September 2000
Environmental Technology
Verification Report
Land Combustion Model
LANCOM Series II
Portable Emission Analyzer
Prepared by
Batfelle
. . . Putting Technology To Worh
Battel le
Under a cooperative agreement with
£EPA U.S. Environmental Protection Agency
ETY ElV ElV
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September 2000
Environmental Technology Verification
Report
ETV Advanced Monitoring Systems Center
Land Combustion Model LANCOM Series II
Portable Emission Analyzer
By
Thomas Kelly
Ying-Liang Chou
Charles Lawrie
James J. Reuther
Karen Riggs
Battelle
Columbus, Ohio 43201
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Notice
The U.S. Environmental Protection Agency (EPA), through its Office of Research and Develop-
ment, has financially supported and collaborated in the extramural program described here. This
document has been peer reviewed by the Agency and recommended for public release. Mention
of trade names or commercial products does not constitute endorsement or recommendation by
the EPA for use.
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Foreword
The U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting the
Nation's air, water, and land resources. Under a mandate of national environmental laws, the
Agency strives to formulate and implement actions leading to a compatible balance between
human activities and the ability of natural systems to support and nurture life. To meet this
mandate, the EPA's Office of Research and Development (ORD) provides data and science
support that can be used to solve environmental problems and to build the scientific knowledge
base needed to manage our ecological resources wisely, to understand how pollutants affect our
health, and to prevent or reduce environmental risks.
The Environmental Technology Verification (ETV) Program has been established by the EPA, to
verify the performance characteristics of innovative environmental technology across all media
and to report this objective information to permitters, buyers, and users of the technology, thus
substantially accelerating the entrance of new environmental technologies into the marketplace.
Verification Organizations oversee and report verification activities based on testing and Quality
Assurance protocols developed with input from major stakeholders and customer groups
associated with the technology area. At present, there are twelve environmental technology areas
covered by ETV. Information about each of the environmental technology areas covered by ETV
can be found on the Internet at http://www.epa.gov/etv.htm.
Effective verifications of monitoring technologies are needed to assess environmental quality,
and to supply cost and performance data to select the most appropriate technology for that
assessment. In 1997, through a competitive cooperative agreement, Battelle was awarded EPA
funding and support to plan, coordinate, and conduct such verification tests, for "Advanced
Monitoring Systems for Air, Water, and Soil" and report the results to the community at large.
Information concerning this specific environmental technology area can be found on the Internet
at http://www.epa.gov/etv/07/07_main.htm.
111
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Acknowledgments
The authors wish to acknowledge the support of all those who helped plan and conduct the
verification test, analyze the data, and prepare this report. In particular we recognize Brian
Canterbury, Paul Webb, Darrell Joseph, and Jan Satola of Battelle, and Daniel Menniti of Land
Combustion, a division of Land Instruments International.
iv
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Contents
Notice ii
Foreword iii
Acknowledgments iv
List of Abbreviations x
1. Background 1
2. Technology Description 2
3. Test Design and Procedures 3
3.1 Introduction 3
3.2 Laboratory Tests 4
3.2.1 Linearity 7
3.2.2 Detection Limit 7
3.2.3 Response Time 7
3.2.4 Interrupted Sampling 7
3.2.5 Interferences 7
3.2.6 Pressure Sensitivity 9
3.2.7 Ambient Temperature 9
3.3 Combustion Source Tests 10
3.3.1 Combustion Sources 10
3.3.2 Test Procedures 11
4. Quality Assurance/Quality Control 15
4.1 Data Review and Validation 15
4.2 Deviations from the Test/QA Plan 15
4.3 Calibration of Laboratory Equipment 17
4.4 Standard Certifications 17
4.5 Performance System Audits 18
4.5.1 Technical Systems Audit 18
4.5.2 Performance Evaluation Audit 18
4.5.3 Audit of Data Quality 20
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5. Statistical Methods 21
5.1 Laboratory Tests 21
5.1.1 Linearity 21
5.1.2 Detection Limit 22
5.1.3 Response Time 23
5.1.4 Interrupted Sampling 23
5.1.5 Interferences 23
5.1.6 Pressure Sensitivity 24
5.1.7 Ambient Temperature 24
5.2 Combustion Source Tests 25
5.2.1 Accuracy 25
5.2.2 Zero/Span Drift 25
5.2.3 Measurement Stability 25
5.2.4 Inter-Unit Repeatability 26
5.2.5 Data Completeness 26
6. Test Results 27
6.1 Laboratory Tests 27
6.1.1 Linearity 27
6.1.2 Detection Limit 29
6.1.3 Response Time 30
6.1.4 Interrupted Sampling 30
6.1.5 Interferences 30
6.1.6 Pressure Sensitivity 34
6.1.7 Ambient Temperature 34
6.1.8 Zero/Span Drift 34
6.2 Combustion Source Tests 38
6.2.1 Relative Accuracy 38
6.2.2 Zero/Span Drift 41
6.2.3 Measurement Stability 43
6.2.4 Inter-Unit Repeatability 43
6.3 Other Factors 47
6.3.1 Cost 47
6.3.2 Data Completeness 47
6.3.3 Maintenance/Operational Factors 47
vi
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7. Performance Summary 48
8. References 49
Figures
2-1. Land Combustion LANCOM Series II 2
3-1. Manifold Test Setup 6
Tables
3-1. Identity and Schedule of Verification Tests Conducted on Land Combustion
LANCOM Series II Analyzers 4
3-2. Summary of Interference Tests Performed 8
3-3. Span Concentrations Provided Before and After Each Combustion Source 13
4-1. Results of QC Procedures for Reference Analyzers for Testing Land Combustion
LANCOM Series II Analyzers 16
4-2. Equipment Type and Calibration Date 17
4-3. Performance Evaluation Results on N0/N02 Standards 19
4-4. Performance Evaluation Results on 02 and Temperature Measuring Equipment 20
6-la. Data from NO Linearity Test of Land Combustion LANCOM Series II Analyzers .... 27
6-lb. Data from N02 Linearity Test of Land Combustion LANCOM Series II Analyzers ... 28
6-2. Statistical Results for Test of Linearity 28
6-3. Estimated Detection Limits for Land Combustion LANCOM Series II Analyzers 29
6-4. Response Time Data for Land Combustion LANCOM Series II Analyzers 31
6-5. Response Time Results for Land Combustion LANCOM Series II Analyzers 32
6-6. Data from Interrupted Sampling Test with Land Combustion LANCOM
Series II Analyzers 32
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6-7. Pre- to Post-Test Differences as a Result of Interruption of Operation of
Land Combustion LANCOM Series II Analyzers 32
6-8. Data from Interference Tests on Land Combustion LANCOM Series II Analyzers .... 33
6-9. Results of Interference Tests of Land Combustion LANCOM Series II Analyzers .... 33
6-10. Data from Pressure Sensitivity Test for Land Combustion LANCOM
Series II Analyzers 35
6-11. Pressure Sensitivity Results for Land Combustion LANCOM Series II Analyzers .... 35
6-12. Data from Ambient Temperature Test of Land Combustion LANCOM
Series II Analyzers 36
6-13. Ambient Temperature Effects on Land Combustion LANCOM Series II Analyzers ... 37
6-14. Data from Linearity and Ambient Temperature Tests Used to Assess
Zero and Span Drift of the Land Combustion LANCOM Series II Analyzers 37
6-15. Zero and Span Drift Results for the Land Combustion LANCOM
Series II Analyzers 38
6-16a. Data from Gas Rangetop in Verification Testing of Land Combustion
LANCOM Series II Analyzers 39
6-16b. Data from Gas Water Heater in Verification Testing of Land Combustion
LANCOM Series II Analyzers 39
6-16c. Data from Diesel Generator at High RPM in Verification Testing of
Land Combustion LANCOM Series II Analyzers 40
6-16d. Data from Diesel Generator at Idle in Verification Testing of
Land Combustion LANCOM Series II Analyzers 40
6-17. Relative Accuracy of Land Combustion LANCOM Series II Analyzers 41
6-18. Data Used to Assess Zero and Span Drift for Land Combustion
LANCOM Series II Analyzers on Combustion Sources 42
6-19. Results of Zero and Span Drift Evaluation for Land Combustion
LANCOM Series II Analyzers 43
6-20. Data from Extended Sampling Test with Diesel Generator at Idle,
Using Land Combustion LANCOM Series II Analyzers 44
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6-21. Results of Evaluation of Measurement Stability for Land Combustion
LANCOM Series II Analyzer 46
6-22. Summary of Repeatability 46
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List of Abbreviations
AMS
Advanced Monitoring Systems
ANSI
American National Standards Institute
Btu/hr
British thermal unit per hour
ccm
cubic centimeter per minute
CEM
continuous emission monitor
CO
carbon monoxide
co2
carbon dioxide
EPA
U.S. Environmental Protection Agency
ETV
Environmental Technology Verification
FID
flame ionization detector
gpm
gallons per minute
kW
kilowatt
LOD
limit of detection
1pm
liters per minute
m3
cubic meters
nh3
anhydrous ammonia
NIST
National Institute of Standards and Technology
NO
nitric oxide
NOx
nitrogen oxides
no2
nitrogen dioxide
o2
oxygen
PE
performance evaluation
ppm
parts per million, volume
ppmC
parts per million carbon
QA
quality assurance
QC
quality control
QMP
Quality Management Plan
RPM
revolutions per minute
SAS
Statistical Analysis System
so2
sulfur dioxide
UHP
ultra-high purity
X
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Chapter 1
Background
The U.S. Environmental Protection Agency (EPA) has created the Environmental Technology
Verification Program (ETV) to facilitate the deployment of innovative environmental tech-
nologies through performance verification and dissemination of information. The goal of the
ETV Program is to further environmental protection by substantially accelerating the acceptance
and use of improved and cost-effective technologies. ETV seeks to achieve this goal by pro-
viding high quality, peer reviewed data on technology performance to those involved in the
design, distribution, permitting, purchase and use of environmental technologies.
ETV works in partnership with recognized testing organizations, stakeholder groups consisting
of regulators, buyers and vendor organizations, and with the full participation of individual
technology developers. The program evaluates the performance of innovative technologies by
developing test plans that are responsive to the needs of stakeholders, conducting field or
laboratory tests (as appropriate), collecting and analyzing data, and preparing peer reviewed
reports. All evaluations are conducted in accordance with rigorous quality assurance protocols to
ensure that data of known and adequate quality are generated and that the results are defensible.
The EPA's National Exposure Research Laboratory and its verification organization partner,
Battelle Memorial Institute, operate the Advanced Monitoring Systems (AMS) Center under
ETV. The AMS Center has recently evaluated the performance of portable nitrogen oxides
monitors used to determine emissions from combustion sources. This verification statement
provides a summary of the test results for the Land Combustion LANCOM Series II portable
emission analyzer.
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Chapter 2
Technology Description
The objective of the ETV A VIS Center is to verify the performance characteristics of environ-
mental monitoring technologies for air, water, and soil. This verification report provides results
for the verification testing of the Land Combustion LANCOM Series II portable emission
analyzer. The following description of the LANCOM Series II analyzer is based on information
provided by the vendor.
The LANCOM Series II analyzer weighs 13.2 pounds, is slightly larger than a laptop computer,
and measures up to eight flue gases (02, NO, N02, S02, C02, H2S, hydrocarbons, and CO), with
both low and high ranges for CO. Analyzer options include semi-continuous monitoring
(pre-determined timed sampling intervals), printing, data logging (1,000 records), and serial
communications, plus various probe lengths. All gas measurements can be stored, downloaded,
or printed. The LANCOM Series II analyzer offers on-board diagnostics, accessible filters and
water catchpot, and a "semi-continuous" operating mode. It provides ppm conversions (mg/'m3,
Ib/mBTU, Ib/hr, etc.), oxygen normalization, and total NOx, on a wet or dry basis.
The LANCOM Series II systems components are mounted on molded PVC and sheathed in
corrosion-resistant plastic. The analyzer can be operated when worn on a shoulder strap or
free-standing on the ground. All controls are
a on the top of the instrument. The batteries are
mounted at the bottom of the case, which
provides enhanced stability when the instru-
ment is on the floor. The large capacity water
catchpot is mounted on the side of the instru-
ment on a hinged assembly. The particulate
and chemical filters are also mounted on the
side of the instrument. All measured param-
eters and operator interface are displayed on a
full function alphanumeric/graphic liquid
crystal display. The LANCOM Series II
analyzer contains two 6V batteries capable of
powering the instrument for eight hours in the
Figure 2-1. LANCOM Series II Analyzer field.
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Chapter 3
Test Design and Procedures
3.1 Introduction
The verification test described in this report was conducted in May 2000. The test was conducted
at Battelle in Columbus, Ohio, according to procedures specified in the Test/QA Plan for
Verification of Portable NO/NO2 Emission Analyzers.^ Verification testing of the analyzers
involved the following tests:
1. A series of laboratory tests in which certified NO and N02 standards were used to
challenge the analyzers over a wide concentration range under a variety of conditions.
2. Tests using three realistic combustion sources, in which data from the analyzers
undergoing testing were compared to chemiluminescent NO and NOx measurements
made following the guidelines of EPA Method 7E.(2)
The schedule of tests conducted on the LANCOM Series II analyzers is shown in Table 3-1.
To assess inter-unit variability, two identical LANCOM Series II analyzers were tested
simultaneously. These two analyzers were designated as Unit A and Unit B throughout all
testing. The Land representative indicated that the electrochemical sensor for N02 in Unit B was
somewhat older than that in Unit A. The commercial analyzers were operated at all times by a
representative of Land Combustion so that each analyzer's performance could be assessed
without concern about the familiarity of Battelle staff with the analyzers. At all times, however,
the Land Combustion representative was supervised by Battelle staff. Displayed NO and N02
readings from the analyzers (in ppm) were manually entered onto data sheets prepared before the
test by Battelle. Battelle staff filled out corresponding data sheets, recording, for example, the
challenge concentrations or reference analyzer readings, at the same time that the analyzer
operator recorded data. This approach was taken because visual display of measured NO and
N02 (or NOx) concentrations was the "least common denominator" of data transfer among
several N0/N02 analyzers tested.
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Table 3-1. Identity and Schedule of Tests Conducted on Land Combustion LANCOM
Series II Analyzers
Test Activity Date Conducted
Laboratory Tests
Linearity
May
24,
2000 a.m.3
Interrupted Sampling
May
22,
p.m. - May 23, a.m
Interferences
May
23,
a.m.
Pressure Sensitivity
May
23,
a.m.
Ambient Temperature
May
23,
p.m.
Combustion Source Tests
Gas Rangetop May 24, p.m.
Gas Water Heater May 24, p.m.
Diesel Generator-High RPM May 24, p.m.
Diesel Generator-Idle May 25, a.m.
3 Linearity tests were done May 22, a.m., but were repeated because of insufficient warm-up of the Land
analyzers prior to the test.
Verification testing began with Land Combustion staff setting up and checking out their two
analyzers in the laboratory at Battelle. Once vendor staff were satisfied with the operation of the
analyzers, the laboratory tests were begun. These tests were carried out in the order specified in
the test/QA plan.(1) However, the linearity and response time tests were redone at the end of the
laboratory test sequence, as noted in Table 3-1, because of the vendor's concern that the
analyzers were not fully warmed up prior to the initial tests. Upon completion of laboratory tests,
the analyzers were moved to a nearby building where the combustion sources described below
were set up, along with two chemiluminescent nitrogen oxides monitors which served as the
reference analyzers. The combustion source tests were conducted indoors, with the gas
combustion source exhausts vented through the roof of the test facility. The diesel engine was
located immediately outside the wall of the test facility; sampling probes ran from the analyzers
located indoors through the wall to the diesel exhaust duct. This arrangement assured that testing
was not interrupted and that no bias in testing was introduced as a result of the weather.
Sampling of source emissions began with the combustion source emitting the lowest N0X
concentration and proceeded to sources emitting progressively more N0X. In all source sampling,
the analyzers being tested sampled the same exhaust gas as did the reference analyzers. This was
accomplished by inserting the LANCOM Series II analyzers' gas sampling probes into the same
location in the exhaust duct as the reference analyzers' probe.
3.2 Laboratory Tests
The laboratory tests were designed to challenge the analyzers over their full nominal response
ranges, which for the LANCOM Series II analyzers were 0 to 2,000 ppm for NO and 0 to
500 ppm for N02. These nominal ranges greatly exceed the actual NO or N02 concentrations
likely to be emitted from most combustion sources. Nevertheless, the laboratory tests were aimed
at quantifying the full range of performance of the analyzers.
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Laboratory tests were conducted using certified standard gases for NO and N02, and a gas
dilution system with flow calibrations traceable to the National Institute of Standards and
Technology (NIST). The NO and N02 standards were diluted in high purity gases to produce a
range of accurately known concentrations. The NO and N02 standards were EPA Protocol 1
gases, obtained from Scott Specialty Gases, of Troy, Michigan. As required by the EPA
Protocol® the concentration of these gas standards was established by the manufacturer within
1 percent accuracy using two independent analytical methods. The concentration of the NO
standard (Scott Cylinder Number ALM 057210) was 3,925 ppm, and that of the N02 standard
(Scott Cylinder Number ALM 031907) was 512 ppm. These standards were identical to NO and
N02 standard cylinders used in the combustion source tests, which were confirmed near the end
of the verification test by comparison with independent standards obtained from other suppliers.
The gas dilution system used was an Environics Model 4040 mass flow controlled diluter (Serial
Number 2469). This diluter incorporated four separate mass flow controllers, having ranges of
10, 10, 1, and 0.1 1pm, respectively. This set of flow controllers allowed accurate dilution of gas
standards over a very wide range of dilution ratios, by selection of the appropriate flow con-
trollers. The mass flow calibrations of the controllers were checked against a NIST standard by
the manufacturer prior to the verification test, and were programmed into the memory of the
diluter. In verification testing, the Protocol Gas concentration, inlet port, desired output con-
centration, and desired output flow rate were entered by means of the keypad of the personal
computer used to operate the diluter, and the diluter then set the required standard and diluent
flow rates to produce the desired mixture. The 4040 diluter indicated on the computer display the
actual concentration being produced, which in some cases differed very slightly from the nominal
concentration requested. In all cases the actual concentration produced was recorded as the con-
centration provided to the analyzers undergoing testing. The 4040 diluter also provided warnings
if a flow controller was being operated at less than 10% of its working range, i.e., in a flow
region where flow control errors might be enhanced. Switching to another flow controller then
minimized the uncertainties in the preparation of the standard dilutions.
Dilution gases used in the laboratory tests were Acid Rain CEM Zero Air and Zero Nitrogen
from Scott Specialty Gases. These gases were certified to be of 99.9995% purity, and to have
the following maximum content of specific impurities: S02 <0.1 ppm, NOx <0.1 ppm,
CO < 0.5 ppm, C02 < 1 ppm, total hydrocarbons <0.1 ppm, and water < 5 ppm. In addition the
nitrogen was certified to contain less than 0.5 ppm of oxygen, while the air was certified to
contain 20 to 21% oxygen.
Laboratory testing was conducted primarily by supplying known gas mixtures to the analyzers
from the Environics 4040 diluter, using a simple manifold that allowed the two analyzers to
sample the same gas. The experimental setup is shown schematically in Figure 3-1. The manifold
itself consisted of a 9.5-inch length of thin-walled 1-inch diameter 316 stainless steel tubing, with
1/4-inch tubing connections on each end. The manifold had three 1/4-inch diameter tubing side
arms extending from it: two closely spaced tubes are the sampling points from which sample gas
was withdrawn by the two analyzers, and the third provided a connection for a Magnehelic
differential pressure gauge (±15 inches of water range) that indicated the manifold pressure
relative to the atmospheric pressure in the laboratory. Gas supplied to the manifold from the
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~•Vent to Hood
Coarse Needle Valves
>¦ Vent to Hood
Differential
P Gauge
Zero Gases
(N2 or Air)
Protocol 1
Standards
(NO or N02
Vacuum
Pump
Analyzer B
Analyzer A
Environics
4040 Diluter
Figure 3-1. Manifold Test Setup
Environics 4040 diluter always exceeded by at least 0.5 1pm the total sample flow withdrawn by
the two analyzers. The excess vented through a "T" connection on the exit of the manifold, and
two coarse needle valves were connected to this "T," as shown in Figure 3-1. One valve con-
trolled the flow of gas out the normal exit of the manifold, and the other was connected to a small
vacuum pump. Closing the former valve elevated the pressure in the manifold, and opening the
latter valve reduced the pressure in the manifold. Adjustment of these two valves allowed close
control of the manifold pressure within a target range of ±10 inches of water, while maintaining
excess flow of the gas mixtures to the manifold. The arrangement shown in Figure 3-1 was used
in all laboratory tests, with the exception of interference testing. For most interference testing,
gas standards of the appropriate concentrations were supplied directly to the manifold, without
use of the Environics 4040 diluter.
Laboratory testing consisted of a series of separate tests evaluating different aspects of analyzer
behavior. The procedures for those tests are described below, in the order in which the tests were
actually conducted. The statistical procedures that were applied to the data from each test are
presented in Chapter 5 of this report. Before starting the series of laboratory tests, the LANCOM
Series II analyzers were calibrated with 1,000 ppm NO and with 100 ppm N02, prepared by
diluting the EPA Protocol Gases using the Environics 4040 dilution system.
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3.2.1 Linearity
Linearity testing consisted of a wide-range 21-point response check for NO and for N02. At the
start of this check, the LANCOM Series II analyzers sampled the appropriate zero gas, and then
an NO or N02 concentration near the respective nominal full scale of the analyzers (i.e., near
2,000 ppm NO or 500 ppm N02). The actual concentrations provided were 2,000 ppm NO and
512 ppm N02. The 21-point check then proceeded without any adjustments to the analyzers. The
21 points consisted of three replicates each at 10, 20, 40, 70, and 100% of the nominal range, in
randomized order, and interspersed with six replicates of zero gas.(1) Following completion of all
21 points, the zero and 100 percent spans were repeated, also without adjustment of the
analyzers. This entire procedure was performed for NO and then for N02. Throughout the
linearity test, the analyzer indications of both NO and N02 concentrations were recorded, even
though only NO or N02 was supplied to the analyzers. This procedure provided data to assess the
cross-sensitivity to NO and N02.
3.2.2 Detection Limit
Data from zero gas and from 10% of full-scale points in the linearity test were used to establish
the NO and N02 detection limits of the analyzers, using a statistical procedure defined in the
test/QA plan.(1)
3.2.3 Response Time
During the NO and N02 linearity tests, upon switching from zero gas to an NO or N02
concentration of 70% of the respective full scale (i.e., about 1,400 ppm NO or 350 ppm N02), the
analyzers' responses were recorded at 10-second intervals until fully stabilized. These data were
used to determine the response times for NO and for N02, defined as the time to reach 95% of
final response after switching from zero gas to the calibration gas.
3.2.4 Interrupted Sampling
After the zero and span checks that completed the linearity test, the LANCOM Series II analyzers
were shut down (i.e., their electrical power was turned off overnight), ending the first day of
laboratory testing. The next morning the analyzers were powered up, and the same zero gas and
span concentrations were run without adjustment of the analyzers. Comparison of the NO and
N02 zero and span values before and after shutdown indicated the extent of zero and span drift
resulting from the shutdown. Near full-scale NO and N02 levels (i.e., 2,000 ppm NO and
512 ppm N02) were used as the span values in this test.
3.2.5 Interferences
Following analyzer startup and completion of the interrupted sampling test, the second day of
laboratory testing continued with interference testing. This test evaluated the response of the
LANCOM Series II analyzers to species other than NO and N02. The potential interferants listed
in Table 3-2 were supplied to the analyzers one at a time, and the NO and N02 readings of the
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Table 3-2. Summary of Interference Tests Performed
Interferant
Interferant Concentration
CO 496 ppm
C02 5.03%
S02 501 ppm
NH3 494 ppm
Hydrocarbon Mixture3 465 ppm Cx, 94 ppm C2,
46 ppm C3 + C4
S02 and NO 451 ppm S02 + 393 ppm NO
' C, = methane; C2 = ethane; and C3 + C4 = 23 ppm propane + 23 ppm n-butane.
analyzers were recorded. The potential interferants were used one at a time, except for a mixture
of S02 and NO, which was intended to assess whether S02 in combination with NO produced a
bias in NO response.
The CO, C02, S02, and NH3 used in the interference test were all obtained as Certified Master
Class Calibration Standards from Scott Technical Gases, at the concentrations indicated in Table
3-2. The indicated concentrations were certified by the manufacturer to be accurate within ± 2%,
based on analysis. The CO, C02, and NH3 were all in ultra-high purity (UHP) air, and the S02
was in UHP nitrogen. The S02/N0 mixture listed in Table 3-2 was prepared by diluting the NO
Protocol Gas with the S02 standard using the Environics 4040 diluter.
The hydrocarbon interferant listed in Table 3-2 was prepared at Battelle in UHP hydrocarbon-
free air, starting from the pure compounds. Small quantities of methane, ethane, propane, and
n-butane were injected into a cylinder that was then pressurized with UHP air. The required
hydrocarbon concentrations were approximated by the preparation process, and then quantified
by comparison with a NIST-traceable standard containing 1,020 ppm carbon (ppmC) in the form
of propane. Using a gas chromatograph with a flame ionization detector (FID) the NIST-traceable
standard was first analyzed. The resulting FID response factor (2,438 area units/ppmC) was then
used to determine the concentrations of the components of the prepared hydrocarbon mixture.
Two analyses of that mixture gave results of 463 and 467 ppm methane; the corresponding
results for ethane were 93 and 95 ppm; for propane 22 and 23 ppm; and for n-butane 23 and
23 ppm.
In the interference test, each interferant in Table 3-2 was provided individually to the sampling
manifold shown in Figure 3-1, at a flow in excess of that required by the two analyzers. Each
period of sampling an interferant was preceded by a period of sampling the appropriate zero gas.
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3.2.6 Pressure Sensitivity
The pressure sensitivity test was designed to quantify the dependence of analyzer response on the
pressure in the sample gas source. By means of two valves at the downstream end of the sample
manifold (Figure 3-1), the pressure in the manifold could be adjusted above or below the ambient
room pressure, while supplying the manifold with a constant ppm level of NO or N02 from the
Environics 4040 diluter. This capability was used to determine the effect of the sample gas
pressure on the sample gas flow rate drawn by the analyzers, and on the NO and N02 response.
The dependence of sample flow rate on pressure was determined using an electronically timed
bubble flow meter (Ultra Flow Primary Gas Flow Calibrator, Model 709, Serial No. 010928;
SKC, Inc.). This flow meter was connected in line (i.e., inserted) into the sample flow path from
the manifold to one of the commercial analyzers. Zero gas was supplied to the manifold at
ambient pressure, and the analyzer's sample flow rate was measured with the bubble meter. The
manifold pressure was then adjusted to -10 inches of water relative to the room, and the
analyzer's flow rate was measured again. The manifold pressure was adjusted to +10 inches of
water relative to the room, and the flow rate was measured again. The bubble meter was then
moved to the sample inlet of the other commercial analyzer, and the flow measurements were
repeated.
The dependence of NO and N02 response on pressure was determined by sampling the
appropriate zero gas, and NO or N02 span gas levels of 1,400 ppm and 350 ppm respectively, at
each of the same manifold pressures (room pressure, -10 inches, and +10 inches). This procedure
was conducted simultaneously on both analyzers, first for NO at all three pressures, and then for
N02 at all three pressures. The data at different pressures were used to assess zero and span drift
resulting from the sample pressure differences.
3.2.7 Ambient Temperature
The purpose of the ambient temperature test was to quantify zero and span drift that may occur as
the analyzers are subjected to different temperatures during operation. This test involved pro-
viding both analyzers with zero and span gases for NO and N02 (at the same span gas levels used
in the pressure sensitivity test) at room, elevated, and reduced temperatures. A temperature range
of about 7 to 40°C (45 to 105 °F) was targeted in this test. The elevated temperature condition
was achieved using a 1.43 m3 steel and glass laboratory chamber, heated using external heat
lamps. The reduced temperature condition was achieved using a commercial laboratory
refrigerated cabinet (Lab Research Products, Inc.).
The general procedure was to provide zero and span gas for NO, and then for N02, to both
analyzers at room temperature, and then to place both analyzers and the sampling manifold into
the heated chamber. Electrical and tubing connections were made through a small port in the
lower wall of the chamber. A thermocouple readout was used to monitor the chamber tempera-
ture and room temperature, and the internal temperature indications of the analyzers themselves
were monitored, when available. After 1 hour or more of stabilization in the heated chamber, the
zero and span tests were repeated. The analyzers, manifold, and other connections were then
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transferred to the refrigerator. After a stabilization period of 1 hour or more, the zero and span
checks were repeated at the reduced temperature. The analyzers were returned to the laboratory
bench; and, after a 1-hour stabilization period, the zero and span checks were repeated a final
time.
3.3 Combustion Source Tests
3.3.1 Combustion Sources
Three combustion sources (a gas rangetop, a gas residential water heater, and a diesel engine)
were used to generate N0X emissions from less than 10 ppm to over 300 ppm. Emissions
databases for two of these sources (rangetop and water heater) exist as a result of prior
measurements, both of which have been published.(4,5)
3.3.1.1 Rangetop
The low-NOx source was a residential natural gas fired rangetop (KitchenAid Model 1340),
equipped with four cast-iron burners, each with its own onboard natural gas and combustion air
control systems. The burner used (front-left) had a fixed maximum firing rate of about 8 KBtu/hr.
The rangetop generates NO in the range of about 5 to 8 ppm, and N02 in the range of about 1 to
3 ppm. The database on this particular appliance was generated in an international study in which
15 different laboratories, including Battelle, measured its NO and N02 emissions.(4)
Rangetop NOx emissions were diluted prior to measurement using a stainless-steel collection
dome, fabricated according to specifications of the American National Standards Institute (ANSI
Z21.1).(6) For all tests, this dome was elevated to a fixed position 2 inches above the rangetop
surface. Moreover, for each test, a standard "load" (pot) was positioned on the grate of the
rangetop burner. This load was also designed according to ANSI Z21.1 specifications regarding
size and material of construction (stainless steel). For each test, the load contained 5 pounds of
room-temperature water.
The exit of the ANSI collection dome was modified to include seven horizontal sample-probe
couplers. One of these couplers was 1/4-inch in size, three were 3/8-inch in size, and three were
1/2-inch in size. These were available to accommodate various sizes of vendor probes, and one
reference probe, simultaneously during combustion-source sampling.
This low-NOx combustion source was fired using "standard" natural gas, obtained from Praxair,
Inc., which was certified to contain 90% methane, 3% ethane, and the balance nitrogen. This
gaseous fuel contained no sulfur.
3.3.1.2 Water Heater
The medium-NOx source was a residential natural gas-fired water heater (Ruud Model P40-7) of
40-gallon capacity. This water heater was equipped with one stamped-aluminum burner with its
own onboard natural gas and combustion air control systems, which were operated according to
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manufacturer's specifications. The burner had a fixed maximum firing rate of about 40 KBtu/hr.
Gas flow to the water heater was monitored using a calibrated dry-gas meter.
The water heater generated NO emissions at approximately 80 ppm, and N02 in the range of 4 to
6 ppm. NOx emissions dropped as the water temperature rose after ignition, stabilizing at the
levels noted above. To assure constant operation of the water heater, a continuous draw of 3 gpm
was maintained during all verification testing. A database on this particular appliance was
generated in a national study in which six different laboratories measured its emissions, including
Battelle.(5)
Water heater NOx emissions were not diluted prior to measurement. The draft hood, integral to
the appliance, was replaced with a 3-inch diameter, 7-inch long stainless-steel collar. The exit of
this collar was modified to include five horizontal sample-probe couplers. One coupler was
1/4-inch in size, whereas the two other pairs were either 3/8- or /4-inch in size. Their purpose
was to hold two vendor probes and one reference probe simultaneously during sampling. This
medium-NOx combustion source was fired on house natural gas, which contained odorant-level
sulfur (4 ppm mercaptan).
3.3.1.3 Diesel Engine
The high-NOx source was an industrial diesel 8 kW electric generator (Miller Bobcat 225D Plus),
which had a Deutz Type ND-151 two-cylinder engine generating 41 KBtu/hr (16 horsepower).
This device generates NOx emissions over a range of about 200 to 330 ppm, depending on the
load on the super-charged engine. High load (3,500 RPM) resulted in the lowest NOx; idle
resulted in the highest NOx. At both conditions, about one-third of the NOx was N02. Data on
diesel generator emissions were generated in tests conducted in the two weeks prior to the start of
the verification test.
NOx emissions from this engine were not diluted prior to measurement. The 1-inch exhaust outlet
of the engine, which is normally merely vented to the atmosphere, was fitted with a stack
designed to meet the requirements of the EPA Method 5.(9) The outlet was first expanded to
2 inches of 1.5-inch diameter copper tubing, then to 15 inches of 2-inch diameter copper tubing,
and finally to 2 inches of 3-inch diameter copper tubing. The 3-inch diameter tubing was
modified to include five horizontal sample-probe couplers. One of these couplers was 1/4-inch in
size, two were 3/8-inch in size, and two were 1/2-inch in size. These couplers held the sample
probes in place. The 3-inch tube was connected to a 3-inch stack extending through the roof of
the test laboratory. This high-NOx combustion source was fired on commercial diesel fuel,
which, by specification, contains only 0.03 to 0.05 weight% sulfur.
3.3.2 Test Procedures
The procedures followed during combustion source testing consisted of those involved with the
sampling systems, reference method, calibration gas supply, and the sources, as follows.
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3.3.2.1 Sampling Systems
Prior to sampling, the Land Combustion representative inserted two of his product's probes into
the exhaust duct of the rangetop, water heater, or diesel engine. The LANCOM Series II probes
were fitted close to each other, sampling from a point within about 1/4 inch of the inlet of the
reference analyzers' probe.
The reference analyzer probe consisted of an 18-inch long, 1/4-inch diameter stainless-steel tube,
the upstream 2 inches of which were bent at a right angle for connection to a stainless steel
bulkhead union in the wall of the exhaust duct. The inner end of the bulkhead union connected to
a short length of 1/4-inch diameter stainless steel tube that extended into the center of the source
exhaust duct. The LANCOM Series II analyzers were each operated with their own sample probe
and sample transfer lines, and with the standard water trap and particulate and chemical filters.
Based on the results of trial runs conducted before the verification tests, neither the reference
sampling probe nor the reference sample-transfer lines were heated. Visible condensation of
combustion-generated water did not occur. The reference analyzer moisture-removal system
consisted of a simple condenser in an ice bath connected to the stainless steel probe by a 2-foot
length of 1/4-inch diameter Teflon® tubing. The downstream end of the condenser was
connected by a 3-foot length of 1/4-inch Teflon tubing to an inlet "tee" connected to both
reference analyzers. The reference particulate-removal system consisted of a 47-millimeter in-
line quartz fiber filter, which was used in sampling of the diesel emissions.
3.3.2.2 Reference Method
The reference method against which the vendor analyzers were compared was the ozone
chemiluminescence method for NO that forms the basis of EPA Method 7E.(2) The reference
measurements were made using two Model 42-C source-level N0X monitors (from Thermo
Environmental Instruments) located on a wheeled cart positioned near the combustion sources.
These monitors sampled from a common intake line, as described above. Both instruments use
stainless steel converters maintained at 650°C (1,202°F) for reduction of N02 to NO for
detection. The two reference analyzers were designated as Unit No. 100643 and 100647,
respectively.
The reference analyzers were calibrated before and after combustion source tests using an
Environics Series 2020 diluter (Serial No. 2108) and EPA Protocol 1 gases for NO and N02
(3,925 ppm, Cylinder No. ALM 15489, and 511.5 ppm, Cylinder No. AAL 5289, respectively;
Scott Specialty Gases). The calibration procedure was specified in the test/QA plan, and required
calibration at zero, 30%, 60%, and 100% of the applicable range value (i.e., 50, 100 or 1,000
ppm, depending on the emission source). Calibration results closest in time to the combustion
source tests were used to establish scale factors applicable to the source test data. The conversion
efficiency of the stainless steel converters was determined by calibrating with both NO and N02
on the applicable ranges, using the EPA Protocol 1 gases. The ratio of the linear regression slope
of the N02 calibration to that of the NO calibration determined the N02 conversion efficiency.
For the Land Combustion source tests, which took place on May 24 and 25, 2000, calibration
results from May 24 were applied. Conversion efficiency values of 91.5% and 100% were found
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for the two reference analyzers, and all reference data were corrected for these conversion
efficiencies.
3.3.2.3 Calibration Gas Supply
Prior to the start of the combustion source tests, the LANCOM Series II analyzers were cali-
brated with NO and N02 concentrations of 100 ppm. In addition, before and after sampling of
each combustion source, both the analyzers undergoing testing and the reference analyzers were
supplied with zero gas and with standard NO and N02 mixtures at levels comparable to those
expected from the source. To prepare these mixtures, Protocol 1 gases identical to those used in
the laboratory testing were diluted using an Environics Series 2020 Multi-Gas Calibrator (Serial
Number 2108). The same Acid Rain CEM zero gases were used for dilution and zeroing as were
used in the laboratory tests. The pre- and post-test span values used with each combustion source
are given in Table 3-3.
Table 3-3. Span Concentrations Provided Before and After Each Combustion Source
Source
NO Span Level (ppm)
N02 Span Level (ppm)
Gas Rangetop
20
10
Gas Water Heater
100
15
Diesel-High RPM
200
50
Diesel-Idle
400
100
The pre- and post-test zero and span values were used to assess the drift in zero and span
response of the tested analyzers caused by exposure to source emissions.
3.3.2.4 Operation of Sources
Verification testing was conducted with the combustion sources at or near steady-state in terms
of NOx emission. For the rangetop, steady-state was achieved after about 15 minutes, when the
water began to boil. For the water heater, steady-state was achieved in about 15 minutes, when its
water was fully heated. Because the water heater tank had a thermostat, cycling would have
occurred had about 3 gpm of hot water not been continuously drained out of the tank.
For the diesel engine, steady-state was achieved in about 10 minutes of operation. The diesel was
operated first at full speed (3,500 RPM) to achieve its lowest NOx emissions. Prior to sampling
the NOx emissions at idle, the diesel engine was operated at idle for about 20 minutes to
effectively "detune" its performance.
The order of operation of the combustion sources was (1) rangetop, (2) water heater, (3) diesel
engine (high RPM), and (4) diesel engine (idle). This allowed the analyzers to be exposed to
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continuously increasing NO and N02 levels, and avoided interference in low level measurements
that might have resulted from prior exposure to high levels.
Sampling of each combustion source consisted of obtaining nine separate measurements of the
source emissions. After sampling of pre-test zero and span gases provided from the calibration
source, and with both the reference and vendor analyzers sampling the source emissions, the
Land Combustion operator indicated when he was ready to take the first set of readings (a set of
readings consisting of the NO and N02 response on both Units A and B). At that time the
Battelle operator of the reference analyzers also took corresponding readings. The analyzers
undergoing testing were then disconnected from the source, and allowed to sample room air until
readings dropped well below the source emissions levels. The analyzers were then reconnected to
the source, and after stabilizing another set of readings was taken. There was no requirement that
analyzer readings drop fully to zero between source measurements. This process was repeated
until a total of nine readings had been obtained with both the vendor and reference analyzers. The
same zero and span gases were then sampled again before moving to the next combustion source.
The last operation in the combustion source testing involved continuous sampling of the diesel
engine emissions for a full hour with no intervals of room air sampling. Data were recorded for
both reference and vendor analyzers at 1-minute intervals throughout that hour of measurement.
This extended sampling was conducted only after nine sequential sets of readings had been
obtained from all the combustion sources by the procedure described above. Results from this
extended sampling were used to determine the measurement stability of the LANCOM Series II
analyzers.
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Chapter 4
Quality Assurance/Quality Control
Quality control (QC) procedures were performed in accordance with the quality management
plan (QMP) for the AMS Center(7) and the test/QA plan(1) for this verification test.
4.1 Data Review and Validation
Test data were reviewed and approved according to the AMS Center QMP, the test/QA plan, and
Battelle's one-over-one approval policy. The Verification Testing Leader reviewed the raw data
and data sheets that were generated each day. Laboratory record notebooks were also signed and
dated by testing staff and reviewed by the Verification Testing Leader.
Other data review focused upon the compliance of the reference analyzer data with the quality
requirements of Method 7E. The purpose of validating reference data was to ensure usability for
the purposes of comparison with the demonstration technologies. The results of the review of the
reference analyzer data quality are shown in Table 4-1. The data generated by the reference
analyzers were used as a baseline to assess the performance of the technologies for N0/N02
analysis.
4.2 Deviations from the Test/QA Plan
During the physical set up of the verification test, deviations from the test/QA plan were made to
better accommodate differences in vendor equipment and other changes or improvements. Any
deviation required the approval signature of Battelle's Verification Testing Leader and Pilot
Manager. A planned deviation form was used for documentation and approval of the following
changes:
1. The order of testing was changed in the pressure sensitivity test to require fewer plumbing
changes in conducting the test.
2. The order of the ambient temperature test was changed to maximize the detection of any
temperature effect.
3. The concentrations used in the mixture of S02 and NO for the interference test were
changed slightly.
4. For better accuracy, the oxygen sensor used during combustion source tests was checked
by comparison to an independent paramagnetic 02 sensor, rather than to a wet chemical
measurement.
5. Single points (rather than triplicate points) were run at each calibration level in calibrating
the reference analyzers, in accord with Method 7E.
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Table 4-1. Results of QC Procedures for Reference Analyzers for Testing of Land
Combustion LANCOM Series II Analyzers
N02 conversion
efficiency (Unit 100643)
N02 conversion
efficiency (Unit 100647)
Calibration of reference
method using four points
at 0, 30, 60, 100% for
NO
Calibration of reference
method using four points
at 0, 30, 60, 100% for
no2
Calibrations
(100 ppm range)
91.5%
100%
Meets criteria
(r2 = 0.9999)
Meets criteria
(r2 = 0.9999)
Meet + 2% requirement (relative
to span)
Unit 100643
Unit 100647
NO
NO
Error, % of
at % of
Error, % of
at % of
Span
Scale
Span
Scale
1.0
30
0.9
30
0.4
60
0.3
60
no2
no2
Error, % of
at % of
Error, % of
at % of
Span
Scale
Span
Scale
0.5
30
0.5
30
0.1
60
0.2
60
Zero drift
Span drift
Interference check
Meets + 3% requirement (relative
to span) on all combustion
sources
Meets + 3% requirement (relative
to span) on all combustion
sources
< + 2% (no interference response
observed)
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4.3 Calibration of Laboratory Equipment
Equipment used in the verification test required calibration before use or verification of the
manufacturer's calibrations. Some auxiliary devices were obtained with calibrations from
Battelle's Instrument Laboratory. Equipment types and calibration dates are listed in Table 4-2.
For key equipment items, the calibrations listed include performance evaluation audits (see
Section 4.5.2). Documentation of calibration of the following equipment was maintained in the
test file.
Table 4-2. Equipment Type and Calibration Date
Equipment Type
Use
Calibration/PE
Date
Gas Dilution System Environics Lab tests
Model 4040 (Serial Number 2469)
Gas Dilution System Environics Source tests
Model 2020 (Serial Number 2108)
Fluke Digital Thermometer
(LN-570068)
Servomex 570A Analyzer
(X-44058)
Dwyer Magnahelic Pressure Gauge
3/9/00; 5/9/00
3/20/00; 5/9/00
Ambient temperature 10/15/99; 5/26/00
test
Flue gas 02
Pressure sensitivity
test
11/22/99; 5/18/00
4/7/00
Doric Trendicator 41 OA Thermocouple
Temperature Sensor (Serial Number 331513)
American Meter DTM 115 Dry Gas Meter Gas flow
(Serial Number 89P124205) measurement
Flue gas temperature 8/5/99; 5/26/00
4/17/00
4.4 Standard Certifications
Standard or certified gases were used in all verification tests, and certifications or analytical data
were kept on file to document the traceability of the following standards:
¦ EPA Protocol Gas Nitrogen Dioxide
¦ EPA Protocol Gas Nitric Oxide
¦ Certified Master Class Calibration Standard Sulfur Dioxide
¦ Certified Master Class Calibration Standard Carbon Dioxide
¦ Certified Master Class Calibration Standard Ammonia
¦ Certified Master Class Calibration Standard Carbon Monoxide
¦ Nitrogen Acid Rain CEM Zero
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¦ Acid Rain CEM Zero Air
¦ Battelle-Prepared Organics Mixture.
All other QC documentation and raw data for the verification test are located in the test file at
Battelle, to be retained for 7 years and made available for review if requested.
4.5 Performance System Audits
Three internal audits were conducted during verification testing. A technical systems audit was
conducted to assess the physical setup of the test, a performance evaluation audit was conducted
to evaluate the accuracy of the measurement system, and an audit of data quality was conducted
on 10% of all data generated during the verification test. A summary of the results of these audits
is provided below.
4.5.1 Technical Systems Audits
A technical systems audit (TSA) was conducted on April 18, 2000, (laboratory testing) and
May 17 and 18, 2000, (source testing) for the N0/N02 verification tests conducted in early 2000.
The TSA was performed by the Battelle's Quality Manager as specified in the AMS Center
Quality Management Plan (QMP). The TSA ensures that the verification tests are conducted
according to the test/QA plan(1) and all activities associated with the tests are in compliance with
the AMS Center QMP(7). All findings noted during the TSA on the above dates were documented
and submitted to the Verification Testing Leader for correction. The corrections were docu-
mented by the Verification Testing Leader and reviewed by Battelle's Quality Manager and
Center Manager. None of the findings adversely affected the quality or outcome of this verifi-
cation test and were resolved to the satisfaction of the Battelle Quality Manager. The records
concerning the TSA are permanently stored with the Battelle Quality Manager.
4.5.2 Performance Evaluation Audit
The performance evaluation audit was a quantitative audit in which measurement standards were
independently obtained and compared with those used in the verification test to evaluate the
accuracy of the measurement system. That assessment was conducted by Battelle testing staff on
May 26, 2000, and the results were reviewed by independent QA personnel.
The most important performance evaluation (PE) audit was of the standards used for the
reference measurements in source testing. The PE standards were NO and N02 calibration gases
independent of the test calibration standards that contained certified concentrations of NO and
N02. Accuracy of the reference analyzers was determined by comparing the measured N0/N02
concentrations using the verification test standards with those obtained using the certified PE
standards. Percent difference was used to quantify the accuracy of the results. The PE sample for
NO was an EPA Protocol Gas having a concentration (3,988 ppm) nearly the same as the NO
standard used in verification testing, but purchased from a different commercial supplier
(Matheson Gas Products). The PE standard for N02 was a similar commercial standard of
463 ppm N02 in air, also from Matheson. Table 4-3 summarizes the N0/N02 reference standard
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performance evaluation results. Included in this table are the performance acceptance ranges and
the certified gas concentration values. The acceptance ranges are guidelines established by the
provider of the PE materials to gauge acceptable analytical results.
Table 4-3. Performance Evaluation Results on NO/NO, Standards
Reference
Analyzer
Standard
Reading on
Diluted Standard
Apparent
Concentration®
Percent Acceptance
Differenceb Limits
Unit 100643
Test Std
PE Std
NO in N2
(ppm)
3,925
3,988
98.8 ppm
100.6 ppm
3,917 ppm
0.2%
±2%
Unit 100647
Test Std
PE Std
NO in N2
(ppm)
3,925
3,988
99.6 ppm
101.4 ppm
3,917 ppm
0.2%
±2%
Unit 100643
Test Std
PE Std
N02 in Air
(ppm)
511.5
463
44.2 ppm
42.5 ppm
482 ppm
5.8%
±5%
Unit 100647
Test Std
PE Std
N02 in Air
(ppm)
511.5
463
49.6 ppm
48.8 ppm
471 ppm
7.9%
±5%
Concentration of Test Standard indicated by comparison to the Performance Evaluation Standard; i.e., Apparent
Concentration = (Test Std. Reading/PE Std. Reading) x PE Std. Cone.; e.g., Apparent Concentration = 98.8/100.6
x 3,988 ppm = 3,917 ppm.
Percent difference of Apparent Concentration relative to Test Standard concentration; e.g., percent difference =
3,925 ppm - 3,917ppm
3,925 ppm
¦x 100= 0.2%.
Table 4-3 shows that the PE audit confirmed the concentration of the Scott 3,925 ppm NO test
standard almost exactly: the apparent test standard concentration was within 0.2% of the test
standard's nominal value. On the other hand, the PE audit results for the Scott 511.5 ppm N02
standard were not as close. The comparison to the Matheson PE standard indicated that the 511.5
ppm N02 Scott standard was only about 480 ppm, a difference of about 7% from its nominal
value. This result suggests an error in the Scott test standard for N02. However, a separate line of
evidence indicates that the Matheson PE standard is more likely in error. Specifically, conversion
efficiency checks on the reference analyzers (performed by comparing their responses to the
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Scott NO and N02 standards) consistently showed the efficiency of the converter in 42-C Unit
100647 to be very close to 100%. This finding could not occur if the concentration of the N02
standard were low. That is, a conversion efficiency of 100% indicates agreement between the NO
standard and the N02 standard; and, as shown in Table 4-3, the NO standard is confirmed by the
PE comparison. Thus, the likelihood is that the Matheson PE standard was in fact somewhat
higher in concentration than its nominal 463 ppm value.
PE audits were also done on the 02 sensor used for flue gas measurements, and on the
temperature indicators used for ambient and flue gas measurements. The PE standard for 02 was
an independent paramagnetic sensor, and for temperature was a certified mercury-in-glass
thermometer. The 02 comparison was conducted during sampling of diesel exhaust; the tempera-
ture comparisons were conducted at room temperature. The results of those audits are shown in
Table 4-4, and indicate close agreement of the test equipment with the PE standards.
Table 4-4. Performance Evaluation Results on 02 and Temperature Measuring Equipment
Analyzer
Reading
Difference
Acceptance Limits
Servomex 570A 02
18.9% 02
0% 02
-
PE Standard®
18.9% 02
Fluke Digital Thermometer
22.1°C
0.1°C
2% absolute T
PE Standard3
22°C
Doric 410A Temp. Sensor
24.8°C
0.2°C
2% absolute T
PE Standard15
25.0°C
0.2°C
a Independent paramagnetic 02 analyzer.
b Certified mercury-in-glass thermometer.
4.5.3 Audit of Data Quality
The audit of data quality is a qualitative and quantitative audit in which data and data handling
are reviewed and data quality and data usability are assessed. Audits of data quality are used to
validate data at the frequency of 10% and are documented in the data audit report. The goal of an
audit of data quality is to determine the usability of test results for reporting technology perfor-
mance, as defined during the design process. Validated data are reported in the ETV verification
reports and ETV verification statement along with any limitations on the data and recom-
mendations for limitations on data usability.
The Battelle Quality Manager for the verification test audited 10% of the raw data. Test data
sheets and laboratory record books were reviewed, and statistical calculations and other
algorithms were verified. Calculations that were used to assess the four-point calibration of the
reference method were also verified to be correct. In addition, data presented in the verification
report and statement were audited to ensure accurate transcription.
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Chapter 5
Statistical Methods
5.1 Laboratory Tests
The analyzer performance characteristics were quantified on the basis of statistical comparisons
of the test data. This process began by converting the spreadsheet files that resulted from the data
acquisition process into data files suitable for evaluation with Statistical Analysis System (SAS)
software. The following statistical procedures were used to make those comparisons.
5.1.1 Linearity
Linearity was assessed by linear regression with the calibration concentration as the independent
variable and the analyzer response as the dependent variable. Separate assessments were carried
out for each Land Combustion analyzer. The calibration model used was
K = h(c) + error
where Yc is the analyzer's response to a challenge concentration c, h(c) is a linear calibration
curve, and the error term was assumed to be normally distributed. (If the variability is not
constant throughout the range of concentrations then weighting in the linear regression is
appropriate. It is often the case that the variability increases as the true concentration increases.)
The variability (gc) of the measured concentration values (c) was modeled by the following
relationship,
o2c =a + kc$
where a, k, and p are constants to be estimated from the data. After determining the relationship
between the mean and variability, appropriate weighting was determined as the reciprocal of the
variance.
weight = wc = —
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The form of the linear regression model fitted was h(c) = a0 + a,c. In the concentration sub-
region where the linear calibration model provides a valid representation of the concentration-
response relation, concentration values were calculated from the estimated calibration curve
using the relation
c = h (Y ) =
ai
A test for departure from linearity was carried out by comparing the residual mean square
1 6 "
~y (Y - a - a,c)2n w
4^—/ V C: O 1 V C: C:
2=1
to an F-distribution with 6-2 = 4 numerator degrees of freedom.
Yci is the average of the nci analyzer responses at the i"1 calibration concentration, q. The
regression relation was fitted to the individual responses; however, only the deviation about the
sample mean analyzer responses at each calibration concentration provide information about
goodness-of-fit.
y y (Y -an -a,c )2 w . = y y (Y - Y )2 w + y (Y -an -a,c)2 n w
< V CI] (J 1 V CI < V CI CV CI < V CI] (J 1 V CI CI
i=l j=l i=l j=l i=1
The first summation on the right side of the equation provides information only about response
variability. The second summation provides all the information about goodness-of-fit to the
straight-line calibration model. This is the statistic that is used for the goodness-of-fit test.
5.1.2 Detection Limit
Limit of detection (LOD) is defined as the smallest true concentration at which an analyzer's
expected response exceeds the calibration curve at zero concentration by three times the standard
deviation of the analyzer's zero reading, i.e., a0 + 3 a0, if the linear relation is valid down to zero.
The LOD may then be determined by
(a + 3a ) - a 3a
LOD =1-2 °- = _2.
where a0 is the estimated standard deviation at zero concentration. The LOD is estimated as the
LOD = 3<70 / C?j standard error of the estimated detection limit is approximately
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SE (LOD) - LOD
N
1
' SE(h,)
2(n-l)
k J
Note that the validity of the detection limit estimate and its standard error depends on the validity
of the assumption that the fitted linear calibration model accurately represents the response down
to zero concentration.
5.1.3 Response Time
The response time of the analyzers to a step change in analyte concentration was
calculated by determining the total change in response due to the step change in concentration,
and then determining the point in time when 95% of that change was achieved. Using data taken
every 10 seconds, the following calculation was carried out:
Total Response = Rc - Rz
where Rc is the final response of the analyzer to the calibration gas and Rz is the final response of
the analyzer to the zero gas. The analyzer response that indicates the response time then is:
Response95o/o = 0.95 (Total Response) + Rz.
The point in time at which this response occurs was determined by inspecting the response/time
data, linearly interpolating between two observed time points, as necessary. The response time
was calculated as:
RT = Time95o/o - Timej,
where Time950/o is the time at which ResponseRT occurred and Timej is the time at which the span
gas was substituted for the zero gas. Since only one measurement was made, the precision of the
response time was not determined.
5.1.4 Interrupted Sampling
The effect of interrupted sampling is the arithmetic difference between the zero data and between
the span data obtained before and after the test. Differences are stated as ppm. No estimate was
made of the precision of the observed differences.
5.1.5 Interferences
Interference is reported as both the absolute response (in ppm) to an interferant level, and as the
sensitivity of the analyzer to the interferant species, relative to its sensitivity to NO or N02. The
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relative sensitivity is defined as the ratio of the observed N0/N02/N0x response of the analyzer
to the actual concentration of the interferant. For example, an analyzer that measures NO is
challenged with 500 ppm of CO, resulting in an absolute difference in reading of 1 ppm (as NO).
The relative sensitivity of the analyzer is thus 1 ppm/500 ppm = 0.2%. The precision of the
interference results was not estimated from the data obtained, since only one measurement was
made for each interferant.
5.1.6 Pressure Sensitivity
At each of ambient pressure, reduced pressure (-10 inches of water), and increased pressure
(+10 inches of water), the analyzer flow rate, the response on zero gas, and the response on span
gas were measured for each analyzer. Variability in zero and span responses for reduced and
increased pressures was assumed to be the same as the variability at ambient pressure. The
variability determined in the linearity test was used for this analysis. The duct pressure effects on
analyzer flow rates and response were assessed by separate linear regression trend analyses for
flow rate and for response. The precision of the pressure effects on zero concentration response
and on span gas response was estimated based on the variability observed in the linearity test.
Statistical significance of the trends across duct pressures was determined by comparing the
estimated trends to their estimated standard errors, based on two-tailed t-tests:
t = fil (0.040825
-------
5.2 Combustion Source Tests
5.2.1 Accuracy
The relative accuracy (RA) of the analyzers with respect to the reference method is expressed as:
S
I ^1 d
I d\ + tn-1 —
RA = = V— x 100%
x
where Prefers to the difference between the average of the two reference analyzers and one of the
tested units and ^corresponds to the average of the two reference analyzer values. Sd denotes the
sample standard deviation of the differences, based on n = 9 samples, while tan4 is the t value for
the 100(1 - a)th percentile of the distribution with n - 1 degrees of freedom. The relative accuracy
was determined for an a value of 0.025 (i.e., 97.5% confidence level, one-tailed). The RA cal-
culated in this way can be determined as an upper confidence bound for the relative bias of the
analyzer ^Jx - where the bar indicates the average value of the differences or of the reference
values.
Assuming that the reference method variation is due only to the variation in the output source
and the true bias between the test and reference methods is close to zero, an approximate
standard error for RA is
SE
S„
ifnx ^
0.3634
2(^-1)
x 100%
5.2.2 Zero/Span Drift
Statistical procedures for assessing zero and span drift were similar to those used to assess
interrupted sampling. Zero (span) drift was calculated as the arithmetic difference between zero
(span) values obtained before and after sampling of each combustion source. The same calcula-
tion was also made using zero and span values obtained before and after the linearity and ambient
temperature tests. No estimate was made of the precision of the zero and span drift values.
5.2.3 Measurement Stability
The temporal stability of analyzer response in extended sampling from a combustion source was
assessed by means of a trend analysis on 60 minutes of data obtained continuously using the
diesel generator as the source. The existence of a difference in trend between the test unit and the
average of the reference units was assessed by fitting a linear regression line with the difference
between the measured concentration for a test unit and the average of the reference units as the
dependent variable, and time as the independent variable. Subtracting the average reference unit
25
-------
values adjusts for variation in the source output. The slope and the standard error of the slope are
reported. The null hypothesis that the slope of the trend line on the difference is zero was tested
using a one-sample two-tailed t-test with n - 2 = 58 degrees of freedom.
5.2.4 Inter- Unit Repeatability
The purpose of this comparison was to determine if any significant differences in performance
exist between two identical analyzers operating side by side. In tests in which analyzer per-
formance was verified by comparison with data from the reference method, the two identical
units of each type of analyzer were compared to one another using matched pairs t-test
comparisons. In tests in which no reference method data were obtained (e.g., linearity test), the
two LANCOM Series II analyzer units were compared using statistical tests of difference. For
example, the slopes of the calibration lines determined in the linearity test, and the detection
limits determined from those test data, were compared. Inter-unit repeatability was assessed for
the linearity, detection limit, accuracy, and measurement stability tests.
For the linearity test, the intercepts and slopes of the two units were compared to one another by
two-sample t-tests using the pooled standard error, with combined degrees of freedom the sum of
the individual degrees of freedom.
For the detection limit test, the detection limits of the two units were compared to one another by
two-sample t-tests using the pooled standard error with 10 degrees of freedom (the sum of the
individual degrees of freedom).
For the relative accuracy test, repeatability was assessed with a matched-pairs two-tailed t-test
with n - 1 = 8 degrees of freedom.
For the measurement stability test, the existence of differences in trends between the two units
was assessed by fitting a linear regression to the paired differences between the units. The null
hypothesis that the slope of the trend line on the paired differences is zero was tested using a
matched-pairs t-test with n - 2 = 58 degrees of freedom.
5.2.5 Data Completeness
Data completeness was calculated as the percentage of possible data recovered from an analyzer
in a test; the ratio of the actual to the possible number of data points, converted to a percentage,
i.e.,
Data Completeness = (Na)/(Np) x 100%,
where Na is the number of actual and Np the number of planned data points.
26
-------
Chapter 6
Test Results
6.1 Laboratory Tests
6.1.1 Linearity
Tables 6-la and b list the data obtained in the linearity tests for NO and N02, respectively. The
response of both the NO and N02 sensors in each analyzer is shown in those tables.
Table 6-2 shows the results of the linear calibration curve fits for each unit and each analyte,
based on the data shown in Tables 6-la and b.
Table 6-la. Data from NO Linearity Test of Land Combustion LANCOM Series II
Analyzers
Actual NO
Unit A NO
Unit A N02
Unit B NO
Unit B N02
Reading
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
1
0
2
0
3
0
2
2000
1998
7
1978
10
3
200
197
1
202
1
4
800
802
2
802
2
5
0
2
0
3
0
6
1400
1406
3
1398
4
7
420
423
1
423
1
8
200
197
1
201
0
9
0
2
0
2
0
10
420
420
1
421
0
11
800
808
1
808
1
12
1400
1416
3
1408
3
13
0
3
0
4
0
14
2000
2009
4
1988
4
15
1400
1416
3
1409
3
16
800
813
2
815
1
17
0
4
0
4
0
18
420
421
0
422
0
19
200
197
0
200
0
20
2000
2020
4
1995
3
21
0
3
0
4
0
27
-------
Table 6-lb. Data from N02 Linearity Test of Land Combustion LANCOM Series II
Analyzers
Actual N02
Unit A NO
Unit A NO,
Unit B NO
Unit B NO,
Number
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
1
0
0
0
0
0
2
512
10
507
9
496
3
50
0
52
0
52
4
200
2
199
2
199
5
0
2
1
0
0
6
350
8
347
7
341
7
105
1
106
1
105
8
50
1
51
0
50
9
0
2
1
0
0
10
105
1
105
1
103
11
200
4
199
3
196
12
350
11
349
10
343
13
0
3
1
1
0
14
512
20
511
16
501
15
350
12
348
10
341
16
200
7
202
6
199
17
0
4
2
2
1
18
105
2
105
2
103
19
50
3
51
1
50
20
512
23
512
19
501
21
0
4
2
2
1
Table 6-2. Statistical Results for Test of Linearity
Unit A Unit B
Linear Regression NO N02 NO N02
Intercept (ppm) (Std Err) 1.526 (0.711) 1.243 (0.244) 2.888 (0.496) 0.564 (0.248)
Slope (Std Err) 1.000 (0.003) 0.993 (0.002) 0.999 (0.002) 0.977 (0.002)
r2 0.9998 1.0000 0.9999 0.9999
The results in Table 6-2 show that the NO response of both units of the LANCOM Series II
analyzers was linear over the tested range of 0 to 2,000 ppm. The regression slopes are
essentially 1.0, and the r2 values are 0.9998 or higher.
28
-------
The N02 linearity results in Table 6-2 show that, over the tested range of up to 512 ppm N02, the
LANCOM Unit A analyzer gave highly linear response, whereas the B unit exhibited a slightly
low regression slope of about 0.98. Inspection of the N02 linearity data shows that the slope of
the Unit B N02 response is close to 1.0 up to about 250 ppm, but that the response is low by
about 2.5% at the 350 and 512 ppm N02 concentrations. This result is probably due to the older
N02 sensor used in the LANCOM Unit B, as compared to that used in Unit A.
The data in Tables 6-la and 6-lb also indicate the extent of cross-sensitivity of the LANCOM
Series II NO and N02 sensors. Regression of the N02 responses in the NO linearity test (Table 6-
la) gives the following results:
Unit A N02 = 0.0024 x (NO, ppm) - 0.08 ppm, with r2 = 0.870, and
Unit B N02 = 0.0028 x(NO, ppm) - 0.34 ppm, withr2 = 0.701.
These results indicate a very slight response of the LANCOM Series II N02 sensors to NO,
amounting to about 0.3% of the NO level present.
Similarly, regression of the LANCOM Series II NO responses in the N02 linearity test (Table 6-
lb) gives the following results:
Unit A NO = 0.030 X(N02, ppm) + 0.51 ppm, with r2 = 0.755, and
Unit B NO = 0.027 x(N02, ppm) - 0.39 ppm, with r2 = 0.841.
These results indicate a small response of the LANCOM Series II NO sensors to N02, amounting
to about 3% of the N02 level present.
6.1.2 Detection Limit
Table 6-3 shows the estimated detection limits for each test unit and each analyte, determined
from the data obtained in the linearity test. These detection limits apply to the calibrations
conducted over a 0 to 2,000 ppm range for NO (Table 6-la) and a 0 to 512 ppm range for N02
(Table 6-lb).
Table 6-3. Estimated Detection Limits for Land Combustion LANCOM Series II
Analyzers3
Unit A
Unit B
NO
no2
NO
no2
Estimated Detection Limit (ppm)
2.45
2.28
2.45
1.59
(Standard Error) (ppm)
(0.78)
(0.72)
(0.78)
(0.50)
a Results are based on calibrations over 0-2,000 ppm range for NO and 0 512 ppm range for NOz.
29
-------
Table 6-3 displays the estimated detection limits, and their standard errors for NO and N02,
separately for each LANCOM Series II analyzer. NO detection limits of about 2.5 ppm, and N02
detection limits of 1.5 to 2.3 ppm, are indicated. It must be stressed that these detection limits are
based on the zero gas responses, interspersed with sampling of high levels of NO and N02 in the
linearity tests. The vendor indicates that, under normal field use, the operator would zero the
analyzer every 20 minutes, thus eliminating any long-term drift and maintaining 1 ppm detection
limits.
6.1.3 Response Time
Table 6-4 lists the data obtained in the response time test of the LANCOM Series II analyzers.
Table 6-5 shows the response times of the analyzers to a step change in analyte concentration,
based on the data shown in Table 6-4.
Table 6-5 shows that the NO response times were quite similar for Units A and B, at 35 and
39 seconds. The N02 response times were substantially longer, and the agreement between Units
A and B not as close (77 vs. 90 seconds). The slightly slower response of Unit B for N02 may be
a result of the older N02 sensor used in that unit.
6.1.4 Interrupted Sampling
Table 6-6 shows the zero and span data resulting from the interrupted sampling test, and
Table 6-7 shows the differences (pre- minus post-) of the zero and span values. Span con-
centrations of 2,000 ppm NO and 512 ppm N02 were used for this test.
Table 6-7 shows that changes in zero readings for both NO and N02 were 2 ppm or less as a
result of the overnight shutdown. The LANCOM Series II analyzers also showed only small
changes as a result of the shutdown. The maximum change observed in the NO span response
was about 3% of the 2,000 ppm NO span value, and the maximum change in the N02 span
response was about 2% of the 512 ppm N02 span value. These small changes in readings indicate
good stability of the analyzers in the face of an instrument shutdown.
6.1.5 Interferences
Table 6-8 lists the data obtained in the interference tests. Table 6-9 summarizes the sensitivity of
the analyzers to interferant species, based on the data from Table 6-8. The results in Table 6-8
use the average of the zero readings before and after the interferant exposure to calculate the
extent of the interference.
Table 6-9 indicates that there were no significant interference effects from CO, C02, NH3, HCs,
and S02, or from S02 in the presence of NO. The response to 393 ppm NO was only slightly
decreased by the presence of 451 ppm S02 (i.e., readings were 0.7 to 2.9% lower than the
303 ppm NO provided). This degree of difference is within the ± 4% accuracy specification of
the Lancom Series II analyzers, and thus no significant effect of S02 is inferred.
30
-------
Table 6-4. Response Time Data for Land Combustion LANCOM Series II Analyzers
Unit A NO
Unit A N02
Unit B NO
Unit B N02
Time (sec)
(ppm)
(ppm)
(ppm)
(ppm)
0
2
1
3
0
10
15
1
5
1
20
546
48
439
43
30
1284
184
1160
172
40
1383
262
1357
249
50
1398
303
1385
291
60
1400
317
1388
305
70
1402
325
1392
314
80
1403
329
1393
319
90
1404
332
1395
322
100
1405
334
1395
324
110
1405
335
1396
326
120
1406
337
1397
328
130
1406
338
1398
329
140
1406
339
1398
330
150
340
332
160
340
332
170
341
333
180
341
334
190
342
334
200
342
335
210
343
335
220
343
336
230
343
336
240
344
337
250
344
337
260
344
338
270
345
338
280
345
338
290
345
338
300
345
339
31
-------
Table 6-5. Response Time Results for Land Combustion LANCOM Series II Analyzers
Unit A
Unit B
NO
no2
NO
no2
Response Time (sec)a
35
77
39
90
a The analyzer's responses were recorded at 10-second intervals; therefore the point in time when the 95 percent
response was achieved was determined by interpolating between recorded times to the nearest second.
Table 6-6. Data from Interrupted Sampling Test with Land Combustion LANCOM Series
II Analyzers
Unit A NO
Unit A N02
Unit B NO
Unit B NO,
Pre-Shutdown Date:
05/22/2000
Time:
17:17
Pre-Shutdown Zero (ppm):
3
1
3
1
Pre-Shutdown Span (ppm):
2006
519
1955
514
Post-Shutdown Date:
05/23/2000
Time:
09:05
Post-Shutdown Zero (ppm):
2
2
1
3
Post-Shutdown Span (ppm):
1940
520
1941
525
Table 6-7. Pre- to Post-Test Differences as a Result of Interruption of Operation of Land
Combustion LANCOM Series II Analyzers
Unit A
Unit B
Pre-Shutdown—Post-Shutdown
NO
no2
NO
no2
Zero Difference (ppm)
1
-1
2
-2
Span Difference (ppm)
66
-1
14
-11
32
-------
Table 6-8. Data from Interference Tests on Land Combustion LANCOM Series II
Analyzers
Interferant
Interferant, Cone.
Response (pp
m equivalent)
Gas
(ppm)
Unit A
Unit A N02
Unit B NO
Unit B N02
Zero
1
0
0
0
CO
496
1
0
0
0
Zero
0
0
0
co2
5.03%
1
0
0
0
Zero
1
0
0
0
nh3
494
1
0
0
0
Zero
1
0
0
0
HCs
605
1
0
0
0
Zero
1
0
0
0
so2
501
1
0
0
0
Zero
1
0
0
0
SO, + NO
451 + 393
380
0
390
1
Table 6-9. Results of Interference Tests of Land Combustion LANCOM Series II Analyzers
Unit A Response ppm Unit B Response ppm
(relative sensitivity, %) (relative sensitivity, %)
Interferant NO N02 NO N02
CO (496 ppm)
0.1%
0
0
0
C02 (5.03%)
0
0
0
0
NH3 (494 ppm)
0
0
0
0
HCs (605 ppm)
0
0
0
0
S02 (501 ppm)
0
0
0
0
S02 (451 ppm) +
NO (393 ppm)
-2.9%
0
-0.7%
0.2%
33
-------
6.1.6 Pressure Sensitivity
Table 6-10 lists the data obtained in the pressure sensitivity test. Table 6-11 summarizes the
findings from those data in terms of the ppm differences in zero and span readings at the different
duct gas pressures and the ccm differences in analyzer flow rates at the different duct gas
pressures.
Tables 6-10 and 6-11 show that only very small changes in LANCOM Series II zero and span
readings resulted from the changes in duct pressure, for both NO and N02. Average zero readings
changed by less than 1 ppm, and span readings changed by no more than 12 ppm for NO (0.9 %
of the 1,400 ppm span level) and 6 ppm for N02 (1.7% of the 350 ppm span level). For both NO
and N02, the span responses were slightly higher under both the reduced and increased pressure
conditions, relative to those at atmospheric pressure. The changes observed do not indicate any
statistically significant effect of pressure on zero or span readings.
Tables 6-10 and 6-11 also show only a small effect of pressure on the sample flow rates of the
LANCOM Series II analyzers. The reduced pressure condition reduced the flow rates by about
3.5%, and the increased pressure condition increased the flow rates by about 2%, relative to the
flows at ambient pressure.
6.1.7 Ambient Temperature
Table 6-12 lists the data obtained in the ambient temperature test with the Land Combustion
LANCOM Series II analyzers. Table 6-13 summarizes the sensitivity of the analyzers to changes
in ambient temperature. This table is based on the data shown in Table 6-12.
Tables 6-12 and 6-13 show that the temperature variations in this test had no significant effect on
the N02 zero readings of either LANCOM Series II analyzer. However, a statistically significant
but small temperature effect was indicated for the NO zero readings. This result is entirely due to
the slightly elevated NO zero readings observed when the analyzers were placed in the heated
chamber (Table 6-12).
Temperature did have a significant effect on the NO and N02 span responses of both LANCOM
Series II analyzers. The effect was consistent for both NO and N02 with both LANCOM units, in
that higher span responses occurred at higher temperatures, and lower responses at lower tem-
peratures, relative to the responses at room temperature. The total difference in span readings
between the cooled and heated environments was 7 to 10% of the 1,400 ppm NO span value, and
about 4% of the 350 ppm N02 span value. Note that the vendor recommends calibrating at the
same temperature at which measurements will be made, and re-zeroing in the event of a
temperature change greater than 20 °F.
34
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Table 6-10. Data from Pressure Sensitivity Test for Land Combustion LANCOM Series II
Analyzers
Pressure
Unit A NO
Unit A N02
Unit B NO
Unit B N02
Ambient
Flow rate (ccm)
1324
1324
1691
1691
Zero (ppm)
1
0
0
0
NO span (ppm)
1367
1
1397
1
Zero (ppm)
2
0
2
0
N02 span (ppm)
1
349
1
355
Zero (ppm)
2
1
1
1
+ 10 in. H20
Flow rate (ccm)
1358
1358
1723
1723
Zero (ppm)
2
0
2
0
NO span (ppm)
1374
1
1406
1
Zero (ppm)
2
0
2
0
N02 span (ppm)
2
355
1
361
Zero (ppm)
2
2
1
2
-10 in. H20
Flow rate (ccm)
1279
1279
1629
1629
Zero (ppm)
2
0
1
0
NO span (ppm)
1379
1
1406
1
Zero (ppm)
3
0
2
0
N02 span (ppm)
2
354
1
361
Zero (ppm)
2
1
1
2
Table 6-11. Pressure Sensitivity Results for Land Combustion LANCOM Series II
Analyzers
Unit A Unit B
NO
no2
NO
no2
Zero
High-Ambient (ppm diffa)
0.334
0.334
0.667
0.334
Low-Ambient (ppm diff)
0.667
0
0.333
0.334
Significant Pressure Effect
N
N
N
N
Span
High-Ambient (ppm diff)
7
6
9
6
Low-Ambient (ppm diff)
12
5
9
6
Significant Pressure Effect
N
N
N
N
Flow
High-Ambient (ccm diffa)
34
32
Rate
Low-Ambient (ccm diff)
-45
-62
a ppm or ccm difference between high/low and ambient pressures. The differences were calculated based on the
average of the zero values.
35
-------
Table 6-12. Data from Ambient Temperature Test of Land Combustion LANCOM Series
II Analyzers
Unit A NO
Unit A N02
Unit B NO
Unit B N02
Condition
(ppm)
(ppm)
(ppm)
(ppm)
(Room Temp.)
Temp. 25.56°C (78°F)
Zero
0
0
0
0
NO span
1381
4
1422
6
Zero
1
1
1
1
N02 span
0
355
1
360
(Heated)
Temp. 39.44°C (103°F)
Zero
5
0
2
0
NO span
1448
2
1494
2
Zero
9
0
5
0
N02 span
13
363
9
367
(Cooled)
Temp. 7.22°C (45°F)
Zero
1
2
0
2
NO span
1351
5
1356
7
Zero
1
0
0
0
N02 span
0
349
0
352
(Room Temp.)
Temp. 22.78°C (73°F)
Zero
0
0
0
0
NO span
1369
2
1388
2
Zero
3
0
1
0
N02 span
4
356
0
361
6.1.8 Zero/Span Drift
Zero and span drift were evaluated from data taken at the start and end of the linearity and
ambient temperature laboratory tests. Those data are shown in Table 6-14, and the drift values
observed are shown as pre- minus post-test differences in ppm in Table 6-15.
36
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Table 6-13. Ambient Temperature Effects on Land Combustion LANCOM Series II
Analyzers
Unit A
Unit B
NO
no2
NO
no2
Zeroa
Heat-Room (ppm diff)
6
-0.25
3
-0.25
Cool-Room (ppm diff)
0
0.75
-0.5
0.75
Significant Temp Effect
Y
N
Y
N
Spana
Heat-Room (ppm diff)
73
7.5
89
6.5
Cool-Room (ppm diff)
-24
-6.5
-49
-8.5
Significant Temp. Effect
Y
Y
Y
Y
a ppm difference between heated/cooled and room temperatures. The differences were calculated using the
average of two recorded responses at room temperature (Table 6 12).
Table 6-14. Data from Linearity and Ambient Temperature Tests Used to Assess Zero and
Span Drift of the Land Combustion LANCOM Series II Analyzers
Unit A
Unit A
Unit B
Unit B
NO
no2
NO
no2
Test
(ppm)
(ppm)
(ppm)
(ppm)
Linearity
Pre-Test Zero
2
0
3
0
Pre-Test Span
1998
507
1978
496
Post-Test Zero
3
2
4
1
Post-Test Span
2020
512
1995
501
Ambient Temperature
Pre-Test Zero
0
1
0
1
Pre-Test Span
1381
355
1422
360
Post-Test Zero
0
0
0
0
Post-Test Span
1369
356
1388
361
37
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Table 6-15. Zero and Span Drift Results for the Land Combustion LANCOM Series II
Analyzers
Unit A
Unit B
NO
no2
NO
no2
Pre- and Post-Differences
(ppm)
(ppm)
(ppm)
(ppm)
Linearity Test
Zero
-1
-2
-1
-1
Span
-22
-5
-17
-5
Ambient Temperature Test
Zero
-1
0.5
0
0.5
Span
12
-1
34
-1
Table 6-15 shows that zero drifts in these tests were 2 ppm or less for both NO and N02 on both
LANCOM Series II analyzers. This result indicates minimal effect of exposure to the high NO
and N02 levels in the linearity test. Span drift for N02 amounted to 5 ppm or less (about 1% of
the 512 ppm span value). Span drift for NO amounted to 22 ppm or less in the linearity test
(1.1% of the 2,000 ppm NO span value) and was 34 ppm or less in the ambient temperature test
(2.4% of the 1,400 ppm NO span value).
6.2 Combustion Source Tests
6.2.1 Relative Accuracy
Tables 6-16a through d list the measured NO, N02, and NOx data obtained in sampling the four
combustion sources. Note that the LANCOM Series II analyzers measure NO and N02, and the
indicated NOx readings are the sum of those data. On the other hand, the reference anayzers
measure NO and NOx, with N02 determined by difference.
Table 6-17 displays the relative accuracy (in percent) for NO, N02, and NOx of Units A and B
for each of the four sources. Estimated standard errors are shown with the relative accuracy
estimates. These standard error estimates were calculated under the assumption of zero true bias
between the reference and test methods. If the bias is in fact non-zero, the standard errors
underestimate the variability.
Table 6-17 shows that relative accuracy for NOx ranged from 1.8 to 17.5% over both analyzers
and all combustion sources. Relative accuracy for NO ranged from 1.2 to 21%, and the relative
accuracy for N02 ranged from 4.2 to 26%. Relatively accuracy was generally better at higher
concentrations. At NO and N02 levels of 6 ppm or less, the LANCOM Series II analyzers were
accurate to within about their 1-ppm measurement resolution.
38
-------
Table 6-16a. Data from Gas Rangetop in Verification Testing of Land Combustion LANCOM Series II Analyzers
Land Combustion Analyzer Data
Reference Analyzer Data
Unit A
Unit B
Unit 100643
Unit 100647
NO
no2
NOx
NO
no2
NOx
NO
no2
NOx
NO
no2
NOx
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
1
6
3
9
5
3
8
5.47
1.98
7.44
4.80
2.27
7.07
2
6
2
8
6
2
8
5.96
1.89
7.85
5.24
2.32
7.57
3
7
2
9
6
2
8
6.12
1.82
7.93
5.46
2.16
7.63
4
7
2
9
6
2
8
6.27
1.73
8.00
5.62
2.19
7.81
5
7
2
9
6
2
8
6.33
1.76
8.09
5.58
2.31
7.89
6
7
2
9
7
2
9
6.38
1.91
8.29
5.63
2.32
7.95
7
7
2
9
6
2
8
6.51
1.91
8.42
5.70
2.38
8.08
8
8
2
10
7
2
9
6.70
1.86
8.57
6.08
2.14
8.22
9
7
2
9
7
2
9
6.51
1.77
8.28
5.82
2.14
7.96
CO
CO
Table 6-16b. Data from Gas Water Heater in Verification Testing of Land Combustion LANCOM Series II Analyzers
Land Combustion Analyzer Data
Reference Analyzer Data
Unit A
Unit B
Unit 100643
Unit 100647
NO
no2
NOx
NO
no2
NOx
NO
no2
NOx
NO
no2
NOx
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
1
79
5
84
79
5
84
80.7
3.5
84.2
79.3
4.24
83.5
2
80
5
85
81
5
86
80.2
4.0
84.3
79.0
4.44
83.4
3
80
6
86
81
5
86
81.3
4.9
86.3
79.9
4.65
84.5
4
78
6
84
80
5
85
79.4
4.6
84.0
77.8
4.85
82.7
5
79
6
85
80
5
85
78.5
4.6
83.1
77.4
4.34
81.8
6
79
6
85
80
5
85
79.8
4.6
84.4
77.7
5.56
83.3
7
80
5
85
81
5
86
79.5
5.0
84.6
78.3
5.15
83.5
8
80
5
85
81
5
86
79.9
4.7
84.6
78.2
5.45
83.7
9
82
6
88
83
5
88
80.5
5.4
85.9
79.3
5.66
84.9
-------
Table 6-16c. Data from Diesel Generator at High RPM in Verification Testing of Land Combustion LANCOM Series II
Analyzers
Land Combustion Analyzer Data
Keterence Analyzer Data
Unit A
Unit B
Unit 100643
Unit 100647
NO
no2
NOx
NO
no2
NOx
NO
no2
NOx
NO
no2
NOx
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
1
165
73
238
171
72
243
165.2
75.7
240.9
163.8
78.9
242.7
2
155
69
224
161
68
229
157.4
70.2
227.7
156.1
73.0
229.0
3
157
69
226
164
68
232
156.5
66.9
223.4
156.1
70.0
226.1
4
155
68
223
163
68
231
156.5
69.1
225.6
156.1
71.0
227.1
5
158
68
226
166
67
233
160.3
66.9
227.3
159.0
70.0
229.0
6
156
70
226
164
69
233
159.4
70.2
229.6
159.0
73.0
231.9
7
158
65
223
166
65
231
159.4
66.9
226.3
159.0
70.0
229.0
8
160
66
226
169
66
235
157.4
65.8
223.3
157.0
68.0
225.1
9
157
66
223
164
65
229
156.5
63.6
220.1
155.1
67.1
222.2
Table 6-16d. Data from Diesel Generator at Idle in Verification Testing of Land Combustion LANCOM Series II Analyzers
Land Combustion Analyzer Data
Reference Analyzer Data
Unit A
Unit B
Unit 100643
Unit 100647
NO
no2
NOx
NO
no2
NOx
NO
no2
NOx
NO
no2
NOx
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
l
219
100
319
226
100
326
219.6
109.7
329.4
217.7
112.4
330.2
2
215
101
316
220
100
320
215.7
108.6
324.4
214.8
112.4
327.3
3
208
100
308
213
100
313
211.9
109.7
321.6
210.0
113.4
323.4
4
215
101
316
222
100
322
217.7
107.5
325.2
216.8
111.4
328.2
5
207
103
310
218
101
319
210.9
109.7
320.6
210.0
115.4
325.4
6
206
104
310
212
102
314
208.0
108.6
316.6
208.1
112.4
320.5
7
199
102
301
204
100
304
204.1
107.5
311.6
204.2
110.5
314.7
8
196
101
297
200
100
300
200.2
108.6
308.8
200.4
112.4
312.8
9
193
101
294
201
100
301
202.1
106.4
308.6
202.3
111.4
313.8
-------
Table 6-17. Relative Accuracy of Land Combustion LANCOM Series II Analyzers
Unit A
Unit B
NO
no2
NOx
NO
no2
NOx
Source
(%)
(%)
(%)
(%)
(%)
(%)
Gas Rangetop
21.021a
14.747
17.496
10.863
14.747
8.802
(6 ppm NO, 2 ppm N02)c
(1.524)b
(4.243)
(1.535)
(1.939)
(4.243)
(1.425)
Gas Water Heater
1.473
26.019
2.181
2.890
13.103
2.712
(80 ppm NO, 5 ppm N02)
(0.352)
(3.420)
(0.279)
(0.409)
(2.965)
(0.280)
Diesel Generator-High RPM
1.160
4.156
1.844
5.492
5.052
3.224
(160 ppm NO, 70 ppm N02)
(0.324)
(0.680)
(0.349)
(0.382)
(0.659)
(0.410)
Diesel Generator-Idle
2.594
9.356
4.472
2.720
9.991
2.867
(210 ppm NO, 110 ppm N02)
(0.377)
(0.430)
(0.231)
(0.434)
(0.295)
(0.252)
a Relative accuracy, percent relative to mean of two reference analyzers.
b Standard error of the relative accuracy value.
c Approximate NO and N02 levels from each source are shown; see Tables 6-16a through d.
The unit-to-unit agreement of the LANCOM Series II analyzers in source combustion tests was
also good. For example, the differences between the average N0X values obtained by LANCOM
Units A and B on the four combustion sources ranged from 0.5 to 7.7%, relative to the mean NOx
values; the corresponding agreement of the two reference analyzers ranged from 1.0 to 3.8%.
These results indicate a high degree of consistency in the performance of the LANCOM
analyzers on combustion sources.
6.2.2 Zero/Span Drift
Table 6-18 shows the data used to evaluate zero and span drift of the LANCOM Series II
analyzers from the combustion source tests.
Table 6-19 summarizes the zero and span drift results, showing that zero and span drift was
rarely more than a few ppm in any of the combustion source tests, for either NO or N02, with
either analyzer. The zero drift values exceeded ±1 ppm only for NO readings of the LANCOM
Series II analyzers with the diesel generator. Those NO zero drift values with the diesel source
are about 1% of the 200 ppm and 400 ppm NO span values used with that source.
The span drift values in Table 6-19 are similarly small. Relative to the respective span values, the
NO span drift was at most 5% of span (relative to the 20 ppm span value used with the gas range-
top), and the N02 span drift was, at most, 10% (relative to the 10 ppm span value used with the
rangetop). These zero and span drift results reflect the ± 1 ppm resolution of the analyzers and
are consistent with those obtained in the laboratory testing (Section 6.1.8).
41
-------
Table 6-18. Data Used to Assess Zero and Span Drift for Land Combustion LANCOM
Series II Analyzers on Combustion Sources
Unit A NO
Unit A N02
Unit B NO
Unit B N02
Source
(ppm)
(ppm)
(ppm)
(ppm)
Gas Rangetop
Pre-Test Zero
1
0
1
0
Pre-Test Span
19
10
19
10
Post-Test Zero
2
0
1
0
Post-Test Span
20
10
19
9
Gas Water Heater
Pre-Test Zero
3
0
1
0
Pre-Test Span
100
14
100
14
Post-Test Zero
3
0
2
0
Post-Test Span
100
14
100
13
Diesel-High RPM
Pre-Test Zero
3
0
3
0
Pre-Test Span
202
46
202
46
Post-Test Zero
0
1
0
1
Post-Test Span
199
47
203
46
Diesel-Idle
Pre-Test Zero
0
0
0
0
Pre-Test Span
391
100
395
98
Post-Test Zero
3
0
1
0
Post-Test Span
386
101
386
98
42
-------
Table 6-19. Results of Zero and Span Drift Evaluation for Land Combustion LANCOM
Series II Analyzers
Unit A
Unit B
Pre-Test—
NO
no2
NO
no2
Post-Test
(ppm)
(ppm)
(ppm)
(ppm)
Gas Rangetop
Zero
-1
0
0
0
Span
-1
0
0
1
Gas Water Heater
Zero
0
0
-1
0
Span
0
0
0
1
Diesel Generator-High RPM
Zero
3
-1
3
-1
Span
3
-1
-1
0
Diesel Generator-Idle
Zero
-3
0
-1
0
Span
5
-1
9
0
6.2.3 Measurement Stability
Table 6-20 shows the data obtained in the extended sampling test, in which the LANCOM
Series II and reference analyzers sampled diesel emissions for a full hour without interruption or
sampling of ambient air. Table 6-21 shows the results of this evaluation in terms of the slopes
and standard errors of the NO, N02, and NOx data with time. Also shown in Table 6-21 is an
indication of whether the slopes observed by the LANCOM Series II analyzers differed from
those observed by the reference analyzers.
Table 6-21 shows that both the LANCOM Series II analyzers and the reference analyzers
indicated increasing trends in NO and NOx and a decreasing trend in N02, during the extended
sampling of the diesel source. The slopes of the trends determined by the LANCOM Series II
analyzers were very close to the slopes determined by the reference analyzers. As a result, there
was no statistically significant difference between the trends determined by the LANCOM Series
II and the reference analyzers.
6.2.4 Inter- Unit Repeatability
The repeatability of test results between the two LANCOM Series II analyzers was assessed in
those cases where the data lent themselves to application of a t-test. The resulting t-statistics and
associated p-values are listed in Table 6-22. Highlighted in bold are those p-values less than 0.05,
which indicate a statistically significant difference between the two LANCOM Series II units at
the 95% confidence level. Significant unit-to-unit differences were found primarily in the area of
relative accuracy.
43
-------
Table 6-20. Data from Extended Sampling Test with Diesel Generator at Idle, Using Land Combustion LANCOM Series II
Analyzers
Land Combustion Analyzer Data
Reference Analyzer Data
Unit A
Unit B
Unit 100643
Unit 100647
NO
no2
NOx
NO
no2
NOx
NO
no2
NOx
NO
no2
NOx
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
1
178
103
281
182
100
282
185.6
106.4
292.1
185.0
109.5
294.4
2
176
102
278
179
101
280
183.7
108.6
292.3
183.0
112.4
295.5
3
174
103
277
177
100
277
182.7
105.3
288.0
181.1
109.5
290.6
4
171
102
273
175
100
275
182.7
107.5
290.2
180.2
112.4
292.6
5
169
104
273
175
101
276
178.8
106.4
285.3
178.2
110.5
288.7
6
168
102
270
172
100
272
177.8
105.3
283.2
177.3
108.5
285.7
7
165
103
268
170
102
272
177.8
105.3
283.2
177.3
110.5
287.7
8
166
102
268
169
100
269
175.9
104.2
280.1
174.4
108.5
282.9
9
166
103
269
176
102
278
178.8
105.3
284.2
180.2
110.5
290.6
10
161
104
265
165
102
267
172.0
106.4
278.4
171.5
111.4
282.9
11
162
102
264
165
101
266
171.0
107.5
278.6
170.5
111.4
282.0
12
163
105
268
167
102
269
171.0
106.4
277.5
170.5
111.4
282.0
13
162
102
264
165
100
265
171.0
105.3
276.4
170.5
109.5
280.0
14
172
104
276
172
102
274
171.0
104.2
275.3
170.5
110.5
281.0
15
162
104
266
165
101
266
174.0
104.2
278.2
174.4
107.5
281.9
16
158
105
263
159
103
262
169.1
105.3
274.4
169.6
110.5
280.0
17
169
99
268
172
97
269
177.8
103.1
281.0
177.3
107.5
284.8
18
170
101
271
170
98
268
175.9
101.0
276.8
175.3
104.5
279.9
19
167
99
266
170
97
267
180.8
104.2
285.0
177.3
109.5
286.7
20
167
102
269
168
99
267
176.9
102.0
278.9
176.3
106.5
282.8
21
163
99
262
166
97
263
175.9
105.3
281.2
174.4
107.5
281.9
22
162
100
262
167
98
265
175.9
101.0
276.8
176.3
105.5
281.8
23
163
97
260
166
95
261
173.0
99.9
272.8
172.4
104.5
277.0
24
164
98
262
172
97
269
176.9
99.9
276.7
179.2
104.5
283.7
25
160
100
260
164
97
261
172.0
101.0
273.0
171.5
105.5
277.0
26
160
98
258
162
97
259
169.1
104.2
273.3
168.6
108.5
277.1
27
164
99
263
163
97
260
171.0
99.9
270.9
169.6
105.5
275.1
28
159
97
256
162
95
257
170.1
102.0
272.1
169.6
104.5
274.1
29
161
99
260
163
96
259
169.1
101.0
270.0
167.6
104.5
272.2
30
160
97
257
164
95
259
176.9
101.0
277.8
175.3
107.5
282.8
-------
Table 6-20. Data from Extended Sampling Test with Diesel Generator at Idle, Using Land Combustion LANCOM Series II
Analyzers (continued)
Land Combustion Analyzer Data
Reference Analyzer Data
Unit A
Unit B
Unit 100643
Unit 100647
NO
no2
NOx
NO
no2
NOx
NO
no2
NOx
NO
no2
NOx
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
31
159
98
257
162
96
258
172.0
98.8
270.8
171.5
102.6
274.0
32
163
95
258
168
93
261
174.0
98.8
272.7
174.4
102.6
276.9
33
157
98
255
164
96
260
173.0
98.8
271.7
173.4
102.6
276.0
34
161
95
256
164
93
257
172.0
98.8
270.8
171.5
104.5
276.0
35
172
96
268
178
95
273
174.9
98.8
273.7
175.3
103.6
278.9
36
161
94
255
165
92
257
175.9
95.5
271.4
175.3
99.6
274.9
37
177
97
274
180
94
274
186.6
92.2
278.8
186.9
97.6
284.5
38
177
96
273
181
93
274
189.5
95.5
285.0
190.8
98.6
289.4
39
177
96
273
180
94
274
186.6
102.0
288.6
186.9
105.5
292.4
40
177
97
274
180
95
275
186.6
96.6
283.2
186.9
101.6
288.5
41
180
95
275
183
93
276
192.4
98.8
291.2
192.7
101.6
294.3
42
181
99
280
183
95
278
190.5
98.8
289.2
190.8
102.6
293.3
43
182
96
278
185
93
278
192.4
98.8
291.2
192.7
103.6
296.2
44
182
97
279
183
95
278
193.4
98.8
292.1
193.6
102.6
296.2
45
185
98
283
188
92
280
195.3
96.6
291.9
194.6
100.6
295.2
46
183
95
278
187
93
280
199.2
98.8
298.0
199.4
102.6
302.0
47
180
98
278
183
93
276
194.4
96.6
290.9
193.6
100.6
294.2
48
182
93
275
185
91
276
194.4
95.5
289.8
194.6
99.6
294.2
49
204
95
299
206
94
300
194.4
101.0
295.3
195.6
106.5
302.1
50
206
94
300
210
92
302
216.7
96.6
313.3
216.8
100.6
317.4
51
210
96
306
213
94
307
219.6
96.6
316.2
219.7
102.6
322.2
52
205
97
302
208
95
303
218.7
97.7
316.3
219.7
101.6
321.2
53
206
97
303
209
95
304
214.8
99.9
314.6
214.8
104.5
319.4
54
204
100
304
207
97
304
210.9
103.1
314.0
211.0
106.5
317.5
55
207
98
305
210
95
305
215.7
99.9
315.6
216.8
103.6
320.3
56
206
99
305
209
97
306
215.7
101.0
316.7
215.8
106.5
322.3
57
207
100
307
209
97
306
215.7
101.0
316.7
215.8
105.5
321.3
58
207
99
306
209
97
306
215.7
103.1
318.9
215.8
107.5
323.3
59
207
100
307
211
98
309
218.7
101.0
319.6
218.7
105.5
324.2
60
205
99
304
205
95
300
217.7
99.9
317.5
218.7
103.6
322.2
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Table 6-21. Results of Evaluation of Measurement Stability for Land Combustion
LANCOM Series II Analyzer
NO
Unit A
no2
NOx
NO
Unit B
no2
NOx
Reference Units
NO N02 NOx
Slope
0.724
-0.120
0.604
0.703
-0.133
0.570
0.740 -0.149 0.592
(Std Err)
(0.083)
(0.017)
(0.092)
(0.083)
(0.016)
(0.092)
(0.077) (0.020) (0.087)
Difference in
Slopesa (ppm/min)
-0.016
0.028
0.012
-0.037
0.016
-0.022
(Std Err)
(0.029)
(0.016)
(0.030)
(0.027)
(0.013)
(0.028)
—
a There was no statistically significant difference in slope between the test units and the average of the reference
units at the 5% significance level.
Table 6-22. Summary of Repeatability
Unit A vs. Unit B
NO
no2
NOx
Linear Regression
Intercept
t-statistic
-1.572
1.952
—
p-valuea
0.147
0.080
—
Slope
t-statistic
0.249
5.965
—
p-value
0.808
<0.001
—
Detection Limit
t-statistic
-0.002
0.786
—
p-value
0.998
0.438
u
—
Relative Accuracy
Gas Rangetop
t-statistic
4.000
D
4.000
p-value
0.004
-
0.004
Gas Water Heater
t-statistic
6.000
3.162
2.530
p-value
<0.001
0.013
0.035
Generator-High
t-statistic
22.030
4.000
14.582
RPM
p-value
<0.001
0.004
<0.001
Generator-Idle
t-statistic
9.086
4.264
7.761
p-value
<0.001
0.003
<0.001
Measurement
Slope
t-statistic
1.640
1.850
2.100
Stability
p-value
0.106
0.070
0.040
a p-value <0.05 indicates that two test units are statistically different at the 5% significance level (in bold text).
b Unit A and Unit B indicated exactly the same N02 readings on the gas burner emission. No matched-pairs
t-statistic was calculated.
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The differences shown in Table 6-22 indicate the variability that may be expected from one
analyzer to the next. Although some statistically significant differences were found, nevertheless
the practical importance of these differences is often small. Considering the relative accuracy
results, for example (Table 6-17), it is apparent that statistically significant differences may exist
even when the two analyzers are equally applicable to the measurement at hand. For example, the
relative accuracy result for NOx for Unit A on the water heater is 2.2%, whereas that for Unit B is
2.7%. These results may differ significantly in the statistical sense, but both units provided
excellent accuracy in that portion of the test, and either unit would be more than adequate for
determining the NOx emissions from that source. The fine degree of discrimination provided by
the statistical tests should not obscure the fact that the two LANCOM Series II analyzers worked
about equally well throughout the verification tests.
6.3 Other Factors
In addition to the performance characteristics evaluated in the laboratory and combustion source
tests, three additional factors were recorded: analyzer cost, data completeness, and maintenance/
operational factors.
6.3.1 Cost
The cost of each analyzer as tested in this verification test was about $12,500.
6.3.2 Data Completeness
The data completeness in the verification tests was 100% for both units of the LANCOM
Series II analyzer.
6.3.3 Maintenance/Operational Factors
The short duration of the verification test prevented assessment of long-term maintenance costs,
durability, etc. but no maintenance was needed and no problems occurred with the LANCOM
Series II analyzers during this test.
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Chapter 7
Performance Summary
The Land Combustion LANCOM Series II analyzers provided linear response for NO and N02
over the tested ranges of 0 to 2,000 ppm and 0 to 512 ppm, respectively. One of the LANCOM
units did exhibit slightly low response to N02 above about 250 ppm, perhaps as a result of an
older sensor used in that unit. Detection limits estimated from these wide-range linearity tests
were about 2.5 ppm for NO and 1.5 to 2.3 ppm for N02. These results may have been affected by
exposure to high NO and N02 levels in the linearity tests. Performance at low levels in com-
bustion source tests indicated detection capabilities comparable to the 1-ppm resolution of the
analyzers. Response times were 35 and 39 seconds for NO and 77 and 90 seconds for N02.
Drift in LANCOM Series II NO and N02 zero readings before and after source combustion and
laboratory tests was within ± 2 ppm in nearly all circumstances. In laboratory tests, span drift for
NO was within about 2%, using 1,400 to 2,000 ppm NO span levels. For N02, span drift was
within 1%, using 350 to 512 ppm N02 span levels. In sampling gas combustion and diesel
sources, absolute NO and N02 span drift was usually within 1 ppm, and span drift exceeded 2%
of the span gas value only at span gas values of 10 to 20 ppm. No interference was found from
any of the following: 496 ppm CO; 5.03% C02; 494 ppm NH3; 605 ppm of total hydrocarbons;
501 ppm of S02; or 451 ppm S02 in the presence of 393 ppm NO.
Over the tested range of + 10 to - 10 in. H20, sample gas pressure had no significant effect on
LANCOM Series II zero or span readings. Reduced pressure lowered the analyzers' sample flow
rates by about 3.5%, and positive pressure increased the flow rates by about 2%. Variations in
ambient temperature over the range of 7 to 39°C (45 to 103°F) had no effect on the LANCOM
Series II zero readings for N02, but a small effect was seen for NO, with higher temperature
increasing zero readings by a few ppm. Over that entire temperature range, span response
increased with increasing temperature by 7 to 10% for NO, and by about 4% for N02.
The relative accuracy of the LANCOM Series II analyzers for NOx ranged from 1.8 to 17.5%
over both analyzers and all combustion sources. Relative accuracy for NO ranged from 1.2 to
21%, and the relative accuracy for N02 ranged from 4.2 to 26%. Relative accuracy was generally
better at higher concentrations. At NO and N02 levels of 6 ppm or less, the LANCOM Series II
analyzers were accurate to within about their 1-ppm measurement resolution. Unit-to-unit agree-
ment for NOx in source testing ranged from 0.5 to 7.7% and was comparable to that of the
reference analyzers. Comparison of verification results from the two LANCOM Series II
analyzers showed some unit-to-unit differences, primarily in relative accuracy; but overall the
performance of the two analyzers was essentially the same.
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Chapter 8
References
1. Test/QA Plan for Verification of Portable NO/NO2 Emission Analyzers, Version 2.0,
Battelle, Columbus, Ohio, August 1999.
2. U.S. EPA Method 7E Determination of Nitrogen Oxides Emissions from Stationary Sources
(Instrumental Analyzer Procedure) Code of Federal Regulations, 40 CFR, Ch 1, Part 60,
Appendix A (1991).
3. Traceability Protocol for Establishing True Concentrations of Gases Used for Calibrations
and Audits of Continuous Source Emission Monitors: Protocol Number 1, Research
Triangle Park, NC: U.S. Environmental Protection Agency, Quality Assurance Division,
June 1978.
4. Interlaboratory Program to Validate a Protocol for the Measurement of NO2 Emissions
from Rangetop Burners, GRI-94/0458, Gas Research Institute, Chicago, Illinois, December
1994.
5. Interlaboratory Study to Determine the Precision of an Emission Measurement Protocol
for Residential Gas Water Heaters, GRI-96-0021, Gas Research Institute, Chicago, Illinois,
March 1996.
6. American National Standards (ANSI Z21.1) "Household Cooking Gas Appliances,"
American National Standards Institute, 24th Edition, American Gas Association, 1990.
7. Quality Management Plan (QMP) for the ETV Advanced Monitoring Systems Pilot, U.S.
EPA Environmental Technology Verification Program, Battelle, Columbus, Ohio,
September 1998.
8. Portable NOx Analyzer Evaluation for Alternative Nitrogen Oxide Emission Rate
Determination at Process Units, Source Testing and Engineering Branch, South Coast Air
Quality Management District, Los Angeles, CA, September 21, 1994.
9. U.S. EPA Method 5, Determination of Particulate Emissions from Stationary Sources,
Code of Federal Regulations, 40 CFR, Ch. 1, Part 60, Appendix A (1991).
10. Determination of Nitrogen Oxides, Carbon Monoxide, and Oxygen Emissions from Natural
49
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Gas-Fired Engines, Boilers, and Process Heaters Using Portable Analyzers, Conditional
Test Method (CTM)-030, U.S. EPA, Office of Air Quality Planning and Standards,
Emission Measurement Center, October 13, 1997.
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