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U.S. EPA
Ambient Air Protocol Gas Verification Program
Annual Report CY 2022
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EPA-454/R-23-005
May 2023
U.S. EPA
Ambient Air Protocol Gas Verification Program
Annual Report CY 2022
U.S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Air Quality Assessment Division
Research Triangle Park, NC
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Table of Contents
Acknowledgements 5
Acronyms and Abbreviations 6
1.0 Introduction 7
2.0 Implementation Summary 9
3.0 Survey and Verification Results 12
4.0 Summary and Conclusions 16
Appendix A QA Reports from Measurement Data Worksheets for 2022 19
Tables
Table 1. RAVL Verification Dates 10
Table 2. Gas Standards Sent to RAVLs 13
Table 3. MQOsforthe AA-PGVP 14
Table 4. AA-PGVP CO and S02 Verifications 15
Table 5. AA-PGVP NO and NOx Verifications 15
Figures
Figure 1. AA-PGVP Flow Chart 11
Figure 2 Annual Survey 12
Figure 3 Verification Trend 13
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Acknowledgements
The following individuals and organizations are acknowledged for their contributions to this project:
US EPA, Office of Air Quality Planning and Standards
Douglas Jager
US EPA, Office of Research and Development
Bob Wright
US EPA Region 7
Thien Bui James Regehr
IV1 o n 11 o r i n g 0 r ga n I z a t i o n s
EPA acknowledges the monitoring organizations that supported the AA-PGVP Annual Survey.
They include:
Albuquerque Environmental Health Department, AQD
Arizona Department of Environmental Quality
Broward County Environmental Protection Department
California Air Resources Board
Cherokee Nation, Oklahoma
Clark County, NV DES
Connecticut Department of Environmental Protection
Florida Dept of Environmental Protection, Northwest District
Forsyth County Environmental Affairs Department
Idaho Department of Health and Welfare-Environment Div.
Indiana Depart of Environ Management
Kentucky Division for Air Quality
Maricopa County Air Quality
Maryland Department of the Environment
Mass Dept Environmental Protection (DAQC)
Miami-Dade County (DERM)
Michigan Dept of Environment, Great Lakes, and Energy
Mississippi DEQ
Missouri Laboratory Services Program
Monterey Bay Unified APCD
New Hampshire Air Resources Agency
New Jersey State Department of Environmental Protection
New Mexico Environment Department
North Carolina Dept of Environmental Quality
North Dakota DEQ
Ohio EPA, Central District Office
Oregon Department of Environmental Quality
Polk County Physical Planning
Rhode Island DEM and DOH
Sacramento County APCD
San Luis Obispo County APCD
South Carolina Department Health and Environ. Control
South Coast Air Quality Management District
South Dakota (DANR)
State of Louisiana
Texas Commission on Environmental Quality
University Hygienic Laboratory (University of Iowa)
Virginia Department of Environmental Quality
Washington State Department of Ecology
Washoe County District Health Department
West Virginia Northern Panhandle Regional Office
Wisconsin Dept of Natural Resources, Air Monitoring Section
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Acronyms and Abbreviations
AA-PGVP Ambient Air Protocol Gas Verification Program
AMTIC Ambient Monitoring Technology Information Center
AQS Air Quality System
CFR Code of Federal Regulations
CO Carbon Monoxide
CONC Concentration
DoE Declaration of Equivalence with the National Institute of Standards and Technology
EPA Environmental Protection Agency
GMIS Gas Manufacturer's Intermediate Standard
ID Identification
MFC Mass Flow Controller
NIST National Institute of Standards and Technology
NMI National Metrology Institute
N02 Nitrogen Dioxide
NOx Nitrogen Oxides
MQO Measurement Quality Objective
NTRM NIST Traceable Reference Material
NVLAP National Voluntary Laboratory Accreditation Program
OAQPS Office of Air Quality Planning and Standards
OAR Office of Air and Radiation
OIG Office of the Inspector General
ORD Office of Research and Development
PQAO Primary Quality Assurance Organization
PRM Primary Reference Material
PSI Pounds per Square Inch
PSIG Pounds per Square Inch Gauge
QA Quality Assurance
QAPP Quality Assurance Project Plan
QC Quality Control
QTR Quarter
RAVL Regional Analytical Verification Laboratory
RD Relative Difference
RPD Relative Percent Difference
SI International System of Units
S02 Sulfur Dioxide
SOP Standard Operating Procedure
SRM Standard Reference Material
URL Upper Range Limit
VSL Netherland's National Metrology Institute; Dutch Von Swinden Laboratorium
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1 n
Background a > ¦ , ogre i ¦ a Is
The basic principles of the U.S. Environmental Protection Agency's (EPA) Traceability Protocol for the Assay
and Certification of Gaseous Calibration Standards (EPA, 2012)1 were developed jointly by EPA, the National
Bureau of Standards (now National Institute of Standards and Technology [NIST]), and specialty gas
producers over 40 years ago. At the time, commercially prepared calibration gases were perceived as being
too inaccurate and too unstable for use in calibrations and audits of continuous source emission monitors
and ambient air quality monitors2. The protocol was developed to improve the quality of the gases by
establishing their traceability to NIST Standard Reference Materials (SRMs) and to provide reasonably priced
products. This protocol established the gas metrological procedures for measurement and certification of
these calibration gases for EPA's Acid Rain Program under 40 Code of Federal Regulations (CFR) Part 75, for
the Ambient Air Quality Monitoring Program under 40 CFR Part 58, and for the Source Testing Program
under 40 CFR Parts 60, 61, and 68. EPA required monitoring organizations implementing these programs
("the regulated community") to use EPA Protocol Gases as their calibration gases. EPA revised the protocol
to establish detailed statistical procedures for estimating the total uncertainty of these gases. EPA's Acid
Rain Program developed acceptance criteria for the uncertainty estimate3.
Specialty gas producers prepare and analyze EPA Protocol Gases without direct governmental oversight. In
the 1980s and 1990s, EPA conducted a series of EPA-funded accuracy assessments of EPA Protocol Gases
sold by producers. The intent of these audits was to:
• increase the acceptance and use of EPA Protocol Gases as calibration gases,
• provide a quality assurance (QA) check for the producers of these gases, and
• help users identify producers who can consistently provide accurately certified gases.
Either directly or through third parties, EPA procured EPA Protocol Gases from the producers, assessed the
accuracy of the gases' certified concentrations through independent analyses, and inspected the
1 EPA-600/R-12/531
2 Decker, C.E. et al., 1981. "Analysis of Commercial Cylinder Gases of Nitric Oxide, Sulfur Dioxide, and Carbon
Monoxide at Source Concentrations," Proceedings of theAPCA Specialty Conference on Continuous Emission
Monitoring-Design, Operation, and Experience, APCA Publication No. SP-43.
3 "Continuous Emission Monitoring," Code of Federal Regulations, Title 40, Part 75
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accompanying certificates of analysis for completeness and accuracy. The producers were not aware that
EPA had procured the gases for these audits.
The accuracy of the EPA Protocol Gases' certified concentrations was assessed using SRMs as the analytical
reference standards. If the difference between the audit's measured concentration and the producer's
certified concentration was more than ±2.0 percent or if the documentation was incomplete or inaccurate,
EPA notified the producer to resolve and correct the problem. The results of the accuracy assessments were
published in peer-reviewed journals and were posted on EPA's Technology Transfer Network website. The
accuracy assessments were discontinued in 1998.
In 2009, the Office of the Inspector General (OIG) published the report EPA Needs an Oversight Program for
Protocol Gases4. One of the report's findings suggested that EPA "does not have reasonable assurance that
the gases that are used to calibrate emissions monitors for the Acid Rain Program and continuous ambient
monitors for the nation's air monitoring network are accurate". OIG recommended that the Office of Air and
Radiation (OAR) implement oversight programs to assure the quality of the EPA Protocol Gases that are used
to calibrate these monitors. It also recommended that EPA's Office of Research and Development (ORD)
update and maintain the document Traceability Protocol for Assay and Certification of Gaseous Calibration
Standards to ensure that the monitoring programs' objectives are met.
In order to address the OIG findings for ambient air monitoring, the Office of Air Quality Planning and
Standards (OAQPS), in cooperation with two EPA Regional Offices, developed an Ambient Air Protocol Gas
Verification Program (AA-PGVP). The program established two gas metrology laboratories to verify the
certified concentrations of EPA Protocol Gases used to calibrate ambient air quality monitors. The program is
designed to ensure that producers selling EPA Protocol Gases are evaluated by the AA-PGVP and provides
end users with information about participating producers and verification results.
The EPA Ambient Air Quality Monitoring Program's QA requirements, as described in Section 2.6.1 of 40 CFR
Part 58, Appendix A, include:
Gaseous pollutant concentration standards (permeation devices or cylinders of compressed gas)
used to obtain test concentrations for CO, S02, NO, and N02 must be traceable to either a National
Institute of Standards and Technology (NIST) Traceable Reference Material (NTRM) or a NIST-
certified Gas Manufacturer's Internal Standard (GMIS), certified in accordance with one of the
procedures given in reference 4 of this appendix. Vendors advertising certification with the
procedures provided in reference 4 of this appendix and distributing gases as "EPA Protocol Gas" for
ambient air monitoring purposes must participate in the EPA Ambient Air Protocol Gas Verification
Program or not use "EPA" in any form of advertising. Monitoring organizations must provide
information to the EPA on the gas producers they use on an annual basis and those POAOs
purchasing standards will be obligated, at the request of the EPA, to participate in the program at
least once every 5 years by sending a new unused standard to a designated verification laboratory.
4 https://www.epa.gov/office-inspector-general/report-epa-needs-oversight-program-protocol-gases-09-P-0235.pdf
Page 8 of 26
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This program is considered a verification program because its current level of evaluation does not allow for a
large enough sample of EPA Protocol Gases from any one specialty gas producer to yield a statistically
rigorous assessment of the accuracy of the producer's gases. As indicated in 40 CFR Part 75 Appendix A, EPA
Protocol Gases must have a certified uncertainty (95 percent confidence interval) that must not be greater
than plus or minus 2 percent (±2.0%) of the certified concentration (tag value) of the gas mixture. This
acceptance criterion is for the Acid Rain Program. The AA-PGVP adopted this criterion as its data quality
objective and developed a quality system to allow the RAVLs to determine whether an individual protocol
gas standard concentration was within ±2% of the certified value.
Purpose "" " lis Document
The purpose of this document is to report the activities that occurred in 2022 and provide the results of the
verifications performed.
Since the AA-PGVP does not sample enough cylinder standards annually to provide a statistically rigorous
assessment of any specialty gas producer, the RAVLs report all valid results as analyzed without declaring a
pass or fail determination for individual specialty gas producers. However, it is suggested that any assay
verification results with a difference greater than ±4% is cause for concern. The AA-PGVP assay verifications
are not intended to provide end users with a scientifically defensible estimate of whether gases of
acceptable quality can be purchased from a specific producer. Rather, the results provide information to
end users that the specialty gas producer is evaluated by the program and with information that may be
helpful when selecting a producer.
This document will not explain the implementation of the AA-PGVP, the quality system or the verification
procedure. That information has been documented in the Implementation Plan, Quality Assurance Project
Plan (QAPP) and standard operating procedures (SOPs). These documents can be found on the AA-PGVP
section on the Ambient Monitoring Technology Information Center (AMTIC)5 website. The AA-PGVP SOPs are
located in the AA-PGVP QAPP as an appendix.
2.0 Implementation Summary
Since the program implementation started in 2010, when most of the initial preparation work took place, no
major new implementation activities took place. However, EPA regional realignments and aging
infrastructure reduced the capabilities of this program. Due to these constraints, the EPA Region 2 Regional
Analytical Verification Laboratory (RAVL) ceased its active participation in the AA-PGVP in calendar year
2019. Since 2020 EPA began reengineering the AA-PGVP and transitioning Region 2 operations to the Region
4 laboratory. However, during 2022 the AA-PGVP continued to operate with only the Region 7 RAVL.
5 www.epa.gov/amtic/ambient-air-protocol-gas-verification-program
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Operations with only a single RAVL resulted in the AA-PGVP unable to swap internal quality control samples
(cylinder standards) between two independent RAVLs.
The following provides a brief overview of the ambient air protocol gas verification program.
Producer Information Data Collection - Beginning in 2010, EPA sent out an Excel spreadsheet to each
monitoring organization to obtain information on the gas standard producers being used by the monitoring
organization and to determine their interest in participating in the program. In 2011, EPA began work with
Research Triangle Institute to develop a web-based survey that one point of contact for each monitoring
organization could access. The intent was to make recording and evaluation of the survey information easier
for the monitoring organizations and EPA. This contracted survey work has since migrated to Battelle.
Based on the information obtained from monitoring organization surveys, EPA would develop a list of the
specialty gas producers being used by the monitoring organizations. From this list, EPA would attempt to
perform representative sampling of the standards from protocol gas production facilities by identifying
regulatory monitoring agencies that use standards from each of these producers. However, for calendar
year 2022 only 42 agencies participated in the survey. With only limited survey results, a systematic
selection of producers could not be performed. During calendar year 2022 the AA-PGVP performed assays
on all cylinders submitted by regulatory monitoring agencies. OAQPS continues to develop an Air Quality
System (AQS) database solution to upgrade and replace the specialty gas usage information that is currently
acquired through the contractor based annual questionnaire. During CY-2022 a cylinder metadata entry
form to support the AA-PGVP was created in AQS. Cylinder usage data that was historically collected via the
annual survey began to be collected via AQS. Both North Dakota DEQ and the California Air Resources Board
used AQS to report the specialty gas producers used for their calibration standards while the remaining 40
agencies used EPA's deprecating annual survey system.
AA-PGVP Verification Dates - OAQPS worked with the Region 7 Regional Analytical Verification Laboratory
(RAVL) to establish verification dates as indicated in Table 1.
Table 1. RAVL Verification Dates
Quarter
Region 7
Cylinder Receipt
Analysis
1
No later than Feb 23
Feb 28-Mar 11
2
No later than Jun 1
Jun 5-Junl7
3
No later than Aug 24
Aug 29 - Sept 9
4
No later than Dec 1
Dec 5 - Dec 16
Open
House
December 19, 2022
Table 1. RAVL Verification Dates
Table 1 RAVL Open House - During Open House the RAVL allows specialty gas producers to visit and ask
questions regarding the laboratory processes and operations. During 2022 no specialty gas producers visited
the Region 7 RAVL.
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Flow of the AA-PGVP
Figure 1 provides a flow diagram of the implementation activities of the AA-PGVP. The major activities in
these steps are explained below. More details of these steps are found in the AA-PGVP Implementation Plan,
QAPP and SOPs.
©
Figure 1. AA-PGVP Flow Chart
0. Specialty Gas Producers procure standards from NIST, or an NMI with a DoE with NIST, to establish traceability of
their EPA Protocol Gas Standards to the SI. RAVLs also procure NIST standards as part of the AA-PGVP.
1. Monitoring organizations order EPA Protocol Gas Standards as a normal course of business.
2. EPA sends reminder e-mails to the monitoring organization's points of contact to enter cylinder metadata in AQS or
complete AA-PGVP's Survey. Based on an annual assessment of this information, monitoring organizations are
selected to send cylinder standards to EPA for assay verification. Through consultation with the participating
monitoring organization, EPA schedules the assay verifications.
3. The participating monitoring organizations send a new/unused standard, certificate of analysis, and chain of custody
form to the RAVLs for the assay verification. Standards are returned to the monitoring organization along with the
verification results for their standards.
4. The RAVLs provide the validated results to OAQ.PS.
5. When the assay verification results are greater than ±4% of the certified concentration, or greater than ±2% when
the expanded measurement uncertainty is included, specialty gas producers are notified by OAQ.PS.
6. GAQPS compiles the year's verification results into an annual report and posts it to the AMTIC website.
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3.0 Survey and Verification Results
Monitoring Organization Survey
Based upon the maximum capability of 40 gas cylinders per RAVL per year, the AA-PGVP selection goal, in
the following order, is:
1) At least one gas standard from every specialty gas producer being used by the monitoring
2) If all specialty gas producers have been assessed at least once, then attempt to verify three
standards per specialty gas producer.
3) If all specialty gas producers have been assessed three times, weigh additional verifications by
producer market share in the ambient air monitoring community.
In order to assess which specialty gas producers are used by the monitoring organizations, EPA uses a web-
based survey that each monitoring organization completes annually. Since 2016, EPA regulations found in 40
CFR Part 58 Appendix A §2.6.1 require monitoring organizations to annually provide this information.
However, as can be seen from Figure 2, participation in the annual survey has not improved since the 2016
monitoring rule revisions.
community.
AA-PGVP / Survey
Participation Trend
300
250
200
100
150
50
0
2011 2012 2013 2014 2015
Year
.»• All AOS Agencies Agencies (S02, CO, N02) \ Surveyed
Figure 2 Annual Survey
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Verification Results
The AA-PGVP received 7 cylinders for assay verification during calendar year 2022. The 7 cylinders received
are listed in Table 2. As can be seen from Table 2, some cylinders contain more than a single calibration gas
standard. A summary of the assay results for these cylinders are provided in Tables 4 and 5.
Table 2. Gas Standards Sent to RAVLs in Calendar Year 2022
Qtr
Cylinder
ID
Pollutant
Lab
Producer
Facility
Agency
3
ET0033566
NO,NOx
7
Airgas
Chicago IL
Utah DEO
3
LL40977
CO,NO,NOx
7
Airgas
Los Angeles CA
South Coast AQMD
3
LL71616
CO
7
Linde
Los Angeles CA
Utah DEQ
3
LL81350
CO
7
Linde
Los Angeles CA
Utah DEQ
3
LL23589
so2
7
Linde
Los Angeles CA
Utah DEQ
3
LL1051310
NO,NOx
7
Linde
Los Angeles CA
Utah DEQ
2
LL123954 n
NO,NOx
7
Linde
Toledo OH
Hygienic Lab (University of Iowa)
Table 2. Gas Standards Sent to RAVLs
Notes: O NOx concentration provided by Producer as "informational only"; concentration not certified by Producer.
All standards verified in calendar year 2022 were within the ±2% acid rain criteria acceptance criterion, and
less than the AA-PGVP action level for concern. Figure 3 below provides a historical trend showing the
improvement in the quality of EPA Protocol Gas Standards from the inception of the program to present.
Figure 3 Verification Trend
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Information related to the analytical reference standards, analytical instruments and methods used, the data
reduction procedures, and the data assessment procedures are found in the AA-PGVP QAPP and SOP. The
AA-PGVP QAPP is located on EPA's AMTIC website. The SOP can be found as an appendix in the QAPP. Table
3 provides the measurement quality objectives (MQOs) that are included in the AA-PGVP QAPP (Table 7-1 of
the QAPP). The acceptance criteria in Table 3 were met for each day of verification. In addition,
conformance to these requirements can be found in the measurement data worksheets that are generated
for each comparison run and are available upon request. Appendix A provides a report of the quality control
(QC) checks associated with each verification run. Table 4 provides the verification results for CO and S02,
and Table 5 provides the NO and NOx verification results. Tables 4 and 5 are grouped by pollutant standard
and then sorted by absolute Bias of the assay result.
Table 3. MQOs for the AA-PGVP
Requirement
Frequency
Acceptance Criteria
Protocol Gas
Comments
Doc. Reference
Completeness
All standards analyzed
95%
Based on an anticipated 40
cylinders per lab per year.
Quarterly Flow
Quarterly -no more than
Calibration flow
2.3.7
Using flow primary
Calibration
1 mo. before verification
accuracy within +1%
standard
Calibrator Dilution
Quarterly -within 2 weeks
+ 1% RD
2.3.5.1
Second SRM. Three or
Check
of assay
more discrete
measurements
Analyzer
Quarterly-within 2 weeks
+ 1% RPD (each point)
2.1.7.2
5 points between 50-90%
Calibration
of assay
Slope 0.89-1.02
of upper range limit of
analyzer + zero point
Zero & Span
Each day of verification
SE mean < 1% and
2.1.7.3, 2.3.5.4
Drift accountability. 3
Verifications
accuracy + 5% RD
discrete measurements of
zero and span
Precision Test1
Day of Verification
+ 1% RD standard
2.3.5.4
SRM at conc. >80% of
error of the mean
analyzer URL
Routine Data
Any Standard with Value
NA
Sample run three times to
Check
>2% Tag Value
verify value.
Lab Comparability
2/year
+ 2 % RPD
NA
Sample run three average
value used.
Standards Certification
Primary flow
Annually certified by
1.0 %
NA
Compared to NIST
standard
NVLAP accredited lab
Traceable
NISTSRMs
Expiration date SRM
Will follow NIST
pressure > 150 psig
recertification
requirements
Table 3. MQOs fop AA-PGVP
1 The precision test does not need to be accomplished if analyzer calibrated on same day as analysis.
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>-PGVP CO and S02 Verifications*
Producer
Facility
Cylinder ID
Pollutant
Assay
Cone
Producer
Cone
%
Bias*
95%
Uncertainty"
Airgas
Los Angeles CA : LL40977
CO
903.9 907.4 0.4
0.28
Linde
Los Angeles CA LL81350
CO 4973.3 4980 0.1
0.20
Linde
Los Angeles CA LL71616
CO 4980 4974 -0.1
0.20
Linde
Los Angeles CA
LL23589
S02
99.72
99.9
0.2
0.16
Table 4. AA-PGVP CO and S02 Verifications
Notes: * Table grouped by Pollutant and sorted by absolute Bias
** Analyzer uncertainty, see Quality Assurance Requirements Section 13.7 of SOP.
(Analyzer uncertainty value is not the expanded measurement uncertainty)
t An Estimate for the national usage for specific protocol gas producers cannot be determined
due to lack of participation in annual survey
11 o : ¦ 1 V \-PGVP - id NOx Verifications*
Producer
Facility
I Cylinder ID
1 Pollutant
Assay
Cone
Producer
Cone
%
Bias*
95%
Uncertainty"
Linde
Toledo OH
1 LL123964
NO
25.45
25.3
-0.6
0.18
Linde
Los Angeles CA
: LL105131
NO
48.85
48.6
-0.5
0.10
Airgas
Chicago IL
ET0033566
NO
50
50.09
0 7
0.11
Airgas
Los Angeles CA
LL40977
NO
43.92
43.86
-0.1
0.10
Airgas
Los Angeles CA
: LL40977
NOx
44.63
44.35
-0.6
0.11
Linde
Los Angeles CA
: LL1051310
NOx
48.91
48.8
-0.2
0.11
Airgas
Chicago IL
! ET0033566
NOx
50.01
50.1
0.2
0.11
Linde
Toledo OH
! LL1239640
NOx
25.44
25.5
0.2
0.14
Table 5. AA-PGVP NO and NOx Verifications
Notes: * Table grouped by Pollutant and sorted by absolute Bias
** Analyzer uncertainty, see Quality Assurance Requirements Section 13.7 of SOP.
(Analyzer uncertainty value is not the expanded measurement uncertainty)
t An Estimate for the national usage for specific protocol gas producers cannot be determined
due to lack of participation in annual survey
CI NOx concentration provided by Producer as "informational only"; concentration not certified by Producer.
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4.0 Summary and Conclusions
General -
The AA-PGVP is successfully implementing a verification process that is blind to the specialty gas producers.
One of the goals for the AA-PGVP as defined in the ambient air monitoring rule (published March 28, 2016) is
for the verifications performed by the RAVLs to be focused on the ambient air monitoring organizations
rather than as a resource to be utilized by specialty gas producers for their own quality assurance. The
purpose of the program (verifications of gas cylinders that are blind to the producers) cannot be
accomplished if EPA relies on the specialty gas producers to submit cylinders for the assessment. All of the
protocol gas cylinder standards submitted for analysis were submitted by SLT ambient air monitoring
programs.
While the program is successfully implementing a blind verification process only 7 cylinders, or 9% of the AA-
PGVP goal of 80 cylinders annually, were analyzed in 2022. These 7-cylinder submissions resulted in only 12
verifications (some cylinders are a blend of multiple gas standards). None of the assay verification results
were greater than the AA-PGVP action level for concern (±4%) or the acceptance criterion is for the Acid Rain
Program (±2.0%). It is difficult to assess whether these results are representative of the overall quality of the
standards used in the national ambient air monitoring networks during 2022 due to the low utilization of the
RAVL by the monitoring programs and low participation rate in the annual protocol gas questionnaire. In
2022 there were 26 commercially operated EPA protocol gas production facilities. It is uncertain how many of
these facilities were used in the ambient air monitoring networks in 2022. Of the 26 protocol gas production
facilities operating, only four were verified by EPA's ambient air protocol gas verification program.
Survey Participation Improvement -
Since its inception, the AA-PGVP has relied on an annual survey to determine which gas production facilities
are used by the SLTs for generating CO, S02, and N02 calibration test atmospheres. Participation in the
annual survey was initially voluntary. To improve the participation rate and to more completely document
which protocol gas producers are utilized by our ambient air monitoring organizations, in 2016 ambient air
monitoring programs using protocol gases were required to annually complete the survey. While it was
thought at the time that this regulatory requirement would increase the participation rate and create a
comprehensive list of the protocol gas producers used in the national network, the survey participation rate
did not improve. In calendar year 2022 participation in the annual questionnaire was about 27% of the
monitoring agencies that operate CO, S02, and N02 ambient air analyzers. OAQPS is actively enhancing EPA's
AQS database as an alternative solution to gather this information. See Data Management Improvement
section below for further details.
RAVL Participation Improvement-
Since the 2016 revisions of the monitoring rule, the AA-PGVP continues to achieve blind verifications of the
protocol gas cylinders used in our ambient air monitoring networks. However, the program still does not
achieve its goal of having every Primary Quality Assurance Organization (PQAO) submit an unused cylinder at
least once every five years for verification. The AA-PGVP's goal to perform 80 protocol gas verifications each
year and to strategically select these protocol cylinders to representatively assess the quality of the routine
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measurement data for the national ambient air monitoring networks was not achieved in calendar year 2022.
Only seven protocol gas cylinder standards were submitted by three PQAOs in 2022 to support this national
program. Region 7 assayed all the cylinders received during this calendar year. A better national sampling of
monitoring programs and protocol gas producers continues to be needed.
The limited verifications performed in 2022 was partially due to the lack of low concentration SRMs currently
available from NIST. This has led to cases where the EPA was forced to decline low concentration cylinder
standards offered by SLT regulatory ambient air monitoring programs for assay verification. OAQPS is
working to add assay capacity in the future by using the EPA Region 4 laboratory as an additional RAVL.
OAQPS is also working collaboratively with NIST to develop solutions to this shortage of SRMs available for
purchase. OAQPS is also investigating the feasibility of obtaining primary reference materials (PRM) from a
NMI that has a DoE with NIST, such as the Netherland's National Metrology Institute; Dutch Von Swinden
Laboratorium (VSL), or NIST Traceable Reference Materials (NTRM) to use as a replacement for NIST SRMs.
Quality System Improvement -
The Quality Assurance Project Plan (QAPP) has not been updated since calendar year 2010. Changes to the
program have occurred since 2010, including regulatory changes in 2016. These documents need to be
reconciled with current program practices and regulatory requirements. OAQPS is working with Battelle to
assist EPA in revising the AA-PGVP QAPP beginning calendar year 2023.
In 2022, the AA-PGVP operated with a single RAVL. As such, the quality assurance designated for the
laboratory intercomparison of the internal standards could not be performed. OAQPS is currently working
with EPA Region 4 to begin using their laboratory as a second RAVL. Once operational, Region 4 RAVL will
allow for both increased assay capacity for the AA-PGVP and provide additional internal quality control
between the two RAVLs.
Data Management Improvement -
The AA-PGVP has historically relied solely on the annual survey for determining which protocol gas standard
producers are used in the national ambient air monitoring networks. The annual survey was originally a
voluntary program and later in 2016 it became a regulatory requirement. Neither implementation of this
process has proven to be fully effective. The data management practices for conducting the annual survey
and storing its results are not optimized to be readily reconciled with the data produced by the RAVLs.
OAQPS continues to actively pursue AQS database solutions to replace the data management practices
historically performed by EPA's contractor. This includes the creation of an AQS form for SLT monitoring
programs to submit their cylinder metadata and modifications to the current AQS "QA-Transaction" file
format for the single point quality control checks and annual performance audits. The modifications being
developed will allow for documenting the protocol gas production facility of the protocol gas cylinder used
for generating the test atmospheres for each of these checks. Utilizing this modified AQS data submission
process will allow EPA to document 100% of the protocol gas production facilities used in the ambient air
monitoring networks as opposed to the current process which has only been 17% effective between 2018-
2022. To facilitate these enhancements, an AQS entry form for submission of cylinder metadata was
developed and deployed in calendar year 2022. Two monitoring programs utilized the maintain cylinder
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form in AQS in 2022 with an additional 10 monitoring programs have used this new AQS feature during the
first quarter of 2023. New AQS features to merge this cylinder metadata with the data stream containing the
single point quality control checks and annual performance audits are currently in stage testing in 2023.
EPA's goal is to have both these new AA-PGVP systems fully operational in AQS during calendar 2023.
Page 18 of 26
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Appendix A ¦ orts from Measureme >" ¦ >ta Workshi ¦ ¦¦ ¦¦ ¦
Ambient Air Protocol Gas Verification Program
QA Reports from Measurement Data Worksheets for 2022
During the verification process, the Regional Air Verification Laboratories perform a number of quality
control checks that are recorded on the Measurement Data Worksheets. This information is reported and
saved along with the verification reports. The following sheets represent the quality control for all
verifications that were implemented in 2022.
Page 19 of 26
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QA Requirements Summary
QA Requirement
Result
Status
Primary SRM Cylinder Expiration Date
14-Sep-25
Primary SRM Gas Standard OK
SRM Gas Standards
Primary SRM Cylinder Pressure >150 psi
1725
Primary SRM cylinder pressure is OK
SRM Dilution Check Cylinder Expiration Date
1-Feb-24
Dilution Check SRM Gas Standard OK
Dilution Check SRM Cylinder Pressure >150 psi
450
Dilution check SRM cylinder pressure is OK
High Flow Standard Expiration Date
8-Feb-23
Standard OK
Laboratory Flow Standard
Low Flow Standard Expiration Date
8-Feb-23
Standard OK
Ultra Low Flow Expiration Date
9-Feb-23
Standard OK
Calibrator (mass flow controllers)
Calibrator Flow Calibration within 2 weeks of assay
5-Jun-22 Icalibrator flow calibration within 2 weeks of assay
Calibrated High Flow MFC Slope Range = 0.99 -1.0
0.9999990 High MFC OK
Calibrated Low Flow MFC Slope Range = 0.99 -1.0"
0.9999804 Low MFC OK
Analyzer Calibration within 2 weeks of assay
6-Jun-22
Analyzer calibration within 2 weeks of assay
Estimate of Uncetainty < 1 % at point #1 (>80% URL)
0.10%
Assay may be conducted at this concentration
Oxides of Nitrogen Gas Analyzer
NO Portion
Estimate of Uncetainty < 1 % at point #2
0.10%
Assay may be conducted at this concentration
Estimate of Uncetainty < 1 % at point #3
0.10%
Assay may be conducted at this concentration
Estimate of Uncetainty < 1 % at point #4
0.11%
Assay may be conducted at this concentration
Estimate of Uncetainty < 1 % at point #5 (-50% URL)
0.11%
Assay may be conducted at this concentration
Analyzer slope is within 0.98-1.02
0.9990
Analyzer Slope is acceptable
Analyzer Calibration within 2 week of assay
6-Jun-22
Analyzer calibration within 2 weeks of assay
Estimate of Uncetainty < 1 % at point #1 (>80% URL)
0.08%
Assay may be conducted at this concentration
Oxides of Nitrogen Gas Analyzer
NOx Portion
Estimate of Uncetainty < 1 % at point #2
0.08%
Assay may be conducted at this concentration
Estimate of Uncetainty < 1 % at point #3
0.09%
Assay may be conducted at this concentration
Estimate of Uncetainty < 1 % at point #4
0.09%
Assay may be conducted at this concentration
Estimate of Uncetainty < 1 % at point #5 (-50% URL)
0.09%
Assay may be conducted at this concentration
Analyzer slope is within 0.98-1.02
0.9984
Analyzer Slope is acceptable
Dilution Check
Dilution Check Date within 2 weeks of assay
6-Jun-22
Dilution check within 2 weeks of assay
Dilution Check Relative % Difference < 1%
0.116%
Dilution Check RSD is OK
Day of Assay Zero Check - Std. Error < 1 %
Std. Error is okay.
Zero Gas Std Error is OK
Day of Assay Zero/Span Check
NO Portion
Day of Assay Zero Check - Relative Difference < 5%
RD is okay
Zero Gas RD is OK
Day of Assay Span Check - Std. Error < 1 %
Std. Error is okay.
Span Gas Std Error is OK
Day of Assay Span Check - Relative Difference <5%
RD is okay.
Span Gas RD is OK
Day of Assay Zero Check - Std. Error < 1%
Std. Error is okay.
Zero Gas Std. Error is OK
Day of Assay Zero/Span Check
NOx Portion
Day of Assay Zero Check - Relative Difference < 5%
RD is okay
Zero Gas RD is OK
Day of Assay Span Check - Std. Error < 1 %
Std. Error is okay.
Span Gas Std Error is OK
Day of Assay Span Check - Relative Difference <5%
RD is okay-
Span Gas RD is OK
Challenge Standard #1 NO Assay
Challenge Standard #1 Std. Error < 1%
Challenge Standard #1 vendor certificate bias
The standard error is okay.
-0.60%
Challenge Standard #1 Std. Error is OK
Challenge Std #1 vendor certificate bias < 2%
Challenge Standard #1 NOx Assay
Challenge Standard #1 Std. Error < 1%
The standard error is okay.
Challenge Standard #1 Std. Error is OK
Challenge Standard #1 vendor certificate bias
0.23%
Challenge Std #1 vendor certificate bias < 2%
Challenge Standard #2 NO Assay
Challenge Standard #2 Std. Error < 1%
The standard error is okay.
Challenge Standard #2 Std. Error is OK
Challenge Standard #2 vendor certificate bias
-0.45%
Challenge Std. #2 vendor certificate bias < 2%
Challenge Standard #2 Std. Error < 1%
The standard error is okay.
Challenge Standard #2 Std. Error is OK
Challenge Standard #2 vendor certificate bias
0.08%
Challenge Std. #2 vendor certificate bias < 2%
Page 20 of 26
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QA Requirement
Result
Status
Primary SRM Cylinder Expiration Date
7-Feb-28
Primary SRM Gas Standard OK
SRM Gas Standards
Primary SRM Cylinder Pressure >150 psi
1900
Primary SRM cylinder pressure is OK
SRM Dilution Check Cylinder Expiration Date
30-Sep-27
Dilution Check SRM Gas Standard OK
Dilution Check SRM Cylinder Pressure >150 psi
1725
Dilution check SRM cylinder pressure is OK
High Flow Standard Expiration Date
8-Feb-23
Standard OK
Laboratory Flow Standard
Low Flow Standard Expiration Date
8-Feb-23
Standard OK
Ultra Low Flow Standard Expiration Date
9-Feb-23
Standard OK
Calibrator Flow Calibration within 2 weeks of assay
5-Jun-22
Calibrator flow calibration within 2 weeks of assay
Calibrator (mass flow controllers]
Calibrated High Flow MFC Slope Range = 0.99 -1.0
0.9999990
High MFC OK
Calibrated Low Flow MFC Slope Range = 0-99 -1.0
0.9999804
Low MFC OK
Analyzer Calibration within 2 week of assay
5-Jun-22
Analyzer calibration within 2 weeks of assay
Estimate of Uncetainty < 1 % at point #1 (>80% URL)
0.30%
Assay may be conducted at this concentration
Estimate of Uncetainty < 1 % at point #2
0.30%
Assay may be conducted at this concentration
Carbon Monoxide Gas Analyzer
Estimate of Uncetainty < 1 % at point #3
0.31%
Assay may be conducted at this concentration
Estimate of Uncetainty < 1 % at point #4
0.32%
Assay may be conducted at this concentration
Estimate of Uncetainty < 1 % at point #5 (-50% URL)
0.33%
Assay may be conducted at this concentration
Analyzer slope is within 0.98-1.02
1.0030
Analyzer Slope is acceptable
Dilution Check
Dilution Check Date within 2 weeks of assay
6-Jun-22
Dilution check within 2 weeks of assay
Dilution Check Relative % Difference < 1%
0.116%
Dilution Check RSD is OK
Day of Assay Zero/Span Check
Day of Assay Zero Check - Std. Error < 1 %
Day of Assay Zero Check - Relative Difference < 5%
Std. Error is okay.
RD is okay.
Zero Gas Std Error is OK
Zero Gas RD is OK
Day of Assay Span Check - Std. Error < 1%
Std. Error is okay.
Span Gas Std. Error is OK
Day of Assay Span Check - Relative Difference <5%
RD is okay.
Span Gas RD is OK
„ Challenge Standard #1 Std. Error < 1%
Challenge Standard #1 Assay
Challenge Standard #1 vendor certificate bias
The standard error is okay.
-0.35%
Challenge Standard #1 Std Error is OK
Challenge Std. #1 vendor certificate bias < 2%
Page 21 of 26
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QA Requirement
Result
Status
Primary SRM Cylinder Expiration Date
27-Jun-23
Primary SRM Gas Standard OK
SRM Gas Standards
Primary SRM Cylinder Pressure >150 psi
850
Primary SRM cylinder pressure is OK
SRM Dilution Check Cylinder Expiration Date
16-Sep-25
Dilution Check SRM Gas Standard OK
Dilution Check SRM Cylinder Pressure >150 psi
1625
Dilution check SRM cylinder pressure is OK
High Flow Standard Expiration Date
8-Feb-23
Standard OK
Laboratory Flow Standard
Low Flow Standard Expiration Date
8-Feb-23
Standard OK
Ultra Low Flow Standard Expiration Date
9-Feb-23
Standard OK
Calibrator Flow Calibration within 2 weeks of assay
5-Jun-22
Calibrator flow calibration within 2 weeks of assay
Calibrator (mass flow controllers) calibrated High Flow MFC Slope Range = 0.99 -1.0
0.9999990
High MFC OK
Calibrated Low Flow MFC Slope Range = 0.99 -1.0'
0.9999804
Low MFC OK
Analyzer Calibration within 2 weeks of assay
8-Jun-22
Analyzer calibration within 2 weeks of assay
Estimate of Uncetainty < 1 % at point #1 (>80% URL)
0.31%
Assay may be conducted at this concentration
Estimate of Uncetainty < 1 % at point #2
0.32%
Assay may be conducted at this concentration
Sulfur Dioxide Gas Analyzer
Estimate of Uncetainty < 1 % at point #3
0.32%
Assay may be conducted at this concentration
Estimate of Uncetainty < 1 % at point #4
0.33%
Assay may be conducted at this concentration
Estimate of Uncetainty < 1% at point #5 (-50% URL)
0.34%
Assay may be conducted at this concentration
Analyzer slope is within 0.98-1.02
1 0013
Analyzer Slope is acceptable
Dilution Check
Dilution Check Date within 2 weeks of assay
6-Jun-22
Dilution check within 2 weeks of assay
Dilution Check Relative % Difference < 1%
0.116%
Dilution Check RSD is OK
Day of Assay Zero/Span Check
Day of Assay Zero Check - Std. Error < 1 %
Day of Assay Zero Check - Relative Difference < 5%
Std. Error is okay.
RD is okay.
Zero Gas Std Error is OK
Zero Gas RD is OK
Day of Assay Span Check - Std. Error < 1%
Std. Error is okay.
Span Gas Std. Error is OK
Day of Assay Span Check - Relative Difference <5%
RD is okay.
Span Gas RD is OK
Challenge Standard #1 Assay
Challenge Standard #1 Std. Error < 1%
Challenge Standard #1 vendor certificate bias
The standard error is okay.
-0.84%
Challenge Standard #1 Std Error is OK
Challenge Std. #1 vendor certificate bias < 2%
Page 22 of 26
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QA Requirements Summary
QA Requirement Result Status
SRM Gas Standards
Primary SRM Cylinder Expiration Date
30-Sep-27
Primary SRM Gas Standard OK
Primary SRM cylinder pressure is OK
Primary SRM Cylinder Pressure >150 psi
2000
SRM Dilution Check Cylinder Expiration Date
7-Feb-28
Dilution Check SRM Gas Standard OK
Dilution check SRM cylinder pressure is OK
Dilution Check SRM Cylinder Pressure >150 psi
1000
Laboratory Flow Standard
High Flow Standard Expiration Date
8-Feb-23
Standard OK
Standard OK
Standard OK
Low Flow Standard Expiration Date
8-Feb-23
Ultra Low Flow Standard Expiration Date
9-Feb-23
Calibrator Flow Calibration within 2 weeks of assay
29-Aug-22
Calibrator flow calibration within 2 weeks of assay
Calibrator (mass flow controllers)
Calibrated High Flow MFC Slope Range = 0.99 • 1.0
0.9999997
High MFC OK
Calibrated Low Flow MFC Slope Range = 0.99 -1.0'
0.9999993
Low MFC OK
Analyzer Calibration within 2 week of assay
30-Aug-22
Analyzer calibration within 2 weeks of assay
Estimate of Uncetainty < 1% at point #1 (>80% URL)
0.38%
Assay may be conducted at this concentration
Estimate of Uncetainty < 1 % at point #2
0.39%
Assay may be conducted at this concentration
Carbon Monoxide Gas Analyzer
Estimate of Uncetainty < 1 % at point #3
0.40%
Assay may be conducted at this concentration
Estimate of Uncetainty < 1 % at point #4
0.41%
Assay may be conducted at this concentration
Estimate of Uncetainty < 1% at point #5 (—50% URL)
0.42%
Assay may be conducted at this concentration
Analyzer slope is within 0.98-1.02
0.9993
Analyzer Slope is acceptable
Dilution Check
Dilution Check Date within 2 weeks of assay
31-Aug-22
Dilution check within 2 weeks of assay
Dilution Check Relative % Difference < 1%
-0.033%
Dilution Check RSD is OK
Day of Assay Zero Check - Std. Error < 1%
Std. Error is okay.
Zero Gas Std Error is OK
Day of Assay Zero/Span Check
Day of Assay Zero Check - Relative Difference < 5%
RD is okay.
Zero Gas RD is OK
Day of Assay Span Check - Std. Error < 1%
Std. Error is okay.
Span Gas Std. Error is OK
Day of Assay Span Check - Relative Difference <5%
RD is okay.
Span Gas RD is OK
Challenge Standard #1 Assay
Challenge Standard #1 Std. Error < 1%
Challenge Standard #1 vendor certificate bias
The standard error is okay.
0.39%
Challenge Standard #1 Std. Error is OK
Challenge Std. #1 vendor certificate bias < 2%
Page 23 of 26
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QA Requirements Summary
QA Requirement Result Status
Primary SRM Cylinder Expiration Date
18-Sep-27
Primary SRM Gas Standard OK
SRM Gas Standards
Primary SRM Cylinder Pressure >150 psi
2000
Primary SRM cylinder pressure is OK
SRM Dilution Check Cylinder Expiration Date
19-Sep-29
Dilution Check SRM Gas Standard OK
Dilution Check SRM Cylinder Pressure >150 psi
1000
Dilution check SRM cylinder pressure is OK
High Flow Standard Expiration Date
8-Feb-23
Standard OK
Laboratory Flow Standard
Low Flow Standard Expiration Date
8-Feb-23
Standard OK
Ultra Low Flow Standard Expiration Date
9-Feb-23
Standard OK
Calibrator Flow Calibration within 2 weeks of assay
29-Aug-22
Calibrator flow calibration within 2 weeks of assay
Calibrator (mass flow controllers) Calibrated High Flow MFC Slope Range = 0.99-1.0
0.9999997
High MFC OK
Calibrated Low Flow MFC Slope Range = 0.99 -1.0'
0.9999993
Low MFC OK
Analyzer Calibration within 2 week of assay
29-Aug-22
Analyzer calibration within 2 weeks of assay
Estimate of Uncetainty< 1%atpoint#1 (>80% URL)
0.30%
Assay may be conducted at this concentration
Estimate of Uncetainty< 1% at point #2
0.30%
Assay may be conducted at this concentration
Carbon Monoxide Gas Analyzer
Estimate of Uncetainty < 1% at point #3
0.31%
Assay may be conducted at this concentration
Estimate of Uncetainty< 1%atpoint#4
0.32%
Assay may be conducted at this concentration
Estimate of Uncetainty < 1% at point #5 (-50% URL)
0.33%
Assay may be conducted at this concentration
Analyzer slope is within 0.98-1.02
1.0007
Analyzer Slope is acceptable
Dilution Check
Dilution Check Date within 2 weeks of assay
29-Aug-22
Dilution check within 2 weeks of assay
Dilution Check Relative % Difference < 1%
0.251%
Dilution Check RSD is OK
Day of Assay Zero/Span Check
Day of Assay Zero Check - Std. Error < 1 %
Day of Assay Zero Check - Relative Difference < 5%
Std. Error is okay.
RD is okay.
Zero Gas Std Error is OK
Zero Gas RD is OK
Day of Assay Span Check - Std. Error < 1%
Std. Error is okay.
Span Gas Std Error is OK
Day of Assay Span Check - Relative Difference <5%
RD is okay.
Span Gas RD is OK
Challenge Standard #1 Assay
Challenge Standard #1 Std. Error < 1%
Challenge Standard #1 vendor certificate bias
The standard error is okay.
0.13%
Challenge Standard #1 Std Error is OK
Challenge Std. #1 vendor certificate bias < 2%
Challenge Standard #2 Assay
Challenge Standard #2 Std. Error < 1%
The standard error is okay.
Challenge Standard #2 Std. Error is OK
Challenge Standard #2 vendor certificate bias
-0.12%
Challenge Std. #2 vendor certificate bias < 2%
Page 24 of 26
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QA Requirement
Result
Status
Primary SRM Cylinder Expiration Date
27-Jun-23
Primary SRM Gas Standard OK
SRM Gas Standards
Primary SRM Cylinder Pressure >150 psi
1675
Primary SRM cylinder pressure is OK
SRM Dilution Check Cylinder Expiration Date
16-Sep-25
Dilution Check SRM Gas Standard OK
Dilution Check SRM Cylinder Pressure >150 psi
1625
Dilution check SRM cylinder pressure is OK
High Flow Standard Expiration Date
8-Feb-23
Standard OK
Laboratory Flow Standard
Low Flow Standard Expiration Date
8-Feb-23
Standard OK
Ultra Low Flow Standard Expiration Date
9-Feb-23
Standard OK
Calibrator Flow Calibration within 2 weeks of assay
29-Aug-22
Calibrator flow calibration within 2 weeks of assay
Calibrator (mass flow controllers) Calibrated High Flow MFC Slope Range = 0.99 -1.0
0.9999997
High MFC OK
Calibrated Low Flow MFC Slope Range = 0.99 -1.0'
0.9999993
Low MFC OK
Analyzer Calibration within 2 weeks of assay
31-Aug-22
Analyzer calibration within 2 weeks of assay
Estimate of Uncetainty < 1% at point #1 (>80% URL)
0.18%
Assay may be conducted at this concentration
Estimate of Uncetainty < 1% at point #2
0.18%
Assay may be conducted at this concentration
Sulfur Dioxide Gas Analyzer
Estimate of Uncetainty < 1% at point #3
0.19%
Assay may be conducted at this concentration
Estimate of Uncetainty < 1% at point #4
0.19%
Assay may be conducted at this concentration
Estimate of Uncetainty* 1% at point #5 (-50% URL)
0.20%
Assay may be conducted at this concentration
Analyzer slope is within 0.98-1.02
1.0015
Analyzer Slope is acceptable
.. . Dilution Check Date within 2 weeks of assay
Dilution Check
Dilution Check Relative % Difference < 1 %
29-Aug-22
Dilution check within 2 weeks of assay
0.251%
Dilution Check RSD is OK
Day of Assay Zero/Span Check
Day of Assay Zero Check - Std. Error < 1%
Day of Assay Zero Check - Relative Difference < 5%
Std. Error is okay.
RD is okay.
Zero Gas Std Error is OK
Zero Gas RD is OK
Day of Assay Span Check • Std. Error < 1%
Std. Error is okay.
Span Gas Std. Error is OK
Day of Assay Span Check • Relative Difference <5%
RD is okay.
Span Gas RD is OK
A Challenge Standard #1 Std. Error < 1%
Challenge Standard #1 Assay
Challenge Standard #1 vendor certificate bias
The standard error is okay.
0.18%
Challenge Standard #1 Std. Error is OK
Challenge Std #1 vendor certificate bias < 2%
Challenge Standard #2 Assay
Challenge Standard #2 Std. Error < 1%
The standard error is okay.
Challenge Standard #2 Std. Error is OK
Challenge Standard #2 vendor certificate bias
-0.29%
Challenge Std #2 vendor certificate bias < 2%
Page 25 of 26
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QA Requirements Summary
QA Requirement Result Status
SRM Gas Standards
Primary SRM Cylinder Expiration Date
14-Sep-25
Primary SRM Gas Standard OK
Primary SRM cylinder pressure is OK
Primary SRM Cylinder Pressure >150 psi
1700
SRM Dilution Check Cylinder Expiration Date
1-Feb-24
Dilution Check SRM Gas Standard OK
Dilution check SRM cylinder pressure is OK
Dilution Check SRM Cylinder Pressure >150 psi
200
Laboratory Flow Standard
High Flow Standard Expiration Date
8-Feb-23
Standard OK
Standard OK
Standard OK
Low Flow Standard Expiration Date
8-Feb-23
Ultra Low Flow Expiration Date
9-Feb-23
Calibrator Flow Calibration within 2 weeks of assay
29-Aug-22
Calibrator flow calibration within 2 weeks of assay
Calibrator (mass flow controllers)
Calibrated High Flow MFC Slope Range = 0.99 -1.0
0.9999997
High MFC OK
Calibrated Low Flow MFC Slope Range = 0.99 -1.01
0.9999993
Low MFC OK
Analyzer Calibration within 2 weeks of assay
3-Sep-22
Analyzer calibration within 2 weeks of assay
Estimate of Uncetainty < 1% at point #1 (>80% URL)
0.13%
Assay may be conducted at this concentration
Oxides of Nitrogen Gas Analyzer
NO Portion
Estimate of Uncetainty < 1 % at point #2
0.13%
Assay may be conducted at this concentration
Estimate of Uncetainty < 1 % at point #3
0.14%
Assay may be conducted at this concentration
Estimate of Uncetainty < 1% at point #4
0.14%
Assay may be conducted at this concentration
Estimate of Uncetainty < 1 % at point #5 (-50% URL)
0.14%
Assay may be conducted at this concentration
Analyzer slope is within 0.98-1.02
1.0028
Analyzer Slope is acceptable
Analyzer Calibration within 2 week of assay
3-Sep-22
Analyzer calibration within 2 weeks of assay
Estimate of Uncetainty < 1 % at point #1 (>80% URL)
0.12%
Assay may be conducted at this concentration
Oxides of Nitrogen Gas Analyzer
NOx Portion
Estimate of Uncetainty < 1% at point #2
0.12%
Assay may be conducted at this concentration
Estimate of Uncetainty < 1% at point #3
0.12%
Assay may be conducted at this concentration
Estimate of Uncetainty < 1%atpoint#4
0.12%
Assay may be conducted at this concentration
Estimate of Uncetainty < 1% at point #5 (-50% URL)
0.13%
Assay may be conducted at this concentration
Analyzer slope is within 0.98-1,02
1.0018
Analyzer Slope is acceptable
Dilution Check
Dilution Check Date within 2 weeks of assay
29-Aug-22
iDilution check within 2 weeks of assay
Dilution Check Relative % Difference < 1%
0.251%
Dilution Check RSD is OK
Day of Assay Zero Check - Std. Error < 1 %
Std. Error is okay.
Zero Gas Std Error is OK
Day of Assay Zero/Span Check
NO Portion
Day of Assay Zero Check - Relative Difference < 5%
RD is okay.
Zero Gas RD is OK
Day of Assay Span Check - Std. Error < 1%
Std. Error is okay.
Span Gas Std. Error is OK
Day of Assay Span Check - Relative Difference <5%
RD is okay.
Span Gas RD is OK
Day of Assay Zero Check - Std. Error < 1%
Std. Error is okay.
Zero Gas Std Error is OK
Day of Assay Zero/Span Check
NOx Portion
Day of Assay Zero Check - Relative Difference < 5%
RD is okay.
Zero Gas RD is OK
Day of Assay Span Check - Std. Error < 1%
Std. Error is okay.
Span Gas Std. Error is OK
Day of Assay Span Check - Relative Difference <5%
RD is okay.
Span Gas RD is OK
Challenge Standard #1 NO Assay
Challenge Standard #1 Std. Error < 1%
The standard error is okay.
Challenge Standard #1 Std. Error is OK
Challenge Standard #1 vendor certificate bias
-0.52% Challenge Std #1 vendor certificate bias < 2%
Challenge Standard #1 NOx Assay
Challenge Standard #1 Std. Error < 1%
The standard error is okay.
Challenge Standard #1 Std. Error is OK
Challenge Standard #1 vendor certificate bias
-0.23%
Challenge Std. #1 vendor certificate bias < 2%
Challenge Standard #2 NO Assay
Challenge Standard #2 Std. Error < 1%
The standard error is okay.
Challenge Standard #2 Std. Error is OK
Challenge Standard #2 vendor certificate bias
0.19%
Challenge Std #2 vendor certificate bias < 2%
Challenge Standard #2 NOx Assay
Challenge Standard #2 Std. Error < 1 %
The standard error is okay.
Challenge Standard #2 Std. Error is OK
Challenge Standard #2 vendor certificate bias
0.17%
Challenge Std. #2 vendor certificate bias < 2%
Challenge Standard #3 NO Assay
Challenge Standard #3 Std. Error < 1%
The standard error is okay.
Challenge Standard #3 Std. Error is OK
Challenge Standard #3 vendor certificate bias
-0.15%
Challenge Std. #3 vendor certificate bias < 2%
Challenge Standard #3 NOx Assay
Challenge Standard #3 Std. Error < 1 %
Challenge Standard #3 vendor certificate bias
The standard error is okay.
-0.63%
Challenge Standard #3 Std. Error is OK
Challenge Std. #3 vendor certificate bias < 2%
Page 26 of 26
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United States Office of Air Quality Planning and Standards Publication No. EPA-454/R-23-005
Environmental Protection Air Quality Assessment Division May 2023
Agency Research Triangle Park, NC
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