February 2008

Environmental Technology 

Verification Report

JSC OPTEC 3.02 P-A 

CHEMILUMINESCENT OZONE ANALYZER 

Prepared by 

Battelle 

Under a cooperative agreement with 

 U.S. Environmental Protection Agency 
February 2008 

Environmental Technology Verification 

Report

ETV Advanced Monitoring Systems Center 

JSC OPTEC 3.02 P-A 

CHEMILUMINESCENT OZONE ANALYZER 

By 

Patricia Holowecky 

Thomas Kelly 

Zachary Willenberg 

Amy Dindal 

Battelle 

Columbus, Ohio 43201 
ii 

Notice 

The U.S. Environmental Protection Agency (EPA), through its Office of Research and 

Development, has financially supported and collaborated in the extramural program described 

here. This document has been peer reviewed by the Agency. Mention of trade names or 

commercial products does not constitute endorsement or recommendation by the EPA for use. 
iii 

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 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. ETV consists of five environmental technology centers. 

Information about each of these centers can be found on the Internet at http://www.epa.gov/etv/. 

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. Under a cooperative agreement, Battelle has received EPA funding 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/ 

centers/center1.html. 
iv 

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. We particularly thank Will Ollison of 

the American Petroleum Institute, Rudy Eden of the South Coast Air Quality Management 

District, and Dennis Mikel of U.S. EPA’s Office of Air Quality Planning and Standards for their 

reviews of this verification report. 
v 

Contents 

Page

Notice.............................................................................................................................................. ii 

Foreword........................................................................................................................................iii 

Acknowledgments.......................................................................................................................... iv 

List of Abbreviations and Acronyms............................................................................................ vii 

Chapter 1 Background ................................................................................................................... 1 

Chapter 2 Technology Description ................................................................................................ 2 

Chapter 3 Test Design and Procedures .......................................................................................... 4 

3.1 Introduction...........................................................................................................................4 

3.2 Test Procedures.....................................................................................................................5 

3.2.1 Accuracy ................................................................................................................... 5 

3.2.2 Linearity.................................................................................................................... 5 

3.2.3 Interference Effects................................................................................................... 6

3.2.4 Comparability ........................................................................................................... 7 

3.2.5 Data Completeness.................................................................................................... 7 

3.2.6 Operational Factors................................................................................................... 7 

3.3 Reference Methods ...............................................................................................................8 

3.4 Verification Schedule ...........................................................................................................8 

Chapter 4 Quality Assurance/Quality Control............................................................................... 9 

4.1 Equipment Calibrations ........................................................................................................9 

4.2 Audits....................................................................................................................................9 

4.2.1 Performance Evaluation Audit.................................................................................. 9 

4.2.2 Technical Systems Audit ........................................................................................ 10 

4.2.3 Audit of Data Quality.............................................................................................. 10 

4.3 QA/QC Reporting...............................................................................................................10 

4.4 Data Review........................................................................................................................11 

Chapter 5 Statistical Methods ...................................................................................................... 12 

5.1 Accuracy .............................................................................................................................12 

5.2 Linearity..............................................................................................................................12 

5.3 Interference Effects.............................................................................................................12 

5.4 Comparability .....................................................................................................................13 

5.5 Data Completeness .............................................................................................................13 

Chapter 6 Test Results ................................................................................................................. 14 
vi 

6.1 Accuracy .............................................................................................................................14 

6.2 Linearity..............................................................................................................................16 

6.3 Interference Effects.............................................................................................................18 

6.4 Comparability .....................................................................................................................21 

6.5 Data Completeness .............................................................................................................25 

6.6 Operational Factors.............................................................................................................26 

Chapter 7 Performance Summary................................................................................................ 27 

Chapter 8 References ................................................................................................................... 29 

Figures

Figure 4-1. Performance Audit of Battelle’s Dasibi 1008 UV Photometer................................. 10 

Figure 6-1. Linearity of 3.02 P-A Response to Ozone in Chamber at High Humidity ............... 17 

Figure 6-2. Linearity of 3.02 P-A Response to Ozone in Chamber at Low Humidity ................ 17 

Figure 6-3. 3.02 P-A Response to Interferents in Chamber at Low Humidity ............................ 18 

Figure 6-4. 3.02 P-A Response to Interferents in Chamber at High Humidity ........................... 19 

Figure 6-5. Photochemical Interferent Test with High Precursor Concentrations....................... 20 

Figure 6-6. Photochemical Interferent Test with Low Precursor Concentrations ....................... 20 

Figure 6-7. 3.02 P-A Response to Ozone During Photochemical Test with High Precursor 

Concentrations ............................................................................................................................. 21 

Figure 6-8. Photochemical Ozone Comparison with High Precursor Concentrations ................ 22 

Figure 6-9. 3.02 P-A Response to Ozone During Photochemical Test with Low Precursor 

Concentrations ............................................................................................................................. 22 

Figure 6-10. Photochemical Ozone Comparison with Low Precursor Concentrations............... 23 

Figure 6-11. 3.02 P-A and FEM Ambient Monitoring Results ................................................... 24 

Figure 6-12. Linear Regression of 3.02 P-A and FEM Data During Ambient Monitoring......... 25 

Tables 

Table 3-1. Interference Testing Conditions ...................................................................................6 

Table 3-2. Photochemical Chamber Testing Conditions ............................................................... 7 

Table 3-3. Test Activities During the Optec 3.02 P-A Verification Test ...................................... 8 

Table 6-1. Percent Recoveries Relative to the Ozone Standard Concentrations .........................14 

Table 6-2. Percent Recoveries of Ozone from High Humidity (70 to 80% RH) Chamber Tests on 

June 13, 2007 ............................................................................................................................... 15 

Table 6-3. Percent Recoveries of Ozone from Low Humidity (<5% RH) Chamber Tests on 

June 14, 2007 ............................................................................................................................... 16 

Table 6-4. Optec 3.02 P-A Testing Activities June 12 to 28, 2007 ............................................. 26 
vii 

List of Abbreviations and Acronyms 

AMS Advanced Monitoring Systems 

°C Degrees Celsius 

COA Chemiluminescent Ozone Analyzer 

cm3 Cubic centimeter 

EPA U.S. Environmental Protection Agency 

ETV Environmental Technology Verification 

FEM Federal Equivalent Method 

GC Gas chromatograph 

MSD Mass selective detector 

m3 Cubic meter 

μg/m3 Microgram per cubic meter 

μm Micrometer 

nm Nanometer 

NO2 Nitrogen dioxide 

O3 Ozone 

OEPA Ohio Environmental Protection Agency 

ppbC Parts per billion carbon 

ppbv Parts per billion by volume 

ppmv Parts per million by volume 

pptv Parts per trillion by volume 

%R Percent recovery 

RPD Relative percent difference 

%RR Percent relative response 

PE Performance evaluation 

QA Quality assurance 

QC Quality control 

QMP Quality Management Plan 

r

2 Coefficient of determination 

RH Relative Humidity 

TSA Technical systems audit 

UV Ultraviolet 

VOC Volatile organic compounds 

V Volt 
1 

Chapter 1 

Background 

The U.S. EPA’s Environmental Technology Verification (ETV) Program verifies the 

performance of innovative technologies that have the potential to improve protection of human 

health and the environment. ETV accelerates the entrance of new environmental technologies 

into the domestic and international marketplaces. Verified technologies are included for all 

environmental media–air, water, and land. 

ETV works in partnership with recognized testing organizations; with stakeholder groups 

consisting of buyers, vendor organizations, and permitters; 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 (QA) protocols to ensure that data of known and adequate quality are generated and 

that the results are defensible. 

The U.S. EPA’s National Exposure Research Laboratory and its verification organization 

partner, Battelle, operate the Advanced Monitoring Systems (AMS) Center under ETV. The 

AMS Center verifies the performance of commercial-ready technologies that monitor 

contaminants and natural species in air, water, and soil. The center tests both field-portable and 

stationary monitors, as well as innovative technologies that can be used to describe the 

environment (site characterization). The AMS Center recently evaluated the performance of the 

JSC Optec Inc. 3.02 P-A chemiluminescent ozone analyzer (COA), a continuous monitor for 

determining ozone (O3) in air. 
2 

Chapter 2 

Technology Description 

The objective of the ETV AMS Center is to verify the performance characteristics of 

environmental monitoring technologies for air, water, and soil. This verification report provides 

results for the verification testing of the JSC Optec 3.02 P-A (referred to in this report as the 3.02 

P-A). The following general description of the 3.02 P-A is adapted from information provided 

by the vendor, and was not verified in this test. 

The 3.02 P-A COA combines a novel solid phase chemilumi-nescence approach with easy to use 

menu-driven software with diagnostic functions, and is intended to provide flexibility and 

reliability in measurement. It is designed to measure ozone concentrations in ambient air. 

The Model 3.02P-A is designed to have the following features: 

- Automatic continuous measurements 

- Automatic internal calibration 

- High sensitivity 

- Fast response time 

- Linearity 

- Menu driven software 

- Digital display 

- Data output 

The 3.02 P-A detects ambient ozone by means of its chemical reaction with a solid-phase 

reactant of proprietary composition, resulting in the emission of light with peak intensity near 
3 

560 nm wavelength. The emitted light is detected by a photomultiplier tube, and converted to a 

digital signal that is linearly proportional to the gaseous ozone concentration. An internal pump 

draws sample air through two alternating flow paths: in the measurement path sample air passes 

directly into contact with the solid-phase reactant, whereas in the zeroing path ozone in the 

sample air is removed by a selective scrubber element before the air contacts the reactant. The 

3.02 P-A thus measures ozone by comparison of the signals from these two paths. An internal 

ozone generator (ultraviolet (UV) lamp), located in the zeroing path downstream of the selective 

scrubber element, provides a calibration mixture to the 3.02 P-A at 10-minute intervals, and the 

internal software automatically adjusts instrument response with each calibration. The measured 

ozone concentration is displayed on the front panel of the 3.02 P-A and can be transmitted via 

analog outputs. The estimated price of the base model analyzer is $5,000. 
4 

Chapter 3 

Test Design and Procedures 

3.1 Introduction 

This verification test was conducted according to procedures specified in the peer-reviewed 

Test/QA Plan for Verification of Chemiluminescent Ozone Analyzer,

(1) and was carried out at 

Battelle laboratories in Columbus, Ohio from June 12 to June 28, 2007. 

The objective of this verification test was to evaluate the performance of the Optec 3.02 P-A, in 

part by comparing it to the response of the UV-absorption Federal Equivalent Method (FEM) for 

ozone. FEMs are established by EPA to assure high quality in ambient air monitoring data. The 

UV-absorption FEM for ozone is the method used for virtually all ambient ozone monitoring in 

the U.S. The specific commercial FEM monitor used in this test was the Thermo Environmental 

Model 49C (method EQOA-0880-047).(2)

The COA was verified by evaluating the following parameters: 

• Accuracy 

• Linearity 

• Interference effects 

• Comparability 

• Data completeness 

• Operational factors such as ease of use, maintenance and data output needs, power and other 

consumables used, reliability, and operational costs. 

Accuracy was determined by assessing the percent recovery of the 3.02 P-A with respect to 

different levels of ozone challenges. Linearity was assessed by a linear regression analysis using 

the ozone challenge concentration as the independent variable and the results from the 3.02 P-A 

as the dependent variable. The interference effects were calculated in terms of the ratio of the 

response when challenged with the interferent, to the actual concentration of the interferent. 

Comparability was assessed by comparing the 3.02 P-A response to that of the FEM in selected 

tests. Data completeness was assessed as the percentage of maximum data return achieved by 

the 3.02 P-A over the test period. Operational factors were evaluated by means of observations 

during testing and records of needed maintenance, vendor activities, and expendables use. 
5 

3.2 Test Procedures 

Prior to testing Battelle staff were trained in operation of the 3.02 P-A by the vendor. This 

training included studying the instrument manual, which had been translated into English from 

the original Russian.(3)

All test procedures were conducted using two units of the 3.02 P-A. One unit was operated 

exactly as recommended by the manufacturer. Results from that unit are the primary focus of 

this verification. In addition, a second unit was operated with a Nafion humidifier tube (obtained 

from 2B Technologies, Inc.) connected to the analyzer’s air inlet. This Nafion tube is designed 

to equilibrate the humidity of the incoming sample stream with that of the room air in the test 

laboratory (i.e., about 50% relative humidity (RH)). However the Nafion modification was not 

optimized to the 3.02 P-A unit so complete equilibration of humidity was probably not achieved 

at the sample flow rate of the 3.02 P-A (i.e., 1.8 L/min). Thus the RH of the sample air entering 

the first 3.02 P-A unit varied with test conditions, as described below, whereas that for the 

second unit was equilibrated towards 50% RH. The Nafion tube was used to assess the impact of 

humidity and humidity control on the 3.02 P-A response. The 3.02 P-A specifications accept a 

humidity range for continuous operation of 15 to 95% RH. However, EPA data quality protocols 

for routine ambient monitoring generally require clean dry air for calibrations and daily zero and 

span checks. The Nafion attachment provides a means to mitigate the effects of humidity 

extremes. As a result, testing with the unmodified 3.02 P-A unit at low relative humidity and 

with the second unit modified by addition of the Nafion attachment provided information 

relevant to routine use of the 3.02 P-A. 

Following are the test procedures used to evaluate the 3.02 P-A. 

3.2.1 Accuracy 

The accuracy of the 3.02 P-A was evaluated by two approaches. One approach determined the 

degree of agreement with ozone standards produced at 100 to 300 parts per billion by volume 

(ppbv) in dry zero air by an Environics Model 6400 ozone generator that was quantified by a 

Dasibi 1008 UV photometer, itself validated by a performance audit, as described in section 

4.2.1. The delivered concentrations of ozone, once shown to be stable by the Dasibi 1008 UV 

photometer, were monitored by the 3.02 P-A unit for 3 to 5 minutes. The 3.02 P-A reading was 

recorded, and the Environics generator was then adjusted to the next desired concentration. 

The second approach used to evaluate accuracy compared the 3.02 P-A and FEM responses to 

ozone generated in dry and humidified zero air in Battelle’s 17.3 m3

 environmental chamber. 

Ozone was added stepwise to clean air in the test chamber at both low (< 5%) and high 

(approximately 70 to 80%) RH. The response of the 3.02 P-A to various ozone concentrations 

was compared to the corresponding response of the FEM. 

3.2.2 Linearity 

Linearity was also evaluated from the chamber test data used to assess accuracy. Linearity was 

determined by linear regression of the response of the 3.02 P-A against the simultaneous FEM 

responses. 
6 

3.2.3 Interference Effects 

Interference effects were evaluated by three approaches in Battelle’s 17.3 m3

 environmental test 

chamber. The first tests were conducted on June 13 and 14 to determine the response of the 3.02 

P-A to ozone added stepwise to clean air in the test chamber at both low (< 5%) and high 

(approximately 70 to 80%) RH. Those tests, which were also used to assess 3.02 P-A accuracy 

and linearity relative to the FEM (Sections 3.2.1 and 3.2.2), indicated whether humidity affected 

3.02 P-A response. 

The second approach evaluated 3.02 P-A interference effects in ozone-free air at both low and 

high humidity, by adding stepwise chemicals found in primary source emissions or produced by 

urban photochemistry that have been found to be potential interferents in ozone monitoring. The 

interference effects and the response of the 3.02 P-A were assessed during Tests 1 and 2 as 

shown in Table 3-1, on June 20 and 22, respectively. In these tests, the 3.02 P-A was challenged 

with a mixture of four interferents added sequentially to the environmental chamber to produce 

their respective designated concentrations shown in Table 3-1. Once the first interferent was 

supplied to the chamber, the instruments were allowed to monitor for several minutes before 

moving on to the next interferent injection. Once all four interferents had been added, an 

integrated sample was taken in the environmental chamber to determine the actual interferent 

concentrations. The interferent concentrations used in these tests were at elevated levels that 

might plausibly exist in the atmosphere near roadways or other sources, or during stagnant 

meteorological conditions. 

Table 3-1. Interference Testing Conditions 

Test RH Interferent 

Target 

Concentration 

Actual 

Concentration 

< 5% Naphthalene 10 ppbv 10.9 ppbv 

< 5% o-nitrophenol 10 ppbv 6.1 ppbv 

1 < 5% p-tolualdehyde 10 ppbv 7.3 ppbv 

< 5% Mercury 50 ng/m3 630 ng/m3a 

(78.7 pptv) b

70 to 80% Naphthalene 10 ppbv 11.0 ppbv 

70 to 80% o-nitrophenol 10 ppbv 9.9 ppbv 

2 70 to 80% p-tolualdehyde 10 ppbv 14.9 ppbv 

70 to 80% Mercury 50 ng/m3 54 ng/m3

 

(6.8 pptv) b 

 a. Mercury was injected into the environmental chamber at a higher concentration than originally planned 

in this test procedure. 

 b. pptv = parts per trillion by volume (=1x10-12 v/v)

 

The third approach assessed the response of the 3.02 P-A to ozone precursors and photochemical 

reactants during photochemical chamber Tests 3 and 4 (Table 3-2) on June 27 and 28, 

respectively. Both of these tests were conducted in a series of steps, starting with monitoring of 

clean dry air, then of humidified clean air, and then proceeding to monitoring of that air spiked 

with a 17-component hydrocarbon mixture and then with NO2. The response of the 3.02 P-A up 

to that point was used to assess the interferent effects of these ozone precursors. After the 

hydrocarbons and NO2 were delivered to the chamber, irradiation of the chamber took place until 

the maximum ozone concentration (approximately 130 ppbv for Test 3 and approximately 80 
7 

ppbv for Test 4) had been passed. The difference between Tests 3 and 4 was the four-fold higher 

hydrocarbon and NO2 concentrations used in Test 4. The hydrocarbon levels targeted in these 

tests (500 and 2,000 ppbC) were chosen to reflect moderate photochemical periods when ozone 

standards are likely to be met, and severe photochemical periods when such standards are likely 

to be exceeded, respectively. 

Table 3-2. Photochemical Chamber Testing Conditions 

Test Step 

Target 

Concentration 

Actual 

Concentration 

Monitor dry zero air < 5% RH < 5% RH 

Monitor humidified air ≈ 80% RH 82% RH 

Add 17-component urban hydrocarbon 

mixture 

500 ppbC 670 ppbC 

(167 ppbv) 

Add NO2 50 ppbv 55 ppbv 

3 

Irradiate chamber contents NA NA 

Monitor dry zero air < 5% RH < 5% RH 

Monitor humidified air ≈ 80% RH 85% RH 

Add 17-component urban hydrocarbon 

mixture 

2000 ppbC 2370 ppbC 

(593 ppbv) 

Add NO2 200 ppbv 200 ppbv 

4 

Irradiate chamber contents NA NA 

NA = not applicable 

Particle number concentrations in the photochemical tests ranged up to approximately 8 x 105 per 

cubic centimeter (cm3

) almost entirely in the 0.3 to 0.5 μm size range, and those particles were 

almost completely removed by the filter on the inlet manifold from which the 3.02 P-A units and 

the FEM drew their sample air. 

3.2.4 Comparability 

Comparability was evaluated by comparing the responses of the 3.02 P-A to the simultaneous 

response of the Thermo Environmental UV Model 49C FEM in the photochemical chamber tests 

and in ambient air monitoring. The comparability of the 3.02 P-A and FEM response in ambient 

air was evaluated during ambient air monitoring over a period of 110 hours June 22-27, 2007. 

During this period the 3.02 P-A units and FEM all remained inside the test laboratory, but 

sampled ambient air outside the laboratory window through a common inlet attached to the 

sampling manifold. Calibration checks were performed periodically during the test, and hourly 

average ozone values were recorded. 

3.2.5 Data Completeness 

No additional test procedures were carried out specifically to address data completeness. This 

parameter was assessed based on the overall data return relative to the total amount of data return 

possible for the technology being tested. 

3.2.6 Operational Factors 

Operational factors such as maintenance needs, data output, consumables used, and ease of use 

were evaluated based on observations by Battelle. A laboratory record book was used to enter 
8 

daily observations on these factors. Examples of relevant information include the daily status of 

diagnostic indicators for the 3.02 P-A, use or replacement of any consumables, the effort or cost 

associated with maintenance or repair, vendor effort (e.g., time on site) for repair or 

maintenance, the duration and causes of any down time or data acquisition failure, the 

sustainability of the analyzer (e.g., power consumed, wastes generated, disposal costs required), 

and operator observations about ease of use of the 3.02 P-A. 

3.3 Reference Methods 

Reference methods for ozone consisted of a commercial photometer, the calibration of which is 

traceable to the primary reference photometer at EPA Region 5 in Chicago (as described in 

Section 4.2), and the Model 49C FEM. The UV-absorption method is used for virtually all 

ambient ozone monitoring in the U.S., and the Model 49C is a commonly used instrument 

established as an FEM for ozone.

During the interference and photochemical tests, integrated samples were taken of the injected 

contaminants and laboratory measurements were used to confirm the interferent compound 

concentrations added to the environmental chamber. Samples of naphthalene, o-nitrophenol, and 

p-tolualdehyde were collected from the chamber using commercially prepared sorbent traps, and 

their chamber concentrations were confirmed by gas chromatography with mass selective 

detection (GC/MSD). Mercury was confirmed by cold vapor atomic fluorescence using a Tekran 

Series 2600 instrument. A total hydrocarbon monitor (flame ionization, VIG Corp), was used 

during the photochemical tests to measure the volatile organic compounds (VOC) content. 

3.4 Verification Schedule 

The 3.02 P-A was verified between June 12 and June 28, 2007. Table 3-3 shows the dates of 

activities relevant to the 3.02 P-A verification. 

Table 3-3. Test Activities During the Optec 3.02 P-A Verification Test 

Date Test Activity

May 7 Optec 3.02 P-A arrive at Battelle 

May 22 Installation of 3.02 P-A into test set up 

June 12 Transfer Standard Performance Audit 

June 13 Ozone Challenge High Humidity 

June 14 Ozone Challenge Low Humidity 

June 20 Interferent Test Low Humidity 

June 22 Interferent Test High Humidity 

June 22-27 Ambient Monitoring 

June 27 Photochemical Test High Concentration 

June 28 Photochemical Test Low Concentration 

June 28 End Testing 
9 

Chapter 4 

Quality Assurance/Quality Control 

QA/QC procedures were performed in accordance with the quality management plan (QMP) for 

the AMS Center(4) and the test/QA plan for this verification test.(1) QA/QC procedures and 

results are described below. 

4.1 Equipment Calibrations 

Prior to the start of the environmental chamber tests a multipoint calibration was performed on 

the FEM using the Environics Model 6400 ozone generator and Dasibi 1008 UV 

photometer. The ozone calibration standards were generated in dry zero air. The FEM was also 

calibrated in the same manner at the start of each day before the start of any tests. 

The 3.02 P-A units were calibrated automatically at 10-minute intervals throughout the entire 

test, using their internal ozone sources. This internal calibration was the basis for all 3.02 P-A 

readings. 

The GC/MSD and mercury fluorescence instruments were calibrated prior to analyses and a 

minimum of a one point calibration was performed on each analysis day. 

4.2 Audits 

Three types of audits were performed during the verification test: a performance evaluation (PE) 

audit of the ozone standard used in testing, a technical systems audit (TSA) of the verification 

test procedures, and a data quality audit. Audit procedures are described further below. 

4.2.1 Performance Evaluation Audit 

A PE audit was conducted on June 12, 2007 to establish the traceability of the Battelle-owned 

Dasibi 1008 UV photometer relative to the standard photometer owned by the Ohio 

Environmental Protection Agency (OEPA), which was also a Dasibi 1008 UV photometer, and 

which is traceable to the primary ozone standard reference photometer located at EPA Region 5, 

Chicago, Illinois. In the PE audit, simultaneous measurements were made from a range of zero 

to 400 ppbv with the Battelle-owned and OEPA photometers using Battelle’s Environics Model 

6400 ozone generator as the ozone source. The results of the audit are provided in Figure 4-1, in 

the form of a linear regression of the Battelle photometer response against the OEPA photometer 

response corrected to match the EPA Region 5 reference photometer. Figure 4-1 shows close 
10 

agreement of the results, with the linear regression showing Battelle O3= 0.9923 (EPA Region 5 

O3) -0.7628 ppbv, with a coefficient of determination (r2) of 1.0. Ozone concentrations delivered 

in testing were determined using Battelle’s photometer, and corrected to the EPA Region 5 

standard using this equation. 

y = 0.9923x - 0.7628

R2

 = 1

0

100

200

300

400

500

0 100 200 300 400 500

Region 5 Photometer O3, ppbv

Battelle Photometer 

O3, ppbv

Figure 4-1. Performance Audit of Battelle’s Dasibi 1008 UV Photometer. 

4.2.2 Technical Systems Audit 

A TSA was conducted by Battelle’s AMS Center Quality Manager during testing on June 22, 

2007. Observations and findings from this audit were documented and submitted to the Battelle 

Verification Test Coordinator for response. No major findings were noted. All minor findings 

were documented, and all required corrective actions were taken. The records concerning the 

TSA are permanently stored with the Battelle Quality Manager. EPA’s ETV QA Officer also 

conducted a TSA on June 14, 2007. No adverse findings were reported from that audit. 

4.2.3 Audit of Data Quality 

Battelle’s Quality Manager traced the test data from the initial acquisition, through reduction and 

statistical analysis, to final reporting to ensure the integrity of the reported results. All 

calculations performed on the data undergoing the audit were checked during the technical 

review process. 

4.3 QA/QC Reporting 

Each audit was documented in accordance with Sections 3.3.4 and 3.3.5 of the QMP for the ETV 

AMS Center.(4) Once the audit report was prepared, the Battelle Verification Test Coordinator 

ensured that a response was provided for each adverse finding or potential problem and 

implemented any necessary follow-up corrective action. The Battelle Quality Manager ensured 

that follow-up corrective action was taken. The results of the TSA were sent to the EPA. 
11 

4.4 Data Review 

Records generated in the verification test received a one-over-one review before these records 

were used to calculate, evaluate, or report verification results. Data were reviewed by a Battelle 

technical staff member involved in the verification test. The person performing the review added 

his/her initials and the date to a hard copy of the record being reviewed. 
12 

Chapter 5 

Statistical Methods 

The statistical methods in this chapter were used to verify the performance parameters listed in 

Section 3.1. 

5.1 Accuracy 

The accuracy of the 3.02 P-A, with respect to either delivered ozone standard concentrations or 

simultaneous FEM readings, was assessed as a percentage recovery (%R), using Equation 1: 

1% ×100 ⎥

⎦

⎤ ⎢

⎣

⎡ ⎟

⎠

⎞ ⎜

⎝

⎛ − +=

X

XY R

(1) 

Where Y is the 3.02 P-A reading and X is the delivered ozone standard concentration, or the 

FEM reading in simultaneous monitoring with the FEM and the 3.02 P-A. The average, and 

range (minimum, and maximum) %R values are reported for each assessment of accuracy. 

5.2 Linearity 

Linearity was assessed using the same 3.02 P-A and FEM data used to assess accuracy, by a 

linear regression of the FEM ozone concentration (independent variable) and the 3.02 P-A 

reading (dependent variable). Linearity was expressed in terms of slope, intercept, and r2

. 

5.3 Interference Effects 

The interference effects of the 3.02 P-A were illustrated by comparison of the response of the 

3.02 P-A when challenged with each chemical interferent. The interference effects were 

considered separately for each of the three sets of interferent tests. Quantitative interference 

effects were calculated as a percent relative response (%RR) to the interferent for the two tests in 

which chemical interferents were added to the test chamber, i.e.: 

100

ppbv tinterferen

responseOppbv RR% 3

×⎟

⎟

⎠

⎞

⎜

⎜

⎝

⎛ = (2) 
13 

5.4 Comparability 

Comparability between the 3.02 P-A results and the FEM analyzer results was illustrated by 

graphing the data for visual comparison and assessed by linear regressions using the FEM 

readings as the independent variable and results from the 3.02 P-A as the dependent variable. 

Linearity was expressed in terms of slope, intercept, and r2

.

 This calculation was done for the 

photochemical ozone chamber tests described in Table 3-2, and for the period of ambient air 

monitoring. Thus comparability was assessed using complex pollutant mixtures, either prepared 

in the test chamber or naturally present in ambient air. The data from these tests are not the same 

as those used to assess accuracy or linearity (Sections 5.1 and 5.2). Comparability calculations 

on the photochemical chamber tests were based on minute-by-minute average data, whereas 

these calculations on the ambient data were based on the hourly average values. Comparability 

was calculated in this way for each of the 3.02 P-A units, relative to the FEM. 

Comparability of the 3.02 P-A to the FEM in the photochemical tests and ambient monitoring 

was also calculated in terms of relative percent difference (RPD), where 

100

FEM

FEM -)A-P (3.02 RPD avg

avg avg ⎟ ×

⎠

⎞ ⎜

⎝

⎛ = (3) 

and 3.02 P-Aavg and FEMavg represent corresponding readings from the two types of monitors, 

i.e., short-term averages in the photochemical tests and hourly averages in the ambient 

monitoring. The RPD is reported at the mean, maximum, and minimum value of the FEM 

readings within each data set. This calculation of RPD was conducted only for the 3.02 P-A unit 

operated normally (i.e., without the added Nafion tube). 

5.5 Data Completeness 

Data completeness was calculated as the percentage of the total possible data return that was 

achieved by the 3.02 P-A over the entire testing period. This calculation used the total hours of 

data recorded divided by the total hours of data in the entire testing period. Testing began on 

June 12 and ended on June 28, 2007, and both 3.02 P-A units operated continuously throughout 

this time, though test procedures did not occupy that entire time. For this calculation, no 

distinction was made between data recorded during calibration or zeroing, or in performance of 

linearity, interference effects, photochemical testing, or ambient monitoring. The causes of any 

substantial incompleteness of data were established from operator observations or vendor 

records. 
14 

Chapter 6 

Test Results 

The results of the verification test of the Optec 3.02 P-A are presented in this section. As noted 

in Section 4.2.1, a correction factor based on the results of the performance evaluation audit and 

the equation in Figure 4-1 was applied to all reference ozone data before the following data 

comparisons were made. Results are presented in this chapter for both units of the 3.02 P-A. It 

must be stressed that the Nafion humidification tube was not optimized for use with the 3.02 PA, but was used on one unit solely to explore whether humidity and humidity control affected 

3.02 P-A response. In all cases results for the 3.02 P-A unit operated normally (i.e., without a 

Nafion tube) are the primary result, and are distinguished from the results of the unit operated 

with an added Nafion humidification tube. 

6.1 Accuracy 

The accuracy of the 3.02 P-A with respect to the ozone standard concentrations was calculated 

using Equation 1 in Chapter 5. Table 6-1 lists the 3.02 P-A results when multi-level ozone 

challenges were delivered to the analyzers in clean dry air from the Environics 6400. The 

average, maximum, and minimum values of percentage recovery are listed. These data were 

obtained from all 3.02 P-A readings in the daily checks performed each day of testing. The 

actual ozone output of the Environics 6400 is shown in the first column of Table 6-1, as 

determined during the PE audit (Section 4.2.1) at nominal ozone settings of 300, 250, 200, and 

100 ppbv respectively. 

Table 6-1. Percent Recoveries Relative to Ozone Standard Concentrations 

Concentration 

ppbv 

N 

Readings 3.02 P-A 

Average 

%R 

Minimum

%R 

Maximum 

%R 

Optec wouta 88.3 88.5 88.2 

289 98 Optec w/Nafb 84.3 65.1 89.5 

Optec wout 85.9 53.2 94.5 

242 51 Optec w/Naf 89.2 80.1 106.6 

Optec wout 85.4 79.0 92.7 

194 169 Optec w/Naf 69.8 61.8 86.7 

Optec wout 107.7 105.8 108.6 

98 10 Optec w/Naf 81.0 80.5 81.4 

a. Optec 3.02 P-A operated without Nafion tube. 

b. Optec 3.02 P-A operated with Nafion tube. 
15 

Table 6-1 shows that the average %R value for the Optec 3.02 P-A analyzer operated normally 

(i.e., without the additional Nafion humidity equilibration tube) was about 85 to 88 %, except for 

the few readings at a delivered concentration of 98 ppbv, for which %R was over 100%. The 

average %R values for the 3.02 P-A with the Nafion tube ranged more widely, from about 70 to 

89%. Note that the ozone standards delivered from the Environics 6400 were in dry zero air (RH 

of 5% or less), and that this RH is below the recommended lower RH limit (15% RH) for 

continuous operation of the Optec 3.02 P-A analyzer. In this case the addition of the Nafion 

humidity equilibration system did not appreciably improve the performance of the 3.02 P-A with 

ozone in dry air; however, the Nafion system was designed for sample flows about 1 liter per 

minute and humidity equilibration of the Optec 3.02 P-A was probably incomplete at the sample 

flow rate of approximately 1.8 liter per minute. 

Accuracy of the 3.02 P-A was also evaluated by comparison to FEM readings obtained 

simultaneously in monitoring of ozone in dry and humid zero air. The calculation of accuracy 

was done using Equation 1 in Chapter 5. Tables 6-2 and 6-3 show those accuracy results in 

terms of the average, maximum, and minimum %R for the ozone chamber tests conducted on 

June 13 and 14, 2007, at high and low RH, respectively. For these tests ozone was added to the 

chamber by brief injections from a high concentration source, and the ozone concentration was 

determined by the average response of the FEM over a series of 10 stable data points. The 

simultaneous 3.02 P-A readings were similarly determined as the average of 10 successive stable 

readings. 

Table 6-2. Percent Recoveries of Ozone from High Humidity (70 to 80% RH) Chamber 

Tests on June 13, 2007 

Concentration 

(ppbv) 3.02 P-A 

Average

%R 

Minimum

%R 

Maximum 

%R 

Optec wouta 93.9 92.7 95.0 

257 Optec w/Nafb 94.9 93.7 96.1 

Optec wout 95.2 93.5 97.0 

223 Optec w/Naf 99.1 92.8 101.5 

Optec wout 94.0 92.8 96.2 

172 Optec w/Naf 96.7 95.0 97.3 

Optec wout 93.2 92.6 94.3 

108 Optec w/Naf 110.3 107.3 113.3 

Optec wout 109.9 108.5 111.5 

51 Optec w/Naf 105.4 103.9 107.2 

a. Optec 3.02 P-A operated without Nafion tube. 

b. Optec 3.02 P-A operated with Nafion tube. 
16 

Table 6-3. Percent Recoveries of Ozone from Low Humidity (<5% RH) Chamber Tests on 

June 14, 2007 

Concentration 

(ppbv) 3.02 P-A 

Average

%R 

Minimum

%R 

Maximum 

%R 

Optec wouta 84.9 84.1 85.7 

260 Optec w/Nafb 70.2 69.5 71.1 

Optec wout 83.8 83.3 84.1 

206 Optec w/Naf 74.5 72.7 81.2 

Optec wout 83.6 83.4 83.9 

163 Optec w/Naf 73.1 72.3 73.9 

Optec wout 83.4 83.2 83.7 

119 Optec w/Naf 73.9 73.3 74.2 

Optec wout 88.3 87.4 90.2 

69 Optec w/Naf 78.1 76.5 87.5 

a. Optec 3.02 P-A operated without Nafion tube. 

b. Optec 3.02 P-A operated with Nafion tube. 

Table 6-2 shows that the average %R value for the 3.02 P-A without the Nafion tube was about 

93 to 95%, when sampling ozone in humid air from the test chamber, except for a %R value of 

about 110% at the lowest ozone concentration The corresponding %R for the 3.02 P-A with the 

Nafion tube was 95 to 99% at the higher ozone levels, with values of 105 to 110% at the lowest 

two ozone concentrations. 

Table 6-3 shows that the average %R value for the 3.02 P-A without the Nafion tube was about 

83 to 88%, when sampling ozone in dry air from the test chamber. The corresponding %R for 

the 3.02 P-A with the Nafion tube was lower, at 70 to 78%. 

These results show that the 3.02 P-A exhibited higher %R values with ozone in humid air than in 

dry air, which is consistent with the recommendation by Optec that the analyzer not operate 

continuously on air of RH less than about 15%. Values of %R near 100% were observed both 

with and without the added Nafion tube when sampling humid air, whereas %R values were 

much lower both with and without the Nafion when sampling dry air. These results suggest that 

the addition of the Nafion tube does not improve the %R results for the 3.02 P-A. It is 

noteworthy that in routine ambient monitoring at standard compliance network sites, it is 

mandatory to produce ozone calibration mixtures in clean dry air. 

6.2 Linearity 

The linearity of the 3.02 P-A was evaluated using the data from the chamber ozone tests at both 

low (< 5%) and high (70-80%) RH. Figure 6-1 shows the results from the high humidity 

chamber test on June 13, 2007. The responses of the 3.02 P-A with and without the Nafion tube 

are shown in relation to the delivered ozone as determined by the FEM. Shown in the figure are 

the slope, intercept, and r2

 of the linear fit for each 3.02 P-A unit. 
17 

y = 0.9176x + 11.985

R2

 = 0.9931

y = 0.9138x + 6.2057

R2

 = 0.9978

0.0

50.0

100.0

150.0

200.0

250.0

300.0

40.0 90.0 140.0 190.0 240.0 290.0

FEM ozone (ppb)

3.02 P-A ozoe (ppb)

Optec w/Naf Optec wout Optec with Naf Optec wout

Optec without Nafion 

Optec with Nafion 

Figure 6-1. Linearity of 3.02 P-A Response to Ozone in Chamber at High Humidity.

Figure 6-2 shows the results from the low humidity chamber test on June 14, 2007. The 

responses of the 3.02 P-A with and without the Nafion tube are shown in relation to the delivered 

ozone as determined by the FEM. Shown in the figure are the slope, intercept and r2

 of the linear 

fit for each 3.02 P-A unit. 

y = 0.6876x + 7.0449

R2

 = 0.9928

y = 0.8378x + 1.0399

R2

 = 0.999

0.0

50.0

100.0

150.0

200.0

250.0

50.0 100.0 150.0 200.0 250.0 300.0

FEM ozone (ppb)

3.02 P-A ozone (ppb)

Optec with Nafion Optec wout Naf Optec with Nafion Optec wout Naf

Optec without Nafion 

Optec with Nafion 

Figure 6-2. Linearity of 3.02 P-A Response to Ozone in Chamber at Low Humidity. 
18 

The linearity results in Figures 6-1 and 6-2 demonstrate linear response by both 3.02 P-A units, 

but confirm the results shown for %R in Section 6.1, in that the linear regression slopes are much 

closer to 1.0 when sampling humid air than when sampling dry air. The degradation of 

performance caused by the added Nafion tube when sampling dry air is evident in Figure 6-2, as 

it was in Table 6-3 (Section 6.1). 

6.3 Interference Effects 

The effect of humidity as an interferent is shown in the preceding sections 6.1 and 6.2. Low 

humidity (< 5% RH) clearly degrades the performance of the 3.02 P-A. As noted above, this RH 

level is below that recommended by the vendor for continuous operation of the 3.02 P-A. 

The responses of the two 3.02 P-A units to the interferents in Test 1 are illustrated in Figure 6-3. 

This test was conducted on June 20, 2007 with low humidity (< 5%) in the chamber. The 

interferents are noted as to the time they were injected into the chamber. 

0.0

0.5

1.0

1.5

2.0

2.5

3.0

10:12:00 10:40:48 11:09:36 11:38:24 12:07:12 12:36:00 13:04:48 13:33:36 14:02:24 14:31:12

Time

3.02 P-A response (ppb)

Optec w/ Nafion Optec wout Naf

Add 6.1 ppb o-nitrophenol

Add 10.9 ppb napthalene

Add 7.3 ppb p-tolualdehyde Add 630 ng/m3 

mercury

Figure 6-3. 3.02 P-A Response to Interferents in Chamber at Low Humidity. 

Figure 6-3 shows that the zero air ozone readings of the 3.02 P-A unit operated normally 

(without the added Nafion tube) were about 0.6 ppbv, and showed no significant changes 

associated with the successive additions of the four potential interferents. The readings of the 

3.02 P-A operated with the added Nafion were higher (about 2.3 ppbv), but also showed no 

trends associated with the additions of the interferents. Thus the %RR values for the 3.02 P-A 

for these four interferents in dry air were all zero. 
19 

Figure 6-4 illustrates the responses of the two 3.02 P-A units to the interferents injected into the 

chamber in Test 2, conducted on June 22 with high (70-80 %) RH in the chamber. Figure 6-4 

shows that the zero air readings of the 3.02 P-A unit without the Nafion tube were about 0.6 to 

0.7 ppbv, whereas those of the unit with the Nafion tube were slightly higher and more variable, 

ranging from 0.5 to 1.2 ppbv. Readings affected by the analyzer’s automatic calibration at 10-

minute intervals are evident in the data for the 3.02 P-A operated without the Nafion. Although 

there is scatter in the data, there is no clear trend associated with the addition of the potential 

interferents. Thus the %RR values for the 3.02 P-A for these four interferents in humidified air 

were all zero. 

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

10:19:12 10:33:36 10:48:00 11:02:24 11:16:48 11:31:12 11:45:36 12:00:00 12:14:24 12:28:48

Time

3.02 P-A response (ppb)

Optec w/ Nafion Optec wout Naf

Add 10 ppb o-nitrophenol Add 11 ppb 

napthalene Add 15 ppb 

p-tolualdehyde Add 54 ng/m3

 mercury

Figure 6-4. 3.02 P-A Response to Interferents in Chamber at High Humidity.

Two photochemical tests were conducted with the addition of a 17 component hydrocarbon 

mixture (both gas and liquid components) and NO2. These tests were performed at a humidity of 

approximately 80%. Figure 6-5 shows the response of the two 3.02 P-A units over time while 

these ozone precursors were injected into the environmental chamber on June 27, 2007 (before 

the chamber lights were turned on to begin ozone production). The hydrocarbon concentration 

injected into the chamber was approximately 2,370 ppbC (593 ppbv) and the NO2 concentration 

was 200 ppbv. 

Figure 6-5 shows that in this test the readings of the 3.02 P-A operated with no Nafion tube were 

about 0.6 ppbv, and those of the other unit were about 3.5 to 4.5 ppbv. Slight shifts of the 

readings can be seen, associated with the analyzers’ autocalibration at 10-minute intervals, and 

the readings of the 3.02 P-A operated with the Nafion tube exhibit some drift. However, there is 

no clear effect on the readings associated with the introduction of any of the ozone precursors. 

The 3.02 P-A unit operated normally (i.e., without the Nafion tube) showed no more than 0.1 

ppbv variation in readings throughout the precursor injections. 
20 

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50

5.00

10:29:17 10:36:29 10:43:41 10:50:53 10:58:05 11:05:17 11:12:29

Time 

3.02 P-A response (ppb)

Optec with Nafion Optec without Naf

Add multiple injections

of light hydrocarbons Add NO2 Add liquid hydrocarbon

Figure 6-5. Photochemical Interferent Test with High Precursor Concentrations.

Figure 6-6 illustrates the response of the two 3.02 P-A units over time while the interferents were 

injected into the environmental chamber on June 28, 2007. The hydrocarbon concentration 

injected into the chamber was approximately 670 ppbC (167 ppbv) and the NO2 concentration 

was 55 ppbv. Also shown in Figure 6-6 is a similar result to that of Figure 6-5, in that the 

readings of the two 3.02 P-A units are unaffected by the addition of the ozone precursors. Thus 

the %RR values for these ozone precursors with the 3.02 P-A appear to be zero. 

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50

10:03:22 10:06:14 10:09:07 10:12:00 10:14:53 10:17:46 10:20:38 10:23:31 10:26:24

Time

3.02 P-A response (ppb)

Optec with Nafion Optec without Naf

Add multiple injections of light hydrocarbons Add NO2 Add liquid hydrocarbon

Figure 6-6. Photochemical Interferent Test with Low Precursor Concentrations.
21 

6.4 Comparability 

Linear regression was used to compare the response of the two 3.02 P-A units to that of the FEM 

during the photochemical tests and ambient monitoring. Figure 6-7 shows the readings of the 

3.02 P-A both with and without the Nafion tube in comparison to the response of the FEM 

during the photochemical ozone test with high precursor concentrations. Figure 6-7 covers the 

time following the injection of precursors into the environmental chamber while ozone was 

being produced. The injections included approximately 2,370 ppbC (593 ppbv) of hydrocarbons 

and 200 ppbv NO2. 

0.00

20.00

40.00

60.00

80.00

100.00

120.00

140.00

10:48:00 12:00:00 13:12:00 14:24:00 15:36:00

Time

Ozone ppbv

FEM Optec with Nafion Optec wout Nafion

Optec with Nafion 

Optec without Nafion 

FEM

Figure 6-7. 3.02 P-A Response to Ozone During Photochemical Test with 

High Precursor Concentrations. 

Figure 6-8 shows the linear regression results for this photochemical chamber test. Shown in the 

figure are the slope, intercept, and r2

 of 3.02 P-A response relative to FEM response. Figure 6-8 

shows that both 3.02 P-A units provided response that was linearly correlated with that of the 

FEM in this photochemical test (e.g., both r2 values exceeded 0.998), but with slopes that were 

substantially lower than 1.0. The 3.02 P-A operated normally (i.e., without the added Nafion 

tube) had a slope of 0.81 relative to the FEM, whereas the unit operated with the Nafion had a 

slope of only 0.63. In this test the chamber RH was near 80%, so the relatively low regression 

slopes cannot be attributed to the effect of lower humidity reported in previous sections. 

In this test the RPD of the 3.02 P-A (operated without the Nafion tube) was -14.2%, -16.0%, and 

-3.5% relative to the FEM at the mean, maximum, and minimum ozone concentrations, 

respectively. 
22 

y = 0.6309x + 8.2231

R2 = 0.9988

y = 0.8146x + 4.0542

R2

 = 0.9985

0.00

20.00

40.00

60.00

80.00

100.00

120.00

0.00 20.00 40.00 60.00 80.00 100.00 120.00

FEM response (ppb)

3.02 P-A response (ppb)

Optec with Nafion Optec wout Nafion Linear (Optec with Nafion) Linear (Optec wout Nafion)

Optec without Nafion 

Optec with Nafion 

Figure 6-8. Photochemical Ozone Comparison with High Precursor Concentrations. 

Figure 6-9 shows the readings of the two 3.02 P-A units in comparison to the response of the 

FEM in the photochemical test with lower precursor concentrations. The data depicted are from 

the time following the injection of precursors into the environmental chamber while ozone was 

being produced. The injections were of approximately 670 ppbC (167 ppbv) of hydrocarbons 

and 55 ppbv of NO2. Occasional offsets are evident in the two 3.02 P-A traces, due to the 

automated internal calibrations performed by these units. 

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

10:19:12 10:48:00 11:16:48 11:45:36 12:14:24 12:43:12 13:12:00 13:40:48 14:09:36 14:38:24

Time

Ozone ppbv

FEM Optec with Nafion Optec wout Nafion

FEM

Optec without 

Nafion 

Optec with Nafion 

Figure 6-9. 3.02 P-A Response to Ozone During Photochemical Test with 

Low Precursor Concentrations. 
23 

Figure 6-10 shows the linear regression results from this photochemical chamber test. Shown in 

the figure are the slope, intercept, and r2

 of 3.02 P-A response relative to FEM response. Figure 

6-10 shows that both 3.02 P-A units provided response that was linearly correlated with that of 

the FEM in this photochemical test (e.g., both r2 values exceeded 0.99). In this test the slope of 

the regression for the 3.02 P-A operated without the Nafion tube was 0.94, close to the optimum 

value of 1.0. However the 3.02 P-A unit operated with the Nafion tube had a regression slope of 

only 0.58 relative to the FEM readings. These results indicate that at less severe hydrocarbon and 

NO2 levels, the 3.02 P-A readings matched those of the FEM relatively closely, but that the 

addition of the Nafion tube degraded the performance of the 3.02 P-A. 

In this test the RPD of the 3.02 P-A (operated without the Nafion tube) was -8.0%, -7.4%, and 

0.2% relative to the FEM at the mean, maximum, and minimum ozone concentrations, 

respectively. 

y = 0.5772x + 4.406

R2

 = 0.9948

y = 0.9414x - 1.2358

R2

 = 0.9974

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00

FEM response (ppb)

3.02 P-A response (ppb)

Optec with Nafion Optec without Nafion Linear (Optec with Nafion) Linear (Optec without Nafion)

Optec without Nafion 

Optec with Nafion 

Figure 6-10 Photochemical Ozone Comparison with Low Precursor Concentrations.

Figure 6-11 shows the response of the two 3.02 P-A units and the FEM during the ambient 

monitoring period of about four and one-half days. The hourly averages are shown. Close 

correspondence is seen of the temporal pattern of readings from the three monitors. In addition, 

the readings from the 3.02 P-A operated normally closely match those of the FEM in most of the 

period, at ozone levels from less than 10 to nearly 80 ppbv. The readings from the 3.02 P-A with 

the added Nafion tube do not track those of the FEM as closely. 
24 

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

6/22/07

12:00

6/23/07

0:00

6/23/07

12:00

6/24/07

0:00

6/24/07

12:00

6/25/07

0:00

6/25/07

12:00

6/26/07

0:00

6/26/07

12:00

6/27/07

0:00

6/27/07

12:00

6/28/07

0:00

Date and Time

Ozone ppb

49C Opt Naf Opt w/o

Figure 6-11. 3.02 P-A and FEM Ambient Monitoring Results. 

The results of the linear regression of ambient monitoring data are shown in Figure 6-12, where 

the response of each 3.02 P-A unit is compared to the response of the FEM. Shown in the figure 

are the slope, intercept, and r2

 of the linear regression for each 3.02 P-A unit. 

Figure 6-12 shows that the regression of data from the 3.02 P-A operated normally against the 

FEM data gives a slope of 0.998, an intercept of 0.19 ppbv, and an r2 value of 0.9954. These 

results indicate an extremely close correspondence of the 3.02 P-A data to the FEM data in the 

ambient monitoring period. The data from the 3.02 P-A operated with the added Nafion tube do 

not agree as well with the FEM data, exhibiting a slope of 0.949, an intercept of 1.6 ppbv, and an 

r

2

 of 0.93. Several data points diverge markedly from the regression line for this unit. 

In ambient monitoring the RPD of the 3.02 P-A (operated without the Nafion tube) was 0.3%, 

-0.4%, and -10.7% relative to the FEM at the mean, maximum, and minimum ozone 

concentrations, respectively. 

The agreement of the Optec 3.02 P-A with the FEM was closer in the ambient monitoring than in 

either photochemical chamber test; this difference was particularly pronounced for the unit 

operating with the added Nafion tube. Although detailed air quality measurements were not 

made in the ambient monitoring period, it is likely that the ambient levels of co-pollutants were 

lower in ambient air than in either of the photochemical chamber tests. Thus the ambient results 

continue the trend of better agreement between the FEM and 3.02 P-A with lower concentrations 

of ozone precursors. 
25 

y = 0.9486x + 1.6496

R2

 = 0.9322

y = 0.9975x + 0.1929

R2

 = 0.9954

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00

FEM repsonse (ppb)

Optec Response (ppb)

Opt Naf Opt w/o Linear (Opt Naf) Linear (Opt w/o)

Optec without Nafion 

Optec with Nafion 

Figure 6-12. Linear Regression of 3.02 P-A and FEM Data During Ambient Monitoring.

6.5 Data Completeness 

The total duration of the verification test was from June 12 to June 28, 2007, a period of 16 days, 

and the two Optec units each operated without problems for that entire period. Testing only 

occurred on 6 of those days. Each 3.02 P-A unit was operational for a total of 6.07 days or 100% 

of the testing time. Table 6-4 shows a breakdown of the operating activities of the 3.02 P-A units 

over those test days. 

Table 6-4 shows that the 6.07 days of testing of the 3.02 P-A consisted of an approximate total of 

0.27 days of calibration, zeroing, and other programmed QC procedures; 4.6 days conducting the 

ambient air monitoring; and a combined total of 1.2 days of chamber testing. Although the 

combined total of hours of testing was 6.07 days, the 3.02 P-A units were running continuously 

throughout June 12 to June 28. 
26 

Table 6-4. Optec 3.02 P-A Testing Activities June 12 to 28, 2007 

Activity 

Number of Measurement 

Intervalsa Days 

Percent of 

Time 

Ambient Air Monitoring 6,668 4.6 75.8% 

 Chamber Testing 1,687 1.2 19.7% 

 

 Calibration/Zeroing/Other Checks 393 0.27 4.5% 

Totals 8,748 6.07 100% 

a: Each measurement was a one-minute average. 

6.6 Operational Factors 

The Optec 3.02 P-A used only electrical power with no other consumables. The 3.02 P-A 

required 220 V power so a converter to 120 V was used for testing. 

Once the 3.02 P-A was turned on, it took approximately 1 hour for the 3.02 P-A to warm up and 

stabilize. The 3.02 P-A has a nominal monitoring range up to 250 ppbv. When the analyzer 

detects ozone above 250 ppbv a repeated alarm is sounded indicating that the analyzer is over its 

programmed detection range. During testing, there were occasions when ozone greater than 250 

ppbv was delivered to the 3.02 P-A, however the alarm would often not sound until the sampled 

ozone concentration reached a range of 270 to 300 ppbv. 

The 3.02 P-A is programmed to internally calibrate and self adjust every 10 minutes. The 

outcome of the internal calibration was often apparent in the data, when the values would 

noticeably shift every 10 minutes. The ozone reading was displayed on the panel of the 3.02 P-A 

in parts per million by volume (ppmv). However, the electronic data output is programmed to 

report readings in micrograms per cubic meter (μg/m3

) at 21 degrees Celsius (oC). The 

electronic data used for reporting were corrected to ppbv units after testing using the actual 

laboratory temperature and pressure. 

No repair was needed during the test and the need for vendor assistance was minimal in the 

operation of the 3.02 P-A. The instrument manual was provided by the vendor, translated from 

the original Russian to English. Although the 3.02 P-A is easy to operate, the translation of the 

manual from Russian to English was difficult to understand in some areas. Overall the 3.02 

P-A operated as expected and required no maintenance during testing. The estimated price of the 

base model analyzer is $5,000. 
27 

Chapter 7 

Performance Summary 

The performance of the Optec 3.02 P-A ozone analyzer was verified by a series of tests that 

included comparison to the EPA-established UV-absorption FEM for ozone. The particular 

FEM instrument used as the reference analyzer was a Thermo Environmental Model 49C (FEM 

EQOA-0880-047). 

The Optec 3.02 P-A ozone analyzer averaged a %R of 85.4 to 107.7% over a concentration range 

of 98 to 289 ppbv when ozone was delivered to the analyzer in dry air from the Environics 

Model 6400. When ozone was added to clean air in the test chamber in stepwise concentrations 

of 51 to 257 ppbv at high humidity (≈ 80% RH), the average %R was 93.2 to 110% relative to 

the response of the FEM. In dry test conditions (< 5% RH) at concentrations of 69 to 260 ppbv, 

the average %R of the 3.02 P-A was 83.4 to 88.3% relative to the response of the FEM. Thus the 

%R of the 3.02 P-A during the high humidity ozone test was higher than its %R during the low 

humidity chamber test. 

The linearity of the 3.02 P-A under humidified (≈80% RH) chamber test conditions showed a 

slope of 0.914, an intercept of 6.2 ppbv, and an r2

 value of 0.998 over a concentration range of 

51 to 257 ppbv. The linearity of the 3.02 P-A in low humidity (<5% RH) chamber conditions 

showed a slope of 0.838, an intercept of 1.0 ppbv, and an r2

 value of 0.999 over a concentration 

range of 69 to 260 ppbv. 

The interferents tested in the environmental chamber caused no response to the 3.02 P-A. The 

analyzer readings remained stable and under 1 ppbv when the organic and mercury vapor 

interferents were added to the chamber and also when the 17-component hydrocarbon mixture 

and NO2 were added. 

The comparison between the 3.02 P-A and FEM during the photochemical test with high 

precursor concentrations showed a slope of 0.815, an intercept of 4.1 ppbv, and an r2

 value of 

0.999 over an ozone concentration range of 20 to 130 ppbv. The photochemical test with lower 

precursor concentrations showed a slope of 0.941, an intercept of -1.2 ppbv, and an r2

 value of 

0.997 over an ozone concentration range of 20 to 80 ppbv. The ambient monitoring comparison 

of the 3.02 P-A and FEM readings over the four day sampling period showed a slope of 0.998, 

an intercept of 0.19 ppbv, and an r2 value of 0.995 over an ozone concentration range of 3 to 80 

ppbv. The RPD of the 3.02 P-A relative to the FEM was -14.2%, -8.0%, and 0.3% at the average 

ozone concentration in the photochemical/high precursors, photochemical/low precursors, and 

ambient air comparisons, respectively. 
28 

The performance of a 3.02 P-A unit operated with an added Nafion humidity equilibration tube 

was reduced in nearly all performance measures, relative to that reported above for the 3.02 P-A 

unit operated normally. The responses of the 3.02 P-A unit with the Nafion tube were reduced in 

chamber tests in comparison with the FEM, and that unit agreed less well with the FEM during 

ambient monitoring. 

Data completeness for the 3.02 P-A was 100%, based on its operation over a total of 6.07 test 

days during a 16 day operational period. Considering only those 6.07 days on which the 

3.02 P-A was tested, there were 4.6 days of ambient monitoring, 0.27 days spent in calibration/ 

zeroing/other instrument checks, and 1.2 days total spent conducting measurements in the 

environmental chamber. Both 3.02 P-A units also operated without problems throughout the 16-

day period in which those 6 test days occurred. 

 

The Optec 3.02 P-A was operated on a 220 V to 120 V converter during testing. When the 3.02 

P-A was turned on, it took approximately 1 hour for the 3.02 P-A to stabilize and it then 

remained functional throughout the entire test period. A repeated alarm sounded only when the 

3.02 P-A was reading ozone concentrations over range. The analyzer calibrated itself internally 

every ten minutes. The ozone measurements were displayed on the front panel in ppmv. No 

repair was needed during the test and the need for vendor assistance was minimal. Manuals were 

provided and although translated from Russian to English, the manuals were somewhat difficult 

to understand. 

The estimated price of the base model Optec 3.02 P-A analyzer is $5,000. 
29 

Chapter 8 

References 

1. Test/QA Plan for Verification of Chemiluminescent Ozone Analyzer, Battelle, Columbus, 

Ohio, June 6, 2007. 

2. List of Designated Reference and Equivalent Methods, U.S. Environmental Protection 

Agency, Office of Research and Development, National Exposure Research Laboratory, 

Issue Date: November 13, 2007, available at http://www.epa.gov/ttn/amtic/criteria.html. 

3. Operation Manual for the Optec 3.02 P-A Chemiluminescent Ozone Analyzer, Optec Ltd., 

St. Petersburg, Russia, 2005. 

4. Quality Management Plan (QMP) for the ETV Advanced Monitoring Systems Center, 

Version 6.0, U.S. EPA Environmental Technology Verification Program, Battelle, 

Columbus, Ohio, November 2005.