EPA/625/R-96/010a
Compendium of Methods
for the Determination of
Inorganic Compounds
in Ambient Air
Compendium Method IO-1.2
DETERMINATION OF PM10
IN AMBIENT AIR USING
THE THERMO ENVIRONMENTAL
INSTRUMENTS (FORMERLY
WEDDING AND ASSOCIATES)
CONTINUOUS BETA
ATTENUATION MONITOR
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
June 1999

-------
Method IO-1.2
Acknowledgments
This Method is a part of Compendium of Methods for the Determination of Inorganic Compounds in
Ambient Air (EPA/625/R-96/010a), which was prepared under Contract No. 68-C3-0315, WA No. 2-10,
by Midwest Research Institute (MRI), as a subcontractor to Eastern Research Group, Inc. (ERG), and
under the sponsorship of the U.S. Environmental Protection Agency (EPA). Justice A. Manning, John
0. Burckle, Scott Hedges, Center for Environmental Research Information (CERI), and Frank F.
McElroy, National Exposure Research Laboratory (NERL), all in the EPA Office of Research and
Development, were responsible for overseeing the preparation of this method. Other support was
provided by the following members of the Compendia Workgroup:
•	James L. Cheney, U.S. Army Corps of Engineers, Omaha, NE
•	Michael F. Davis, U.S. EPA, Region 7, KC, KS
•	Joseph B. Elkins Jr., U.S. EPA, OAQPS, RTP, NC
•	Robert G. Lewis, U.S. EPA, NERL, RTP, NC
•	Justice A. Manning, U.S. EPA, ORD, Cincinnati, OH
•	William A. McClenny, U.S. EPA, NERL, RTP, NC
•	Frank F. McElroy, U.S. EPA, NERL, RTP, NC
•	William T. "Jerry" Winberry, Jr., EnviroTech Solutions, Cary, NC
This Method is the result of the efforts of many individuals. Gratitude goes to each person involved in
the preparation and review of this methodology.
Author (s)
•	William T. "Jerry" Winberry, Jr., EnviroTech Solutions, Cary, NC
•	Stephe Edgerton, Midwest Research Institute, Cary, NC
Peer Reviewers
•	Rick Taylor, Missouri Department of Natural Resources, Jefferson City, MO
•	David Brant, National Research Center for Coal and Energy, Morgantown, WV
•	John Glass, SC Department of Health and Environmental Control, Columbia, SC
•	Jim Cheney, U.S. Army Corps of Engineers, Omaha, NE
•	Charles Rodes, Research Triangle Institute, RTP, NC
•	Danny France, U.S. EPA, Region 4, Athens, GA
•	David Harlos, Environmental Science and Engineering, Gainesville, FL
•	Jim Tisch, Graseby, Cleves, OH
•	A1 Wehr, Texas Natural Resource Conservation Commission, Austin, TX
•	Richard Shores, Research Triangle Institute, RTP, NC
•	Lauren Drees, U.S. EPA, NRMRL, Cincinnati, OH
ii

-------
DISCLAIMER
This Compendium has been subjected to the Agency's peer and administrative review, and it has
been approved for publication as an EPA document. Mention of trade names or commercial
products does not constitute endorsement or recommendation for use.
iii

-------
Method IO-1.2
Determination of PM10 in Ambient Air
Using the Thermo Environmental Instruments
(formerly Wedding) Continuous Beta Attenuation Monitor
TABLE OF CONTENTS
Page
1.	Scope		1.2-1
2.	Applicable Documents		1.2-3
2.1	ASTM Standards 		1.2-3
2.2	Other Documents 		1.2-3
3.	Summary of Method 		1.2-3
4.	Significance		1.2-4
5.	Definitions		1.2-5
6.	Interferences 		1.2-5
7.	Apparatus 		1.2-5
7.1	Sampler PM10 Inlet 		1.2-6
7.2	Analog Board		1.2-6
7.3	Micro-Controller Board		1.2-6
7.4	Tape Drive and Sampling Module 		1.2-6
7.5	Filter Media		1.2-7
7.6	Radioactive Source		1.2-7
7.7	Detector Assembly 		1.2-7
7.8	Data Output Devices		1.2-8
7.9	Critical Flow Device		1.2-8
7.10	Vacuum Pump		1.2-9
8.	Assembly		1.2-9
9.	Siting Requirements		1.2-10
10.	Instrument Operation		1.2-11
10.1	Instrument Start-up		1.2-11
10.2	Loading the Filter Tape		1.2-11
10.3	Setting Up the Instrument		1.2-12
10.4	Commencing Sampling 		1.2-14
10.5	Other Control Keys		1.2-15
11.	Replacing the Filter Tape		1.2-16
12.	Printer Paper Replacement (if applicable) 		1.2-16
13.	Maintenance		1.2-17
13.1	Detector		1.2-17
13.2	Sampling Inlet		1.2-17
14.	Instrument Calibration		1.2-17
14.1	Mass Determination 		1.2-17
14.2	Flow Rate		1.2-18
14.3	Single-Point External Flow Rate Audit Procedure Using a Flow Transfer
Standard		1.2-18
14.4	Mass Determination Audit 		1.2-20
14.5	Leak Checking		1.2-20
15.	Safety		1.2-20
iv

-------
TABLE OF CONTENTS (continued)
Page
16.	Performance Criteria and Quality Assurance (QA) 	 1.2-20
16.1	Standard Operating Procedures (SOPs)	 1.2-20
16.2	QA Program 	 1.2-21
17.	References	 1.2-21
v

-------
This page intentionally left blank
vi

-------
Chapter 10-1
CONTINUOUS MEASUREMENT OF SUSPENDED
PARTICULATE MATTER (SPM)
IN AMBIENT AIR
Method 10-1.2
DETERMINATION OF PM10 IN AMBIENT AIR
USING THE THERMO ENVIRONMENTAL INSTRUMENTS
(FORMERLY WEDDING) CONTINUOUS BETA ATTENUATION MONITOR
1. Scope
1.1	The area of toxic air pollutants has been the subject of interest and concern for many years. Recently
the use of receptor models has resolved the elemental composition of atmospheric aerosol into components
related to emission sources. The assessment of human health impacts resulting in major decisions on control
actions by federal, state and local governments is based on these data. Accurate measures of toxic air
pollutants at trace levels are essential to proper assessment.
1.2	Suspended particulate matter (SPM) in air generally is a complex, multi-phase system of all airborne
solid and low-vapor pressure liquid particles having aerodynamic particle sizes from below 0.01 pm to
100 pm and larger. Historically, SPM measurement has concentrated on total suspended particulates (TSP),
with no preference to size selection.
1.3	The EPA reference method for TSP is codified at 40 CFR 50, Appendix B. This method uses a
high-volume sampler to collect particles with aerodynamic diameters of approximately 100 pm or less. The
high-volume samples 40 and 60 ft3/min of air with the sampling rate held constant over the sampling period.
The high-volume design causes the TSP to be deposited uniformly across the surface of a filter located
downstream of the sampler inlet. The TSP high volume can be used to determine the average ambient TSP
concentration over the sampling period, and the collected material subsequently can be analyzed to determine
the identity and quantity of inorganic metals present in the TSP.
1.4	Research on the health effects of TSP in ambient air has focused increasingly on those particles that can
be inhaled into the respiratory system, i.e., particles of aerodynamic diameters < 10 pm. Researchers
generally recognize that these particles may cause significant, adverse health effects.
1.5	On July 1, 1987, theU. S. Environmental Protection Agency (EPA) promulgated a new size-specific air
quality standard for ambient particulate matter. This new primary standard applies only to particles with
aerodynamic diameters ^10 micrometers (PM10) and replaces the original standard for TSP.
1.6	To measure concentrations of these particles, the EPA also promulgated a new federal reference method
(FRM). This method is based on the separation and removal of non-PM10 particles from an air sample,
followed by filtration and gravimetric analysis of PM10 mass on the filter substrate. These smaller particles
are able to reach the lower regions of the human respiratory tract and, thus, are responsible for most of the
adverse health effects associated with suspended particulate pollution.
1.7	Monitoring methods for particulate matter are designated by the EPA as reference or equivalent methods
under the provisions of 40 CFR Part 53, which was amended in 1987 to add specific requirements for PM10
methods. Part 53 sets forth functional specifications and other requirements that reference and equivalent
June 1999
Compendium of Methods for Inorganic Air Pollutants
Page 1.2-1

-------
Method IO-1.2
Thermo Beta Gauge
Chapter 10-1
Continuous PMin Analyzers
methods for each criteria pollutant must meet, along with explicit test procedures by which candidate methods
or samplers are to be tested against those specifications. General requirements and provisions for reference
and equivalent methods are also given in Part 53, as are the requirements for submitting an application to the
EPA for a reference or equivalent method determination.
1.8	Under the Part 53 requirements, reference methods for PM10 must use the measurement principle and
meet other specifications set forth in 40 CFR 50, Appendix J. They must also include a PM10 sampler that
meets the requirements specified in Subpart D of 40 CFR 53. Appendix J specifies a measurement principle
based on extracting an air sample from the atmosphere with a powered sampler that incorporates inertial
separation of the PM10 size range particles followed by collection of the PM10 particles on a filter over a 24-h
period. The average PM10 concentration for the sample period is determined by dividing the net weight gain
of the filter over the sample period by the total volume of air sampled. Other specifications are prescribed
in Appendix J for flow rate control and measurement, flow rate measurement device calibration, filter media
characteristics and performance, filter conditioning before and after sampling, filter weighing, sampler
operation, and correction of sample volume to the EPA reference temperature and pressure. In addition,
sampler performance requirements in Subpart D of Part 53 include sampling effectiveness (the accuracy of
the PM10 particle size separation capability) at each of three wind speeds and "50% cutpoint" (the primary
measure of 10-micron particle size separation). Field tests for sampling precision and flow rate stability are
also specified. In spite of the instrumental nature of the sampler, this method is basically a manual
procedure, and all designated reference methods for PM10 are therefore defined as manual methods.
1.9	This document describes the protocol for the operation of a continuous particulate mass monitor that
directly measures mass concentrations of atmospheric particulate matter as PM10 on a real-time basis.
1.10	The instrument uses the beta gauge method, which is based on the attenuation of beta particles as they
pass through the particulate matter that has been deposited on a filter.
1.11	With certain specifications, the instrument has been designated as an equivalent method for PM10 (24-h
average concentration) by the EPA under Designation No. EQPM-0391-081, effective March 5, 1991 (1).
Except as otherwise noted, this protocol addresses the configuration and operation of the instrument as an
equivalent method for PM10.
Page 1.2-2
Compendium of Methods for Inorganic Air Pollutants
June 1999

-------
Chapter 10-1
Continuous PMin Analyzers
Method 10-1.2
Thermo Beta Gauge
2. Applicable Documents
2.1	ASTM Standards
•	D1356 Definitions of Terms Related to Atmospheric Sampling and Analysis.
2.2	Other Documents
•	Thermo Environmental Instruments Technical Manual (2).
3. Summary of Method
3.1	Particle-laden air is drawn through a sampling inlet at a constant volumetric flow rate of 18.9 L/min, the
design flow rate for the Thermo Environmental Instruments (formerly Wedding and Associates) PM10 inlet.
The sample air stream passes downward through a filter tape collection substrate where the particles are
deposited.
3.2	Upon completion of the sampling cycle, the filter tape is shifted to the beta source/detector to measure
the attenuated count rate due to the presence of collected particles.
3.3	The silicon semiconductor beta detector has high sensitivity and fast response, enabling the instrument
to measure the ambient mass concentration with a resolution of approximately 3 pg/m3 of collected particles
for a 1-h sampling period.
3.4	The Thermo Critical Flow Device maintains a constant volumetric flow rate through the instrument.
3.5	A microcomputer-based data acquisition system controls the filter tape drive, monitors temperature and
pressure, calculates flow rate and mass concentration values, and provides the necessary analog outputs for
a telemetry system. Custom system software can be provided by Thermo to assist the users to meet the
particular, unique requirements of their application.
[Note: The PMI0 concentrations calculated by the original instrument are in terms ofjAg per actual m3. These
values must be converted by the user into pig per standard m3. Instruments modified with a manufacturer-
provided retro-fit kit (described later) report concentrations in either jAg per actual or standard m3.]
June 1999
Compendium of Methods for Inorganic Air Pollutants
Page 1.2-3

-------
Method IO-1.2
Thermo Beta Gauge
Chapter 10-1
Continuous PMin Analyzers
4.	Significance
4.1	SPM in air generally is a complex, multi-phase system of aerodynamic particle sizes from below 0.01 pm
to greater than 100 pm. Historically, SPM measurement has concentrated on TSP, with no preference to size
selection. Research on the health effects of TSP in ambient air has focused increasingly on those particles
that can be inhaled into the respiratory system (i.e., particles of aerodynamic diameter less than 10 pm
[PM10]). Researchers generally recognize that those particles may cause significant adverse health effects.
4.2	Because of the health effects of PM10, this continuous particulate monitor has been developed to allow
mass measurement of PM10 concentration on a quasi, real-time basis.
4.3	The monitor utilizes a filter-based measuring system for providing quasi, real-time mass monitoring
capability. The particulate matter sample is retained on the filter tape. With certain specifications, the
monitor has been designated by EPA as an equivalent method for determining the 24-h average ambient
concentration of PM10. In addition, the instrument can be operated outside the equivalent method
specifications to perform other types of PM sampling programs.
5.	Definitions
[Note: Definitions used in this method are consistent with the definitions found in ASTM D1356. All
abbreviations and symbols are defined within this document at the point of first use. Any user prepared
standard operating procedures (SOPs) should also conform to the definitions of ASTM D1356.]
5.1	Air pollution. The presence of unwanted material in the air. The term "unwanted material" here refers
to material in sufficient concentrations, present for a sufficient time, and under concentrations, present for a
sufficient time, and under circumstances to interfere significantly with comfort, health, or welfare or persons
or with the full use and enjoyment of property.
5.2	Beta particle. An elementary particle emitted by radioactive decay, that may cause skin burns.
5.3	Coarse and fine particles. Coarse particles and those with diameters (aerodynamic) greater than 2.5 (im
that are removed by the sampler's inlet; fine particles are those with diameters (aerodynamic) less than 2.5 |im.
These two fractions are usually defined in terms of the separation diameter of a sampler.
5.4	Filter. A porous medium for collecting particulate matter.
5.5	Mass concentration. Concentration expressed in terms of mass of substance per unit volume of gas.
5.6	Particle. A small discrete mass of solid or liquid matter.
5.7	Particle concentration. Concentration expressed in terms of number of particles per unit volume of air
or other gas.
[Note: On expressing particle concentration the method of determining the concentration should be stated.]
Page 1.2-4
Compendium of Methods for Inorganic Air Pollutants
June 1999

-------
Chapter 10-1
Continuous PMin Analyzers
Method 10-1.2
Thermo Beta Gauge
5.8	Sampling. A process consisting of the withdrawal or isolation of a fractional part of a whole. In air or
gas analysis, the separation of a portion of an ambient atmosphere with or without the simultaneous isolation
of selected components.
5.9	Sampling, continuous. Sampling without interruptions throughout an operation or for a predetermined
time.
6. Interferences
6.1	Because the measurement mechanism has no moving parts, the instrument is not sensitive to vibrations
(e.g., vacuum pump vibration or mechanical noise) that can affect the accuracy of some other types of
continuous PM monitors.
6.2	Unlike some types of continuous PM monitors, this instrument does not require the ambient air stream
to be heated to a particular standard temperature. This feature eliminates a potential source of inaccuracy;
heating can volatilize some semivolatile materials that would otherwise be deposited on the filter, leading to
inaccuracies in both mass measurements and later chemical analyses.
6.3	The instrument should be protected against condensation in the sampling system, which can affect the
accuracy of the mass measurements.
7. Apparatus
The instrument includes two custom cabinets, one for PM sampling and control and one for the vacuum
pump. The insulated main particle sampling cabinet (shown in Figure 1) is heated and cooled so that it can
operate under ambient conditions. However, the instrument should be housed in a heated and air conditioned
shelter. The heating and cooling are independently controlled to preclude temperature extremes within the
cabinet.
After assembly, the inlet tube extends upward from the main sampling cabinet and is topped by the PM10 Inlet
(see Figure 2). The front cabinet door opens to reveal the filter reels, LCD define display, particle sampling
module, the source/detector fixture, communication ports, keypad, and printer, as shown in Figure 1. Newer
units are not equipped with a printer because users typically connect the unit to a data logger or computer for
data storage and access. Figure 3 illustrates the back of the cabinet, where the main power cord enters and
the power supply cord and vacuum tubing that lead to the vacuum pump emerge.
A modification kit, available from the manufacturer, includes new temperature sensors, new software
contained on a new EPROM chip, a calibration foil, installation instructions, and a manual supplement, and
provides improved accuracy of flow measurement and other features.
The vacuum pump cabinet contains a separate cooling fan that is activated when the pump operates. As
illustrated in Figure 3, the vacuum sampling tube is connected from a fitting on the pump cabinet to a fitting
on the particle sampling cabinet. The power to the pump cabinet also comes from the main cabinet. The
major components of the instrument are described below.
7.1 Sampler PM10 Inlet
June 1999
Compendium of Methods for Inorganic Air Pollutants
Page 1.2-5

-------
Method IO-1.2
Thermo Beta Gauge
Chapter 10-1
Continuous PMin Analyzers
A modified Thermo inlet, originally developed for the dichotomous sampler, is used as the sampling inlet for
the PM10 beta gauge. The inlet achieves proper particle size separation at a sampling rate of 16.7 L/min, the
design flow rate of the instrument. TSP and PM2 5 inlets are also available from the manufacturer.
The PM10 sampling inlet is illustrated in Figure 4. The inlet employs an omnidirectional cyclone fractionator,
which allows the particles to enter from any angle of approach. An angular impetus is imparted to the
particle motion via the eight, evenly-spaced entrance vanes. As the particles enter the inlet, they follow the
fluid stream lines along the lower radius and enter the cyclone fractionator through the vane system. Particle
removal is realized on the oiled surfaces of the inner collection tube. The transmitted particles then enter the
middle tube, where the flow direction is altered 180°. A final turn is made giving the particles a downward
trajectory to the collection substrate.
7.2	Analog Board
The analog board consists of the various circuits used for supplying DC power, motor control, relaying,
temperature sensing, and signal conditioning needs for the instrument. Most of the wiring for the instrument
is provided by the analog board.
7.3	Micro-Controller Board
The micro-controller board provides operational controls, time and flow-rate data recording, and all data
calculations and conversions.
7.4	Tape Drive and Sampling Module
The instrument uses a bi-directional tape drive system. First, a background beta count is taken on the area
of the filter tape that is situated in the measurement position (i.e., between the beta source and the detector).
When the background count is completed, the particle sampling module opens, the tape advances, and the
filter spot on which the background count was taken is positioned beneath the sample inlet tube. The particle
sampling module then closes and seals, and sampling is initiated by starting the vacuum pump. After the 1-h
sampling cycle is completed, the sampling module opens, the filter tape with deposited PM10 is shifted back
to the measurement position, the sample module closes, and a beta count is taken. Mass concentration is
determined based on the mass of PM10 accumulated and the volumetric flow rate of the instrument during the
sampling cycle.
The standard instrument is programmed to repeat the sampling and measurement cycle four times on a single
spot before the filter tape advances to an unused spot. Thus, total sampling time on each spot is 4 h. The
instrument also is programmed to go to a shorter cycle if PM10 is accumulating so fast that the flow rate will
be reduced to an unacceptable level in less than 4 h. The manufacturer can supply software for different
sampling cycles, but the current model of the instrument does not allow the user to select the sampling cycle.
7.5	Filter Media
Thermo offers two choices of filter substrates-glass fiber (P/N BG-320) and membrane (P/N BG-310). The
instrument is designated as an equivalent method for PM10 using the glass fiber filter medium. This filter
medium can accumulate extremely high PM loadings without incurring a significant increase in pressure drop
across the filter. The membrane medium is made of Teflon®, and is not affected by moisture.
Page 1.2-6
Compendium of Methods for Inorganic Air Pollutants
June 1999

-------
Chapter 10-1
Continuous PMin Analyzers
Method 10-1.2
Thermo Beta Gauge
The filter medium is supplied as a tape on a reel. The tape is threaded from the supply reel, through the
measurement and sampling positions, to the takeup reel. Instructions for replacing the filter tape are
presented in Section 11.
7.6	Radioactive Source
A carbon-14 radioactive source is mounted into the fixture positioned beneath the filter tape. In no case
should the front (top) surface of the source or source fixture be touched. Should the source laminate become
scratched, the radioactive material may leak. A damaged source must be returned to Thermo for disposal
and replacement. The radioactive source has the following characteristics: (1) an isotope of 14C, (2) an
activity of < lOOpCi, (3) a half-life of 5,730 yr, (4) a maximum energy of 155KeV, and (5) a laminate-sealed
housing. In addition, this source is described as a Thermo 1186 Series 14C Source.
The long half-life of carbon-14 precludes the need for recalibration and replacement of the source. The use
of the fast-response, low noise semiconductor detector makes it possible to use a low activity, low energy beta
source. Carbon-14 also has the added advantage of being a pure beta emitter without residual gamma
radiation.
The radioactive labels, positioned on the side of the cabinet, clearly provide instructions to the user for
disposition of the device and by-product material if necessary. At no time should the labels be removed. See
Section 14 for a discussion of safety considerations.
7.7	Detector Assembly
An ion-implanted silicon semi-conductor (IISS) detector and a preamplifier acquisition board (PACB) are
packaged in one fixture. The IISS detector is used to stop beta particles and permit counting of particles that
penetrate the filter medium. The IISS detector accepts an exceptionally high incidence of beta, having a
maximum count-rate of 100,000 cps, possesses ultra low-noise characteristics, and is a ruggedly designed.
The detector is optimized individually for each unit to stop beta particles emitted from the carbon-14 source.
The IISS detector has low leakage current (1-10 nA/cm2/100 pm), which makes it well suited for measuring
low-energy beta particles.
7.8	Data Output Devices
[Note: The instrument does not store measurement or calculation data. The user must provide a suitable data
handling system to maintain a record of measured and calculated parameters.]
7.8.1	Parallel Printer. Older units are equipped with a built-in parallel printer, but the units now being
shipped do not have this feature. When activated, this printer records all measurements and calculated values
generated by the instrument. However, this printer should not be operated when the instrument is unattended
because the printer paper can interfere with the filter tape drive mechanism.
7.8.2	Telemetry (Analog) Output. The instrument provides up to six channels of 0-5 volts direct current
(VDC) output for use with telemetry applications (two channels are standard). These data channels are
available through a 25-pin connector located on the main instrument panel.
7.8.3	RS-232 (Digital) Output. A second 25-pin connector on the main instrument panel serves as the
connection point for a serial printer or digital communications device, such as a data logger or computer.
In communications mode, this port can be used for remote control over the instrument.
June 1999
Compendium of Methods for Inorganic Air Pollutants
Page 1.2-7

-------
Method IO-1.2
Thermo Beta Gauge
Chapter 10-1
Continuous PMin Analyzers
7.9	Critical Flow Device
The collection of accurate and meaningful PM10 or TSP concentrations is intimately related to proper flow
control. Flow control provides an accurate denominator for the calculation of mass concentrations, whether
PM10 or TSP is being measured, and maintains the design flow rate of the PM10 fractionating element so that
it operates at the specific air velocities for which it was intended.
The Critical Flow Device (CFD), a critical flow system requiring no periodic calibration, is used as a flow
control device for the instrument. Use of the CFD provides for accurate flow rate measurement. The critical
flow orifice within the CFD is sized specifically for use with only one type of filter medium (i.e., either glass
fiber of Teflon®) to provide the flow rate necessary for proper particle size selection by the PM10 inlet. Each
instrument is calibrated at the factory, and an instrument-specific flow coefficient constant is supplied with
each unit for accurately calculating the flow rate during operation. This constant is entered into the
instrument's battery-backed random access memory (RAM) at the factory and duplicated on a label affixed
to the instrument panel. In the event of battery failure, the user must re-enter the constant into RAM (see
Section 10.3.1).
Caution: Use of a filter medium other than that originally specified for the instrument may result in a flow
rate different from that for which the PMI0 inlet is designed.
The flow rate through the filter tape is continuously monitored during operation by the micro-controller
board. Atmospheric pressure is measured with an electronic pressure transducer when the pump is off
between sampling periods. The stagnation pressure (i.e., the absolute pressure downstream from the filter
medium) is measured while the vacuum pump is operating during the sampling cycle. The microcomputer
outputs the flow rate and the average values of temperature and pressure for the sampling period.
A modification kit, which is available from the manufacturer and is highly recommended, provides a
temperature sensor to measure ambient (outdoor) temperature to allow the instrument to more accurately
calculate the actual volumetric flow rate at the sample air inlet. This modification also allows the instrument
to report flow rates in either actual or standard volume units and likewise calculate mass concentrations in
either pg per actual of EPA-standard cubic meters.
7.10	Vacuum Pump
The vacuum pump cabinet houses a Gast Model #523-101Q-G18DX or G21DX vacuum pump for power
supplies of 115 volts alternating current (VAC)/60 Hertz (Hz) or 220-240 VAC/50 Hz, respectively. A
cooling fan is activated when the pump operates. The pump is connected to the main sampling cabinet with
a vacuum tube supplied by the manufacturer. Power to the pump cabinet comes from the main cabinet.
8. Assembly
8.1	The instrument is delivered on a pallet protected by foam packaging and a cardboard outer container.
Remove the instrument from the packaging by cutting the metal bands on the outside of the container. Save
the container in the event that the instrument needs to be transported or repackaged.
8.2	After removing the metal bands and opening the cardboard container, locate and remove the instrument
components from the foam packing material. The separate pieces are as follows: main sampling cabinet,
Page 1.2-8
Compendium of Methods for Inorganic Air Pollutants
June 1999

-------
Chapter 10-1
Continuous PMin Analyzers
Method 10-1.2
Thermo Beta Gauge
pump cabinet, inlet, inlet tube, inlet tube support ring, cleaning brush, cabinet keys, and manual. (The inlet
tube support ring, cleaning brush, and keys should be in a plastic bag.)
8.3	Once all components have been located and removed from the box, assemble the instrument. First,
insert the inlet onto the end of the inlet tube (it will only fit on one end of tube).
8.4	If the instrument is to be operated with either an extension to the inlet tube or under ambient conditions
where high winds may be encountered, install the support ring onto the inlet tube. Slide the support ring onto
the inlet tube and tighten the four screws. Do not overtighten the screws or indentations in the tube could
be run and, thus, alter the air flow. Attach guide or support wires to the heads of the four screws. If a
nonstandard inlet tube (such as an extension) is to be used, contact Thermo for guidance.
8.5	Insert the inlet tube into the main cabinet of the instrument. Use extreme caution because forcing the
tube into the cabinet could damage the instrument. Rotate the tube and push it carefully into the cabinet to
avoid damaging the O-rings inside the coupler. The tube is fully inserted when resistance from the coupler
is felt. When assembled with the standard inlet tube, the inlet is at a height of about 2 meters above the base
of the main cabinet.
8.6	Insert the key into the rear door of the main cabinet and rotate the key counterclockwise until the door
opens. Check all electrical connections. Make sure there are no loose or unattached cables.
8.7	Instruments sold before November, 1996 should be modified with the modification kit provided by
Thermo. Install the kit according to instructions provided by Thermo. The kit provides new temperature
sensors and electronics for improved accuracy of flow measurements, enabling reporting of concentration in
either |ig per actual or EPA-standard cubic meters.
8.8	Attach the vacuum pump to the main cabinet with the Tygon® tubing inside the vacuum pump cabinet.
This step requires a 9/16" open end wrench or adjustable wrench to tighten the bulkhead fittings.
8.9	Plug the pump cabinet power cord (male) into the power supply cord (female) extending from the rear
of the main cabinet.
8.10	Open the door of the main cabinet that houses the instrument panel. First, make sure that the power
switch at the top of the instrument panel is in the "OFF" position. Then supply power to the unit
(115 VAC/60 Hz or 220 VAC/50 Hz) through the power-in cord (male) located on the rear door of the
cabinet. The instrument is now ready for start-up and operation.
9. Siting Requirements
9.1 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 monitoring project is to select a site or sites where the collected particulate
mass is representative of the monitored area.
June 1999
Compendium of Methods for Inorganic Air Pollutants
Page 1.2-9

-------
Method IO-1.2
Thermo Beta Gauge
Chapter 10-1
Continuous PMin Analyzers
9.2	Basic siting criteria for the placement of ambient air samplers are documented in Table 1. This list is
not a complete listing of siting requirements; instead, an outline to be used by the operating agency to
determine a sampler's optimum location. Complete siting criteria are presented in 40 CFR 58, Appendix E.
9.3	Additional factors not specified in the Code of Federal Regulations (CFR) must be considered in
determining where the sampler will be deployed. These factors include accessibility under all weather
conditions, availability of adequate electricity, and security of the monitoring personnel and equipment. The
sampler must be situated where the operator can reach it safely despite adverse weather conditions. If the
sampler is located on a rooftop, care should be taken that the operator's personal safety is not jeopardized
by a slippery roof surface during inclement weather. Consideration also should be given to the fact that
routine operation (i.e., calibrations, filter installation and recovery, flow checks and audits) involves
transporting supplies and equipment to and from the monitoring site.
9.4	To ensure that adequate power is available, consult the manufacturer's instruction manual for the
sampler's minimum voltage and power requirements. Lack of stable power source can result in the loss of
many samples because of power interruptions.
9.5	The security of the sampler itself depends mostly 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.
10. Instrument Operation
The instrument is operated with the keypad located in the main particle sampling cabinet (see Figure 1).
Records of stored data can be obtained from the unit using the built-in 20-column parallel printer (when so
equipped), the RS-232 communications port, or the telemetry port. When activated, the 20-column parallel
printer, which is part of the instrument, provides a continuous printout of all sampling data. If needed, the
RS-232 port is used to communicate with a separate computer. The telemetry port (labeled Analog Port on
the instrument) provides the necessary signals to send data to an off-site source via telemetry.
10.1	Instrument Start-up
To begin operation, move the power ON/OFF rocker switch at the top of the instrument panel to the "ON"
position (the red light should be on). The LCD will show several messages followed by the "PRESS A KEY"
prompt. The valid control keys are shown in Figure 5, and a brief summary of each key, including the
location and function, is shown in Table 2.
10.2	Loading the Filter Tape
Caution: NEVER turn the take-up (right side) tape drive manually, or the drive system will be damaged.
The filter tape drive system is illustrated in Figure 6. The filter substrate is a continuous tape. The tape
lifetime is based upon the total number of samples and the ambient concentration levels. A reel of glass fiber
tape lasts approximately 8 months using the standard sampling cycle.
10.2.1 The tape replacement commands are accessed from the keypad, but the loading procedure must
be followed as written in this section. Press the key titled "LOAD TAPE." The following message is
displayed:
Page 1.2-10
Compendium of Methods for Inorganic Air Pollutants
June 1999

-------
Chapter 10-1
Continuous PMin Analyzers
Method 10-1.2
Thermo Beta Gauge
LOAD NEW TAPE
OPENING SYSTEMS
After the instrument has performed the necessary mechanical functions for the loading of a new filter tape
reel, the following message is displayed:
LOAD NEW TAPE
OPENING SYSTEMS
REFER TO MANUAL &
PRESS A KEY TO LOAD
10.2.2	Install an empty take-up reel on the right tape drive. First, remove the black plastic pronged knob
from the right tape drive. Place the empty reel on the right tape drive, being sure to slide the hub onto the
shaft so that the shaft pin fits into the slot on the hub. Replace the black knob and tighten snugly.
Caution: Tighten the knob and hold the reel at the same time. Do not apply excessive torque to the drive
shaft, or the motor may be damaged.
10.2.3	Place a new filter supply reel on the left tape drive, ensuring that the pin on the shaft fits snugly
into the slot on the black hub of the reel. (Note that these slots and pins define the vertical plane of the tape.
The drive system will malfunction if the pins are not secured in the slots.) Replace the black knob.
10.2.4	Unwind about 24" (60 centimeters) of filter tape by rotating the supply side (left tape drive) in a
counterclockwise direction. Feed the free end of the tape over the left side of the No. 1 transnational roller,
as illustrated in Figure 6. Pass the free end of the tape, from left to right, between the No. 1 upper
compression shaft and No. 1 lower compression roller, through the detector/sampling module and between
the No. 2 upper compression shaft and the No. 2 lower compression roller. Continue by passing the tape on
the right side of the No. 2 transnational roller. Wrap the tape in a counterclockwise fashion on the hub of
the right (take-up) reel.
10.2.5	Tape the free end to the center of the take-up hub. Be sure that the filter tape is parallel to the
edges of the reels. The tape must be in the same vertical plane along its entire path.
[Note: Be sure that the tape passes approximately in the center of all rollers and the sampling module so the
tape is centered as it passes through the source, detector, inlet, and both (supply and take-up) reels.]
10.2.6	Depress any key to start the tape advancement, which is pre-programmed to operate for a specific
time period (about 1 min). When the tape advancement is complete, ensure that the tape is properly
positioned approximately in the center of both the No. 1 and No. 2 transnational rollers, that the tape is
smooth and flat against each roller, and that it lies in the same vertical plane between supply and take-up reel.
Additionally, the tape should be perfectly aligned between the upper compression shafts and the lower
compression rollers and should be in the center of the detector/sampling module.
10.3 Setting Up the Instrument
10.3.1 The "C" key is used to set the calibration constant in battery-backed RAM in case it has been lost
through battery failure. The five-digit constant, which is unique to each unit, is supplied by W&A and
displayed on a label between the filter reels. To set the calibration constant, press the "C" key and input the
five-digit constant as given on the label. After entering the fifth digit, the prompt "CHANGE (Y/N)?" will
June 1999
Compendium of Methods for Inorganic Air Pollutants
Page 1.2-11

-------
Method IO-1.2
Thermo Beta Gauge
Chapter 10-1
Continuous PMin Analyzers
appear on the LCD. If the constant is incorrect, restart the procedure by pressing the "YES" key. If the
constant is correct, press the "NO" key. The "PRESS A KEY" prompt will return to the screen. (This step
is not necessary for instruments equipped with the CFCASF flow controller.)
10.3.2	The "D" key is used to set the expected maximum mass concentration for the sampling site in
battery-backed RAM. This five-digit constant contains no decimal point, and five digits must be entered.
For example, if the maximum anticipated concentration is 250 pg/m3, the input constant is 00250. To set the
constant, press the "D" key and enter the five-digit constant. After entering the fifth digit, the prompt
"CHANGE (Y/N)?" will appear on the LCD. If the constant is incorrect, restart the procedure by pressing
the "YES" key. If the constant is correct, press the "NO" key. The "PRESS A KEY" prompt will return to
the screen.
[Note: Do not set an upper limit that is arbitrarily high because this will reduce the resolution of the telemetry
(analog) output.]
10.3.3	The "SETUP" key is used to enter the correct date and time into the computer. When the
"SETUP" key is pressed, the date and time will appear on the LCD followed by the prompt "CHANGE?
(Y/N)". If the displayed date and time are incorrect, press the "YES" key. The prompt "INPUT DATE" will
appear on the LCD. Enter the six-digit date with zeros preceding single digit days or months. Following the
input of the date, the prompt "INPUT TIME" will appear on the LCD. Enter the six-digit time (hours,
minutes, and seconds) based on a 24-h clock; the new date, time, and the prompt "CHANGE? (Y/N)" will
appear on the LCD. When the correct date and time are displayed, press the "NO" key to complete the setup
operation.
10.3.4	Press the "PROGRAM SAMPLING SCHEDULE" key to program the time at which the
instrument is to begin a sampling cycle. The programmed date and time will appear on the LCD, followed
by the prompt "CHANGE? (Y/N)". If the displayed date and time are incorrect, press the "YES" key. The
prompt "INPUT START DATE" will appear on the LCD. Enter the six-digit start date, with zeros preceding
single digit days or months; the prompt "INPUT START TIME" will appear on the LCD. Enter the six-digit
start time (hours, minutes, and seconds) based on a 24-h clock; the prompt "PRESS A KEY" will appear on
the LCD.
[Note: The input start time must be at least 15 min later than the actual time as indicated by the real-time
clock.]
10.3.5	Verify that the "FLOW TEMP CORR" is ON (modified units) and select "STAN COND=ON" if
flow and concentration are desired in standard volume units.
10.3.6	Press the "PARALLEL PRINTER ON/OFF" key to enable or disable the parallel printer (if so
equipped). One of two messages will appear: "PARALLEL PRINTER ON" or "PARALLEL PRINTER
OFF." To change the printer mode, press the "PARALLEL PRINTER ON/OFF" key again. If the unit is
left unattended, the built-in parallel printer should be in the off mode because the paper may interfere with
the mechanical movements.
10.3.7	The "RS-232 PRINTER ON/OFF" key operates in the same manner as the "PARALLEL
PRINTER ON/OFF" key described above. A serial printer cannot be enabled at the same time the RS-232
communication port is on. (Only one device, a serial printer or a communications device, can be connected
to the RS-232 port on the instrument panel.)
10.3.8	Press the "RS-232 COMM ON/OFF" key to enable or disable the communication port that
provides the necessary signals to transmit data off-site. One of the following two messages will appear on
the LCD. (1) If the communication port was in the off mode, the current baud rate is displayed followed by
the prompt "CHANGE? (Y/N)". To change the baud rate, press the "YES" key and select a baud rate using
Page 1.2-12
Compendium of Methods for Inorganic Air Pollutants
June 1999

-------
Chapter 10-1
Continuous PMin Analyzers
Method 10-1.2
Thermo Beta Gauge
the numbered key that corresponds to the desired baud rate shown on the LCD. To accept the baud rate,
press the "NO" key; the message "COMM. PORT ON" will appear on the LCD. (2) If the communication
port was in the on mode, the message "COMM PORT OFF" will appear on the LCD. This communication
port cannot be enabled at the same time the RS-232 serial printer is on.
10.4 Commencing Sampling
10.4.1 To check the instrument prior to commencing sampling, press the "TROUBLE SHOOT" key to
initiate a series of 13 diagnostic tests. The results of each test will appear on the LCD with a "PASS" or
"FAIL" message. The following four LCD messages illustrate all 13 tests and their results.
1) MODULE DN
PASS
2) COMP. UP
PASS
3) ADVANCE
PASS
4) COMP. DN.
PASS
5) TRANS. RT.
PASS
6) TRANS. LT
PASS
7) MODULE UP
PASS
8) PRESSURE
PASS
9) BETA CNT.
PASS
10) FLOWRATE
PASS
11) PS15
PASS
12) PS12
PASS
13) PS5
PASS
If a "FAIL" indication is displayed for any of the tests, make sure that all sampling information was entered
correctly. Also, check the instrument for loose cables or other obvious problems (e.g., make sure the filter
tape has been loaded). Press the "TROUBLE SHOOT" key again, and if the "FAIL" message still appears,
contact the manufacturer for further service information.
10.4.2	Press the "STATUS" key to confirm the status (on/off) of the parallel printer port, serial printer
port, and communications port. Press this key twice to confirm the actual status of these ports. If the status
is not as desired, use the appropriate keys as described in Sections 10.3.5 through 10.3.7 to enable the
desired output device(s).
[Note: The RS-232 serial printer and RS-232 communications cannot be on at the same time.]
10.4.3	Press the "BEGIN SAMPLING" key to begin sampling operations. The LCD will show the
messages "INITIALIZING SYSTEM" and "PLEASE STANDBY" while the unit undergoes the necessary
mechanical movements and checking procedures to permit the system to begin operation. When initialization
is finished, the LCD shows the actual date and time, the sampling period, the mass concentration of the
previous sampling period, and the message "A OR B TO TERMINATE." (All other control keys are
disabled.) To immediately terminate sampling, press the "B" key. To terminate sampling at the end of the
sampling period (approximately at the end of each hour), press the "A" key; the prompt "PRESS A KEY"
will appear on the LCD. At this time, all valid control keys are enabled.
June 1999
Compendium of Methods for Inorganic Air Pollutants
Page 1.2-13

-------
Method IO-1.2
Thermo Beta Gauge
Chapter 10-1
Continuous PMin Analyzers
10.5 Other Control Keys
These keys are enabled only when the instrument is not in sampling mode.
10.5.1	A description of the "LOAD TAPE" key, which is used when loading a new filter tape, is
provided in Section 10.2.1.
10.5.2	Press the "RESET" key to reinitialize the instrument. The LCD messages and prompts will be
the same as when the instrument was turned on.
10.5.3	Press the "MODULE UP/DOWN" key to activate the sampling module motor. The sampling
manifold will open and must be closed by pressing the "MODULE UP/DOWN" key again.
10.5.4	Press the "COMP UP/DOWN key to activate the compression rollers. The compression rollers
will open and must be closed by pressing the "COMP UP/DOWN" key again.
10.5.5	Press the "TRANS LEFT/RIGHT" key to translate the tape left or right. Following the first
translation from left to right (i.e., from the measurement position to the sampling position), the message
"ROLLERS MUST BE TRANSLATED LEFT TO EXIT" will be displayed. Press the "TRANS
LEFT/RIGHT" key again to move the translation mechanism back to the original position (i.e., from the
sampling position back to the measurement position).
10.5.6	Press the "VACUUM PUMP ON/OFF" key to test the vacuum pump. This action turns the
vacuum pump on, and the message "VACUUM PUMP MUST BE TURNED OFF TO EXIT" will be
displayed. Press the key again to turn the vacuum pump off.
Note: This key is only for testing the vacuum pump. Turn off the pump after testing for proper automatic
operation of the instrument.]
10.5.7	Press the "ADVANCE TAPE" key to advance the filter tape one position. The message
"ADVANCING" will be displayed on the LCD as the necessary operations take place. The operation may
take up to 2 min because it requires the sampling module and compression rollers to be opened before the
tape is advanced.
10.5.8	Press the "TEMP/PRESSURE" key to display the current cabinet temperature and atmospheric
pressure.
10.5.9	Press the "BETA COUNT" key to determine if the beta count is acceptable. After a period of
time, the message "COUNT ACCEPTABLE" or "COUNT UNACCEPTABLE" will appear on the LCD.
If the "COUNT UNACCEPTABLE" message is displayed, make sure that all sampling information was
entered correctly. Also, check the instrument for loose cables or other obvious problems. If the beta count
remains unacceptable, fill out the troubleshoot questionnaire provided in Addendum 1 of the operating manual
and contact the manufacturer for further service information.
10.5.10	Press the "FLOWRATE" key to display the actual flow rate of air through the instrument in
cm3/min. If the displayed flow rate is unacceptable (off by more than 10% of the design flow rate of
16,700 cm3/min), make sure that all sampling information was entered correctly. Also, check the instrument
for loose cables or other obvious problems such as obstructions in the inlet tube or system vacuum tubing.
If the flow rate remains unacceptable, fill out the troubleshoot questionnaire provided in Addendum 1 of the
operating manual, follow the procedures outlined in Section 14.3 of the operation manual (flow rate audit
procedure), and contact the manufacturer for further service information.
11. Replacing the Filter Tape
Caution: NEVER turn the take-up (right side) tape drive manually, or the drive system will be damaged.
The filter tape drive system is illustrated in Figure 6.
Page 1.2-14
Compendium of Methods for Inorganic Air Pollutants
June 1999

-------
Chapter 10-1
Continuous PMin Analyzers
Method 10-1.2
Thermo Beta Gauge
11.1	Press the "LOAD TAPE" key. The functioning of this key is described in Section 10.2.1.
11.2	Remove the full take-up reel from the tape drive on the right. Hold the reel firmly to keep it from
rotating, loosen the black plastic pronged knob, and slide the reel off the shaft.
11.3	Move the previous supply reel (now empty) from the left tape drive to the right drive. First, loosen
the black plastic pronged knob. Next, remove the reel and place it on the now-vacant right tape drive. Be
sure to slide the hub onto the shaft so that the shaft pin fits into the slot on the hub. Replace the black knob
and tighten snugly.
Caution: Tighten the knob and hold the reel at the same time. Do not apply excessive torque to the drive
shaft or the motor may be damaged.
11.4	Complete the tape replacement by following the steps described in Sections 10.2.3 through 10.2.6.
12.	Printer Paper Replacement (if applicable)
In instruments with a built-in printer, a full roll of paper is initially supplied with the parallel printer. The
printer system is illustrated in Figure 7.
12.1	To replace an empty roll, gently press the printer faceplate latches and pull to remove.
12.2	Locate the metal tab adjacent to the paper sensor (LED), press it, and gently slide the printer out until
it stops.
12.3	Remove the old roller and insert a fresh roll of printer paper. The printing surface of the paper is on
the outside of the roll. Make certain the roll turns in a counterclockwise direction (referenced from the paper
access area) as the paper unrolls.
12.4	Locate the paper slot in front of the small white roller at the bottom of the printer. Insert or feed the
paper into the slot, pressing the feed switch until the paper comes out the printer head.
12.5	Gently slide the printer back into the housing and replace the faceplate.
13.	Maintenance
The instrument is specifically designed to require minimal maintenance by the user. Four principal areas
require attention. Two of these, replacing the filter tape and replacing the parallel printer paper, are
discussed in Sections 11 and 12, respectively. Maintenance of the detector and sampling inlet are discussed
below.
13.1 Detector
In general, the IISS detector should not be disturbed or removed from its mounting. If testing indicates that
the detector surface is contaminated, the surface of the detector may be cleaned, very carefully, by using a
suitable cleaning agent supplied by the manufacturer.
June 1999
Compendium of Methods for Inorganic Air Pollutants
Page 1.2-15

-------
Method IO-1.2
Thermo Beta Gauge
Chapter 10-1
Continuous PM,n Analyzers
Caution: The sensitive area of the detector is delicate and should never be touched, except very lightly with
a soft cotton swab.
13.2 Sampling Inlet
After operating for an extended period of time under high mass concentration conditions, the sampling inlet
must undergo periodic maintenance. The maintenance procedure is a simple brushing technique to remove
accumulated PM from the primary deposition area in the inlet.
Remove the maintenance access port and run the supplied cleaning brush down through the inner tube three
times, twisting the handle between the fingers to insure that the brush touches all surfaces. This procedure
should be repeated once after every 15 days of sampling operations.
14. Instrument Calibration
The instrument calibration may be checked and changed, if necessary, by the user. This section describes
the initial calibration procedures used by the manufacturer for the instrument as well as field audit procedures
for the user.
14.1 Mass Determination
14.1.1	The Thermo Beta Gauge system undergoes a complete calibration using aerosol standards in the
laboratory. The laboratory calibration involves the generation of monodisperse solid particles injected into
the Thermo Wind Tunnel Facility. The concentration level in the facility can be adjusted over the range of
25 to 300 jj,g/m3. The calibration procedure is performed to determine the attenuation coefficient, which is
used in the instrument's internal calculations to determine the mass of PM10 collected on the filter.
In the calibration procedure, parallel samples of the particle cloud are collected using identical PM10 inlets.
One sample is collected using an appropriate filter substrate and subsequently analyzed fluorometrically to
determine mass concentration. This mass concentration is then used to calculate mass density of particles on
the filter tape. The second sample is analyzed using the Thermo Beta Gauge.
The procedure is repeated for a range of particle loadings. The beta attenuation values from the beta gauge
are then related to the mass density levels determined from the first sampler. The attenuation coefficient for
the beta gauge system is determined by a least-squares fit to a straight line on a plot of the various mass
density values vs. corresponding attenuation values.
14.1.2	The manufacturer has performed this calibration procedure to determine generally-applicable
attenuation coefficients for instruments that use glass fiber and membrane filter media (the attenuation
coefficient differs slightly depending on filter medium). Each individual instrument is subjected to the same
procedures before shipment to confirm that the generally-applicable attenuation coefficient is accurate for that
instrument.
14.1.3	The long half-life of carbon-14 minimizes the need for recalibrating and replacing the beta
source. During operation, the instrument continually runs internal diagnostic checks to ensure the proper
operation of the source/detector system. The foil calibration feature, available on new or kit-modified units,
may be used by the operator to check the calibration of the instrument and, if necessary, to change the
calibration constant (attenuation coefficient), using a calibration foil provided by the manufacturer. Follow
the instructions for this feature in the Operator's Manual or Manual Addendum.
Page 1.2-16
Compendium of Methods for Inorganic Air Pollutants
June 1999

-------
Chapter 10-1
Continuous PMin Analyzers
Method 10-1.2
Thermo Beta Gauge
14.2	Flow Rate
14.2.1	As discussed in Section 7.9, flow control for the instrument is achieved using a critical flow
system. Each instrument is calibrated by the manufacturer to determine the instrument-specific flow
coefficient that is used in internal calculations to determine the flow rate.
14.2.2	The manufacturer recommends no periodic recalibration by the user. However, a quarterly field
audit is required by EPA for any instrument operating as an equivalent method for PM10. The audit procedure
is presented in the following section.
14.3	Single-Point External Flow Rate Audit Procedure Using a Flow Transfer Standard
14.3.1	Background. This section describes an external means of auditing the volumetric flow rate of
the instrument. An NIST-traceable primary standard is used to calibrate a transfer standard which, in turn,
is used to verify the calibration of the instrument's CFD.
Several commercially available transfer standards can be used in this audit procedure. Table 3 lists
recommended transfer standards, their applicable flow ranges, references for transfer calibration procedures,
and necessary equipment to perform calibrations. (This table has been adopted from the EPA Quality
Assurance Handbook for air pollution measurement systems [EPA 600/4-77-027A].) Because the design flow
rate for the PM10 inlet is 16.7 L/min, the transfer standard should be calibrated in the flow rate range of
approximately 15 to 20 L/min. The transfer standard should not cause a pressure drop of more than 4.0" of
water.
After selecting a transfer standard, use a leak-tight adapter to connect the transfer standard to the instrument
inlet tube as depicted in Figure 8. The adapter may be fabricated by a third party, purchased commercially,
or requested from the manufacturer.
Normally, a station log book or audit data sheet is used to document audit information. This information
normally includes, but is not limited to, an identification of the transfer standard, its serial number,
traceability documentation for the audit information, and the ambient temperature and pressure as well as the
actual audit data collected during audit procedures.
14.3.2	Audit Procedure.
14.3.2.1	Remove the PM10 inlet from the instrument. Install the adapter, referring to Figure 8 for
details. Connect the flow transfer standard, as depicted in Figure 9, using suitable tubing.
14.3.2.2	Press the key on the keypad titled "FLOWRATE". (This command will establish necessary
audit conditions, such as advancing the tape to a new/unused area of the medium.) Be sure that the filter tape
is fully loaded and the sampling module is in the closed position.
14.3.2.3	Allow time for the flow transfer standard to equilibrate, which requires operating the system
for approximately 5 min. During this operation, the inlet of the transfer standard is open to ambient air, and
the outlet of the transfer standard is connected via the adapter to the inlet tube of the instrument.
14.3.2.4	Record all pertinent parameters required to make calculations from the flow transfer
standard's previous calibration. These parameters may include, but are not limited to, ambient pressure and
temperature and transfer standard readings such as volts, pressure drop, timings or revolutions, etc. During
this time the instrument's computer will calculate, and the LCD will display, a continuing series of flow rate
values based upon measured flow conditions. Time-averaged flow rate values will be produced and updated
every 2 min. These values allow the operator to make comparisons between readings of the flow transfer
standard and the values output to the LCD by the computer.
June 1999
Compendium of Methods for Inorganic Air Pollutants
Page 1.2-17

-------
Method IO-1.2
Chapter 10-1
Continuous PMin Analyzers
Thermo Beta Gauge
[Note: New or modified instruments displays flow rates in either standard or actual cm3/min. Always be sure
that the instrument and transfer standard flow rates are in the same terms (actual or standard) before
comparing them.]
14.3.2.5	Depending upon the purpose or nature of the audit, the flow rate values displayed on the LCD
should agree within a specified percentage of the flow rate transfer standard values. For purposes of flow
rate audits required by the EPA, all values displayed on the LCD should agree within ± 7% of the flow rate
transfer standard values. If not, check all calculations to ensure that the flow rates are in the same terms
(actual or standard volumes). These values need not necessarily be the design flow rate value of 18.9 L/min.
14.3.2.6	If the flow transfer standard and the instrument do not agree within ±7%, refer to
Section 9.4.1 (Trouble Shooting). Fill out the detailed trouble-shooting check list in the Addendum to the
manufacturer's technical manual (2). In particular, items 4-10 relate directly to flow rate verification.
Report these results to Thermo for further information.
14.3.2.7	To compare the design flow rate of 18.9 L/min to the actual flow rate displayed on the LCD,
remove both the external transfer standard and the external transfer standard adapter. Replace the PM10 inlet
onto the inlet tube. Allow approximately 1-2 min for the flow to equilibrate; observe the series of flow rate
values displayed on the LCD. Make sure that the instrument is reading the flow rate in actual volumetric
units, and apply and percentage correction determined in Section 14.3.2.5. These values should be within
± 10% of the design flow rate value of 16.7 L/min; if not, refer to Section 14.3.2.6.
14.4	Mass Determination Audit
As noted in Section 14.1.3, the foil calibration feature, available on new or kit-modified units, may be used
by the operator to check the calibration of the instrument and, if necessary, to change the calibration constant
(attenuation coefficient), using a calibration foil provided by the manufacturer. Follow the instructions for
this feature in the Operator's Manual of Manual Addendum.
14.5	Leak Checking
The instrument is assembled and leak checked before it is shipped to the user. No routine definitive leak
checking procedures are conducted thereafter. The manufacturer does not recommend positive or negative
pressure leak checking because this activity could rupture the gaskets in the sampling module. To check for
leaks, examine the vacuum tubing and verify that all connections at the inlet, inlet tube, and vacuum tubing
are secure. Examine the filter tape to verify that all spots where PM has been collected are sharply-defined
circles. Poorly-defined sample spots indicate leaking sampling module gaskets.
This instrument uses a radioactive source to measure PM10. The Nuclear Regulatory Commission does not
require the user of this low-energy, beta-emitting source to be licensed (however, Thermo is so licensed).
The beta source is sealed at the factory and should never be opened or tampered with. The entire instrument
should be returned to Thermo for service or disposal of the beta source.
15. Safety
Page 1.2-18
Compendium of Methods for Inorganic Air Pollutants
June 1999

-------
Chapter 10-1
Continuous PMin Analyzers
Method 10-1.2
Thermo Beta Gauge
16. Performance Criteria and Quality Assurance (QA)
Required quality assurance measures and guidance concerning performance criteria that should be activated
within each laboratory are summarized and provided in the following section.
16.1	Standard Operating Procedures (SOPs)
16.1.1 SOPs should be generated by the users to describe and document the following activities in their
laboratory:
•	Assembly, calibration, leak check, and operation of the specific sampling system and equipment
used;
•	Preparation, storage, shipment, and handling of the sampler system;
•	Purchase, certification, and transport of standard reference materials; and
•	All aspects of data recording and processing, including lists of computer hardware and software
used.
16.1.2 Specific instructions should be provided in the SOPs and should be readily available to and
understood by the personnel conducting the monitoring work.
16.2	QA Program
The user should develop, implement, and maintain a quality assurance program to ensure that the sampling
system is operating properly and collecting accurate data. Established calibration, operation, and
maintenance procedures should be conducted on a regularly scheduled basis and should be part of the quality
assurance program. Calibration verification procedures provided in Section 14, operation procedures in
Section 10, and the manufacturer's instruction manual should be followed and included in the QA program.
Additional QA measures (e.g., trouble shooting) as well as further guidance in maintaining the sampling
system are provided by the manufacturer. For detailed guidance in setting up a quality assurance program,
the user is referred to the Code of Federal Regulations (3) and the U. S. EPA Handbook on Quality Assurance
(4).
17. References
1.	Equivalent Method Designation: PM10 Beta Gauge Automated Particle Sampler, Federal Register,
Vol. 56, No. 43, March 5, 1991, pp. 9216-9217.
2.	Wedding, J. B., and Weigland, M.A., Wedding & Associates' PM10 (or TSP) Beta Gauge Automated
Particle Sampler Operations and Maintenance Manual. Fort Collins, CO, February 1991.
3.	40 CFR, Part 58, Appendices A and B.
4.	Quality Assurance Handbook for Air Pollution Measurement Systems, Volume II—Ambient Air Specific
Methods, (Interim Edition), EPA 600/R-94/038b.
June 1999
Compendium of Methods for Inorganic Air Pollutants
Page 1.2-19

-------
Method 10-1.2 Chapter 10-1
Thermo Beta Gauge	Continuous PMin Analyzers
5. U.S. Environmental Protection Agency, Quality Assurance Handbook for Air Pollution Measurement
Systems, Volume I: A Field Guide for Environmental Quality Assurance, EPA-600/R-94/038a.
Page 1.2-20
Compendium of Methods for Inorganic Air Pollutants
June 1999

-------
Chapter 10-1
Continuous PMin Analyzers
Method 10-1.2
Thermo Beta Gauge
TABLE 1. EXAMPLE OF MINIMUM SAMPLER SITING CRITERIA
Scale
Height above
ground,
meters
Distance from supporting
structure, meters
Other spacing criteria
Vertical
Horizontal"
Micro
2 to 7
>2
>2
1.	Should be > 20 meters from
trees.
2.	Distance from sampler to
obstacle, such as buildings, must
be twice the height that the
obstacle protrudes above the
sampler.a
3.	Must have unrestricted airflow
270 degrees around the sampler
inlet.
4.	No furnace or incineration flues
should be nearby.*3
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 E).
Middle, neighbor-
hood, urban, and
regional scale
2 to 15
>2
>2

aWhen inlet is located on rooftop, this 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. As a
precautionary measure, the sampler should be placed at least 5 meters from the furnace or incinerator flue.
June 1999
Compendium of Methods for Inorganic Air Pollutants
Page 1.2-21

-------
Method IO-1.2
Thermo Beta Gauge
Chapter 10-1
Continuous PMin Analyzers
TABLE 2. SUMMARY OF KEYPAD CONTROL KEYS
ROW
COLUMN
III II RINO ON KI Y
DESCRIPTION
1
1
procram sampling;
SCHEDULE
allows inpul of the desired start dale and start
time in which the sampling cycle will begin
1
2
MODULE
UP/DN
moves the sampling module one full cycle (i.e.,
move down and back up)
1
3
TEMP/
PRESS
displays the cabinet temperature and pressure
readings on the LCD
1
4
PARALLEL PRINTER
ON/OFF
output directed to parallel printer (telemetry output
still active)
1
5
SETUP
allows viewing and resetting of the battery-backed
real-time clock
2
1
BEGIN SAMPLING
starts or begins the sampling cycle
2
2
COMP.
UP/DN
moves the compression rollers one full cycle
(i.e., move up and back down)
2
3
BETA COUNT
determines if beta particles are being counted
acceptably or unacceptably
2
4
RS-232
PRINTER ON/OFF
output directed to RS-232/serial printer (telemetry
output still active)
2
5
STATUS
reads and displays the status of the external I/O
devices (i.e., parallel printer, serial printer,
RS-232 communications)
3
1
LOAD TAPE
refers user to manual, opens mechanical systems
3
2
TRANS.
LEFT/RIGHT
moves the translation assembly one full cycle
(i.e., move right and back left)
3
3
FLOW RATE
displays the sampler flow rate reading on the LCD
3
4
RS-232 COMM.
ON/OFF
allows setting the RS-232 baud rate for off-site
communications
3
5
TROUBLE SHOOT
executes a series of analog, digital, and
mechanical diagnostics and displays the results on
the LCD
4
1
ADVANCE TAPE
advances the filter media one location
4
2
VACUUM PUMP ON/OFF
tests the vacuum pump
7
1
C
allows input of the calibration constant in
battery-backed RAM if lost through battery failure
8
1
D
allows setting the maximum mass concentration
limit in battery-backed RAM
8
3
RESET
resets the computer
5
1
A
interrupts sampling at the conclusion of the current
sampling/measurement cycle (key enabled only
while in sampling mode)
6
2
B
interrupts sampling immediately (key enabled only
while in sampling mode)
Page 1.2-22
Compendium of Methods for Inorganic Air Pollutants
June 1999

-------
Method 10-1.2	Chapter 10-1
Thermo Beta Gauge	Continuous PM10 Analyzers
tap>t,f;3. ex amp
1 OF Rl COXIX11 \ 1) 1 1) STANDARDS AND ASSOCP
vTF.D 1 01 II'XII \ 1 FOR FFOW RATF AUDITS
Transfer siandard1
Opiiinum llou range
0
1 i|iiipmc'Ni
Cnimnenis
Calibraiion equaiim!1'-'
Calibraiinn ol' iranslcr siandard reference
I I (laminar
flow elenieni)
15.0 20.0 l.'inin
II
Thernionie ler' baronie ler'1
Manometer6, Filters,
Adapter
Should ha\e filiered air eniering 1.11 .
Subjecl lo fluclualions due lo leniperalure
changes. Manometer must be used in its
temperature range. Must equilibrate.
( i Lowers oM,
I . S. 1 n\ inininenial Proicciioii Agencv
Procedures for Calibraling a Laminar Llou
Element (LFE) against an NBS Calibrated
LFE: Standard Operating Procedures
EMSL/RTP SOP-QAD-003, November 1991
MFM (mass flow
meter)
15.0-20.0 L/min
MFM
Thermometer/barometer11
Filters, Adapter
Recommended LCD display for outdoor use.
Must equilibrate to ambient conditions.
(Volts) (CF) = Q,td
Quality Assurance Handbook for Air
Pollution Measurement Systems - Vol. II
Ambient Air Specific Methods, Section 21,
EPA 600/4-77-027A, May 1977.
DGM L/rev (dry
gas meter)
15.0-20.0 L/min
DGM
Thermometer/barometer11
Stopwatch/Filters, Adapter
Should time through five revolutions.
Repeat each timing 3 times.
Volume ppj q
time std
Quality Assurance Handbook for Air
Pollution Measurement Systems - Vol. II
Ambient Air Specific Methods, Section 3.3
EPA 600/4-77-027B, August 1977.
Orifice
15.0-20.0 L/min
Orifice
Thermometer/barometer ,d
Manometer,6 Filters, Adapter
Good only in range &P < 8 in.
P l1'2
m * H2°Y" + b = Qstd
Quality Assurance Handbook for Air
Pollution Measurement Systems - Vol. II
Ambient Air Specific Methods, Section 2.2
EPA 600/4-77-027A. May 1977.
aTransfer standard should not cause more than 4.0" of H20 flow resistance to the sampler flow.
'Traceable and referenced to EPA standard conditions:
Qa = Qst.
"Calibration equations for determining flow rates may vary from those presented due to the transfer standard calibration relationship. CF = correction factor.
•"Thermometer capable of measuring temperature to the nearest _+_lC. Barometer capable of accurately measuring barometric pressure to the nearest + 1 mm Hg.
eThe design or size of the LFE or orifice will determine the manometer range necessary and the resolution. The manometer resolution must be capable oF detecting a flow change of 1% and represent a flow
resistance less than 4.0" H20.
"Stopwatch or timer capable of accurately measuring time intervals of 30 s to several minutes to nearest 0.1 s.
Page 1.2-23
Compendium of Methods for Inorganic Air Pollutants
June 1999

-------
Method IO-1.2
Thermo Beta Gauge
Chapter 10-1
Continuous PM,n Analyzers

Figure 1. The Thermo beta gauge main particle sampling cabinet.
Page 1.2-24
Compendium of Methods for Inorganic Air Pollutants
June 1999

-------
Chapter 10-1
Continuous PMin Analyzers
Method 10-1.2
Thermo Beta Gauge
1.250 DIA

30
71 250

30.000
9 290
? TTT
r
u
-35.000-
Figure 2. Main cabinet with PM10 inlet and inlet tube.
June 1999
Compendium of Methods for Inorganic Air Pollutants
Page 1.2-25

-------
Method IO-1.2
Thermo Beta Gauge
Chapter 10-1
Continuous PMin Analyzers
CD
g
03
o
Ph
cj
03
>
a
o
CJ
CD
a
a
o
O
CD
g
03
o
.S
cd
O
S—i
03
CD
&
CD
S-H
a
3P
E!
Page 1.2-26
Compendium of Methods for Inorganic Air Pollutants
June 1999

-------
Chapter 10-1
Continuous PMin Analyzers
Method 10-1.2
Thermo Beta Gauge
MAINTENANCE
ACCESS PORT
INNER TUBE
(PERFECT
ABSORBER
SURFACE)
MIDDLE
TUBE
PROTECTIVE
HOUSING
HOUSING—DEFLECTOR
SPACING a
AERODYNAMIC INLET
PATHWAY
PLUG
AERODYNAMIC FLOW
DEFLECTOR
WScA SETA GAUGE
INLET TUBE
Figure 4. Thermo PM10 inlet.
June 1999
Compendium of Methods for Inorganic Air Pollutants
Page 1.2-27

-------
Method IO-1.2
Thermo Beta Gauge
Chapter 10-1
Continuous PMin Analyzers

VALID
CONTROL
KEYS



J
PARALLEL
ROGRGM
TEMP/
MODULE
SAMPLING
PFHWTER
SETUP
LfRiDN
PRESSURE
CHEDULE
ON/OFF
RS-232
BEGIN
CQpflR
PRINTER STATUS
SinMPLING
UP/ON
COUNT
ON/OFF
TRAfJS
RS-232
LOAD
FLOW
TROUBLE
left/
cowui
TAPE
RATE
QN/OFF*
RIGHT
VACUUM
ADVANCE
PUMP
TAPE
OWOFF
©00
Figure 5. Thermo PM10 instrument keypad.
Page 1.2-28
Compendium of Methods for Inorganic Air Pollutants
June 1999

-------
Chapter 10-1
Continuous PMin Analyzers
Method 10-1.2
Thermo Beta Gauge
DETECTOR/
SOURCE
NO. 2 UPPER
COMPRESSION
SHAFT
NO. 1 UPPER
COMPRESSION
SHAFT
NO. 2 LOWER
COMPRESSION ROLLER
NO. 1 LOWER
COMPRESSION ROLLER
TRANS LOT 10 NAL
ROLLER
TRAKSUVT IC'NAL
ROLLER
MEDIA TAKE-UP REEL
MEDIA SUPPLY REEL
Figure 6. Filter tape drive system.
June 1999
Compendium of Methods for Inorganic Air Pollutants
Page 1.2-29

-------
Method IO-1.2
Thermo Beta Gauge
Chapter 10-1
Continuous PMin Analyzers
MAIN UNIT
MAIN UNfT FITTING
PAPER END SENSOR
(LED)
¦FEED SWITCH
PAPER CUTTER
HOOK FOR REMOVING FRONT PANEL
UNIT CASE
PRINTING SURFACE
P.C.B.
PAPER ROLL
PRINTER
PAPER ROLL SHAFT
PRINT HEAD
FEED
PRINTING
SURFACE
RUBBER ROLLER
Figure 7. Replacing paper in the parallel printer.
Page 1.2-30
Compendium of Methods for Inorganic Air Pollutants
June 1999

-------
Chapter 10-1
Continuous PMin Analyzers
Method 10-1.2
Thermo Beta Gauge
TO EXTERNAL
TRANSFER STANDARD
0.375 NPT TD BARB
CONNECTOR
O-RING
ALUMINUM EXTERNAL
CALIBRATION ADAPTER
(W&A P/N BG590)
V&A BETA GAUGE
INLET TUBE
Figure 8. Adapter for external flow transfer standard.
June 1999
Compendium of Methods for Inorganic Air Pollutants
Page 1.2-31

-------
Method IO-1.2
Thermo Beta Gauge
Chapter 10-1
Continuous PMin Analyzers
EXTERNAL
TRANSFER
STANDARD
2^

REMOVED
PMIO INLET
EXTERNAL
TRANSFER
STANDARD
ADAPTER
INLET
TUBE
PR* BUE£
iiifDMBiMQaj
Figure 9. Configuration of external flow transfer standard.
Page 1.2-32
Compendium of Methods for Inorganic Air Pollutants
June 1999

-------
TABLE 3. EXAMP
,E OF RECOMMENDED STANDARDS AND ASSOCIATED EQUIPMENT FOR FLOW RATE AUDITS






LFE (laminar
flow element)
15.0-20.0 L/min
LFE
Thermometer/barometerd
Manometer6, Filters,
Adapter
Should have filtered air entering LFE.
Subject to fluctuations due to temperature
changes. Manometer must be used in its
temperature range. Must equilibrate.
(aH20)(CF) = Q,td
U.S. Environmental Protection Agency
Procedures for Calibrating a Laminar Flow
Element (LFE) against an NBS Calibrated
LFE: Standard Operating Procedures
EMSL/RTP SOP-QAD-003, November 1991
MFM (mass flow
meter)
15.0-20.0 L/min
MFM
Thermometer/barometer11
Filters, Adapter
Recommended LCD display for outdoor use.
Must equilibrate to ambient conditions.
(Volts) (CF) = Q,td
Quality Assurance Handbook for Air
Pollution Measurement Systems - Vol. II
Ambient Air Specific Methods, Section 21,
EPA 600/4-77-027A, May 1977.
DGM L/rev (dry
gas meter)
15.0-20.0 L/min
DGM
Thermometer/barometer11
Stopwatch/Filters, Adapter
Should time through five revolutions.
Repeat each timing 3 times.
Volume ppj q
time std
Quality Assurance Handbook for Air
Pollution Measurement Systems - Vol. II
Ambient Air Specific Methods, Section 3.3
EPA 600/4-77-027B, August 1977.
Orifice
15.0-20.0 L/min
Orifice
Thermometer/barometer ,d
Manometer,® Filters, Adapter
Good only in range aP < 8 in.
P 11/2
m * H2°Y" + b = Qstd
Quality Assurance Handbook for Air
Pollution Measurement Systems - Vol. II
Ambient Air Specific Methods, Section 2.2
EPA 600/4-77-027A. May 1977.
aTransfer standard should not cause more than 4.0" of H20 flow resistance to the sampler flow.
'Traceable and referenced to EPA standard conditions:
Qa = Qst
'Calibration equations for determining flow rates may vary from those presented due to the transfer standard calibration relationship. CF = correction factor.
•"Thermometer capable of measuring temperature to the nearest _+_lC. Barometer capable of accurately measuring barometric pressure to the nearest _+_l mm Hg.
The design or size of the LFE or orifice will determine the manometer range necessary and the resolution. The manometer resolution must be capable of detecting a flow change of 1% and represent a flow
resistance less than 4.0" H20.
•Stopwatch or timer capable of accurately measuring time intervals of 30 s to several minutes to nearest 0.1 s.

-------