the control chart for the field
validation of flow rates. When plotting this value, use a different
symbol than is normally used for plotting values that are obtained during
sampling periods. If the design flow rate percentage difference is less
than or equal to ±7 percent, the sampler calibration is acceptable.
Those differences exceeding *7 percent will require recalibration. Dif-
ferences exceeding ±10 percent may result in the invalidation of all data
obtained subsequent to the last calibration or valid flow check. Before
invalidating any data, double-check the sampler's calibration, the ori-
fic'e transfer standard's certification, and all calculations.
-------
Section No.: 2.11.3
Date: January 1990
Page: 31
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-------
-------
Section No.: 2.11.4
Date: January '1990
Page: 1
2.11.4 FILTER PREPARATION AND ANALYSIS
?M!° sai"P1in9 Program depends on several factors. A primary
naue Th! labora*°^ staff's attention to detail and balance tech-*
nique. This section offers guidelines to enhance the accuracy of the laboratory
operation and, hence, the determination of PM10 mass concentrations laboratory
PM10 fiUe?s:Cy ""^ ** aW3re °f two Pn'mary sources of error in the handling of HV
1. Loss of particles during shipment or handling. Subsection 4 1 oresents
guidelines to help prevent post-sampling particle loss. Presents.
t^thf fn™™f 10?Arr°rS a^e ^aused by the retention of sulfur dioxide
•in the form of sulfate particulate on alkaline filters. The results of
experiments involving a variety of filters indicated that sulflte loadina
'
0? • Pr?«dulr« for *»" laboratory apparatus
"'' '
currently the ""'y cornnercfally available HV
4.1 Filter Handli
ng
i °
to '
-------
Criteria
Section No.: 2.11.4
Date: January 1990
Page: 2
TABLE 4.1. SUMMARY OF FILTER ACCEPTANCE CRITERIA
40 CFR 50, Appendix J
Explanation
Collection Greater than 99 percent as
efficiency measured by the dioctyl
phthalate (DOP) test, with
0.3 pm particles at the
sampler's operating face
velocity.
Integrity 5 /ig/m3, measured as the
concentration equivalent
corresponding to the differ-
ence between the initial and
final weights of the filter,
assuming a 24-hr sample
volume of 1600 m3.
Alkalinity Less than 25 microequiva-
lents/gram of filter.
The apparatus needed to perform
this test is not available for a
typical analytical laboratory. The
operating agency must insure that
the filter manufacturer has
complied with this guideline.
During a simulated sampling test, .
all sampling procedures are fol-
lowed EXCEPT the HV PM10 sampler is
not turned on. The tare weight of
the equilibrated- filter must agree
within ±8 mg of final weight.
Refer to Subsection 3, Field Opera-
tions, for recommended HV PM10
sampling procedures.
A typical'analytical laboratory
capable of conducting this test
measurement of alkalinity (see"
Reference 8).
is
-------
Section No.: 2.11.4
Date: January 1990
Page: 3
aanrpn J6 QUartZ f11ter' consi'stency tn labeling these filters will allow the
referenc?nPn nf°^ S'V^T t0/he filter ID number *or documentation and cross-
"nq thTfmer c^t^fo^ 1°™*' *ThiS V" als° e1imi'nate confusion in ?oad-
ImhnccL K ?u cassettes for subsequent sampling. If the filter ID number is to be
SSaoP anX f 0Peratln9 a9ency, gentle pressure must be used to avSid ffuer
damage, and extreme care must be taken to avoid duplication or missed numbers
Visual Filter Inspection
ing iii n
contaimng numerous defects should be returned to the supplier
The following are specific defects to look for:
K PJ5ho]e--A small hole appearing as a distinct and obvious briqht
'
of
01
th.t .<,ht be evidence
'•
*
4-3 Filter Equilibration
* 1co
'fc
-------
Section No.: 2.11.4
Date: January 1990
Page: 4
4.4 Initial Weighing Procedures (Tare Height)
Enough filters-to last for at least a 3-mo sampling period should be numbered
and weighed at one time.
Filters must be weighed on an analytical balance with a minimum resolution of
0.1 mg and a precision of 0.5 mg. Each balance used in the weighing procedures
must be identified by a balance number. Each balance should be assigned a block of
filter numbers to be used sequentially. Procedures are as follows:
1. Make sure that the balance has been calibrated (at least annually) and
maintained according to manufacturer's recommendations. If the balance
is out of calibration, have it calibrated according to manufacturer's
directions.
2. .Zero the balance according to manufacturer's directions.
3. Perform a QC "Standard Weight" check on the analytical balance. (Proce-
dures are outlined in the next subsection.).
4. If filters must be weighed outside the conditioning chamber, take care to
avoid interference with ambient hygroscopic particles, and begin the
weighing procedure within 30 s. Weigh the filter according to manufac-
turer's instructions, making sure that a stable reading is obtained. At
'routine intervals, check the zero and calibration of the balance as out-
lined in the next subsection.
Note; Be careful when loading and unloading the balance with quartz
TTTters. The corners and edges of the filter should not bump the balance
door because, the filter may break or filter material may be lost.
5. Place the tared filter, with the filter ID number facing upwards, in its
original container or a comparably sized box. Place a sheet of
8-1/2 x 11-in. tracing paper between each filter.
6. Record the balance number, the filter ID number, and the tare weight on
the Laboratory Data/Coding Form (see Figure 4.1) or alternative data
recording medium. When bound, these forms serve as a laboratory note-
book. Any filter'weight outside of the normal range of 3.7 to 4.7 g
should be investigated immediately. Sequentially number each form in the
upper right-hand corner.
7. Perform the tare and gross weight QC checks.as detailed in the following
subsection and submit all data to the QC supervisor for review. (Minimum
QC supervisor activities are also presented in Subsection 4.5.)
4.5 Internal QC
During the filter weighing process, the following QC checks are recommended.
All QC data, including the actual and measured weights, the date, and the opera-
tor's initials, should be recorded on an Internal Quality Control Log Sheet (see
Figure 4.2).
-------
Section No.: 2.11.4
Date: January 1990
Page: 5
Quality Control
Supervisor
Figure 4.1. Example laboratory data/coding form.
-------
Section No.: 2.11.4
Date: January 1990
Page: 6
N
CO
3-
L.
O)
Q
Balance
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-------
Section No.: 2.11.4
Date: January 1990
Page: 7
-
Control Log Sheet to the laboratorv nr 1™ h««i V °; f °" the Inte™> Quality
tained on each balance and also °ncl2Sed ?n ?he'loS°^7 'r^5 ^"^ be "ain-
cate any excess drift caused by an inltJent Ll?Snc??on. ""' ^^ ""' 1ndi-
and rIcordedTdraVJa?r ""^ dai'ly C6rtify the ac«ptability of all filter weights
4'6 P°'st-Samiiling Documentation and
adhereUP?S tfl]?" ^ the "•""- the »«P'« custodian shou,d
ai
field operator or if a
-------
Section No.: 2.11.4
Date: January 1990
Page: 8
2. If the exposed filter was packaged for shipment, remove the filter from
its protective envelope and examine the shipping envelope. If sample
material has been dislodged from a filter, recover as much as possible by
brushing it from the envelope onto the deposit on the filter with a soft
camel's-hair brush.
3. Match the filter ID number with the correct laboratory data/coding form
on which the original balance ID number, filter ID number, filter tare
weight, and other information are inscribed. The sample custodian should
group filters according to their recorded balance ID numbers. Initial
separation of filters by balance ID number will decrease the probability
of a balance error that could result from the use of different balances
for tare and gross weights. :
4. Remove the filter from the protective manila folder. Should the filter
be retained in its filter cassette, loosen the nuts on the top and remove
the filter. Overtightening of the nuts may cause the filter to adhere to
the cassette gasket. Gently remove it by the extreme corners to avoid
damage. .Inspect the filters for any damage that may have occurred during
sampling. Conduct a secondary'check of a sample's validity (as presented
in Subsection 3.3). If insects are embedded in the sample deposit,
remove them with Teflon-tipped tweezers and disturb as little of the
sample deposit as possible. If more than 10 insects are observed, refer
the sample to the supervisor for a decision on acceptance or rejection of
' the filter for analysis. , .
5. Place defect-free filters in protective envelopes and forward them to the
laboratory for weighing and analysis. File the data sheets for subse-
quent mass concentration calculations.
6. Place defective filters, with the type of defect(s) listed, in separate
clean envelopes, label the envelopes, and submit them to the laboratory
supervisor for final approval of filter validity.
4.7 Final Weighing Procedure (Gross Weight)
1. Place the defect-free filter(s) in a conditioning environment and allow
them to equilibrate according to procedures outlined in Subsection 4.3.
2. Repeat Steps 1 through 6 of the HV PM10 filter tare-weighing procedure
(Subsection 4.4). Record the indicated gross weight on the Laboratory
Data/Coding "Form.
3. Perform the internal QC checks described in Subsection 4.5 to ensure the
validity of reweighing.
4. If the HV PM10 filter is not to receive additional analysis, p-1ace it
into a protective envelope or folder. Deliver weighed filters to the
sample custodian for archiving.
-------
Section No.: 2.11.4
Date: January 1990
Page: 9
4-8 Calculation of PHIQ net Filter Loading
of PMlSefo'r0tShSae1nlIetret " "V PM1° filter
-------
Section No.: 2.11.4
Date: January 1990
Page: 10
>*
Ul
REPARATION AND ANALYSIS
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-------
Section No.: 2.11.5
Date: January. 1990
Page: 1
2.11.5 CALCULATIONS, VALIDATIONS, AND REPORTING OF PM10 DATA
Ho*0,M?aSUr?T"tS °f PI210 mass concentration in the atmosphere that are used to
determine attainment of the National Ambient Air Quality Standards for participa
3 ' "*1 1" ""^ °f micr°9rams P«r standard ?ub?c mete? &/"«
e measurements, "standard" means EPA-standard conditions of
•
air o
• 2 , -r conons o
'and pr?ssure' which are 25 •€ (298 K) and 760 mm Hg (101 k?a) ?espec-
sS^ifffSfsss ::; sal
Particle size discrimination by Inertia! separation requires that soecific air
"a "
and barometric pressure (Tav aUd P^rfo? the slmpU JSr,'« j*ual "era3e temperature
-------
Section No.: 2.11.5
Date: January 1990
Page: 2
5.1 Calculations
5.1.1. Flow Rate Calculations - Because flow control methods (and hence, calibra-
tion procedures) vary among different sampler models, the calculations necessary to
determine the average actual flow rate during a sample run will also differ. The
following general procedures are recommended for calculating the average ambient
flow rate of the HV PM10 sampler. In this subsection, it is assumed that the sam-
plers have been calibrated according to procedures outl.ined in Subsection 2.
Note: Consistency in units is required. Adoption of uniform designations of
K for temperature and mm Hg (or kPa) for pressure is recommended in all calcula-
tions.
HFC Sampler - The average actual flow rate for the sample period is calculated by
determining (a) the average of the initial and final manometer readings (APex) [or
the average flow recorder trace], (b) the average ambient temperature (Tav), and
(c) the average ambient barometric pressure (Pav) during the sampling period and
applying these values to the calibration relationship.
Each sampler's flow measurement system should be calibrated periodically, and
the calibration should be described by a mathematical expression (e.g., a least-
squares linear regression equation) that indicates the slope and intercept of the
calibration relationship. Following the procedure in Subsection 2, this expression
is in the'form of:
Qa = {[APex(Tav+30)/Pav]1/2 - b} {1/m}
(Eq. 9)
where:
Qa = the sampler's average actual flow rate for the sample period,
m^/min
APex s average of initial and final sampler manometer readings, (APexi +
. APexf)/2, mm (or In.) H20
Tav s average ambient temperature for the sample period, K (K = °C +
273)
Pav = average barometric pressure for the sample period, mm Hg (or kPa)
b s intercept of the sampler calibration relationship
m = slope of the sampler calibration relationship.-
[For the flow recorder,
Qa = {7[(Tav+30)/Pav]l/2 .
where:
(Eq. 9a)
I = average flow recorder reading for the sample period.]
The average actual flow rate is then corrected to EPA-standard conditions,
calculated as:
-------
Section No.: 2.11.5
Date: January 1990
Page: 3
Qstd = Qa(Pav/Pstd)(Tstd/Tav) (Eq. la)
where:
Qstd = average sampler flow rate corrected to EPA-standard volume flow
_ rate units, std. m-Vmin
P
-------
Section No.: 2.11.5
Date: January 1990
Page: 4
Qa = average actual sampler flow rate for the sample period,
m^/min '•
Pstd = standard barometric pressure, 760 mm Hg (or 101 kPa)
Tstd - standard temperature, 298 K
5.1.2 Calculation of PM10 Concentrations - Accurate reporting of total PM10 mass
concentration data requires the calculation of the total standard volume of air-
sampled (Equation 21) and the final computation of total PM10 mass concentration
(Equation'22).
1. • Calculate the total standard volume of air sampled:
Vstd = (Qstd)(t) (Eq. 21)
where: ' ' ;
Vstd = total volume of air sampled in standard volume units, std. m^
Qstd = average sampler flow rate corrected to EPA-standard condi-
tions, std. m3/min
t = total .elapsed sampling time, min.
2. Calculate total PM10 mass concentration in ^g/std. m3:
• PM10 = (105)(Wg - Wt)/Vstd (Eq. 22)
where: .
PM10 = PM10 mass concentration, /jg/std. m3
10^ = conversion factor, pg/g
Wg, Wt = gross and tare weights of the HV PM10 filter, respectively, g
Vstd s total sample volume in standard volume units, std. m3
5.2 Calculation Validation
Data that are needed to compute the mass concentration of PM10 originate from
two main sources: field operations and laboratory operations. These data must be
validated to ensure that all reported PM10 measurements are accurate relative to
the overall scope of the quality assurance program. When the final mass concentra-
tion of PM10 in a sample has been computed, the validation procedure not only will
check on these computations, but also will aid in the flagging of questionable mass
concentrations (i.e., extremely high or low values). Therefore, should a mass
concentration approach the primary or secondary ambient air quality standard, this
validation procedure will provide checks for all preliminary field and laboratory
operations. The steps of the calculation validation procedure are as follows:
1. Gather the following data for each sample:
• Total sampling time (min)
• Average actual volumetric flow rate, Qa (m3/min)
• Tare and gross weights, Wt and Wg, of the HV PM10 filter (g)
-------
Section No.: 2.11.5
Date: January 1990
Page: 5
Recalculate. the total mass concentration of PM10 for 7 samples per 100
(minimum of 4 per lot) as specified in Subsections 5.1.1 or 5.1.2. These
«;Sr?!nr fre;ju?nc1es may be ^justed subsequently, based on accumulated
experience and level of data quality. Decrease the frequency if experi-
ence indicates that data are of good quality, or increase it if data are
OT marginal or poor quality. It is more important to be sure that the
validation check is representative of the various conditions that may
influence data quality than -to adhere to a fixed frequency. '
Compare each validated PM10 concentration with the originally reported
datfof rorrprJ'any ^"V^* are f°und' initia1 the^ and Indicate the
tinna? «?rM» T ' i * ^ Per(?enta9e of errors is found, check addi-
tional calculated values. If consistent errors are found check all val-
ues in the block of data and investigate and correct the caSsI
4' f?3!!31^.1?431 TaSS c°ncentration values; note those that appear exces-
sively high or low and investigate. Repeat Steps 2 and 3 for these sam-
5' Mnh1! m?SS C0(?centrat|on computations appear correct and questionably
high or low values still exist, review all raw data (i.e. sample time
HSrH'^^-J^Tr1'0 fl°W rate''and its subsequent orrectP on to '
standard conditions) for completeness and correctness.
5.3 • Data Reporting . .
on , °f the standards for particulate matter in the ambient air is based
?ation of PMW JSl3 c°"centrati°n °fuPM1°- Inf°nnation on report ng and interlrl-
5S C?R ?J, Appendix K reSf>eCt t0 the attainme"t of these standard! is covered in
-------
Section No.: 2.11.5
Date: January 1990
Page: 6
TABLE 5.1. FORMULAS ASSOCIATED WITH PM10 MONITORING
Calculation
Formula
Equation
Conversion of flow rate
from actual to standard
volume units
Conversion of average flow
rate from actual to stand-
ard volume units
Conversion of flow rate
from standard to actual
volume units
Uncorrected air volume
measured by standard
volume meter
Correction of air volume
measured by std. vol. meter
to ambient baro. pressure
Actual volumetric flow
rate measured by standard
volume meter
Actual volumetric flow
rate measured by orifice
transfer standard
Transformed exit orifice
pressure for MFC sampler
calibration relationship
Transformed flow recorder
reading for MFC sampler
calibration relationship
Regression model (y=mx+b)
for calibration of MFC
sampler
Regression model (y=mx+b)
for calibration of MFC
sampler using flow recorder
Qstd = Qa(Pa/Pstd)(Tstd/Ta)
Qstd = Qa(Pav/Pstd)(Tstd/Tav)
Qa = Qst'd(Pstd/Pa)(Ta/Tstd)
(Eq. la)
(Eq. 2)
AVol. '= Final Volume - Initial Volume (Eq. 3)
Va = AVol.(Pa - AHg)/Pa
Qa = Va/ATime
(Eq. 4)
(Eq. 5)
Qa(orifice) = {[AH20(Ta/Pa)]l/2 - b} {1/m} (Eq. 6)
APext = [APex(Ta+30)/Pa]l/2
It = I[(Ta+30)/Pa]l/2
APext = m[Qa(orifice)] + b
It = m[Qa(orifice)] + b
(Eq. 7)
(Eq. 7a)
(Eq. 8)
(Eq. 8a)
(continued)
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Section No.: 2.11.5
Date: January 1990
Page: 7
Calculation
TABLE 5.1. FORMULAS ASSOCIATED WITH PM10 MONITORING (Cont'd)
Formula Equation
Calibration relationship.
for MFC sampler
Calibration relationship .
for MFC sampler using
flow recorder
Set-point flow rate for
MFC sampler
Set-point manometer
reading for MFC.sampler
Set-point reading for
MFC sampler using flow
recorder
Conversion of manometer
reading in inches of
H20 to mm Hg
Absolute stagnation
pressure
Stagnation press, ratio
Avg. stagnation press, ratio
Regression model (y=mx+b)
for calibration of VFC
sampler
Calibration relationship
for VFC sampler
Audit or-QC flow check
of sampler calibration
Audit or QC flow check
of sampler operational
flow rate
Regression model (y=mx+b)
for provisional calibration
of VFC sampler for audit
Qa = {[APex(Tav+30)/Pav)]l/2 . b} {1/m} (Eq. 9)
Qa = {T[(Tav+30)/Pav]l/2 - b} {1/m} (Eq. 9a)
SFR = (1.13)(Ps/Pa)(Ta/Ts)
SSP = [Pa/(Ta + 30)] [m(SFR)' + b]2
SSP = [m(SFR) + b][Pa/(Ta+30)]l/2
(Eq,
(Eq.
(Eq.
10)
11)
lla)
mm
Hg = 25.4(in. H20/13.6)
(Eq. 12)-
Pl = Pa - APstg. PI = Pa-- APstg
Stagnation press, ratio = Pi/Pa
Avg. stag, press, ratio = "PT/Pav
Pi/Pa = m[Qa(orifice)]/[Ta]l/2 +
(Eq.
(Eq,
(Eq.
13)
14)
14a)
(Eq. 15)
Qa(sampler) = {[(Pl/Pav) - b][Tav]l/2}{i/m} (Eq
^ diff. = [Qa(sampler) - Qa(auditn r i
I\Qa(audit)J [100J
< difference = [Qa(audit) - 1.13
1.13
[100]
(Eq.
16)
17)
18)
(Pl/'Pa). = m'[Qa(audit)] + b1
(Eq. 19)
(continued)
-------
Section No.: 2.11.5
Date: January 1990
Page: 8
TABLE 5.1. FORMULAS ASSOCIATED WITH PM10 MONITORING (Cont'd)
Calculation Formula Equation
Provisional calibration of
VFC sampler for audit Qa(audit) = [(Pi/Pa) * b']/m' (Eq. 20)
Total air volume sampled Vstd = (Qstd)(t) ' (Eq. 21)
PM10 mass concentration PM10 = (106)(Wg - Wt)/Vstd (Eq.- 22)
Corrected sampler flow rate Qa(corr. sampler)
under normal operating con-
ditions during audits and Tna/eam«i«J [100 - % difference! (Eq. 23)
QC flow checks s [Qa(sampler] [-ygg•j
SYMBOLS
b Intercept of linear regression calibration -relationship
b' Intercept of linear regression for provisional calibration for audit
of VFC sampler
AH£0 Pressure drop across a transfer standard orifice, mm (or in.) of
water column
AHg Differential pressure at inlet to standard volume meter, nan Hg (or
kPa)
I Flow recorder chart reading, arbitrary units on square-root-function
scale
I Average flow recorder chart reading over the sample period, arbi-
trary units on square-root-function scale
It Transformed flow recorder reading, for calibration relationship
m Slope of linear regression calibration relationship
m1 Slope of linear regression for provisional calibration for audit of
. VFC sampler
Pa Current ambient barometric pressure, mm Hg -(or kPa)
Pav Average ambient barometric pressure for the sample period, mm Hg (or
kPa)
APex Pressure in exit orifice plenum of sampler, measured with respect to
atmospheric pressure, mm (or in,,) water column
APex Average of initial and final APex readings, mm (or in.) H20
(continued)
-------
Section No.: 2.11.5
Date: January 1990
Page: 9
TABLE 5.1. FORMULAS ASSOCIATED WITH PM10 MONITORING (Cont'd)
SYMBOLS (cont'd)
APext
" PM10
Pstd
APstg
APstg
PI
Pi
Pi/Pa
., Q*
QS
Qa(audit)
Qa(orifice)
Qa(sampler)
Qstd
Qstd
SFR
SSP
t
Ta
Tav
Transformed exit orifice plenum pressure, for calibration relation-
snip, mm (or in.) water column
PM10 mass concentration, /Kj/std. n>3 ' '
EPA-standard atmospheric pressure, 760 mm Hg (or 101 kPa)
Relative stagnation pressure, measured with respect to atmospheric
pressure, mm Hg
Average of initial and final APstg readings, mm Hg
Absolute stagnation pressure, mm Hg
Average absolute stagnation pressure for the 'sample period, 'mm Hg
Ratio of absolute stagnation pressure to current barometric pressure
Average ratio of absolute stagnation pressure to barometric pressure
for the sampler period
Sampler flow rate measured in actual volumetric units, m3/min
Average sampler f Tow rate for the sample period measured in actual
volumetric units, nH/min
Sampler flow rate in actual volumetric units determined by a flow
rate audit, . nH/min
Flow rate measured by an orifice transfer standard in actual
volumetric units, m3/min
Flow rate in actual volumetric units indicated by sampler's calibra-
tion relationship during flow rate audit or QC flow check, m3/min
.Flow rate measured in EPA-standard volumetric units, std. m3/min
f°r the Sanp1e peHod in standard
Set-point Mow rate in actual volumetric units for MFC sampler
m-Vnnn . . r '
MFr™n * mf°m!ter reading [or flow recorder reading] for
MFC sampler needed to obtain SFR, mm Hg [or I]
Total, elapsed sampling time, min
Current ambient temperature, K (K = °C + 273)
Average ambient temperature during the sample period, K
(continued)
-------
Section No.: 2.11.5
Date: January 1990
Page: 10
TABLE 5.1. FORMULAS ASSOCIATED WITH PM10 MONITORING (Cont'd)
SYMBOLS (cont'd)
ATime Elapsed time during which a flow rate is measured by a standard
volume meter, min - •
Tstd EPA-standard temperature, 298 K
Va Actual air volume measured by standard volume meter at ambient tem-
perature and barometric pressure, m^
AVol Uncorrected air volume measured by standard volume meter, m^
Vstd Total sample volume measured in standard volume units, m^
Wg, Wt Gross and tare weights of the HV PM10 filter, respectively, g
-------
Section No.: 2.11.6
Date: January 1990
Page: 1
2.11.6 MAINTENANCE
Maintenance is defined as a program of positive actions aimed toward prevent-
ing failure of monitoring and analytical systems. The overall objective of a rou-
tine preventive maintenance program is to increase measurement system reliability
and to provide for more complete data acquisition. -
This section outlines general maintenance procedures for HV PM10 samplers
r?IIP Jfr ^ °rjatl'on °n a Particular sampler or on laboratory equipment
h mnufaturer's instruction manual for the individual
°f thiS Section' su™-izes maintenance activities
Recor^ should be maintained for the maintenance schedule of each HV PM10
nl't ^ ?hou1d ref1e^ the history of maintenance, including all replace-
parts suppliers, costs, expenditures, and an inventory of on-hand spare
equipment for each sampler. Check sheets should be used to record preventive
and/or corrective maintenance activities and the subsequent sampler calibration
6 . 1 Maintenance Procedures
The HV PM10 sampler is comprised of two basic components: the inlet and the
flow control system. Because of the differences between sampler models ft will be
necessary to refer to the manufacturer's instruction manual for specific steo-bv-
step maintenance guidelines and necessary supplies. speuiTic, step oy- .
6.2 Recommended Maintenance Schedules
the following maintenance frequencies.
!mpact1on Inlet -.The impaction inlet should be dismantled and
^^m%m^s^<"^~-
-------
Section No.: 2.11.6-
Date: January 1990
Page: 2
6.2.3 HFC Base - The MFC base is equipped with the following items:
1. Connecting tubing and power lines, which must be checked for crimps,
cracks, or obstructions on sample recovery days. Fittings should be
inspected periodically for cross-threading and tightness.
2. A filter screen, which should be inspected on sample recovery days for
any impacted deposits.
3. Filter cassette gasRets, which need to be inspected each time a cassette
is loaded. A worn cassette gasket -is characterized on exposed filters by
a gradual blending of the'boundary between the collected particulates and
the filter border.
4. Motor and housing gaskets, which should be .checked at 3-mo intervals and
replaced as necessary.
5. Blower motor brushes, which should be replaced before they become worn to
the point that damage may occur. Although motor brushes usually require
replacement after 600 to 1,000 h of operation, the optimum replacement
interval must be determined by experience. A pumice stone can be used
against the motor's, contacts to ensure high conductivity. Change the
brushes according to manufacturer's instructions, and perform the opera-
tor's field-calibration check as presented in Subsection 3.5. If the
sampler's indicated flow rate exceeds the manufacturer-specified design-
flow-rate range, adjust the sampler before the next run day.
To achieve the best performance, new brushes should be properly seated on
the motor's commutator before full voltage is applied to them. After the
brushes have been changed, operate the sampler at 50 to 75 percent of
normal line voltage for approximately 30 min. The motor should return to
full performance after an additional 30 to 45 min at normal line voltage.
Caution; The motors that are used for HV PM10 samplers are higher-cur-
rent versions of the motors that have been used for HV total suspended
particulate samplers. The brushes for the two types of motor are differ-
ent. Make sure.that the correct replacement brushes are used for the
maintenance of HV PM10 samplers.
6. If a motor needs to be replaced, be sure to use the higher-current ver-
sions that are needed for HV PM10 sampling. When lower-current motors
are installed in- HV PM10 samplers, the flow rate has been found to vary
with changes in the line voltage.
7. A flow controller, which should be replaced if the flow recorder indi-
cates no flow, low flow, excessive flow, or erratic flow. 'Minor adjust-
ments can be made to alter sampling flow rates; however, the controller
generally cannot be repaired in the field.
8. A flow recorder, which requires very 'little maintenance, but does deteri-
orate with age. Difficulty in zeroing the recorder and/or sign-ificant
-------
Section No.: 2.11.6
Date: January 1990
Page: 3
differences (i.e., greater than 0.3 m3/nrin) in average flow rates ob-
tained from consecutive sampling periods usually indicate a faulty re-
corder. The recorder pens should be replaced every 30 recording days
In dry climates, a more frequent replacement schedule may be required.
6.2.4 VFC Base - The VFC base is equipped with the following items:
Power lines, which must be checked for crimps or cracks on sample recov-
ery days Fittings should be inspected periodically for cross-threading
1.
and tightness.
2. A filter screen and the throat of the choked-flow venturi,.which should
be inspected on sample recovery days for any impacted deposits.
3. Filter cassette gaskets, which should be checked each time a filter is
Innr^ f?\i H°rn CfSuUu 9asket is characterized on exposed filters by
a gradual blending of the boundary between the collected particulates and
the filter border.
4.
5.
?nrSni!?t?ha?rHSheS| Whl'Ch Sh°Uld be reP]aced before they become worn to
the point that damage may occur. Although motor brushes usually requir*
" ^0 " °f °Peration' ^ °P«™« replLS
m st bede '
nt tKo J aetenmned by experience. A pumice stone can be used
against the motor's, contacts to ensure high conductivity. Change the
?Jr'sef,>l5°rJr8 to.»anu^turer's instructions, and perform the opera-
tor s f eld-calibration check as presented in Subsection 3.5. If the
sampler s indicated flow rate exceeds the manufacturer-specified desiqn-
f low-rate range, recalibrate the sampler before the next run day. 9
To achieve the best performance, new brushes should be properly seated on
the motor's commutator before full voltage is applied tb them After the
brushes have been changed, operate the sampler at 50 to 75 wrcent Sf
normal line voltage for approximately 30 min. The motor sho^S retu n to
full performance after an additional. 30 to 45 min at normal line voltage?
The motors that are used for HV PM10 samplers are hiaher-
replacement brush
mointenance or HV PM10 samplers.
6. If ,
5e/ePIaced. »e sure to use the higher-current
ver-
-------
Section No.: 2.11.6
Date: January 1990
Page: 4
6.3 Refurbishment of HV PM10 Samplers
If operated in the field for extended periods, HV PM10 samplers may require
major repairs or complete refurbishment. If so, refer to the manufacturer's in-
strument manual before work is undertaken. A sampler that has undergone major
repairs or refurbishment must be leak-checked and calibrated prior to sample col-
lection.
-------
Section No.: 2.11.6
Date: January 1990
Page: 5
CO
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-------
-------
Section No.: 2.11.7
Date: January 1990
Page: 1
2.11.7 AUDITING PROCEDURES
The operating agency must perform QA audits and process evaluations to deter-
mine the accuracy of the PM10 monitoring system and, hence, the data it produces
The primary goal of an auditing program is to identify system errors that may re-
sult in suspect or invalid data. The efficiency of the monitoring system (i.e.
labor input vs. valid data output) is contingent upon effective QA activities '
This true assessment of the accuracy and efficiency of the PM10 measurement system
can only be achieved by conducting an audit under the following guidelines: .
• Without special preparation or adjustment of the system to be audited.
By an individual with a thorough knowledge of the instrument or process
being evaluated, but not by the routine operator.
With accurate, calibrated, NIST-traceable transfer standards that are
completely independent of those used for routine calibration and OC flow
checks.
With complete documentation of audit information for submission to the
operating agency. The audit information includes, but is not limited to
types of instruments and audit transfer standards, instrument model and '
serial numbers, transfer-standard traceability, calibration information,
and collected audit data. •
n ™n d?scrib*d in this subsection produce two quantitative
tf 3 ° !fP1er s Performance: The audit flow rate percentage differ-
31?" °W ra!6 Percenta9e difference. The audit flow rate percent-
fere"ce. ^ermines the accuracy of the sampler's indicated flow rate by
r nir? \ W1tj * flow rate from the audit transfer standard. The design flow
the iS?ete2eSa?an f(nere^e deHtenTn'nes "?0w c1osely the sampler's flow rate.matches
tne inlet design flow rate under normal operational conditions.
obser^r should be Pres^t for the audit, preferably the rou-
nteaitv o th , -*5*"^"9^'11??6 nt' uThis practice -not on^ Contributes to the
integrity of the audit, but also allows the operator to -of fer anv exDlanations an^
informat^n that will help the auditor to determine the po sible^auses of 5? creo-
ancies between audit-standard values and the sampling equipment values. Q1screp
i different mod^s of samplers because of dif-
rates, flow-controlling devices, options utilized fi P
continuous-flow recorder) , -and the configuration of the samplers The audit orace
dures provided in this section are specific to high-vofuJI fflj ) mil samolers that'
^K^1^^^
e^
-------
Section No.: 2.11.7
Date: January 1990
Page: 2
7.1 Flow-Rate Performance Audit Procedure for Mass-Flow-Controlled
(MFC) HV PM10 Samplers
For this MFC procedure, the following conditions are assumed:
• The MFC sampler utilizes an electronic mass-flow controller for flow-rate
control.
• The sampler's flow rate.is measured by a water or oil manometer connected
to the exit orifice plenum pressure port [or, if necessary, by a continu-
ous flow recorder connected to the exit orifice port and equipped with
square-root-scale chart paper].
• The sampler inlet is designed to operate at a flow rate of 1.13 m^/min at
actual conditions; the acceptable flow-rate fluctuation range is ±10 per-
cent of this value (i.e., 1.02 to 1.24 m3/min).
• The calibrated, NIST-traceable audit transfer standard is an orifice
device with an associated water or oil-manometer.
• The audit orifice transfer standard'.s calibration relationship is ex-
pressed in actual volumetric flow-rate units (Qa) as described in Subsec-
tion 2.2.
Note: Do not attempt to audit HV PM10 samplers under windy conditions.
Short-term wind velocity fluctuations will produce variable pressure readings by
the audit orifice transfer standard's manometer. The audit will be less precise
because of the pressure variations.
The auditor should adhere to the following procedures during an audit of the
MFC sampler:
1. Transport the following equipment to the monitoring site:
• Audit orifice transfer standard with calibration relationship in
actual volumetric flow-rate (i.e., Qa) units and traceable to NIST
(see Subsection 2.2). This orifice transfer standard should not be
the same one that is used for routine calibrations and QC flow
checks.
• An associated water or oil manometer, with a 0- to 400-mm (0- to
16-in.) .range and minimum scale divisions of 2 mm (0.1 in.).
• A thermometer, capable of accurately measuring temperature over an
appropriate range to the nearest ±1 °C and referenced to an'NIST or
ASTM thermometer within ±2 °C at least annually.
-------
Section No.: 2.11.7
Date: January 1990
Page: 3
A portable aneroid barometer (e.g., a climber's or engineer's altim-
eter) capable of accurately measuring ambient barometric pressure
over the range of approximately 500 to 800 mm Hg (66 to 106 kPa) to
the nearest- mm Hg and referenced within ±5 mm Hg to a barometer of
known accuracy at least annually.
MFC Sampler Audit Data Sheet such as shown in Figure 7.1 (blank
forms appear in Subsection 12). y ^,cn*
Clean filter [and clean recorder chart, if a flow recorder is used
to quantitatively measure the flow rate].
SfhTr nl^o! V?e-at°r isr«Ponsifale for providing the manometer (or
other device) that is normally used for measuring the sampler's flow
rate the sampler calibration relationship that is currently in effect
for determining the flow rate for sample periods, and any other informa-
tion or equipment that is normally used tb determine ^sampler's in™-
cdie •
[If a continuous flow recorder is bei'ng used quantitatively in lieu of a
s/rsis: *; rare sa;p1r flow rate record the *"* *°« ° J s4ie
S/N date, and the auditor's initials on the blank side of a clean re-
recordVr c'hart °P?? th* £?"* "T °f the $ampler and ^'a^ the clean
2S?£ rharJ £* +t J sampler was calibrated by using square-root-
-rh*rt ±H **?£*' the audlt must be conducted with the same type of
chart paper. Observe the recorder zero setting. If necessary instruct
the operator to adjust the pen to indicate true zero.] 55dry' ,instruct
3' ,!:!trUSM!!! °P!l?^i:.t0,inSta.11 a.?lean.fi1ter in the HV PM10. DO NOT
on the
ren at-i; samPer
screen. An audit filter should never be used for subsequent semoli
?heea?n?e?ais1Cr ?Ldar9?h ^^ 1° ^ Can 5? C°11ected on^he ffuSr
me iniet is raised. The sampler mass wil be biased as a result of
using a filter for both an audit and subsequent sampling.
Chec^tha^th^ilicJT1" transfe!; standard's faceplate on the sampler.
Check that the gaskets are in good condition and have not deteriorated.
nuts evenly on alternate corners to
hgn and uniformly seat the gaskets. The nuts should be hand-
only, too much compression can damage the sealing gaskets.
.5. Install the audit orifice transfer standard with no 'resistance Plate or
J va ve of a vanah-ia_^Qcip + ,«^« ----x---- TTP _ " ' ul
onnK , e o
^r* i?ValvVf a variab'le-resistance orifice wide open. Forrsist-
ance plate orifices, make sure the orifice gasket is present and the
riflr Standard is not crosf-threadedPon the
Standard'S P-sure port
-------
Section No.: 2.11.7
Date: January 1990
Page: 4
MFC SAMPLER AUDIT DATA SHEET
Station Location
Sampler
MlLfoe.D
Date
J/J//39 Time
. mm Hg. Ta
°C
"2-7
K, Unusual Conditions
IO3<2~7
Orifice Calibration Date /2. //5/ o%
Audit Orifice S/N
Orifice Calibration Relationship: m = /• 2.*V3O b » ~O- OQ &2- r ~ 0.9*777
Sampler Calibration Relationship: m = O- 9/37 b = O-2.g2.*7 r , Q. 9977
Orifice Pressure Drop UH2O) 5-*7 in. H2O Qa (audit)3 '• / ' ' m3/min
With Orifice Installed Without Orifice Installed
H.O
Sampler Pressure Drop
Qa (sampler)15
1. 1
in. H2O
m3/min
I-J5J
in. H2O
m3/min
Audit Flow Rate Percentage Difference0
Qa (corrected sampler)01 __ _ I.I//
• _ -7 i_;
£-' '
Design Flow Rate Percentage Difference6
. m3/min
%
aFor calculation of audit orifice standard flow rates:
Qa (audit) = {U(H2O)(Ta/Pa)r/z - b} {1/m|
''For calculation of sampler flow rates:
Qa (sampler) - {(UPex/PaMTa + 30)I'/2 - b> Ji/mj
"Audit % Difference
(sampler) - Qa (orifice) 1 r
Qa (orifice)
^Qa (corrected sampler) * Qa (sampler) -
orifice installed.
11 iuu | where Qa (sampler) is measured with the
100 - Audit % Difference
100
where Qa (sampler) is measured
without the orifice installed
-^ „ fOa (corrected sampler) - 1.13 1 r ~\
eDesign Flow Rate % Difference = 10°
Auditor
Observer
Figure 7.1. Example MFC sampler audit data sheet.
-------
Section No.: 2.11.7
Date: January 1990
Page: 5
6. Leak test the audit system (refer to Subsection 2.3.2, Step 5). Identify
and correct any leaks before continuing.
7. Inspect the audit orifice manometer connecting tubing for crimps or
cracks. Open the manometer valves fully and blow gently through the
tubing, watching for the free flow of the fluid'. Adjust the manometer
rnn n? It -!?*that the zero 11ne is at the bottom of the meniscuses.
Connect the audit manometer to the pressure port on the orifice. Make
sure the unconnected side of the manometer is open to the atmosphere.
Make sure that the tubing fits snugly on the'pressure port and on the
manometer.
8" to™ min)^ 5amp1er and a11°W U to warm up to °Pei"ating temperature (3
f71^folhf/al!pl!r*1nlet may be Partially lowered over the audit orifice "
transfer standard to act as a draft shield (if a shield is not otherwise
provided)., use a-block to provide at least 2 in. of clearance at thT
bottom for air flow and for the manometer tubing.
h6 3nd reC°rd the f°11owin9 Parameters on the MFC Sampler Audit Data
Sampler location, date, time. • '
Sampler model and-S/N, and calibration relationship
Ambient temperature (Ta), K (K •= °C +'273)
Ambient barometric pressure (Pa), mm Hg or'kPa.
Unusual weather conditions.
Audit orifice transfer standard S/N and calibration information
10. When the sampler has warmed up to operating temperature, observe the
pexor thP rJetrat°r "t0^ead the Samp1er exit orifl'ce "anometer reading,
data sheet!! C°ntinuOUS f1ow Border response, I], and record it on the
•12. Turn off the sampler and remove the audit orifice transfer standard h.it
do not remove the filter. Turn the sampler on again and repeat Step H
for the normal operating flow rate. repeal btep u
13. Gather together all audit data, including the audit orifice transfer
standard's calibration information, the MFC sampler's ca ibrat?Sn data
[and the recorder chart that graphically displays the sampler response].
14. Verify that the correct readings have been inscribed on the data sheet.
standard, ,s
-------
Section No.: 2.11.7
Date: January 1990
Page: 6
16.
17.
18.
19.
Qa(audit) = {[AH20(Ta/Pa)]l/2 - b} {1/m}
(Eq. 6)
where:
Qa(audit) = actual volumetric flow rate as indicated by the audit
orifice transfer standard; nwmin
AH20 s pressure drop across the orifice, mm (or in.) H20
Ta * ambient temperature, K (K = °C + 273)
Pa = ambient barometric pressure, mm Hg (or kPa)
b - intercept of the audit-orifice transfer standard's cali-
bration relationship.
m - slope of the audit orifice, transfer standard's calibra-
tion relationship
Instruct the operator to calculate the sampler's indicated flow rate,
Qa(sampler) with and without the orifice installed, as it is normally
done, using the sampler's calibration relationship (Equation 9 [or 9a],
Subsection 2.3.3) and record both Qa(sampler) values on the data sheet.
Calculate the percentage difference between the sampler's indicated flow
rate, Qa(sampler) with the orifice installed, and the corresponding audit
flow rate, Qa(audit), determined from the audit orifice transfer standard
as:
tadit fl« rate Vdiffere.ee v['"(""''&LilJ)("""t)]
100
(Eq. 17)
If
Record the audit flow rate percentage difference on the data sheet.
the audit flow rate percentage difference is less than or equal to
±7 percent, the sampler calibration is acceptable. Differences exceeding
±7 percent require sampler recalibration. Differences exceeding ±10
percent may result in invalidation of all data subsequent to the last
calibration or valid flow check. Before invalidating any data, double-
check the sampler's calibration, the audit orifice transfer standard's
certification, and all calculations.
Calculate the corrected sampler flow rate, Qa(corrected sampler), using
Equation 23:
Qa(corr. sampler) = [Qa(sampler)]
100 - audit
100
difference]
(Eq. 23)
where Qa(sampler) is for the measurement without the audit orifice trans-
fer standard installed. Be sure to carry over the sign of the audit %
difference from Step 17.
Calculate the design flow rate percentage difference between the cor-
rected sampler flow rate, Qa(corr. sampler), and the inlet design flow
rate of 1.13 m^/min as:
-------
Section No.: 2.11.7
Dat<••; January 1990
Page: 7
Design flow rate _ fQa(corr. sampler) - 1.131 r,nrti
% difference ' [ - 1.13 ' - ^ [lOOj (Eq. 18)
2°' r^rl^6 JeS1'9J- H°W rate. Pontage difference. If the design flow
niir KVK J?e dlfference i? less than or equal to ±7 percent, the sam-
pler calibration is acceptable. Differences exceeding ±7 percent should
be investigated, and deviations exceeding ,10 percent (or the acceptab e
?™]?-/]°W~ra*e ra"3e sP<*lfled fay the inlet manufacturer) may result in
valfd ??n10rh °V VP °^tai?^ sub^quent to the last calibration or
or ft! £™S?i'«, Bejore(invalld?^ng any data, double-check the audit
orifice transfer standard's certification and all calculations.
Note: Deviations from the inlet design flow rate may be caused in cart
by deviations in the ambient temperature and pressure from the seasonal
°110n CCUlatethe °t P-
C?nCUla
-------
Section No.: 2.11.7
Date: January 1990
Page: 8
Install filter and orifice
on sampler and leak check
(Steps 1-8)
Measure audit flow rate,
Qa (audit)
(Steps 9.12)
Sampler operator measures
stagnation pressure ratio
and determines indicated
flow rate, Qa (sampler)
from sampler caJbration
(Steps 10.11.13)
P1/Pa not on
lookup table
Calculate tentative
% difference for
sampler calibration
(Steps 14.15.16)
%diff. not within ±6%
Measure stagnation pressure and
Qa (orifice) at 2 or more additional
flow rates and compute provisional
calibration slope and intercept
(Steps 23. 24)
%dffl. within ±6%
Audit flow rate %
difference is firm
Remove orifice; operator measures
stagnation pressure at normal
operating flow rate, with fitter
(Steps 25. 26. 27)
Remove orifice; operator measures
stagnation pressure at normal
operating flow rate, with filter
(Steps 16.17. 13)
JL
JL
Calculate Qa (sampler) and Qa (audit)
at normal operating flow rate
(Step 28)
Operator determines indicated flow rate,
Qa (sampler), at normal operating flow
rate. (Step 19)
I
Compute audit flow rate % difference
of Qa (sampler) with respect to
Qa (audit) (Steps 29,30)
Calculated Qa (corrected sampler)
using audit flow rate % difference
(Step 20)
Compute design flow rate % difference
of Qa (audit) with respect to design flow-
rate. (Steps 31.32)
Calculate design flow rate %
difference using Qa (corrected sampler)
(Steps 21. 22)
t
One-Point Audit is Complete
t
Three-Point Audit is Complete
Figure 7.2. Flow chart of performance audit procedures for
volumetric-flow-controlled PM10 samplers.
-------
Section No.: 2.11.7
Date: January 1990
Page: 9
1. Transport the following equipment to the monitoring site:
Audit orifice transfer standard wi.th calibration relationship in
actual volumetric flow-rate (Qa) units and traceable to NIST. The
audit orifice transfer standard's faceplate or filter cassette may
require modification to ensure a good seal during the performance
audit. The audit orifice transfer standard should not be the same
one that is used for routine calibrations and QC flow checks.
• An associated water or oil manometer, with .a 0- to 400-mrn (0- to
16-in.) range and minimum scale division of 2 ram (0.1 in'.).
A thermometer, capable of accurately measuring temperature over an
appropriate range to the nearest ±1 «C and referenced to an NIST or
ASTM thermometer within ±2 °C at least annually.
A portable aneroid barometer (e.g., a climber's or engineer's altim-
eterj, capable of accurately measuring ambient barometric pressure
over the range of approximately 500 to 800 mm Hg (66 to 106 kPa) to
the nearest mm Hg and referenced within ±5 mm Hg of a barometer of
known accuracy at least annually.,
• • VFC Sampler Audit Data Sheet such as shown in Figure 7.3 (blank
forms appear in Subsection 12).
• A clean filter.
The S1te operator is respons-.ble for providing the manometer (or
<™nP^ Te m?aSUring device) that is n°™a11y used for measuring the
sampler s stagnation pressure, the sampler lookup table or alternative
ffow r^I°^ecatTShip ^al is current]y in effect for determining the
thS? i* ™™ i? P1ln.9 Periods, and any other information or equipment
that is normally used to determine the sampler's indicated flow rate.
2. Instruct the operator to install a clean filter in the VFC sampler. A
nr™!riCa5 iVay be US!d if the audit orifl'ce transfer standard can be
properly mounted on top of the cassette. -Otherwise, install the filter
without the cassette. An audit filter should never be used for subs" '
thTfilS h?i thUSe Partic1es.larger than '10 jm can be collected on
' a rplu f * the inlet is raised.- The sample mass will, be biased as
a result of using a filter for both an audit and subsequent sampling
3' Check'1 Jh^%hpd^ ?rJfl'Ce transfe!: standard's faceplate on the sampler..
Check that the gaskets are in good condition and have not deteriorated.
Caution: Tighten the faceplate nuts evenly on alternate corners to
?ia°hPt±Ha1T T1 unif«r»ly S6at the gask*tS' The nut* sh™d be hand-
tightened only; too much compression can damage the sealing gaskets
-------
Section No.: 2.11.7
Date: January 1990
Page: 10
VFC SAMPLER AUDIT DATA SHEET (Part 1)
Station Location -*-/*" **' *™ t roL-\^> Date / I-2-^1 V I Time
Sampler Model W.gJ>£ //Vg- s/N /OV & ~7 ;, Orifice Calibration Date (~2-\ I S~ I & o
Orifice Calibration Relationship: m « t'l-^go D _ -a.ooCa, r , Q
Sampler Calibration Relationship: m - L^qolfoP b - 7~A&£-£ r -
Orifice Pressure Drop UH2O) */-*?" in. H2O Qa (audit)3 f' ° ^ ^> _ m3/min
With Orifice Installed Without Orifice Installed
Stagnation Pressure UPstg) _ -3 1 * "3> "7 mm Hg 3 3. o 2 — mm Hg
Absolute Stagnation Pressure (P1)5 £ *7 *?• & -3 mm Hg "7 ^ .£"* 7 ^ mm Hg
Stagnation Pressure Ratio (P1/Pa) O fe?¥6~7 (see Note) ^-^ ^V-3 (see NOte)
Qa (sampler)0 ' /- / 2. / m3/min / ^/V ^ m3/mjn
Audit Flow Rate Percentage Difference*1 ^^ ^ "/o (see Note)
Qa (corrected sampler)" _ t'flf~^> _ m3/min
, tJ. -)
Design Flow Rale Percentage Difference' _ ' *• ^ — _ %
Note: If Pi/Pa is less than the values that are listed in the manufacturer's lookup table or if audit flow rate
percentage difference is greater than ± 6 percent, proceed to Part 2 of the VFC Sampler Audit
Data Sheet. Otherwise, complete this part.
(orifice) - {U(H2O)(Ta/Pa)r/» - b} {1/m}
bP1 - Pa - .iPstg
cDetermine Qa (sampler) from manufacturer's lookup table (or from alternate calibration relationship)
dAudit % Difference » (Qa (sampler) - Qa (audit)
Qa (audit)
[100] where Qa (sample) is measured with the
orifice installed.
eQa (corrected sampler) » Qa (sampler)
100 - Audit % Difference
•[•
_ . _, _ „, _.„ Qa (corrected sampler) - 1.13
'Design Row Rate % Difference
where Qa (sampler) is measured
100 without the orifice installed
1-13
Auditor R. ^ I a- ft T- _ Observer K •
(continued)
Figure 7.3. Example VFC sampler audit data sheet. (Part 1 of 2)
-------
Section No.: 2.11.7
Date: January 1990
Page; 11
VFC SAMPLER AUDIT DATA SHEET (Part 2)
(continued from Part 1 of this form)
Station Location /VJP/JA/A Pe Lf 3 Date '
Sampler Model —W£T>Ki AS/Z. S/N ( g V^>7^
** -2-^2—mmHg, Ta (_L °C _2rfL^K, Unusual Conditions
Audit Orifice S/N
Time 3-," /£
Orifice Calibration Relationship: m - A
Orifice Calibration Date
b - —
Provisional Sampler Calibration Relationship: X = Qa (Orifice), Y * (Pi/Pa)
~
Qa (Orifice)'
(m3/min)
Measurements with filter installed and Audit Orifice Transfer Standard removed-
APst9 - 33.01- • - _ mm Hg
Pi/Pa _ <^ , <
Qa (audits /
m3/mjn Qa (samp,er)d
Audit Flow Rate Percentage Difference6 _
Design Flow Rate Percentage Difference'
-V. a
aP1 «. Pa - APstg
bQa (orifice) . {[(AH2O) (Ta/Pa)J1/z - b} {1/m}
cQa (audit) « {(Pi/Pa) - b'|/m'
dOa (sampler) is determined from the lookup table or .alternative calibration relationship
eAudit Flow Rate o/o Difference = RQa ^rnp'er) - Qa (audit)]
I Qa (audit) . j L100J
'Design Flow Rate % Difference - [ Qa (audit) ~ 1-131 [100]
L 1.1*3 j
Auditor
.o
.mm Hg
. m3/min
Figure 7.3. Example VFC sampler audit data sheet. (Part 2 of 2)
-------
Section No.: 2.11.7
Date: January 1990
Page: 12
4. Install the audit orifice transfer standard with no resistance plate, or
open the valve of a variable-resistance orifice wide open. For resist-
ance plate-type orifices, make sure the orifice gasket is present and
that the audit orifice transfer standard is not cross-threaded on the
faceplate. Seal the audit orifice transfer standard's pressure port and
the stagnation pressure port with rubber caps or similar devices,
5. Leak test the audit system-(refer to Subsection 2.4.2, Step 4). Identify
and correct any leaks before proceeding.
6. Inspect the audit manometer connecting tubing for crimps or cracks.
Fully open the valves and blow gently through the tubing, watching for
the free flow of the fluid. Adjust the manometer sliding scale so that
the zero line is at the bottom of the meniscuses. Connect the audit
manometer to the pressure port on the audit orifice transfer standard.
Make sure the unconnected side of the manometer is open to the atmos-
phere. Make sure that the tubing fits snugly on the pressure port and on
the manometer.
7. Read and record the following parameters on the VFC Sampler Audit Data
Sheet:
Sampler location, date, time.
Sampler model and S/N.
Ambient temperature (la), °C and K (K = °C + 273). .
Ambient barometric pressure (Pa), mm Hg (or kPa.).
Unusual weather conditions.
Audit orifice transfer standard's S/N and calibration relationship.
Sampler lookup table number or other calibration relationship cur-
rently in effect.
8. Turn on the sampler and allow it to warm up to operating temperature (3
to 5 rain).
Note; The sampler inlet may be partially lowered over the audit orifice
transfer standard to act as a draft shield (if a shield is not otherwise
provided). Use a block to provide at least 2 in. of clearance at the
bottom for air flow and for the manometer tubing.
9. When the sampler has warmed up to operating temperature, observe the
pressure drop across the orifice by reading the total manometer deflec-
tion and record as AH2<3 on the audit data sheet.
10. Instruct the operator to measure the sampler's relative stagnation pres-
sure (i.e. relative to atmospheric pressure) with the manometer (or other
pressure measurement instrument) normally used to measure stagnation
pressure. Record the relative stagnation pressure as APstg on the data
sheet. If APstg is measured in inches of water, convert the reading to
mm Hg using Equation 12:
-------
Section No.: 2.11.7
Date: January 1990
Page: 13
mm Hg = 25.4 (in. H20)/13.6 (Eq. 12)
11. Compute the absolute stagnation pressure, PI, as:
PI - Pa - APstg (Eq. 13)
and the absolute stagnation pressure ratio as:
Stagnation pressure ratio = Pi/Pa (Eq. 14)
Record the Pi/Pa ratio on the audit data sheet.
Qa(audit) - {[4H20(Ta/Pa)]l/2 - b} {1/n} (Eq. 6)
where:
Qa(audit) = actual volumetric flow rate as indicated by the audit
orifice transfer standard, m3/min '
AH20 = pressure drop across- the orifice, mm (or in.) H?0
Ta = ambient temperature, K (K = °C + 273)
Pa = ambient barometric pressure, mm Hg (or kPa)
b = intercept of the audit orifice transfer standard's cali-
bration relationship .
m = slope of the audit orifice transfer standard's calibra-
tion relationship.
13" rUC tl'e °P
-------
Section No.: 2.11.7
Date: January 1990
Page: 14
16. Turn off the sampler and remove the audit orifice transfer standard.
17. With a filter installed on the sampler in the normal sampling configura-
tion (i.e., with a filter cassette, if normally used), turn on the sam-
pler and allow it to warm up to operating temperature.
18. Instruct the operator to measure the sampler's relative stagnation pres-
sure, APstg, and to calculate the absolute stagnation pressure ratio,
Pi/Pa, as specified in Steps 10 and 11. Record these data on Part 1 of
the audit data sheet. Turn off the sampler, and replace the vacuum cap on
the stagnation pressure port.
19. Calculate the sampler's indicated operational flow rate, Qa(sampler),
using the Pi/Pa value obtained in Step 18 and the sampler's lookup table
or alternative calibration relationship. Record this flow rate on Part 1
of the audit data sheet.
20. Calculate the corrected sampler flow rate using Equation 23:
Qa(corrected sampler) = [Qa(sampler)] [10° " Audi^ Difference] (Eq_ 23)
where Qa(sampler) is obtained from Step 19 and the audit flow rate per-
centage difference is obtained from Step 14. Record this value on Part 1
of the audit data sheet.
21. Calculate the design flow rate percentage difference between the cor-
rected sampler flow rate.from Step 20 and the inlet design flow rate of
1.13 nH/min as:
Design flow rate _ FQa(corrected sampler) - 1.131 finnl /c 1QN
% difference ~ I 1713 J [100j (Eq" 18)
Record this value on Part 1'of the audit data sheet.
22. If the design flow rate percentage difference is within ±7 percent, the
sampler calibration is acceptable. Differences exceeding ±7 percent
should be investigated. Differences exceeding ±10 percent (or the
acceptable flow-rate range specified by the inlet manufacturer) may
result in the invalidation of all data obtained subsequent to the last
calibration or valid flow check. Before invalidating any data, double-
check the audit orifice transfer standard's certification, and all cal-'"
culations.
This completes the one-point audit. Return the sampler to its normal
operating configuration.
23. Repeat Steps 8 through 12 for at least two additional audit flow rates,
obtained with resistance plates or by adjusting the variable resistance ^
-------
Section No.: 2.11.7
Date: January 1990
Page: 15
valve. These additional flow rates should be within or only sliqhtlv
below the acceptable flow-rate range (i.e., 1.02 to 1.24 m3/min) of the
sampler inlet, if possible. Record the data from all three points on
Part 2 of the audit data sheet.
Note: Resistance plates supplied by the manufacturer of the audit ori-
IJSftJnJ!!? JriSt?!ld-rt !?3y Hav! t0 be modified (i.e., holes enlarged or
additional holes drilled) to obtain appropriate flow rates. -•
24. For each calibration- point, calculate and record the quantities (Pi/Pa)
and Qa(onfice). For the linear regression model,
(Pi/Pa) = m'[Qa(orifice)] + b1 (Eq. 19)
Calculate the linear regression slope (m1), intercept (b') and correla-
tion coefficient (r«) . Be sure to include the data obtained for [he
rinJl -°W ^TK in StePs.n and 12 in the calculation of the linear
regression. The regression calculations require a total of at least
three points. Record these values on Part 2 of the audit data sheet.
£pte: This is a temporary, provisional calibration relationship that is
thVca°cuTla9 be°aUSe n° temPerature te™ is included in
thVcacuTlations
25. Turn off the sampler and remove- the audit orifice transfer standard.
26' ?ion r/i1161"-^513]-?? °n the Sampler in the normal sampling configura
lllr «d inn V* tCr cassette' if normally used), turn on the lam-
pier and allow it to warm up to operating temperature.
sureAPst Htnr 5fP1er'5 r*]ative stagnation pres
Pl/Pa « Itrif J°.ca^ulate the absolute stagnation pressure ratio,
n S6S 10 and n« Record these data °n Part 2 of
28' SjISn1?!6 DwDSamp!er'S indicated operational flow rate, Qa(sampler)
or altern.t 7 V? H* ?taine? 1n Step 27 and the sampler's lookup able
?L IISKr ve ca1l5ratlon/elationshiP. Calculate the audit value for
the sampler's operatTonal flow rate, Qa(audit), using the (Pi/Pa) value
?i^?1lniStep ?7Kand the Slope (m') and intercePt9(b') if the prb -
sional samp er calibration relationship obtained in Step 24 Record
these two flow rates on Part 2 of the audit data sheet
[IOQ]
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Section No.: 2.11.7
Date: January 1990
Page: 16
Record this value on Part 2 of the audit data sheet.
30. If the audit flow rate percentage difference is within ±7 percent, the
sampler calibration is acceptable. Differences exceeding ±7 percent will
require recall" brat ion. Differences exceeding ±10 percent may result in
the.invalidation of all data subsequent to the last calibration or valid
flow check. Before invalidating any data, double check the sampler's
calibration, the audit orifice transfer standard's certification, and all
calculations.
31. Calculate the design flow rate percentage difference between the
Qa(audit) obtained from Step 28 and the inlet design flow rate of 1.13
m-Ymin as:
Design flow rate _ fQa(audit) - 1.131 finn] /P ,«>
% difference ~ I 1.T3" J 1100J (Eq' 18)
Record this value on Part 2 of the audit data sheet.
32. If the design flow rate percentage difference is within ±7 percent, the
sampler calibration is'acceptable. Differences exceeding ±7 percent
should be investigated. Differences exceeding ±10 percent (or the
acceptable flow-rate range specified by the inlet manufacturer) may
•- result in the invalidation of all data obtained subsequent to the last
calibration or valid flow check. Before invalidating any data, do.uble
check the audit orifice transfer standard's certification, and all calcu-
lations.
This completes the three-point audit. Return the sampler to its normal
operating configuration.
7.3 Audit Data Reporting -
The operating agency should be given a copy of the audit preliminary results
at the completion of the audit. The audit data sheet should be signed by.both the
auditor and the observer, and the results should be discussed. These preliminary
data should never be used to make monitoring system adjustments. Auditors may make
mistakes, and calibration curves may shift. A post-audit verification of audit
equipment and data is essential before inferences can be drawn regarding the samp-
ler's performance. An auditor should be able to "support audit data with complete
pre- or post-audit equipment verification documentation.
Final verified audit data should be submitted to the operating agency as soon
as possible. Delays may result in data loss; a sampler out of audit limits is also
out of calibration limits, and the data collected may.be invalid. If a sampler
exhibits unsatisfactory agreement with the verified audit results (i.e., audit flow
rate percentage differences exceeding ±7 percent), a calibration should be per-
formed immediately, certainly before the next run day.
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Section No.: 2.11.7
Date: January 1990
Page: 17
7-4 Flow-Rate Performance Audit Frequency -
7.5 System Audit -
additional detailed procedures and
1-. Use the operational flow rates as reported on the sample data sheets
"
ance operator's technique the auditor^hnnirt'rJl! ajd1ti°n *« observing the bal-
posed filter reweighinj as discussed "n Sect?™ ? ¥l *1 ^de^endent ™<^ of ex-
formance evaluation of the HV PM10 fiitPr w«!nJ- ° his volume- "The per-
the following manner: r wei9»"ng process should be conducted in
-------
Section No.: 2.11.7
Date: January 1990
Page: 18
1. Instruct the operator to weigh a set of three to five Class S standard
weights covering the range normally encountered during gravimetric analy-
sis. The weighed value should agree within ±0.5 mg of the stated values.
2. Observe the balance operator's technique, and review the laboratory
weighing procedure for determining both the tare and gross weights of the
sampling filters.
3. Review the maintenance and calibration log for each balance. Routine
balance maintenance and calibrations must be performed by the manufactur-
er's service representative at manufacturer-specified scheduled inter-
vals. In no case should the interval between calibrations exceed 1 year.
A. Review QC data records for the filter-weighing process. Ensure that the
following QC activities have been performed and documented:
• . Standard weight check every day of balance operation.
• Zero checks after every 5 to 10 filter weighings, calibration checks
after every 15, unless longer term stability of the balance has been
established by records (at least 1 calibration check per day).
• At least five filters reweighed each day. '
If any of these QC checks are out.of limits, note what action was taken.
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Section No.: 2.11.7
Date: January 1990
Page: 19
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-------
Section No.: 2.11.8
Date: January 1990
Page: 1
2.11.8 ASSESSMENT OF MONITORING DATA FOR PRECISION AND ACCURACY
8.1 Precision
fn .One.or\more monitoring sites within the reporting organization are selected
for duplicate, collocated sampling as follows: "for a network of 1 to 5 sites 1
sue is selected; for a network of 6 to 20 sites, 2 sites are selected- and for
f ^ i -han-2° SlteS' 3 SiteS are Selecied- Wherfpo s ble
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of S «. fS11"! 1S ?nC?!Ta9ed- Annual mean P^ticulate atter concentrons
h F "9 ^he hl'9hest ^ Percent of the annual mean
8.2 Accuracy
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-------
Section No.: 2.11.8
Date: January 1990
Page: 2
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Date:.January 1990
Page: 3
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2.11.9 RECOMMENDED STANDARDS FOR ESTABLISHING TRACEABILITY
Section No.: 2.11.9
Date: January 1990
Page: 1
n,nr **???* *? essential for attaining accurate data: (1) the measurement
process must be under statistical control at the time of the measurement, and
(2) the combination of systematic errors and random variation (i.e., measurement
errors) must yield a suitably small uncertainty.. The attainment -of accurate data
requires the performance of QC checks, independent audits of the flow measurement
process- careful documentation of monitoring data, and the use of equipment and
standards that can be traced to appropriate primary 'standards.
9 '• 1 . Recommended Standards for Establishing Traceabilitv
1. Class-S weights of NIST specifications are recommended for the laboratory
balance calibration. See Subsection 4.5 for details on balance cali-
bration checks.
2. Use of a positive-displacement standard volume meter (e.g. a RootsR
Meter) is recommended for calibrating the flow-rate transfer standards
that are used to calibrate and audit the HV PM10 sampler.
Note: As they are sold, standard volume meters may not be traceable to
NIST Traceability can be established through NIST or through the meter
manufacturer's repair department. Periodic recertification is not nor-
" !fl y Iequyed "nder Clean servi« conditions unless the meter has been '
damaged and must be repaired. Subsection 2 presents, detai Is on HV PM10
sampler calibration, and Subsection 7 presents details on the flow-rate
performance audits.
3' Inr J;13?5?^"16 met^ Sh°u1d be checked UP<™ initial receipt and refer-
min/da an™ally against an accurate timepiece to within 15
4. The accuracy of associated monitoring equipment (i.e., thermometers
nffL5' ,SJ°P yVatCheS' etC') Sh°uld be check^ at routfnTintervals,
'
un ,
traceable to NIST0"06 Per y6ar' a9ai'n5t 5tandards of known accuracy and
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