United States
Environmental Protection
Agency
Environmental Monitoring Systems
Laboratory
Research Triangle Park NC 27711
Research and Development
EPA-600/S4-83-003  Apr. 1983
Project Summary
Performance Test  Results  and
Comparative Data for Designated
Reference and  Equivalent
Methods for Ozone

F. W. Sexton, R. M. Michie, Jr., F. F. McElroy, V. L. Thompson, and J. A. Bowen
  This report summarizes the results
of both laboratory and field tests on
seven commercially available ambient
ozone analyzers to determine their per-
formance, reliability, and operational
peculiarities.
  This Project Summary was developed
by EPA's Environmental Monitoring
Systems Laboratory, Research Triangle
Park. NC, to announce key findings of
the research project that is fully docu-
mented in a separate report of the
same title (see Project Report ordering
information at back).

Introduction
  Under Part 53 of Title 40 of the Code of
Federal Regulations (40 CFR Part 53), the
U.S.  Environmental  Protection Agency
(EPA) designates specific ambient moni-
toring methods and analyzers as reference
or equivalent methods acceptable for use
in National Air Monitoring Stations (NAMS),
State and Local Air Monitoring Stations
(SLAMS), and Prevention  of Significant
Deterioration (PSD)  monitoring.   The
Methods Standardization Branch  (MSB)
of the Environmental Monitoring Systems
Laboratory (EMSL) of Research Triangle
Park, NC, is responsible for EPA's refer-
ence and equivalent method designation
program.  In this capacity, MSB has ac-
quired performance data and other infor-
mation on these methods, most of which
are commercially available analyzer models.
  To summarize this data and make it
available to those who may find it bene-
ficial in selecting analyzers, MSB, with the
assistance of the Research Triangle Insti-
tute, prepared this report on designated
methods for ozone. The data are offered
with  minimum interpretation, leaving
readers to draw their own conclusions.

Types of Tests Conducted
  Two principal types of postdesignation
tests were conducted by MSB.  Phase I
tests were laboratory tests similar to the
predesignation tests required by 40 CFR
Part 53. Phase II tests simulated actual
use conditions and compared simultane-
ously operating analyzers.  Results from
these postdesignation tests provide most
of the data in this report
  The ozone analyzers that were tested
and their respective detection principles
are as follows:
Bendix 8002

MeloyOA 350-2 R

Beckman 950-A

Monitor Labs
  8410E
McMillan 1100-2

Philips PW 9771

Dasibi 1003-AH
Ozone/ethylene
chemiluminescent
Ozone/ethylene
chemiluminescent
Ozone/ethylene
chemiluminescent
Ozone/ethylene
chemiluminescent
Ozone/ethylene
chemiluminescent
Ozone/rhodamine
B chemiluminescent
Ultraviolet absorption
Phase I Test Description  and
Results
  Phase I laboratory performance  tests
were conducted in accordance with the
same procedures and specifications re-
quired for the applicant's predesignation

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tests, with the exception that fewer trials
(usually fou r) were performed for each test
parameter.   All  calibrations, apparatus,
pollutant standards, test procedures, test
atmospheres, and test documentation were
as specified in40 CFR Part53. (Individual
reports containing more detailed informa-
tion on the Phase I tests for each analyzer
are available from MSB.)
  Analyzers undergoing Phase I tests were
first  set up  and allowed to operate for
several weeks  prior to actual testing.
During this  start-up period, preliminary
calibrations and linearity checks were per-
formed If a failure occurred during testing,
the manufacturer was notified and given
the opportunity to correct the failure.  At
the conclusion of the test all failures and
manufacturer's involvement were included
in routine documentation.  The following
analyzers were  tested during the  stated
periods:
  Meloy OA 350-2 R
  Monitor Labs
    8410E
  Bendix 8002
  Dasibi 1003-AH
  Philips PW9771
  Beckman 950-A
  McMillan  1110-2
May 1977 to
September 1977
November 197 7 to
April 1978
   Phase I tests included output signal noise,
 lower detectable limit (LDL), interference
 equivalent 12 h and 24 h zero drifts, span
 drift at 2096 and at 80% of full scale, lag
 time, rise time, fall time, and precision.
 Results are reported in Table 1. The total
 interferent equivalent, zero drift, and span
 drift data reported are averages of absolute
 values;  all other values  represent the
 arithmetic averages of four repetitions.
  Phase  I tests  indicate that all ozone
analyzers  tested met or exceeded the
performance specifications.

Phase II Test Description  and
Results
  Phase II tests were intended to test the
analyzer in a more or less typical ambient
monitoring configuration where the analyzer s
stability, reliability, general performance,
and operational peculiarities can be ob-
served, recorded, and compared with other
analyzers.  The tests  were conducted
simultaneously on groups of ozone analyzers
over a period of several  months.   All
analyzers  measured  ambient air sampled
from a common manifold.  The ambient
pollutant concentrations were sometimes
augmented with artificially generated pol-
lutant to increase the concentration read-
ings.
  All test analyzers were installed, cali-
brated, operated, and maintained in strict
accordance with the manufacturer's  in-
struction  manual and  good monitoring
practice.  Analyzers  received a multipoint
calibration initially and once per month
during the test period.  Zero and span
checks were made two or three times per
week Zero adjustments were made only if
the zero response was not within  3% of
full scale response  from nominal;  span
adjustments were made only if the span
(slope of the calibration curve) changed by
more than   7% from nominal.  For this
report, data were collected from strip chart
recorders, reduced by hand, and entered
weekly  into  a  Hewlett-Packard 9821A
Desk Top Computer.  The Phase II tests
were conducted during three periods with
three analyzers per  test  Because there
were seven analyzers to be tested, the
                                                             Bendix 8002 was chosen to run in all
                                                             three tests as a reference,  with the re-
                                                             maining six analyzers segregated in groups
                                                             of two. Phase II test groups and correspon-
                                                             ding dates are listed below.

                                                             Group 1:  Bendix 8002     Test period:
                                                                      Meloy OA 350-2 R September
                                                                      Monitor Labs 8410    1977 to
                                                                                         December
                                                                                             1977
                                                             Group 2: Bendix 8002
                                                                      Philips PW 9771
                                                                      Dasibi 1003-AH
                          Test period:
                           May 1978
                                   to
                          September
                                1978
Group 3: Bendix 8002      Test period:
         McMillian 1100-2 June  1978
         Beckman 950-A            to
                          September
                                1978

  Similar procedures were used for each
analyzer group.  A UV photometer was
used to verify the ozone working standard.
The frequency of calibrations, zero,  and
span checks remained the same. Test data
indicate that the Bendix 8002 was stable
throughout the studies.
  Phase II results indicate that the ozone
analyzers tested are among the most stable
and reliable of continuous air monitoring
analyzers. The comparative data presented
in Table 2 indicate consistently high cor-
relation coefficients of 0.99, mean differ-
ences of < 3 ppb, and standard deviations
of differences of < 3 ppb.
 Table 1.   Phase I Postdesignation Test Results-Designated Ozone Analyzers
Performance
parameters
Noise - 0% URL
Noise - 80% URL
Lower detectable limit
Interferents
H2O
H2S
CO2
Total
Zero drift - 12 h
Zero drift - 24 h
Span drift - 20% URL
Span drift - 80% URL
Lag time
Rise time
Fall time
Precision -20% URL
Precision -80% URL
EPA
specifications
0.005 ppm
0.005 ppm
0.01 ppm

0.02 ppm
0.02 ppm
0.02 ppm

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Statistics
Correlation coefficients
Mean difference, ppb
Standard deviation of
differences, ppb
Number of absolute
differences >20
Bendix
0.99
-0.36
2.47
2
Meloy
0.99
0.49
2.44
4
Beckman
0.99
0.54
2.52
0
Monitor Labs
0.99
0.41
2.10
2
McMillan
0.99
0.66
2.22
0
Philips
0.99
2.63
3.68
0
Dasibi
0.99
-0.11
2.72
0
CSI
Not tested
Not tested
Not tested
Not tested
F.  W. Sexton and R. M. Michie, Jr.  are with the Research Triangle Institute,
  Research Triangle Park, NC 277O9; the EPA authors F. F. McElroy, V.  L.
  Thompson (also the EPA Project Officers, see below), andJ. A. Bowen are with
  the Environmental Monitoring Systems Laboratory, Research Triangle Park, NC
  27711.
The complete report, entitled "Performance Test Results and Comparative Data
  for Designated Reference and Equivalent Methods for Ozone," (Order No. PB
  83-166 686; Cost: $11.50, subject  to change) will be available only from:
        National Technical Information Service
        5285 Port Royal Road
        Springfield. VA 22161
        Telephone: 703-487-4650
The EPA Project Officers can be contacted at:
        Environmental Monitoring Systems Laboratory
        U.S. Environmental Protection Agency
        Research Triangle Park, NC 27711
                  WJ.S. Government Printing Office:  1983-659-017/7029

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United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Postage and
Fees Paid
Environmental
Protection
Agency
EPA 335
Official Business
Penalty for Private Use $300
                  0000320

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