&EPA
•d States
Environmental Protection
Agency
Environmental Monitoring and Support
Laboratory
Research Triangle Park NC 27711
Research and Development
A Summary of the
Interlaboratory
Source Performance
Surveys for EPA
Reference Methods
6 and 7 — 1977
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2 Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL MONITORING series.
This series describes research conducted to develop new or improved methods
and instrumentation for the identification and quantification of environmental
pollutants at the lowest conceivably significant concentrations. It also includes
studies to determine the ambient concentrations of pollutants in the environment
and/or the variance of pollutants as a function of time or meteorological factors.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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A SUMMARY OF THE INTERLABORATORY SOURCE PERFORMANCE SURVEYS
FOR EPA REFERENCE METHODS 6 AND 7 - 1977
by
R. G. Fuerst, R. L. Denny and M. R. Midgett
Quality Assurance Branch
Environmental Monitoring and Support Laboratory
U. S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
ENVIRONMENTAL MONITORING AND SUPPORT LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
RESEARCH TRIANGLE PARK, NORTH CAROLINA 27711
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DISCLAIMER
This report has been reviewed by the Environmental Monitoring and Support
Laboratory, U.S. Environmental Protection Agency, and approved for publication,
Mention of trade names or commercial products does not constitute endorsement
or recommendation for use.
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FOREWORD
Measurement and monitoring research efforts are designed to anticipate
potential environmental problems, to support regulatory actions by developing an
in-depth understanding of the nature and processes that impact health and the
ecology, to provide innovative means of monitoring compliance with regulations
and to evaluate the effectiveness of health and environmental protection efforts
through the monitoring of long-term trends. The Environmental Monitoring and
Support Laboratory, Research Triangle Park, North Carolina, is responsible for
development of: environmental monitoring technology and systems; agency-wide
quality assurance programs for air pollution measurement systems; and technical
support to the Agency's operating functions including the Office of Air, Noise
and Radiation, the Office of Toxic Substances and the Office of Enforcement.
The primary concern of this study was to initiate a nationwide quality
assurance program with which to estimate the analytical and computational
accuracy that could be expected from users of EPA source reference method 6
for sulfur dioxide and method 7 for nitrogen oxides. Statistical analysis
was used to characterize the data.
Thomas R. Mauser
Director
Environmental Monitoring and
Support Laboratory
111
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ABSTRACT
This report summarizes the 1977 results of a stationary source test method
survey program conducted by the Quality Assurance Branch of the Environmental
Monitoring and Support Laboratory, U.S. Environmental Protection Agency. In
this program, quality assurance samples were sent to interested participants
for analysis by EPA Reference Method 6 for sulfur dioxide (SO-) and EPA
Reference Method 7 for nitrogen oxides (NO ). Each participant returned the
analytical results to the Quality Assurance Branch for evaluation; an individual
report was returned to each participant after processing.
This report contains a summary of the survey results for the analytical
portion of these two source test methods.
iv
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CONTENTS
Foreword iji
Abstract iv
Tables vi
Acknowledgments vii
1. Introduction 1
2. Summary 2
3. Recommendations 3
4. Survey Design ....... 4
Survey procedures 4
Prospective participants ............ 4
Preparation and distribution of survey materials
for methods 6 and 7 5
5. Statistical Data Handling 6
6. Discussion of Method 6 Results ............ 7
7. Discussion of Method 7 Results ........ 16
References 24
Appendices
A. S0? data summary 25
B. N(T data summary 38
A
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TABLES
Number Page
1 Method 6 Survey 0577 - Laboratory Distribution 7
2 Method 6 Survey 1177 - Laboratory Distribution 7
3 Method 6 Acceptance Ranges (Survey 0577) 8
4 Method 6 Acceptance Ranges (Survey 1177) 8
5 Method 6 Sample Range Cumulative Distribution ... 9
6 Method 6 Target Range Cumulative Distribution 9
7 Method 6 Survey 0577 - Frequency Distribution 11
8 Method 6 Survey 1177 - Frequency Distribution .... 12
9 Method 6 Survey 0577 - Summary Statistics 13
10 Method 6 Survey 0577 - Summary Statistics
(Outliers Removed) 13
11 Method 6 Survey 1177 - Summary Statistics 14
12 Method 6 Survey 1177 - Summary Statistics
(Outliers Removed) 14
13 Method 7 Survey 0577 - Laboratory Distribution 16
14 Method 7 Survey 1177 - Laboratory Distribution 16
15 Method 7 Acceptance Ranges (Survey 0577) 17
16 Method 7 Acceptance Ranges (Survey 1177) 17
17 Method 7 Sample Range Cumulative Distribution .' 18
18 Method 7 Target Range Cumulative Distribution 18
19 Method 7 Survey 0577 - Frequency Distribution 20
20 Method 7 Survey 1177 - Frequency Distribution . 21
21 Method 7 Survey 0577 - Summary Statistics 22
22 Method 7 Survey 0577 - Summary Statistics
(Outliers Removed) 22
23 Method 7 Survey 1177 - Summary Statistics 23
24 Method 7 Survey 1177 - Summary Statistics
(Outliers Removed) 23
vi
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ACKNOWLEDGMENTS
The authors wish to thank Mr. Michael Osborne, who while a member of the
Quality Assurance Branch staff, helped initiate the source survey program. We
also express thanks to Mr. Steven Atkinson and Ms. Ellen Streib, who analyzed
the survey samples under our Acceptance Testing Program, and the programmers
of the Statistical and Technical Analysis Branch, EMSL, for developing the data
management systems necessary to store and summarize the survey data. In
addition, our appreciation is extended to each of the survey participants.
vii
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SECTION 1
INTRODUCTION
The periodic analysis of a quality control reference sample originating
outside the laboratory in which it is used, should be an integral part of any
laboratory quality assurance program. Therefore, in 1972 the Environmental
Protection Agency (EPA) organized a nationwide performance audit program to
provide consistent audit materials for use with ambient air reference methods.
Since that time, a number of performance audits of laboratories measuring
ambient air pollutants have been conducted (1,2). In 1976, EPA expanded this
program to provide quality assurance materials that could be used to perform
similar performance surveys of stationary source test methods. This latter
program had three main purposes:
• to verify that the analytical parts of the specific reference methods
were being used properly;
• to uncover any laboratory bias in the analytical portion of the test
method; and
• to improve the quality of the measurements being made.
These goals were realized by sending specific performance materials to
interested laboratories for analysis.
In our first two surveys, we chose to examine the analytical part of
Method 6 for sulfur dioxide (S02) and Method 7 for nitrogen oxides (NOX) (3,4).
This report describes the preparation and evaluation of these surveys held in
May and November of 1977.
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SECTION 2
SUMMARY
The quality assurance surveys conducted in 1977 by the Quality Assurance
Branch (QAB) of EPA's Environmental Monitoring and Support Laboratory included
participants from industry, contracting firms, universities, foreign countries,
and governmental agencies.
An average of 120 participants requested samples for the first two surveys
of Method 6 (S02), rfith an average data submission rate of about 69%. The
number of participants requesting samples for the two surveys of Method 7 (NO )
averaged 113, with an average response rate of 58%. This response was judged*
acceptable with respect to earlier EPA ambient air audits.
The first survey for Method 6 (S02) (survey 0577 conducted in May 1977}
reveals that 50% of the participants measured their samples at a 2.15% or less
absolute difference from their true values; in the second survey (survey 1177
conducted in November 1977), this difference was lower at 1.69%.
For Method 7 (NO ), the absolute difference was 15.14% or less for 50% of
the participants in sQrvey 0577, while in survey 1177, the absolute difference
was 7.41% or less. These statistics indicate the pronounced difficulty of
Method 7 for the analyst, relative to Method 6.
Examination of the data generated by the five test samples sent to each
participant for each method indicated that for Method 6 (S0«) 17% of the par-
ticipants in survey 0577 had 2 or less samples correctly measured within the
target range while in survey 1177, 14% were within this range. Method 7
results show that in survey 0577, 42% of the participants had 2 or less
samples correctly measured within the target range while survey 1177 had 25%
within this range. Presently, the sample and target ranges are based on the
results of a collaborative test (5) of Methods 6 and 7, and a titration
specification for Method 6 that is listed in the Federal Register. These
ranges are more adequately defined in Section 5 (Statistical Data Handling).
Fcllow-up surveys will examine trends in the analytical abilities of users
of these source methods by evaluating a participant's results based on previous
results in that same concentration range.
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SECTION 3
RECOMMENDATIONS
To create a sample repository the Quality Assurance Branch of the Environ-
mental Monitoring and Support Laboratory intentionally produced an oversupply
of samples for the surveys of EPA Methods 6 and 7 discussed,in this report.
These samples are available to any laboratory having a legitimate need for them,
such as training new analysts, and conducting periodic external quality control
checks of the laboratory. Included with these practice samples is a statement
of true concentration with no requirement for return of data to EPA. We would
like to recommend to any participant use of this sample repository especially
if their reported values fell outside the target range in more than two out of
five samples. We hope that through use of this sample repository, laboratories
will increase their overall analytical skills concerning these particular EPA
reference methods.
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SECTION 4
SURVEY DESIGN
The source sample surveys of this report incorporate experience gained
from previous ambient air audits in such areas as survey procedures,
prospective participants, types and preparation of survey materials, and
data handling. Most procedures described in this section closely follow the
manner in which ambient air audits have been performed.
SURVEY PROCEDURES
All surveys began with a master list of prospective laboratories who had
in the past participated or indicated that they wished to take part in such a
program.
Prospective participants were sent a description of the Method 6 and 7
surveys and instructions for participation. Through a response card, each
laboratory indicated if it wished to participate. Response cards were returned
to the appropriate EPA Regional Quality Control Coordinator (RQCC) who collected,
logged, and forwarded them to the EPA contractor preparing the survey materials
under contract to the Quality Assurance Branch. Participating laboratories were
assigned an identification number to facilitate storage of their data in the
computer's data bank, and to maintain confidentiality for each participant.
At a prearranged date, requested survey materials were shipped to the partici-
pants along with instructions for sample analysis; a blank data card to report
the completed analysis values; and a mailing label for return of the data card
to the QAB. When the survey was completed each participant received a computer
data sheet informing them of their performance. At the completion of several
studies, a summary of all the participants' results will-be published without
reference to any specific laboratory.
PROSPECTIVE PARTICIPANTS
Many governmental agencies were contacted to generate a master list of
prospective participants including federal, state, and local agencies. To
contact industrial, university, or consultant firms, several publications
specializing in source sampling and analysis were examined. Announcements
of the source surveys were placed in such periodicals as the EPA Quality
Assurance Newsletter, Stacksampling News, and the Journal of the Air Pollution
Control Association. Invitations were extended to all prospective participants.
Other laboratories were added to the master list through their direct contact
with the QAB or the RQCC.
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PREPARATION AND DISTRIBUTION OF SURVEY MATERIALS FOR METHOD 6 AND 7
Four different concentration levels of simulated source S0? and NOX samples
were prepared for survey 0577, and five for survey 1177. These solutions
enabled the participants to analyze and calculate different concentration levels
of S02 and NOX using Methods 6 and 7. The "true values" of these samples were
based on theoretical concentrations calculated from gravimetric preparations,
and certain assumed volume measurements. After sample solutions were made,
their concentrations were verified with the appropriate methods. This was
initially conducted by contractor personnel and then by EPA personnel, via a
process known as Acceptance Testing.
In survey 0577, samples were distributed in 15 ml glass vials sealed with
inert lined screw-cap closures. Each laboratory received one vial each of the
four concentration levels and a duplicate of one level. The samples were pack-
aged in a styrofoam mailer and a cardboard box lined with absorbent material
in case of breakage during shipment. In survey 1177, each sample solution was
sealed in a 25 ml glass ampoule, and five different concentration levels were
shipped to the participating laboratories. Glass ampoules were preferred over
vials to prevent leakage and to insure longevity of the concentrations. The
ampoules containing NOX samples were autoclaved to destroy bacteria that might
possibly attack the solutions.
In the first survey each vial contained in excess of 10 ml of solution; in
the second survey ampoules contained approximately 20 ml.
Instructions for the Method 6 samples prescribe that 5 ml of the test
solution be diluted to 100 ml through the addition of 30 ml of 3% hydrogen
peroxide (H^) and distilled water. An aliquot of this solution was then
titrated with barium perchlorate (BaCClO^) in the presence of thorin indicator
to a characteristic peach color endpoint. To complete Method 6 calculations,
the participants assumed they had an original sample volume of 100-ml, and had
sampled 21 x 10"J DSCM (dry standard cubic meter) of stack gas.
The analysis of Method 7 samples involved a 5 ml dilution of the original
test sample with 25 ml of absorbing reagent; adjustment of the pH to approxi-
mately 9 to 12; and dilution to 50 ml with distilled water. After a digestion
procedure, colorimetric analysis follows. To complete Method 7 calculations,
the participants were to assume they had sampled 2000 ml of stack gas.
In each of our surveys, the samples were number coded. In the first
survey (0577), each sample was given a unique five digit number, where the
middle digit indicated one of the four concentration levels used in preparing
the sample sets. For the second survey (1177), the key for the five concen-
tration levels was based on the first digit of the sample number.
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SECTION 5
STATISTICAL DATA HANDLING
Establishing criteria in order to evaluate reported data was a major
concern of the survey program. The most ideal approach would have been to
evaluate a large number of analyses of the same sample made by laboratories
across the nation at different times. Since this was impossible, as an alter-
native, performance ranges were established based on the collaborative studies
of Method 6 and 7 conducted by Southwest Research Institute (SwRI) (5) under
contract to EPA. The SwRI collaborative study estimated the within-laboratory
standard deviation (a) for the analytical phase of Method 6 to be 1.1% of the
true concentration (5) over a simulated range of 283 to 848 mg SOg/DSCM.
Therefore, a = 0.0116 was used for the Method 6 survey. The following are two
performance ranges employed to describe participants' results. The sample
range for each concentration level was determined as ± (1.96)(0.0116) or
approximately ± 2.2% of 6; the target range was set at twice that or ± 4.4%
of 6. The t-statistic, 1.96, was used to estimate where 9.5 percent of the
analysis was expected to fall assuming normally distributed sample results.
Section 4.3 of Method 6 specifies that replicate titrations must agree within
1% or 0.2 ml, whichever is larger. Since this titration specification affects
all sample ranges below a concentration of 686 mg/DSCM, it was used rather
than the collaborative study results to establish the sample and target ranges
for concentrations below this level.
The two performance ranges for the Method 7 survey were calculated from a
regression equation developed from the aforementioned SwRI collaborative test
data. Using collaborative test data, equation 1 describes the within-laboratory
standard deviation (a^) for Method 7 (NOX) over a simulated concentration range
of 125 to 375 mg NO^/m3, assuming a sample volume of 2000 ml.
SN = 0.0314286 + 0.5802 mg/m3 (1)
Thus, the sample range was defined as ± 1.96aN with a target range twice that
value or ± 2 (1.96aN). The target range was established to separate marginally
adequate results from the more questionable ones.
It is important to note that sample and target ranges are bench marks, and
judgment must be used by the participants in interpreting their results.
Furthermore, the combined performance of all five analyses has a bearing on the
adequacy of a participant's skills.
In summarizing the collected data, an outlier test (6) deletes data lying
outside the mean of the reported values by a factor of from 2 to 3.3 standard
deviations, depending on the number of samples for a particular test.
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SECTION 6
DISCUSSION OF METHOD 6 RESULTS
The participants' organization and the distribution of source sulfur
dioxide survey numbers 0577 and 1177 are shown in Table 1 and 2 below.
TABLE 1. METHOD 6 SURVEY 0577
Laboratory Pi stri buti on
Contractor Industrial Federal State Local University Foreign Total
Agencies
requesting 77 14 2 12 8 1 2 116
samples
Agencies
returning 46 12 2 11 8 1 2 82
data
TABLE 2. METHOD 6 SURVEY 1177
Laboratory Distribution
Contractor Industrial Federal State Local University Foreign Total
Agencies
requesting 71 20 3 16 12 0 2 124
samples
Agencies 50 12 1 11 8 0 2 84
returning
data
Participants were instructed to use Method 6 for all analyses and report
their results, based on equation 6-2 of the method (mg SO?/DSCM), on a blank
data card.
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In both Method 6 surveys (0577 and 1177), only the sample and target
ranges (Tables 3 and 4) of low S0? concentrations (266.91 and 137.30 mg/DSCM)
were affected by Method 6 titration specifications and reflect this by their
larger values. The participants should realize that the titration specifica-
tion was not reflected in the initial reports received; therefore, samples 1
and 9 in survey 0577, and sample 5 in survey 1177 should be examined to see if
their values do fall within the new sample and target ranges. These new ranges
are reflected in all Method 6 statistics within this report.
TABLE 3. METHOD 6 ACCEPTANCE RANGES (SURVEY 0577)
Sample
number
1 & 9
2 & 7
3 & 6
4 & 8
Concentration1
level
266.
5338.
3812.
2097.
91
19
99
15
k
Sample range
Percent
± 5
± 2
± 2
± 2
.7
.2
.2
.2
Concentration*
251.6
5220.7
3729.1
2051.0
- 282.
- 5455.
- 3896.
- 2143.
1
6
8
3
Target range
Percent
± 5.7
± 4.4
± 4.4
± 4.4
Concentration*
251.6
5103.3
3645.2
2004.8
- 282
- 5573
- 3980
- 2189
.1
.0
.7
.4
*A11 sample concentrations are in mg SO«/DSCM.
TABLE 4. METHOD 6 ACCEPTANCE RANGES (SURVEY 1177)
Sample
number
2
4
5
7
8
Concentration1
level
4346.
5147.
137.
1410.
2592.
90
60
30
90
90
k Sample range
Percent
±.2.
± 2.
±11.
± 2.
± 2.
2
2
1
2
2
Concentration*
4251
5034
122
1379
2535
.2
.3
.0
.8
.8
- 4442
- 5260
- 152
- 1441
- 2649
.5
.8
.5
.9
.9
Target range
Percent
± 4.4
± 4.4
±11.1
± 4.4
± 4.4
Concentration*
4155.6
4921.1
122.0
1348.8
2478.8
- 4538.1
- 5374.0
- 152.5
- 1472.9
- 2706.9
*A11 sample concentrations are in mg S02/DSCM.
Also noteworthy is that for sample concentrations below 305 mg/DSCM the
sample and target range percentages are the same since the percent difference
from the true value allowed by the titration specification is larger than that
determined from collaborative testing data; and doubling a sample range based
on this specification, as in target ranges, would mean one could exceed the
8
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titration specification and still be within the target range. Using the
previously defined sample and target ranges, a tabulation of all data (Table 5)
indicates that 15% of the laboratories in survey 0577 recorded "none" correctly
measured within the sample range; however, in survey 1177, only 6% measured
"none" correctly.
TABLE 5. METHOD 6 SAMPLE RANGE CUMULATIVE DISTRIBUTION
No. of correctly % Participants correct
measured samples Survey 0577 Survey 1177
1
2
3
4
5
85
68
58
41
24
94
74
68
56
46
Of the participants in survey 0577 (Table 6), 11% measured no sample correctly
within the target range, and 6% in survey 1177 measured none correctly.
TABLE 6. METHOD 6 TARGET RANGE CUMULATIVE DISTRIBUTION
No. of correctly % Participants correct
measured samples
1
2
3
4
5
Survey 0577
89
83
77
65
43
Survey 1177
94
86
84
82
70
We found that in survey 1177, 68% (Table 5) of the participants measured
three or more samples correctly within the sample range, and 84% (Table 6)
measured three or more correctly within the target range. These tables can
inform a participant of his relative performance in comparison to all
participants.
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Tables 7 and 8 are frequency distributions of the absolute percent
differences between the participant's reported values and EPA values for each
concentration level. The differences were calculated as follows:
Absolute percent difference =
Reported value - EPA value
EPA value
x 100
(2)
Table 7 reveals that 50% of the reported results for all sample concentra-
tion levels of Method 6 survey 0577 were less than or equal to an absolute per-
cent difference of 2.15. The bottom line of this table compiles all the data
regardless of concentration. Table 7 is also useful for self-evaluation. For
instance, a participant reporting a value for sample 4 having a significantly
greater than 3.52% difference would recognize the discrepancy, since more than
70% of the participants performed more accurately. The minimum (Min) and
maximum (Max) values listed in Tables 7 and 8 show the lowest and highest
individual percent differences reported in the survey.
All results are grouped according to increasing reported concentration
levels in Appendix A to allow individuals to note their exact placement in the
survey results.
Tables 9 and 11 list summary statistics based on all data received. In
contrast, Tables 10 and 12 list summary statistics based on data remaining
after statistical tests for outliers had been performed. Equations 3, 4, and 5
were used to calculate the statistics in these tables:
Coefficient of variation = -2-x 100;
(3)
Skewness =
s(X1 - I)'
n(a)3
Accuracy = Ml " 6 x 100
(4)
(5)
where: a = one standard deviation
)f = mean value
X.. = individual value
Mi = median value
6 = true value
n = number of values
10
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TABLE 7. METHOD 6 SURVEY 0577 - FREQUENCY DISTRIBUTION OF ABSOLUTE PERCENT DIFFERENCE
No. Min 10% 20% 30% 40% 50% 60% 70% 80% 90% Max Mean
# Within sample range 82 00 1 1 2 3 4 4 55 5
# Within target range 82 0023445555 5
Sample 1 50 0.00 0.22 0.75 1.49 1.99 3.03 5.10 6.8511.2118.05 122.6611.23
Sample 2 53 0.04 0.15 0.89 1.16 1.43 2.05 2.68 4.06 5.95 14.58 130.79 14.04
Samples 51 0.03 0.18 0.55 0.82 1.13 1.36 2.35 3.49 5.0613.51 131.9911.58
Sample 4 53 0.04 0.23 0.47 0.67 1.11 1.65 2.45 3.52 4.2511.64 152.8613.10
Sample 6 45 0.24 0.45 0.64 0.93 1.17 1.86 2.28 3.36 4.50 6.20 98.01 7.90
Sample 7 48 0.01 0.20 0.42 0.96 1.44 1.84 2.55 3.71 5.21 80.51 131.65 14.72
Samples 48 0.01 0.09 0.41 0.55 0.82 1.43 2.47 3.13 3.8412.17 98.9910.36
Sample 9 49 0.11 0.56 0.94 1.61 2.59 2.96 3.08 6.00 9.40 25.63 1313.81 37.78
All samples 397 0.00 0.32 0.63 1.00 1.43 2.15 3.00 3.83 6.32 28.66 1313.81 15.12
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TABLE 8. METHOD 6 SURVEY 1177 - FREQUENCY DISTRIBUTION OF ABSOLUTE PERCENT DIFFERENCE
No. Min 10% 20% 30% 40% 50% 60% 70% 80% 90% Max Mean
# Within sample range 84 01 12345555 5
# Within target range 8401 44555555 5
Sample 2 84 0.030.32 0.51 0.78 1.07 1.31 1.64 2.05 2.70 5.04 19.16 2.43
Sample 4 83 0.01 0.26 0.56 0.87 1.06 1.43 1.78 2.52 3.06 5.33 19.41 2.63
Sample5 83 0.000.73 1.09 1.97 2.33 2.77 3.86 6.7012.4526.66 318.06 13.73
Sample 7 85* 0.040.40 0.79 1.06 1.34 1.68 2.19 2.62 3.11 6.57 32.89 3.13
Samples 84 0.000.34 0.61 0.88 1.16 1.35 1.72 2.25 2.90 3.95 19.53 2.27
All samples 419 0.00 0.40 0.75 1.04 1.31 1.69 2.22 2.69 4.00 8.02 318.06 4.82
*0ne participant received two number 7 samples and lacked a number 5.
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TABLE 9. METHOD 6 SURVEY 0577 - SUMMARY STATISTICS
Sample #
1
# of samples 50
True value*
Mean*
Median*
Std. dev.*
% Coef. var.
Skewness
Accuracy
266
266
268
73
27
-0
0
.91
.08
.05
.57
.65
.04
.43
9
49
266.91
321.71
267.80
508.01
157.91
6.39
0.33
4
54
2097.15
2070.41
2085.20
770.93
37.24
1.22
-0.57
8
48
2097.15
1903.28
2085.85
551.13
28.96
-2.78
-0.54
3
51
3812.
3661.
3783.
1152.
31.
0.
-0.
99
93
00
60
48
28
79
6
45
3812.99
3614.52
3774. ?0
824.18
22.80
-3.28
-1.00
2
53
5338.
4927.
5274.
1830.
37.
-0.
-1.
19
29
30
05
14
37
20
7
48
5338.19
4917.33
5299.45
1879.45
38.22
-0.16
-0.73
*A11 sample
concentrations are
TABLE 10. METHOD
Sample #
# of samples
True value*
Mean*
Median*
Std. dev.*
% Coef. var.
Skewness
Accuracy
1
47
266
270
268
19
7
0
0
.91
.29
.50
.88
.36
.07
.60
6 SURVEY
9
48
266.91
249.79
267.50
68.97
27.61
-2.72
0.22
in mg/DSCM.
0577 -
4
51
2097.15
1952.62
2083.00
490.86
25.14
-3.51
-0.67
SUMMARY
8
44
2097.15
2063.80
2087.55
114.35
5.54
-3.36
-0.46
STATISTICS (OUTLIERS
3
48
3812.
3704.
3783.
531.
14.
-3.
-0.
99
68
50
70
35
38
77
6
'43
3812.99
3778.20
3776.20
307.20
8.14
1.91
-0.96
2
52
5338.
4785.
5274.
1523.
31.
-2.
-1.
REMOVED)
19
12
25
99
85
58
20
7
44
5338.19
5075.96
5316.60
964.97
19.01
-3.79
-0.40
*A11 sample concentrations are in mg/DSCM
13
-------
TABLE 11. METHOD 6 SURVEY 1177 - SUMMARY STATISTICS
Sample #
# of samples
True value*
Mean*
Median*
Std. dev.*
% Coef. var.
Skewness
Accuracy
5
83
137.30
147.19
138.70
54.83
37.25
5.73
1.02
7
85
1410.90
1393.95
1391.70
78.39
5.62
2.63
-1.36
8
84
2592.90
2567.51
2562.60
94.92
3.70
0.24
-1.17
2
84
4346.90
4304.32
4298.70
177.74
4.13
0.86
-1.11
4
83
5147.60
5071.62
5085.70
220.28
4.34
-0.09
-1.20
*A11 sample
TABLE 12
concentrations are
. METHOD 6 SURVEY
in mg/DSCM.
1177 - SUMMARY STATISTICS (OUTLIERS REMOVED)
Sample #
# of samples
True value*
Mean*
Median*
Std. dev.*
% Coef. var.
Skewness
Accuracy
5
82
137.30
141.98
138.65
27.70
19.51
0.97
0.98
7
82
1410.90
1388.02
1391.45
43.21
3.11
-0.28
-1.38
8
81
2592.90
2563.91
2562.40
50.68
1.98
0.22
-1.18
2
80
4346.90
4289.43
4295.70
88.74
2.07
-0.67
-1.18
4
79
5147.60
5073.45
5085.70
110.78
2.18
0.28
-1.20
*A11 sample concentrations are in mg/DSCM.
14
-------
As previously stated, participants in survey 0577 received a set of five
samples from the four prepared concentration levels. These contained one
sample from each concentration level and one duplicate. Samples 6 through 9
were prepared as duplicates of samples 1 through 4. No sample 5 was prepared.
For instance, a participant could receive sa.nples 1, 2, 3, 4, and 8. In this
particular set of samples, the duplicate sample concentrations were numbers 4
and 8. When randomizing the distribution of duplicates for the four S09
concentration levels sent out, all sets of samples that included more than one
set of duplicate concentrations were rejected; thus, each sample could act as
a duplicate an approximate equal number of times.
In survey 1177 participants received one sample from each of the five
prepared concentration levels. In both surveys the sample numbers were chosen
at random from 0 through 9.
From an examination of Tables 10 and 12, it seems apparent that a nega-
tive bias exists in survey 0577 as judged by its skewness values (Table 10),
particularly when outliers are removed. However, the differences between true
and mean values were not statistically large enough to confirm a bias. This
is also implied by the low accuracy values. Survey 1177 (Table 12) shows no
indication of bias. Therefore, the "true value" adopted by EPA to represent
the absolute true value and the mean agree well, indicating that the gravi-
metric preparation, reference method, and procedure for the survey coincide.
All samples listed in Tables 9 and 10 are in increasing concentration
levels inclusive of duplicate samples.
15
-------
SECTION 7
DISCUSSION OF METHOD 7 RESULTS
The source nitrogen oxides Survey 0577 and 1177 began, as with the
Method 6 surveys, in May and November of 1977, respectively. The following
tables describe the organization and distribution of those samples.
TABLE 13. METHOD 7 SURVEY 0577
Agencies
requesting
samples
Agencies
returning
data
Laboratory Distribution
Contractor Industrial Federal State Local University Foreign Total
72 8298 1 2 102
39 8 266 1 2 64
TABLE 14. METHOD 7 SURVEY 1177
Agencies
requesting
samples
Agencies
returning
data
Laboratory Distribution
Contractor Industrial Federal State Local University Foreign Total
70 20 3 16 12 0 3 124
43 9 1670 2 68
Participants were instructed to use Reference Method 7 for their analysis
and report their results based on equation 7-4 of the method as mg NO /DSCM.
Under Part 6 (Calculations) of Method 7, the analyst is required to calculate
the concentration of NO samples as NO,,.
X c.
16
-------
Sample and target ranges (TablesJS and 16) were defined using the
regression equation described in Section 5.
TABLE 15. METHOD 7 ACCEPTANCE RANGES (SURVEY 0577)
Sample
number
1 and
2 and
3 and
4 and
6
9
7
8
Concentration*
level
1913
95
669
1435
.80
.70
.80
.40
60
3
21
45
/%
°N
.73
.59
.63
.69
Sample range
concentration*
1794.8
88.7
627.4
1345.9
- 2032
- 102
- 712
- 1525
.8
.7
.2
.0
Target range
concentration*
1675.8
81.6
585.0
1256.3
- 2151.
109.
- 754.
- 1614.
9
8
6
5
*A11 sample concentrations are in mg NOX/DSCM.
TABLE 16. METHOD 7 ACCEPTANCE RANGES (SURVEY 1177)
Sample Concentration* jj
number level N
1 421.00
2 151.30
3 803.80
7 1837.00
9 1531.00
13.81
5.33
25.84
58.31
48.70
Sample range
concentration*
393.9 -
140.9 -
753.2 -
1722.7 -
1435.6 -
448.1
161.8
854.4
1951.3
1626.4
Target range
concentration*
366.9 -
130.4 -
702.5 -
1608.4 -
1340.1 -
475.1
172.2
905.1
2065.6
1721.9
*A11 sample concentrations are in mg NOX/DSCM.
Using the previously defined performance ranges, a tabulation of all reported
data (Table 17) reveals that 42% of those laboratories analyzing samples n
survey 0577 measured none correctly within the sample range. In survey 1177
(Table 18 only 32% measured none correctly within the sample range.
17
-------
TABLE 17. METHOD 7 SAMPLE RANGE CUMULATIVE DISTRIBUTION
No. of correctly % Participants correct
measured samples Survey 0577 Survey 1177
1
2
3
4
5
58
44
31
14
9
68
56
44
34
19
In survey 0577, 32% of the participants recorded none correctly measured
within the target range, compared to only 16% of survey 1177.
TABLE 18. METHOD 7 TARGET RANGE CUMULATIVE DISTRIBUTION
No, of correctly
measured samples
1
2
3
4
5
% Participants correct
Survey 0577 Survey 1177
68
58
45
34
27
84
75
69
57
47
From Table 18 (Survey 0577), we find that 45% had three or more samples
within the target range.
Frequency distributions (Tables 19 and 20) demonstrate that 50% of the
results for all concentrations levels of Method 7, inclusive of both surveys,
were less than or equal to an absolute percent difference of 15.14 and 7.41%,
respectively. Note the magnitude of these values relative to the Method 6
results of 2.15 and 1.69% (Tables 7 and 8). Once again, the bottom line of
each table examines the total data.
Tables 19 and 20 are useful for a participant's self-evaluation. For
instance, a participant reporting a value for sample 1 (Table 19, Survey 0577)
18
-------
significantly greater than 21% from the true value, should realize that 70%
of the results were numerically closer.
All sample numbers were randomized with respect to concentration levels as
with Method 6, and are grouped according to increasing concentration levels in
Appendix B to allow participants to note their exact placement in the results.
Tables 21 through 24 tabulate summary statistics based on the total data
and data where previously described outlier tests had removed spurious results.
Examination of Tables 21 through 24 justifies several observations. No
method bias is evident. This is supported by low skewness, and similar median
and mean values.
The accuracy values tend to indicate a small analytical bias between
gravimetric "true values" and responses as a whole. Yet the scatter was so
large, even when judged against the limits prescribed in the collaborative
study, that one must conclude that the method is difficult to implement
uniformly. However, good data was attainable as proven by the aforementioned
9 and 19% (Table 17) who correctly measured all five samples within the sample
ranges. Therefore, the QAB will continue to examine the survey results in
order to identify specific problems, so that the accuracy of users of Method 7
can be improved.
19
-------
ro
o
TABLE 19. METHOD 7 SURVEY 0577 - FREQUENCY DISTRIBUTION OF ABSOLUTE PERCENT DIFFERENCE
No. Min 10% 20% 30% 40% 50% 60% 70% 80% 90% Max Mean
# Within sample range 64 000001223 4 5
# Within target range 64 000012345 5 5
Sample 1 37 0.18 1.57 2.73 4.05 5.52 12.90 16.05 20.97 46.18 95.05 123.48 29.90
Sample 2 34 0.31 0.84 2.82 3.87 5.43 9.09 12.33 15.46 24.14 61.55 1338.35 59.64
Sample3 40 0.04 1.88 5.11 7.66 8.8215.1421.4235.0650.88 79.40 116.9529.77
Sample 4 36 0.15 0.68 2.13 4.27 8.13 13.56 20.48 23.66 42.60 48.24 105.81 24.27
Sample 6 44 1.37 2.86 3.98 9.75 14.12 20.31 39.50 48.06 89.84 98.99 279.28 44.76
Sample 7 46 0.25 0.48 4.43 5.17 6.45 8.99 16.75 25.80 52.93 98.97 111.26 30.31
Samples 42 1.60 2.50 5.27 6.8114.4220.4833.2046.1586.36 98.98 117.1538.85
Sample 9 39 0.10 0.63 2.19 3.34 4.9115.9924.8749.7478.47 98.96 131.9736.17
All samples 318 0.04 1.88 ,3.87 5.55 8.9915.1420.9842.6061.55 98.981338.3536.49
-------
TABLE 20. METHOD 7 SURVEY 1177 - FREQUENCY DISTRIBUTION OF ABSOLUTE PERCENT DIFFERENCE
No. Min 10% 20% 30% 40% 50% 60% 70% 80% 90% Max Mean
# Within sample range 68 000012344 5 5
# Within target range 68 001234555 5 5
Sample 1 67 0.24 0.55 2.38 3.33 4.51 6.77 8.60 10.45 16.25 40.62 127.79 15.50
Sample 2 65 0.26 1.12 2.64 4.56 6.41 7.8010.9113.6828.35 40.981083.08 34.32
Sample 3 67 0.37 1.02 1.83 2.95 4.76 6.56 9.57 13.41 16.37 67.43 124.68 19.14
Sample 7 68 0.53 1.02 2.66 3.70 4.93 6.80 9.80 13.34 19.22 42.84 129.07 16.61
Sample 9 67 0.13 0.76 1.92 3.01 5.86 9.16 10.74 13.29 17.90 36.04 136.71 16.00
All samples 334 0.13 1.24 2.21 3.83 5.29 7.41 10.19 13.41 20.07 44.89 1083.08 20.22
-------
TABLE 21. METHOD 7 SURVEY 0577 - SUMMARY STATISTICS
Sample #
# of samples
True value*
Mean*
Median*
Std. dev.*
% Coef. var.
Skewness
Accuracy
2
34
95
137
99
221
160
5
3
.70
.65
.30
.44
.87
.13
.76
0
39
95.70
99.09
96.60
51.75
52.22
0.20
0.94
3
40
669.80
637.26
673.25
295.98
46.45
-0.08
0.52
7
46
669.80
647.77
688.75
321.94
49.70
0.05
2.83
4
36
1435
1388
1451
523
38
-0
1
.40
.01
.75
.35
.35
.22
.14
8
42
1435.40
1460.42
1497.50
788.86
54.02
0.12
4.33
1
37
1913
1888
1883
918
48
0
-1
.80
.08
.70
.00
.62
.10
.57
6
44
1913.80
1911.41
1866.75
1328.66
69.51
1.54
-2.46
*A11 sample concentrations are in mg/DSCM.
TABLE 22. METHOD 7 SURVEY 0577 - SUMMARY STATISTICS (OUTLIERS REMOVED)
Sample # 29374816
# of samples 33 39 39 46 34 42 36 43
True value* 95.70 95.70 669.80 669.80 1435.40 1435.40 1913.80 1913.80
Mean* 100.12 99.09 616.35 647.77 1382.36 1460.42 1821.72 1787.06
Median* 99.20 96.60 669.50 688.75 1451.75 1497.50 1881.85 1859.00
Std. dev.* 33.99 51.75 268.23 321.94 411.07 788.86 836.19 1053.92
% Coef. var. 33.95 52.22 43.52 49.70 29.74 54.02 45.90 58.98
Skewness 0.22 0.20 -0.60 0.05 -1.00 0.12 -0.28 0.47
Accuracy 3.66 0.94 -0.04 2.83 1.14 4.33 -1.67 -2.86
*A11 sample concentrations are in mg/DSCM.
22
-------
TABLE 23. METHOD 7 SURVEY 1177 - SUMMARY STATISTICS
Sample #
# of samples
True value*
Mean*
Median*
Std. dev.*
% Coef. var.
Skewness
Accuracy
*A11 sample
TABLE 24.
2
65
151.30
188.33
158.20
207.51
110.18
7.08
4.56
concentrations are
METHOD 7 SURVEY
1
67
421.00
442.06
435.00
119.51
27.04
1.83
3.33
in mg/DSCM
3
67
803.80
863.90
831.50
278.67
32.26
1.10
3.45
9
67
1531.00
1597.47
1577.10
441.25
27.62
2.03
3.01
7
68
1837.00
1944.77
1909.35
541.53
27.84
1.13
3.94
1177 - SUMMARY STATISTICS (OUTLIERS REMOVED)
Sample #
# of samples
True value*
Mean*
Median*
Std. dev.*
% Coef. var.
Skewness
Accuracy
2
64
151.30
163.30
158.20
48.85
29.91
2.31
4.56
1
64
421.00
422.77
434.25
79.06
18.70
0.06
3.15
3
64
803.80
823.99
828.75
212.20
25.75
0.10
3.10
9
64
1531.00
1520.76
1570.70
258.44
16.99
-1.49
2.59
7
65
1837.00
1913.84
1905.00
370.94
19.38
1.04
3.70
*A11 sample concentrations are in mg/DSCM
23
-------
REFERENCES
1. Bromberg, S. M., B. I. Bennett and R. L. Lampe. Summary of Audit
Performance: Measurement of S02, N02, CO, Sulfate, Nitrate - 1976.
EPA-600/4-78-004, U.S. Environmental Protection Agency, Research
Triangle Park, North Carolina 27711. 75 pp.
2. Bromberg, S. M., R. L. Lampe, and B. I. Bennett. Summary of Audit
Performance: Measurement of S09, N09, CO, Sulfate, Nitrate, Lead,
and Hi-Vol Flow Rate - 1977. EPA-600/4-79-014, U.S. Environmental
Protection Agency, Research Triangle Park, North Carolina 27711
160 pp.
3. Standards of Performance for New Stationary Sources. Revision to
Reference Method 1-8. Federal Register, 41(111):23060-23000
(June 8, 1976).
4. Standards of Performance for New Stationary Sources. Revision to
Reference Method 1-8. Federal Register, 42(160):41782-41786
(August 18, 1977).
5. Hamil, H. F., D. E. Camann and R. E. Thomas. The Collaborative Study
of EPA Methods 5, 6, and 7 in Fossil Fuel-Fired Steam Generators.
EPA-650/4-74-013, U.S. Environmental Protection Agency, Research
Triangle Park, North Carolina 27711. 33 pp.
6. Chauvenet, W. Manual of Spherical and Practical Astronomy: Volume II -
Theory and Use of Astronomical Instruments (Method of Least Squares).
J. B. Lippincott and Co., Philadelphia, Pennsylvania, 1863. pp. 558-565.
24
-------
APPENDIX A
S02 SUMMARY DATA
INTER-LA30RATORY STUDY
POLLUTANT - S02
SAMPLE NUMBER - 1
V 50
TRUE-tVALUE 266.91
1£AN 266.08
1 EDI/IN 268.35
(ATA IN ASCENDING ORDER
0577
UNITS - riLLI&RAflS PER DRY STO CUBIC METER
RANGE 591.60
VARIANCE 5412.73
STD. DEV. 73.57
COEF. VAR. 27.65
C.I.(UPPER) 286.47
C.I.CLOWE R) 245.69
SKEHNESS -.04
ACCURACY .43
2.70
5.20
213.90
236.40
237.00
237.00
247.50
253.20
256.00
256.70
257.10
261.00
261.33
261.60
261.90
262.CO
263.00
264.80
266.10
266.60
266.90
266.90
267.00
267.50
.267. 6C
26E.5C
266.60
26E.90
270.00
270.7C
270.90
271.10
272.00
274.50
275.00
275.00
275.00
281.60
282.70
2S3.00
284.10
285.20
294.40
296.50
297.60
293.20
305.20
315.10
321.70
594.30
INTER-LABORATORY STUDY
POLLUTANT - S02
SAMPLE NUMBER - 1
TRUE-VALUE
"EAN
MEDIAN
47
266.91
270.29
268.50
U»flTS - MILLIGRAMS PER DRY STD CUBIC METER
**** WITH OUTLIERS REMOVED •***
RANGE
VARIANCE
STD. D£V.
corr. VAR,
108.73
395.36
19.83
7.3S-
C.I.(UPPER) 275.98
C.I.(LOVE R> 264.61
SKEUMESS .07
ACCURACY .60
DATA IN ASCENDING ORDER
213.00
236.40
237.00
227.00
247.30
253.30
256.30
256.70
257.10
261.30
261.30
261.60
261.90
262.00
263.00
264.JSO
266.10
266.£3
266.93
266.90
267.00
267.50
267.60
26E.50
268.60
268.9G
270.00
27D.70
270.90
271.10
272.00
274.50
275.00
275.00
275.00
2S1.60
282.70
293.00
284.10
285.20
294.40
296.50
297.60
298.20
305.20
315.10
321.70
25
-------
INTER-LA30RATORY STUDY
POLLUTANT - S02
SAMPLE NUMBER - Z
1 53
TRUE-VALUE 5338.19
1E»N 4927.29
"ED1AN 5274.30
DATA IN ASCENDING ORDER
0577
UNITS - MILLIGRAMS PER DRY STD CUBIC PETER
RANGE 122S6.30
VAMAKCE 3349096.23
STD. DEV. 1c30.05
COEF. WAR. 37.14
C.I.(UPPER)5419.99
C.I.(LOWE R)4434.59
SKEUNESS -.37
ACCURACY -1.20
53.70
67.DO
162. £0
291.50
429.50
4560.00
4559.60
4274.60
4904.SO
5310.DO
5089.40
5095.00
5140.00
5140.00
5160.40
5184.40
5209.00
5220.90
5221.70
5223.60
5233.10
5245.00
5262.10
5262.50
52 6£.40.
5274.20
52?4.30
52E7.00
5300.00
5307.60
5330.00
5331.00
533t.50
5340.30
5342.80
5350.00
5362.00
53S5.60
5390.00
5390.30
5392.10
5400.00
5407.60
5432.00
5439.00
5447.50
5481.00
54E9.EO
5554.SO
55 6 7 . 1 0
55*9.00
5656.00
12320.00
INTER-LA30RATORY STUDY
POLLUTANT - S02
SAMPLE NUMBER - 2
V 52
TRUE-VALUE 5338.19
1EAN «7o5.72
-------
INTER-LABORATORY STUDY
POLLUTANT - S02
SAMPLE NUMBER - 3
1 51
TRUE-VALUE 3812.99
,£AN 3661.93
MEDIAN 37S3.DO
DATA IN ASCENDING ORDER
0577
IITS - MfLLIGRAMS PER DRY STD CUBIC METER
RANGE 8fcQ7.53
VARIANCE 13284EE.14
STD. DEV- 1152.63
COEF- VAR. 31.46
C.I.CUPPtR)3978.27
C.I.(LOWE R>3345.59
SKEWNESS »28
ACCURACY ~«79
38.20
49.90
715.60
2703.60
3298.00
3340.20
3370.00
3502.30
3548.SO
3559.00
35&0.00
3630.00
3680.60
3721.30
3729.20
3744.90
3758.60
3761.00
3764.00
3766.50
3768.50
3770.00
3773.00
3776.50
3775.00
3763.00
37E4.0C
3790.00
3792.00
3795.10
3759.QO
3300.00
3S04.80
3308.50
S811.90
S814.8Q
J816.1Q
3820.(JQ
S837.QO
3844.40
J'847.9o
3357.20
3870.30
3902.70
39Q3.0D
3920.00
3957.60
3965.70
4006.00
52Q5.30
6545.70
INTER-LA30RATORV STUDY
POLLUTANT - SOZ
SAMPLE NUMBER - 3
„ 48
TRUE-VALUE 3812.99
4EAN 3704.53
MEDIAN 37S3.50
DATA IN ASCENDING ORDER
0577
UNITS - MILLIGRAMS PER DRY STD CUBIC M£T£R
**** WITH OUTLIERS REMOVED ****
RANGE 4*89.73 C.I.(UPPER>3E55.10
VARIANCE 252703.15 C.I.CLOWE RJ3554.Z5
STD. DEV. 531.70 SKEMNESS -3.38
COEF. VAR. 14.35 ACCURACY -.77
715.50
2703.50
3298.00
3340.20
3370.00
3502.30
3548.50
3559.00
3560.00
3560.00
3680.60
3721.30
3729.20
3744.93
3758.60
3761.00
3764.00
3766.50
3768.50
3770.00
3773.00
3776.50
3779.00
37E3.00
37EC.OO
3750. 00
3792.00
37H.10
3799.00
3300.oo
3804.80
SE08.50
5811.9Q'
3814.BQ
3816.1Q
5820.oo
3837.00
3844.4Q
3847.90
SB57.20
3S70.30
3902.70
3903.00
3920.00
3957.60
3965.70
4006.00
5205.30
27
-------
INTER-LA30RATORY STUDY
POLLUTANT - S02
SAMPLE NUMBER - 4
M 53
TRUE-VALUE 2097.15
1EAN 2070.41
1ED1AN 2035.20
DATA IN ASCENDING ORDER
O577
UNITS - MILLIGRAMS PER DRY STD CU&IC
RANGE 52E1.83
VARIANCE 594355.25
SID. DEV. 770.93
CCEF. VAR. 37. 24
C.I.(UPPER)2277.97
C.I. (LOWE R M862.8S
SKEJNESS 1.22
ACCURACY -.57
21.00
26.30
40.40
1E28.00
1353.00
1579.90
1990.30
1992.00
2005.00
2021.50
2322.30
2022.33
2030.03
2032.60
2043.10
2054.SO
2056.CO
2060.00
2070.50
2072.OD
2072.00
2073.90
2074.00
23tD.OO
20E2.EO
2083.00
23E5.20
20E6.00
2367.20
20E7.7Q
20S-D.OO
23SS.OCI
2100.00
2100.00
2102.00
2102.QO
2103.4-Q
2109.5Q
2109.9Q
2117.3o
2118.oo
2127.30
2121.20
2133.50
21 4&.
21 53.
2161.
21 70.
21 76.
2196.
60
50
30
90
00
20
4645.70
5302.80
INTER-LA30RATORT STUDY
POLLUTANT - 502
SAMPLE NUMBER - 4
* 51
TRUE-VALuE 2Q97.15
•IEAN 1952.62
«!EDJAN 20b3.30
DATA IN ASCENDING ORDER
0577
UNITS - MILLIGRAMS PER DRY STD
**** WITH OUTLIERS- REMOVED ****
RANGE 2^5.23
VARIANCE 240144.44
STD. DEV. 490.86
COEF. VAR. 25.14
C.I.(OPPER)20S7.34
C.I.CLOUE R)1817.90
SKEWNESS -3.51
ACCURACY -.67
21. 90
26.30
40.40
1523.30
1353.30
1379.90
1990.00
1992.00
2008.30
2321.50
2022.30
2022.30
2030.03
2032.60
2043.10
2054.SO
2056.00
2060.03
2070.50
2072.00
2072.00
2073.90
2374.00
20EO.OO
29B2.60
236Z.00
2365.20
20E6.00
20E7.2C
20E7.70
2050.oo
2096.00
205E.6t
2100.00
2100.00
2102.QO
2102.QO
2103.4o
2109.5Q
2109.90
2117.8Q
2118.00
2127.30
2131.80
2133.50
214S.60
2113.50
2161.30
2170.90
2176.00
2196.20
28
-------
INTE8-LA90RATORY STUDY
POLLUTANT - S02
SAMPLE NUMBER - 6
N 45
TRUE-VALUE 3E12.99
KEAN 3614.52
MEDIAN 3774.9Q
DATA IN ASCENDING ORDER
0577
UNITS - MILLIGRAMS PER DRY S T t> CUelC METER
RANGE 5247.03
VARIANCE 679277.0?
STD. DEV. fc24.15
COEF. VAR. 22.83
C.I.3373.71
SKEWNESS -3.28
ACCURACY -1.00
76.30
115.00
2692.40
3566.70
3576.40
3589.70
3602.00
3620.00
3650.00
3665.10
3632.00
36B5.0D
36E6.30
3700.00
3728.30
3731.30
373B.20
3741.90
3746.80
3759.90-
376E.50
3771.00
3774.90
3776.20
3779.20
37B2.6C
3750.QO
3790.30
3753.8c
375C.2C
5797.60
S797.90
3822.QO
5830.30
5837.30-
5846.5o
5848.30
S8S5.00
5872.40
5890.00
3900*00
3920.00
3954.60
3984.70
5323.00
INTER-LA90RATORY STUDY
"OLLUTANT - S02
SAMPLE NUMBER - 6
N 43
TRUE-VALUE 3E12.99
"EAN 3778.20
1EDIAN 3776.20
DATA IN ASCENDING ORDER
0577
UV1TS - MILLIGRAMS PER DRV STD CUBIC "ETER
**** WITH OUTLIERS REMOVED ****
2630.60
RANGE
VARIANCE
STD. DEV.
COEF. VAR.
2D7.3?
8.14
C.I.CUPPER)3870.07
C.I.CLOWE R)3686.32
SKEWNESS 1.91
ACCURACY -.96
2692.4Q
3566.90
3576.40
3569.70
3602.00
3620.00
3650.30
3665.10
3662.00
3685.00
3686.30
3700.00
3728.30
3731.30
3738.20
3741.90
3746.80
3759.90
37fcE
3771
3774
3776
3779
3762
3790.00
3790.30
3793.8Q
50
00
90
20
20
60
J794.20
5797.60
5797.9o
J822.QO
5830.3b
5637.30
5S46.5Q
5848.3Q
5855.00
3872.40
3890.00
3900.00
3920.00
3954.60
3984.70
5323.00
Z9
-------
INTEH-LA30RATORY STUDY
POLLUTANT - S02
SAMPLE NUMBER - 7
V 48
TRUE-VALUE 5338.19
1EAN 4917.33
MEDIAN 5299.45
DATA IN ASCENDING ORDER
0577
UNITS - KILL I GRAMS PER DRY STD CUBIC
RANGE 12298.SD
VARIANCE 3S12349.94
SID. DEV. 1J79.45
COEF. VAR. 38.22
C.I.(UPPER J5449.03
C.I.(LOWE R)43S5.63
SKEHNFSS -.16
ACCURACY -.73
67.20
91.50
165.20
713.30
1040.40
3503.20
5000.70
5060.00
5079.00
5105.70
5125.40
5139.90
5149.00
5199.20
5201.90
5204.70
5237.90
5239.80
5250.00
5250.70
5260.BO
5277.3Q
52E1.9C
52B4.9C
5314.00
531?.20
5 3 21. 2 C
5321.90
533B.9U
5340.QO
5343.70
S348.60
5359.00
5360.50
5371.QO
53E4.1o
538B.QO
5389.5Q
5396.&o
5415.00
5432.
5471,
5480.
5500.
5552.
5623.
5661 .
70
70
00
30
00
30
CO
12365.70
INTER-LABORATORY STUDY
POLLUTANT - S02
SAMPLE NUMBER - 7
N 44
TRUE-VAL'JE 5338.19
1EAN 5075.96
IIEDIAN 5316.60
DATA IN ASCENDING ORDER
0577
UNITS - MILLIGRAMS PER DRY STD
**** WITH OUTLIERS REMOVED ****
RANGE 4547.70
VARIANCE 931159.43
STD. DEV. 954.97
COEF. VAR. 19.01
C.I.(UPPER)5361.09
C.I.(LOWE R)479o-fi!
SKE-lNESS -3.79
ACCURACY -.to
713.30
1040.40
3308.20
5000.70
5060.DO
5079.00
5105.70
5125.40
5139.90
5149.00
5199.20
5201.90
5204.70
5237.93
5239.30
5250.00
5250.70
5260.83
5277.30
5281.9e
52E4.90
5314.00
5319.20
5321.20
5321.90
533E.9C
5340.00
5343.70
5348.60
5359.QO
5360.50
5371-00
53S4.1Q
5388-00
5389.5Q
5396.&0
5415.PO
5432.JO
5471.70
54BC.DO
5500.00
5552.00
5623.30
56t1.00
30
-------
INTER-LA30RATORY STUDY
POLLUTANT - S02
SAMPLE NUMBER - 8
1 48
TRUE-VALUE 2097.15
1EAN 1903.28
KEDIAN 2085.35
DATA IN ASCENDING ORDER
0577
UNITS - M1LL1GRV1S PER Ofcr STD CUBIC METER
RANGE 2156.53
VARIANCE 503739.31
STD. DEV. 551.13
CGEF. VAR. 28.95
C.I.
-------
INTER-LA30RATORY STUDY
POLLUTANT - SOZ
SA1PLE NUMBER - 9
H 49
TRUE-VALUE 266.91
HERN 321.71
«!EDI«N 267.80
DATA IN ASCENDING ORDER
0577
UNITS - KILL1GRIMS PER DRY STD CUBIC METER
RANGE 3769.03
VARIANCE 258059.99
STC. CEV. 508.01
COEF. VAR. 157.91
C.I.(UPPER) 463.95
C.I.(LOWE R) 179.47
SKEWNESS 6.39
ACCURACY .33
8.10
49.30
61.40
193.50
350.50
253.30
257.00
258.30
258.70
258.90
258.90
259.00
259.20
250.03
262.60
263.SO
264.00
264.30
264.40
265
265
267
266
26$
269
270
,00
• 00
.70
-20
.80
,4G
.00
.40
.50
271.30
271.BO
273.30
273.7Q
274.QO
274.3o
274.50
275.QO
275.1Q
276.QO
284.0o
286.CD
2E9.IO
292.00
293.00
29B.20
298.20
302.CC
3773.60
INTER-LA30RATORY STUDY
POLLUTANT - S02
SAMPLE NUKBER - 9
if 48
TRUE-VALUE 266.91
DEAN 249.79
1EDIAN 267.50
DATA IN ASCENDINS ORDER
0577
UNITS - MILLIGR^S PER DRV STD
'ETER
***•* WITH OUTLIERS REMOVED ****
RANGE
VARIANCE
STD. DFV.
COEF. VAR.
297.43
4756.62
68.97
27.61
C.I.CUPPER) 269.30
C.I.(LOWE R) 23Q.2!
SKEWNESS -2.72
ACCURACY .22
4.60
.8.10
49.30
61.40
198.50
250.90
253.30
257.30
258.30
253.70
255.90
258.90
259.03
259.20
260.GO
262.60
263.£0
264.CO
264.30
264.»0
2f5.00
2 6 5 • o (,'
2t5.70
267.2C
2 6 7 . F 0
2 6 ? . 4 C
269.CG
2 6 9 . 4 C
270. 51-
271.3.j
271.30
273.30
273.70
274.QO
274.3Q
274.5Q
275.0o
2.75.1Q
276.oo
2S4.0C
2E5.00
266.00
289.50
292.00
292.00
29E.20
29C.20
3C2.00
32
-------
1NTER-LA30PATORY STUDY
POLLUTANT - S02
SAMPLE NUMBER - 2
S 84
TRUE-VALUE 4346.90
MEAN 4304.12
1EDHN 4296.70
5 AT A IN ASCENDING ORDER
1177
UNITS - MILLIGRAMS PER DRY STD CUBIC TETER
RANGE
VARIAKCE
STD. DEV.
CGEF. VAR
! 1:9 2. 29
177.74
4.13
C.I.(UPP£H)4342.33
C.I.(LOWE R)4266.31
SKE'.'NESS .66
ACCURACY -1.11
3514.20
3982.70
4044. 60
4093.00
4096.50
4121.00
4127.70
4148.50
4148.70
4200.20
4200.40
4207.70
4229. SO
4232.50
4236.00
4236.40
423S.30
4246.30
4250.20
4255.40
425S.OO
4259.00
4263.00
4266.10
4271.00
4272.00
4273.40
4275.CO
4277.00
4279.00
4280.00
4285.00
4295.20
4290.00
425D.CC
425C.OG
425.'. 00
4252.CC
42*3.30
4 2 51. 5 C
4254.20
4257.20
43CD.20
43C1.2C
43C5.0C
4206.60
43D7.30
43CC.OO
4310.80
4313.40
43 IE.60
4319.50
4320.SO
4321.10
4324.00
4324.00
4324.80
4325.00
4325.00
4326.00
4326.70
4328.00
43:o.OO
4340.50
4341.20
43.42.30
4342.90
4345.40
4355.00
4157.40
4360.60
4366.30
4380.80
4381.00
4384.
4412.
4417.40
4413.30
4449.40
4477.
4543.
4834.
4920.
.00
.20
.00
.10
.00
.00
5140.00
INTER-LABORATORY STUDY
POLLUTANT - S02
SAHPLE NUMBER - 2
M EO
TRUE-VALUE 4346.90
*EAN
-------
INUR-LA30RATORY STUDY
POLLUTANT - S02
SAMPLE NUKBER - 4
V £3
TRUE-VALUE 5147.60
»EAN 5071.62
1ED1AN 5C&5.70
DATA IN ASCENDING ORDER
1177
RAkGE
UNITS - MILLIGRAMS PER DRY STD CUFIC KETE*
STO. DEV.
COEF. VAR.
1S46.33
8522.73
120. 21
A. 34
C.I. .40
51 56.4C
5161.CO
51 66.5C
516E.OO
5173.00
5201.00
S25G.6G
53C2.CC
53C5.1C
5529.3C
56fct.OO
6095.00
5099. 2C
51 C D . 0 G
5140.00
5140.60
INTfcR-LABOR ATORY STUt>Y
POLLUTANT - S02
SAMPLE NUMBER - 4
0 79
TRUE-VALUE 5147. iO
«EAN 5C73.45
*S 50c5.70
1177
UNITS - MILLIGRAMS PER 0RY STD CU&IC
**** WITH OUTLIERS REMOVED <*»*
RANGE 759.30
VARIANCE 12271.79
STD. DEV. 110-75
COEF. VAR. 2.1S
C.I.(UfPER>5097:£e
C.I.(LOWE R)504V.Q2
SKE^NESS .£E
ACCURACY -1.20
DATA IN ASCEN6ING ORPER
4770.DO
4755.90
4517.30
4S50.30
4573.00
4911.00
4916.10
4920.30
4941.50
4955.CO
49&2.QO
4967.50
5001.00
5004.10
5C07.70
5010.30
5015.00
501t.90
5016.00
5027.30
5G2&.23
5030.00
5033.00
5037.00
5039.40
5039.40
5056.00
5059.00
5059.43
5064.20
5066.00
5071.40
5072.CO
5073.00
5074.20
5077.3C
5 0 7 F . 1 C
50E1.7C
53t3.0C
5065.70
50fcJ.CC
50&1.3C
5293.CC
5091.50
50?;.30
5096.50
509E.OC
5099.2C
5100.
5102,
5102.
5103.
51C3.
5107,
510£.
5109.
5117.
5119,
5119,
5122,
5123,
513C,
5135,
00
20
6C
20
so
00
so
zc
20
00
00
70
60
00
00
si4o.ro
51 46.1C
5149.40
5156.40
5161.00
5166.50
S16E.OG
5173.CO
5201.00
525C.6D
53C2.00
5305.10
5529.30
5140.00
34
-------
INTER-LA90R ATORY STUDY
POLLUTANT - S02
SAMPLE NUMBER - 5
TKUE-VALUE 1 37 .10
«EAN 147.19
«!ED1AN 13E.70
DATA IN1 ASCENDING ORDER
1 177
UNITS - MldLIGRuMS P£R DRY STO CUelC METER
R ANGE
VAR
STD. OEV.
CCEF. VAR
S44.90
3C.06.51
SA.fcJ
37.25
C.J.(UPPER) 15S.98
C.l.CLG.E R) 1?5.39
SKfcWKESS 5.73
ACCURACY 1.02
29.10
91.iO
100.70
105.30
117.10
120.00
124.30
127.60
123.10
130.00
131.00
131.50
131.70
132.DO
132.40
132.90
133.50
133.50
133.60
133.60
134.10
134.20
134.50
135.00
13 5 . 00
135.00
13 5 . 00
135.70
135.fcO
135.90
135.9Q
136.40
137.00
137.30
1 37.
117.
137.
13C.
13E.
13E.
136.
13E.
13f.
13E.
135.
139,
140,
740,
140,
14C.
30
30
90
30
3C
5C
6U
70
70
EC
40
80
OC
CO
00
1L
140.20
140.20
140.50
140.50
14Q.6Q
140.SQ
140.90
141.00
141.60
141.7Q
141.9o
142.00
142.fiQ
143.00
144.00
144.bO
14S.70
149.30
149.50
150.00
151.30
154.40
157.
1S£.
166.
169.
176,
196,
220,
220,
243,
24S,
00
00
00
fO
30
60
00
00
30
00
574.00
INTER-LABORATORY STUDY
POLLUTANT - S02
SATPLE NUMBER - 5
N P2
TRUE-VALUE 137.30
rfAN 141.96
rEDlAN 135.65
BATA IN ASCENDING ORDER
1177
UNITS - MILLIGRAMS PER DRY STD CUBIC PETER
»*** WITH OUTLIERS REMOVED ****
P ANGF
VARIANCE
STD. DEV.
C OEF . VAR .
218.90
767.13
27.73
19.51
C.I.(UPPER) 147.98
C.I.tLOUE R) 135.99
SKEUNESS *?7
ACCURACY .98
29.10
91.60
100.70
105.00
117.10
120.00
124.30
127.50
128.10
130.00
131.00
131.10
131.70
112.30
132.40
132.50
133.50
113.50
133.60
133.60
134.10
134.20
134.50
135.00
1*5.00
135.00
135.00
135.70
135.60
135.90
135.90
136.40
137.00
137.30
137.30
137.30
157.9C
13E.
13E.
13B.
13E.
13E
13E
140.
143.
140.
14D.1Q
14C.21
.30
.30
.50
•6C
.70
.70
• ec
.40
. at
,oc
.oc
.00
140.20
140.50
140.50
140.60
IAD.SO
140.90
141.00
141.60
141.7Q
141.9Q
142.QO
142.80
143.QO
144.0Q
144.SQ
146.70
149.30
149.50
150.00
151.30
154.40
157.00
156.00
166.00
169.fO
176.30
196.60
220.00
220.CO
243.30
24&.00
35
-------
rNTE'-LABORATORv STUDY
POLLUTANT - S02
SAfPLE NUMBER - 7
H E5
TRUE-VALUE 1410.90
»EAk 1393.95
1EDIAN 1291.70
DATA IN ASCENDING ORDER
1177
UNITS - MILLIGRAMS PER DRY STD CUMC
RANGf 734.10
VARIANCE 6144.57
STD. DEV. 7£.3?
COEF. VAR. 5.62
C.I.(UPPER)I410.61
C.l.CLOk'E R51377.2?
SKECKFSS 2.63
ACCURACY -1.26
1140.90
1220.00
1257.CO
1297.50
1111
1517.
1320.
1127.
1342
1345,
1348.00
1353.50
1363.40
1367.00
1369.60
1370.DO
1371.60
1:72.60
.70
.50
.00
.60
.20
.60
1372.90
1373.00
1374.00
1375.20
1376.40
1376.80
1377.00
1377.20
1377.30
1379.70
13SO.CO
1381.60
13S3.00
13S3.00
13E2.90
1355.50
1336.40
1387.ZQ
13 t E. 0 0
13fcE.Ou
1390.00
1390.10
13 9 D. 2 C
1391.20
1391.7C
1392.00
1392.6j
1J 5 3 . 6 C
1394.00
1354.10
1395.30
1395.60
1395.60
139£.00
1396.30
1397.OC
13"7.9C
1398.00
1399.4Q
1400.00
1400
J401
1401
1402
1405.20
1405.30
1406
1410
1410
1410.0Q
1410.30
14T6.60
1416.60
1417.20
.90
•00
, OQ
50
00
00
I4ic.no
1422.CO
1425.00
1425.10
1427.4C
14'35. 20
1441.50
144i.DO
1446.40
15C3.*C
1556.CO
1652.rO
1E75.DO
INTER-LABORATORY STUDY
POLLUTANT - S02
SAMPLE NUKPER - 7
N t2
TRUE-VALUE 141Q.9Q
>1EAN 1358.02
IEDIAN 1191.45
DATA IN ASCENDING ORDER
1177
UNITS - MILLIGRAMS PER DRY STD CUBIC
**** VITH OUTLIERS REMOVED *»*•
RANGE
VARIANCE
STD. BEV.
COEF. VAR.
33E.OO
1?67.09
43.21
3.11
C.I.CUPPfRJ1397.37
C.I.CLOWE R31376.67
SKE.NESS -,2f
ACCURACY -1.38
1Z20.3Q
1257.00
1297.50
1311.70
1317.50
1320.00
1327.60
1342.20
1345.50
1348.00
1353.50
1363.40
1367.00
1369.60
1370.00
1371.60
1372.60
1372.*0
1373.00
1374.00
1375.20
1376.40
1376.60
1377.00
1377.20
1377.30
1375.70
13EO.CO
13S1.00
1333.00
1383.00
1363.90
13P5.50
13E6.40
13t7.2C
131E.OC
1390.00
1390.1C
13VC.2L
1391.20
1391.7C
1392.00
1 3 9 2 . 6 C
1392.6C
1394.00
1394.10
1395.3C
1395.6C
1395.60
1396.CU
1396.30
1307.00
1397.90
1398.0Q
13P9.4Q
1400.0Q
1400.9Q
1401 ,QO
1401.60
1402.00
1405.20
1405.
1406.
1410.
1410.
.30
•50
•00
• 00
1416.40
14 16.60
1417.30
14 1b.f)C
1422.00
1425.00
1425.10
1427.40
1435.20
1441.5C
1441,.CO
1446.40
1503.60
ISSb.OO
1410.00
1410.30
36
-------
INTER-LA30R ATORt STUDY
POLLUTANT - S02
SAMPLE NUMBER - 8
TRUE-VALUE 2592.90
MEAN 2567.51
«!£OIAN 25o2.60
DATA IN ASCENDING ORDER
1177
UNITS - P.ILLIGRHMS PER DRY STD CUEIC METER
RAFGE T42.50
VARIANCE 9C10.41
STD. DEV. 94.92
COEF. VAR. 3.70
C.1.(UPPER)25£7.81
C.I.(LOVE R>254'7.21
SKEWNESS .26
ACCURACY -1.17
23S6.50
2420.DO
2440-00
2458^
24 74
24S9.
.40
.00
.20
2490.40
2511
2514
2514
2516.50
2517.30
2517.50
2518
2518
2525
.CO
.00
.30
20
50
00
2526.10
2526.70
2532.10
2534.43
2534.53
2534.&D
2536.93
2539.50
2540.CO
2543.00
2546.00
254&.40
2S4E-.70
2548.90
2551.00
2551.40
2551.40
2554.40
255E.PC
2555.4C
255?.OC
2559.3C
25 tO
256C
2561
2562
2562
2563
2564
2564
25C4
2566
2570
2570.60
2570.90
01
OC
10
4C
8C
00
CO
3C
70
OC
Dt
2572.00
2573.70
2575.00
2577.30
2578.00
25PO.OO
25S2.40
2584.oo
2584.60
25E6.00
2592.00
2592.90
2594.40
25-56.50
2596.70
2605.00
26C5.00
2605.20
2606.£0
2608.90
2613.10
2615.20
2619
26'21
2627
2635
2644
2662
2676
26S2
2732
2E79
60
00
70
00
SO
00
.00
.30
.00
3029.00
INTER-LA30R ATORY STUDY
POLLUTANT - S02
SAMPLE NUMPCR - 8
TRUt-VALUE 2592.90
•EAN . 2563.91
MEDIAN 2562.40
DATA IN tSCENOINS ORDER
1177
UNITS - MILLIGRAMS PER DRY STD CUBIC KETER
*+** WITH OUTLIERS REMOVED *«**
RANGE 312.3D
VARIANCE 2166.05
STO. CEV. 50.6E
COEF. VAR. 1.95
C.I.CUPPEB)2S74.94
C.I.(LOWE RJ2552.67
SKEW NESS .22
ACCURACY -1.18
2420.00
2440.00
2458.40
2474.CO
2(89.20
2490.40
2511.00
2514.00
2514.00
2516.60
2517.00
2517.BO
2518.20
2516.50
2525.30
2526.10
2526.70
2532.10
2534.40
2534.50
2534.80
2536.90
2539.50
2540.00
2543.00
2546.00
2548.40
2548.70
2548.90
2551.00
2551.40
2551.40
2554.40
255.E.OO
255F.4C
2559.DC
2555.30
2560.00
256C.OG
2561.10
2562
2562
25t3
25t4
2564
2564
256i
25/0
257C
2573.70
2575.00
40
EC
00
00
3C
70
00
PO
CO
257C.90
2572.00
2578.0Q
2550.00
2522. «0
2584.QO
2584.60
2586.0Q
2592.00
2592.90
2594.4Q
2596.50
2596.70
2605.00
2605.00
2605.20
260&.80
2606.90
2613.10
2615.20
2619.60
2621.00
2627.70
2635.00
2644.BO
2662.00
267o.30
2682.00
2732.30
37
-------
INTE3-LA30SATORY STUDY
POLLUTANT - NOX'
SAMPLE NUM9ER - 1
N 37
TRUE-VALUE 1913.30
•1EAN 1668.08
APPENDIX B
NO SUMMARY DATA
x
0577
UMITS - MILLIGRAMS PER DRY STD CUBIC «tT£R
RAN6E 4270.10
VARIANCE £42723.21
STD. OEV. S18.00
COEF. VAft. 48.62*
C.I.
-------
INTER-I.A30RATORY STUoY
•OLLUTANT - NOX
NUMBER - 2
0577
TRUE-VALUE 95.70
1EAN 137.66
MEDIAN 99.30
DATA IN ASCENDING ORDER
UYITS - MILLIGRAMS PER DRY STD CUBIC I»ETER
RANGE 1275.6D
VARIANCE 49CJ6.52
STD. DCV. L21.44
COEF. tf AR . 160.E7
C.I.(UPPER) 212.09
C.I.CLOWE R) 63.22
SKEI.NESS 5.13
ACCURACY 3.76
43.90
50.00
76.JO
64.00
67.00
68.50
89. 40
92.00
92.50
93.00
93.60
96.00
96.00
57.30
59.2C
99.4C
1CC.OO
1C0.3G
1C0.90
104.00
104.40
107.50
109.10
109.50
110.50
113.90
117.
116.
154.
183.
194,
10
GO
60
50
00
1376.50
INTER-LA90*ATORt STUDY
POLLUTANT - NOX
SAMPLE NUMBER - 2
33
95.70
100.12
99.20
DATA IN ASCENDING ORDER
TRUE-VALUE
1EAN
0577
UK1TS - MILLIGRAMS PER DRY STD CUBIC !"ET£K
*»** WITH OUTLIERS REMOVED «*•*
RANGE
VARIANCE
STD. DEV.
COEF. VAR
193.13
1155.11
53.99
33.95
C.1. 111.71
C.I.(LOWE R) J&.52
SKEWNEiS .22
ACCURACY 3.66
.90
43.90
50.30
76.30
84.00
87.30
&S.50
89.40
52. DO
92.50
93.00
93.80
96.00
96.00
56.5C
57.3C
59.20
5?.4U
1CO.OC
100.30
1LD.90
104.00
104.40
107.50
109..10
109.50
110.50
113.50
117.10
1 IS.EG
154.60
1£3.50
194.00
39
-------
INTER-LA30RATORY STUDY
POLLUTANT - NOX
SAMPLE NUMBER - 3
v 40
TRUE-VALUE 669.30
•EAN 637.26
1EDIAN 673.25
DATA IN ASCENDING ORDER
0577
UNITS - MILLIGRAMS PER DRY STO CUC1C f£T£R
R ANGE
VARIANCE
STD. OEV.
CCEF. VAR
1^6.5D
•7625.61
295.93
46. 45
C.I.(UPPER) 726.99
C.I.CLOWE R) 545.54
SKEWNESS -.08
ACCURACY .52
6.60
6.»0
76.90
138.30
160.40
332.90
367.50
360.30
435.00
559.70
563.40
602.90
610.70
611.CO
614.00
630.00
647.00
657.20
&6I.OC
669.5C
677.Ou
6E5.0G
697.90
7D4.00
7C5.8C
7C7.00
7E1.1D
726.00
710.00
748.EO
787.50
803.60
813.30
824.50
827.&0
829.70
1310.60
1100.PO
11EO.OO
1453.10
INYER-LASORATORY STUDY
POLLUTANT - S'OX
SA1PLE NUMBER - 3
TRUE-VALUE
1EAN
•EDIAN
39
669.50
616.35
669.50
O577
UNITS - MILLIGRAMS PER DRY STO CUD1C r£T£K
**** VITH OUTLIERS REMOVED •***
RANGE 1173.43
VARIANCE 71>46.47
STD. DEV. ZS8.23
CGEF. VAR. 43.52
C.I.(UPPER) 7C0.5J
C.I.CLOWE R) 532.16
SKEWNESS -.60
ACCURACY -.04
DATA IN ASCENDING ORDER
6.&0
6.30
76.90
138.30
180.40
332.?0
367.50
JbO.DO
415.00
559.70
568.40
602.9C
610.70
611.00
614.00
630.00
647.00
657.20
663.CO
sts.sc
577.OC
6E5.0C
657.9C
704.OC
706.80
707.00
721.10
726.00
730.00
748.20
787.50
803.60
813.30
824.50
ez7.eo
82V.70
131C.60
11CC.CD
lltO.PO
40
-------
INTER-LA90RATORY STUDf
POtLUTANT - NOX
SAMPLE NUMBER - 4
V 36
TRUE-VALUE 1435.40
•EAN 13&B.31
1E01AM 14S1.75
DATA IN ASCENDING ORDER
0577
UNITS - MILLIGRAMS PER DRY STO CUBIC METER
RASiGE 2S4C.43
VARIANCE 2&3205.71
STD. DEV. £22.35
COEF. VAR. 38.35
C.J.(UPPER)t561.91
.C.I.CLOWE. 8)1214.11
SKEWNESS -.22
ACCURACY 1.14
13.50
154.50
523.20
743.00
7SQ.OO
810.30
701.70
113S.90
1141.20
1292.30
1296.60
1356.00
1405.00
1409.00
1415.70
1425.73
1426.OC
1427.5C
1466.00
14&4.5C
1496.70
145E.3C
1553.00
1523.50
1552.10
1600.00
1620.00
1645
1702
1729
8jO
20
iO
1749.80
1775.00
.1796.30
2046.90
2059.30
2954.20
1NTER-LA30RATORY STUOV
POLLUTANT - NOX
SAMPLE NUPI9ER - 4
M 34
TRUE-VALUE 1435.40
1EAN 13&2.36
"EDlfiN 1451.75
DATA IN ASCENDING ORDER
0577
UNITS - MILLIGRAMS PER DRY STD CUBIC KETER
*«*« WITH OUTLIERS REMOl/ED *»**
RANGE 1?04v4D
VARIANCE 168980.7D
STD. DEV. 411.07
COEF. VAR. 29.74
C.I.CUPPERJ1520.54
£.J.(LOUE R21244.19
SKEWdiESS -1.00
ACCURACY 1.14
154.90
528.00
743.DO
790.00
310.00
901.70
1138.90
1141.20
1292.30
1296. fiO
1405.00
1409. CO
1415.70
1425.7C
1426.00
1427.5C
14t6.0C
14fcA.SC
1496.7C
1533.00
1533.50
1552.10
160Q.
1630,
1645.
.op
.00
.ac
1702.20
1729.30
1749.EO
1775.00
1796.30
2046.90
2059.20
41
-------
INTER-LA90RATOR» STUDY
POLLUTANT - NOX
SA1PLE NUMBER - 6
v) 44
TRUE-VALUE 1913.50
•EAM 1911.41
1EDIAN 1566.75
DATA IN ASCENDING ORDER
0577
UMTS - MILLIGRAMS PER DRY STD CUDIC
7153.20
VARIANCE 1715347.05
SID. DEV. 1328.66
COEF. VAR. 49.51
C.I.CUPPER32304.01
C.I.(LOWE R>151H.S2
SKEW-NESS 1.54
ACCURACY -2.46
5.50
19.20
19.40
1&1.30
194.50
214.20
762.DO
974.10
994.00
998.00
1049.00
T075.C3
1355.03
1490.00
1523.73
1643.50
1677.03
1727.20
1S45.0C
155C.OC
IS 59.00
1S 7 < . 5 C
1377.00
1.94C.OC
19IZ.OC
19E9.9C
2006.
2051.
2090.
2136.
00
30
00
40
2161.90
2219.
2-290.
2300.
00
00
00
2491.10
2669.60
3090.00
3625.00
36£0.00
3937.80
4536.CO
725E.70
2302.50
JHTEP-LA30RATORY STUDY
POLLUTANT - NOX
SAfPLE NUM3ER - 6
1 43
TRUE-VALUE 1913.30
*EAN 1757.36
"EOIAH 1659.30
»ATA IN ASCE^OIN5 ORDER
0577
UNITS - MILLIGRAMS PE.R DRY STD CU6IC "ETC"
**** WITH OUTLIERS REMOVED ****
RANGE 45.30.53
VARIANCE 1110749.70
STD. DEV. 1G53.92
COEf. VAR . 58.93
C.I.CUPPER)2102.07
C.I.CLOWE RM472.04
SKEYfceSS .47
ACCURACY -2.b6
5.50
19.20
19.40
1E1.50
194.50
264.20
762.30
974.10
994.30
998.00
1049.CO
1075.00
1355.00
1490.00
1533.70
1643.50
1677.00
1727.20
1746.OC
1S45.00
1S5D.OC
1S55
1S74
1B77
1940
OC
5C
OC
OC
1912.00
1969.90
2006.00
2051.30
2090.00
2136.40
2161.90
2219
2290
2300
00
00
00
2491.10
2669.EO
309C.CC
2635.00
361:0.30
3937.£0
4836.00
2302.50
42
-------
INTER-LABORATORY STUD>
POLLUTANT - NOX
SAMPLE NUM9ER - 7
S 46
TRUE-VALUE 669.30
«!EAN 447.77
MEDIAN 668.75
DATA IN ASCENDING ORDER
O577
RAKGE
UNITS - MILLIGRAMS P£R &RY STD CUBIC K£TEK
STD. OEV.
COEF. VAR
1413.13
1G3£46.64
121.94
49.70
C.I.(UPPER) 740.cO
C.I.(LOVE R) 554.71
SKEU.MESS .05
ACCURACY 2.63
1.90
5.90
6.70
6.90
78.50
268.00
115.30
336.50
376.70
497.00
545.10
60C.OO
617.00
632.60
635.20
643.00
649.00
667.00
666.10
673.00
672.DC
675.Q:
67E.CC
6*9.5C
700.OC
7C2.3C
7C4.QC
704.6C
710.7t
712.30
713.00
714.00
730.00
730.OP
730.00
745.70
7.60.50
782.00
7S3.30
810.30
620.CO
862.60
1300.00
1303.00
1395.00
1415.00
INTE"»-tA90R ATORY STUDY
POLLUTANT - NOX
SAMPLE NUMBER - 7
46
669.30
647.77
6&6.7S
DATA IN ASCENDIN6 ORDER
TRUE-VALUE
1EAN
0577
UNITS - MILLIGRAMS PER DRY STD CUBIC KETER
**** WITH OUTLIERS REttOYEO ****
RANGE 1413.13
VARIANCE 1Q2C46.&4
STD. DEV. 321.94
CCEF. VAR. 49.73
C.I.(UPPER) 740.80
C.I.ILOUE R) 554.73
SKEW NESS .05
ACCURACY 2.63
1.90
5.90
6.70
6.90
78.50
268.00
315.30
336.50
376.70
497.00
545.10
600.00
617.03
632.60
635.20
643.00
649.00
667.00
66?. 10
673.03
673.00
675.00
659.50
7CO.OO
7C2.30
704.00
704.60
710. 7C
71?. 3C
713.00
714.00
730,00
730.00
730.00
745.70
760.50
752.00
7S3.30
810.20
820.00
1300.00
1303.00
1395.00
1415. CO
43
-------
INTER-LA30RATORY STUDY
"QILUTANT - NOX
SAMPLE NUI»?IR - 8
S 42
TRUE-VALUE 1435.40
»EAN HtO.42
«! E 0 1A N 1497. 50
DATA IN ASCENDING ORDER
057?
UNITS - KILL IGRM1S PfcR DRY STD CUD1C PETER
K/.fcGF 3112.60
VAKIAKCE 622299.82
STD. DEV. 7?8.65
CCEF. VftR. 54.C2
C.I.(UPPER)I699.00
-C.I. (LOWE, H)12?1.tC
SKEW NESS .12
ACCURACY A.33
4.20
13.60
14.70
110.40
1S4.&0
579.30
7A7.00
773.00
319.00
95£.<>0
1143.00
1205.00
12°1.00
1313.00
1337.60
1341.00
1412.50
1460.00
14 £ 9.1 C
1471.20
1455.00
1500.DC
15CD.OC
1511.00
1512.00
1522.1C
1574.9C
1642.40
1662,
1 690.
1 729,
1805.
1810,
1946,
00
00
30
40
00
60
00
2269.20
2675.CO
2773.ro
3070.DO
3109.€0
31 17.DC
1996.40
INTE8-LA30RATORY STUDY
POLLUTANT - NOX
SAMPLE NUMBER - 6
N 42
TRUE-VALUE 1435.40
«EAN 1460.42
MEDIAN 1497.50
DATA 1H ASCENDING ORDER
0577
UNITS - MILLIGRAMS PER DRY STD CUBIC "ETEK
**** U1TH OUTLIERS REMOVED ****
RANGE 3112.50
VAKIAKCE 622299.82
STD. DEV. 7&B.B6
COEF. VAR. 54.02
C.I.(UFPER)1699.CO
C.I.(LOWE RM221.it
SKEWNESS .12
ACCURACY 4.3!
4.20
13.iO
14.70
110.40
154.50
579.00
747.00
773.00
519.00
95E.aO
1143.00
1205.00
1291.CO
1313.03
1337.60
1341.00
1412.50
1460.00
146?.1C
1471.30
1 4 9 5 . 0 f •
15CC.OC
1500.OC
1511.00
1512.OC
15 3 2 . 1 C
1574.9C
1642.40
1662.00
1690.00
1729.3Q
1799.40
1805.00
1310.60
1946.00
1996.40
2269.20
2675.rO
2773.00
3070.00
3109.60
31 17.00
44
-------
INTEH-LA90RATORY STUDY
POLLUTANT - NOX
SASPLE NUMBER - 9
H 39
TRUE-VALUE 95.70
IEAN 99.39
YEDIAN 96.60
DATA IN ASCENDING ORDER
0577
UNITS - MILLIGRAMS PER DRY STD CUBIC METER
K ANGE
VARIANCE
STC. DEV.
CGEF. VAR
J21.13
2677.69
51.75
52.22
C.I.(UPPER) 115.34
C.I.CLOWE R) £2.85
SKEVNESS .20
ACCURACY .94
.90
1.30
1,?0
20. 60
36.30
44.QO
43.10
52.00
76.43
86.63
90.00
92.CO
92.50
93.60
93.70
93.90
5 5 . 8 C
91. 0G
96.30
96.6G
57.80
9E.OO
9E.90
1DD.OC
100.
100,
106.
111.
111.
118.
119.
30
40
00
QO
00
50
50
128.00
133.10
158.00
181.00
1EE.20
152.CO
193.FO
222.00
INTEU-LA90RA10RY STUDY
POLLUTANT - HOX
SAMPLE NUMBER - 9
N 39
TRUE-VALUE 95.70
1EAN 99.09
•EDIAN 96.60
DATA IN ASCENDING ORDER
O577
UNITS - MILLIGRAMS PER DRY STD CUBIC ("ETER
>*** WITH OUTLIERS REMOVED »«**
RANGE 221.13
VARIANCE 2677.8?
STD. DEV. 51.75
COEF. VAR. 52.22
C.I.(UPPER) 115.34
C.I.(LOWE R) 82.85
SKEWNESS .20
ACCURACY .94
.90
1.00
1.20
20.60
36.30
44.30
48.10
52.00
76.40
86.60
90.00
92.00
92.50
93.60
93.7D
93.93
55.80
$£.00
9e.3C
(£.60
97.80
9E.OO
VS.90
1CC.OC
100.30
100.40
106.00
111.
111.
118.
119.
&0
00
50
50
128.00
133.10
158.00
181.00
1S8.20
192.00
193.80
222.00
45
-------
INTES-LA30RATORY STUDY
"OLLUTANT - NOX
SAMPLE NUMBER - 1
V 67
TRUE-VALUE 421.00
*(.KH 442.36
1ED1AN 435.30
DATA IN ASCEKD1MS ORDER
1 177
UNITS - MILLIGRAMS PLR DkY S70 CUbIC
RA'.'GE 749.03
VARIANCE 14i£3.4?
S TD. OFV. 119.51
COEF. VAR. 27.C4
C.I. CUPPER ) 472.68
C.I.(LOWE R) 413.44
SKEWNESS 1.S3
ACCURACY 3.23
210.0Q
229.00
252.00
250.00
251.50
2oE.70-
326.20
326.iO
375.50
3&3.50
397.30
400.30
400.40
404.30
408.OD
409.50
412.90
415.3D
419.70
420.GO
422.50
422.60
423.00
423.30
427.20
42E.CD
425.40
429.90
4 31.PL
433.01-
434.CO
4-4.00
4 2 4 . 5 T
435.OC
4 3 E . 0 C
430.80
439.00
4 3 ? . 7 U
4 4 C . 0 0
442.21
445.Ou
446.OC
449.50
450.00
450. 3C
451.60
452.20
455.60
456.'jO
457.20
457.4c
461.iD
461.fcD
462.£0
465.00
466.70
471.4Q
475.iO
4t5.CO
4S£.40
485.40
505.50
5UE.30
761.70
7t2.70
? 1fc.70
959.CC
INTES-LA30RATORY STUDY
POLLUTANT - NOX
SA-PLE NUM3ER - 1
>i 64
TRUE-VALUE 42100
"c/»N 422.77
MEDIAN 434.25
DATA IN 4SCEKOING ORDtR
1177
UNITS - KILLIGRAHS PER DRY STO CUtlC
>**» WITH OUTLIERS REMOVED •***
RANGE
VARIA\CE
STD. D£V.
COEF. VAR
6^50.52
79.Q6
18.7D
t.I.(UPPER) 442.14
C.I.(LOWE R) 403.43
SKEUNE'SS .06
ACCURACY 3.15
no.30
229.30
232.00
250.30
251.30
263.70
326.00
326.SO
375.50
I«3.50
397.00
400.30
400.40
404.00
40£.OD
409.50
412.90
415.30
41 9 . 73
420.00
422.50
422.60
423.03
423.30
427.23
42t.00
42E.4C
429.9C
421.00
4 13 . 0 C
434.OC
434.OC
4-4.5C
4 2 5 . 0 d
435.CC
4 3 E . S C
439.OC-
439.7C
440.CC
442.20
445.00
446.0Q
449.50'
450.QO
450.3Q
451.60
452.20
455.6Q
456.0Q
457.to
457.40
4M.60
461.C0
462.ro
4 6 5 . C 0
466.7C
471.40
475.40
4£5.0C
4£i.4Q
4&9.4Q
505.50
50E.30
761.OC
46
-------
INTER-LA?ORATORY STUCY
POLLUTANT - NOX
SAMPLE NUMBER - 2
V 65
TRUE-VALUE 151.50
MEAN 1e6.33
• EOIAN 15f.20
DATA IN ASCENDING ORDER
1177
UNITS - PILllGRAKS PCR DRY ST6 CUfcIC
RANGE 1T14.33
VAKjASCE 43C5E.94
S7D. DEV. i'07.51
COEF. VAff. 110.13
C.I.(UPPER) 23S.78
C.I.CLOWE R) 117.38
SKEXNESS 7.OB
ACCURACY 4.56
75.70
e7.40
89.40
95.00
96.50
97.30
131.40
135.30
136.20
133. 3D
138.00
146.00
145.50
146.tD
147.33
1*£.CO
148.9D
150.00
15C.03
131.73
153.00
153.GO
153.00
153.40
153.6D
153.90
154.00
155.51
157.5L
157.70
15E.2C;
15E.2C
ISC.50
15?.20
1t1.CC
Itl.OC
1t1.it
It 1.7;;.
1t1.£('
Its.DC
163.10
166.30
166.6c
167.6.0
168.00
170.0Q
171.00
171.00
172.QO
172.6Q
173.20
173.60
176.6C
179.90
1E6.9Q
194.20
206.iQ
213.10
234.00
30£.9Q
315. £0
396.00
1790.00
1NTE3-LA20RATORY STUoY
POLLUTANT -. \ox
SAMPLE WUKDES - 2
M 64
TttUt-VALuE 151.30
^E»N 1c3.30
•ED1AN 155.20
DATA IN ASCENDING ORDER
1177
UNITS - IIILLIGR^MS PER DRY S7D CUBIC K£T£R
**»« WITH OUTLIERS REKOYEO *•**
RANGE
VARIANCE
ST6. CEV.
CCEF. VAR.
4£.£5
29.91
C.I.tL'PPES) 175.27
C-.HLOUE R) 15!.
SKE.NESS 2.31
ACCURACY 4.56
75.70
87.40
£9.40
95.CO
V6.50
97.00
131.CO
135.30
136.30
138.00
138.00
142.30
144.30
145.50
146. JiD
147.30
1U.03
14&.VD
150.00
150.00
151.73
151.03
153.03
153.00
153.40
153.63
153.9u
in.or
1 5 5. 5 C
157.5U
157.7C-
15E.2C
15E.2C
15£.5C
159. 31'
161.DC
Itl.Ou
161.4C
1 M . 7 I
161.30
162.00
162.5Q
163.10
166.3Q
166.6Q
167. 8p
168.0Q
170.0Q
172. oo
172.6Q
173
173
176
179
1E6
194
206
213.30
234.00
3CE.9Q
315.HO
396.00
20
60
60
90
00
20
SO
47
-------
INTE3-LABORATORY STUOV
OOLL'JTAI.T - NOX
SAMPLE NUM?ER - i
v 67
TRUE-VALUE E03.SD
•; EAN E63.90
"EDIAh 631.50
DATA IN ASCENDINS ORDER
1 177
UM1TS - MLL1GK*MS PER CHY Sit) CUf>SC ^ E 1 E
RANGE 1f.SO.OD
VAK1AT.CE 77tS7.94
S7D. DEV. :7£.67
CCEF. VAR. ;2.2 i
C.i.(LO-E. R) 757.IT
'SKE«'NFSS 1-1^
ACCURACY 3-*5
156. DO
160.00
4E3.00
470.30
521.30
$53.30
678.70
752.00
760.00
765.50
767.00
7E1.DO
783.30
7S3.6C
769.10
790.30
797. 5C
600. £,0
B1C.UO
SIO.fcQ
812.00
81 4. DO
£15.00
B16.0D
£17. 5D
S2S
322
£27
527
SIC
,00
. oc
,Su
.00
531.5L
353.00
StG.Ot:
3 «, 3. 0 0
?t^.?^
353.7D
3 J * . 5 i.
351.3"
? 5 7 . 4 c
658.00
665.00
867. OQ
871 .CO
E75.90
8BG.70
SS1.3Q
891 .20
901.QO
902.00
911.60
917.20
917.70
926.50
732.20
932. JO
9:5.40
134S.EG
15 CD. 30
1541. CO
1655.00
16&4.50
1306.20
STUcY
POLLUTANT - xox
SAMPLE NUMBER - 3
V 64
TRUE-VALUE £u3.EO
•EAN 323.99
£28.75
1177
U»<1TS - MILLIGRAMS PER PRY S T D CUBIC
«*** WJTH CUTLIfRS REMOl/ED ****
RANGE
VARIANCE
SIP. OEV.
C OEF . VAR .
i;.°4.03
45.27.41
;12.23
25.75
C.I.(UPPER) 175.9f
CiI. (LOWE R ) 772 .01
SKErfNCSS .10
ACCURACY S.1C
PATA IN ASCEMJN3 OhPER
156.00
160.00
423.00
470.00
C93.?.0
521.SO
653.10
575.70
752.30
760.00
765.50
767.30
7&1.CO
7E3.0C
7SS.60
769.10
790.30
797.50
B10.0C
£10. HO
£12.00
£12.00
314. CD
El 4. 03
£15. CO
S11.0C
S 1 7 . 5 r
E2C.Ot
3I2.6C
£27.DC
E27.5C
830.DC
8i.1.5"
833.DC
840.CC
343.OC
8 4 4 . £ I.
S 5 3 . 7 C
854.50
656.50
857.40
858.GO
865.up
867.00
871.00
E75.9o
850.7o
881 .Oo
835.AC
891.20
901.QO
902.00
911 .60
917.20
917.70
926.50
932.20
932.€0
935.40
1004.30
1345. fD
1500.CO
154C.OO
48
-------
IN7ER-LA30RATORY STUDY
"OLLUTANT - NOX
SAMPLE NUMBER - 7
M 68
TRUE-VALUE 1fai7.DO
l£AN 1944.97
«EDlftN 1509.35
DATA IN ASCENDING ORDER
1177
UNITS - MILLIGRAMS P£R DRY STD
RANGE 4i*0.30
VAKiAKCE 293T52.e?
STD. DEV. HI.S3
COEF. VAR. 27.64
C.I.2073.69
C.I.CLOWE R>1S16.2<
SKEWNESS 1.13
ACCURACY 3.54
147.7Q
1009.00
1D50.DO
1138.70
1227.JO
1377.60
1(28.10
1568.00
U43.00
1692.00
1740.10
1753.50
1765.30
1766.50
1769.00
177E.OD
17E6.40
1803.50
1803.52
161&.30
1620.CD
1827.30
1848.03
1fc45.23
1851.40
1£5fc.OO
1575.43
U76.00
1S&D.CC
1815.8L
13 t f . 0 L
IBfcr.OC
1S57.0C
19C5.DC
1 9 1 3 . 7 0
1920.DC
19Z5.0&
1927.61.
192E.OO
1932.8C
195C.OC
195E.OC
1955.30
1962.00
1954.50
19?5.CO
1994.QO
2015.90
2017.QO
2026.9Q
2047.00
20S1.1Q
2070.2Q
20£1.<3o
2052.0Q
20?6.70
2104,
21 15,
2133,
2177,
2190,
2193;
2267.
2769,
3177.
3356.
60
10
DD
30
10
10
50
60
00
20
3503.00
4205.00
INTER-LA30RATORY STUDT
POLLUTANT - NOX
SAMPLE NUKSEa - 7
* 65
TRUE-VALuE 1C37.30
1513.E4
19C5.00
1177
UNITS - MILLIGRAMS PER DRY S7o CUBIC f»ETER
**** WITH OUTLIERS REHOtfEO ****
RA.VGE 2277.20
VARIAKCE 137593.72
STD. DEV. 370.94
CCEF. VAR. 19.33
C.1.CUPPERJ2C04.02
C.I.(LOWE R)1i23.66
SKE»hESS 1.Q4
ACCURACY 3.70
DATA IN ASCEHDINu ORDER
1009.0Q
1050.SO
113&.7Q
1227.30
1377.50
U23.10
1568.CO
1643.00
1592.00
1740.10
1753.50
1765.00
1766.50
1769.00
177E.OO
1736.40
1803.50
1SC3.50
1618.33
1820.00
1C27.30
1648.00
1S49.20
1851.40
1858.00
1875.43
1S76.CO
13£p.OO
1S£E.OC
1SS7.0C
1905. OC
1913. 7C
1920. OC
1925.00
1927.60
192E.OC
1932.8o
1953.00
195f.CC
195E.Cc
1962.00
19S4.50
1985.00
1994.QQ
2015.9Q
2017.Q0
2026.90
2047.QQ
E.051.10
2070.2o
2081.&Q
20B2.00
20S6.70
2104.60
2115.10
2123.00
2177.30
2190.10
2153.10
2267.90
2769.60
3177.00
3366.20
49
-------
INTER-LAHORATORY STUDY
POLLUTANT - MOX
SAXPLE NUMBER - 9
N 67
TRUE-VALUE 1531.CO
"EAN 1557.47
"EPIAN 1577.10
DATA IN «SCE*3IHS ORDER
1 177
UNITS - MILLIGRAMS P£R DRY STo CUBIC
RANGE. 2(91.03
VARIANCE i;«EV. 253.44
COEF. VAR. 16.99
C.I. (UF'PtR J1 5U.O?
C.I.CLOWE RJU57.44
SKEvNFSS -1-.49
ACCURACY 2.5«
733.00
!02.00
=16.CO
SbO.CO
979.20
997.30
1157.4C
1171.00
1257.00
13C1.00
1344.40
1I4B.OO
1370.50
1432.00
141E.60
1499.50
1503.10
150E.OO
1524.13
1529.03
1537.50
1539.00
1540.00
1542.70
1545.03
1550.03
15 5 c . 0 (..
15S2.00
15tC.«C
15 11. 9 C
15 14 . t C
1566.00
15 7 5 . 41
1577.1C
15iC.CC
1&C2.0C
1604. 9i_
1612.70
16U-.OC-
1620.
1623.
1625.
1637.
1656.
1657,
1671.
1671.
16?5.
1687.
1691.
16«?2. ID
16C5.5c
.70
.00
, GO
• Oc
>6p
.30
.20
.20
•10
.GO
17C4.ro
172S.OC
1727.50
1734.5C
1755.SO
1756.40
1769.00
1776.6C
17t9.80
1519.60
1S54.JC
1684.40
50
-------
TECHNICAL REPORT DATA
'.Plcssc read fimr.icnciHS on the /v'.vnv ic.'orc
EPA" 500/4-79-045
2.
3. RECIPIENT'S ACCE55IQi>NO.
rL= A.\O SUBTITLE
A SUMMARY OF THE INTERLABORATORY SOURCE PERFORMANCE
SURVEYS FOR EPA REFERENCE METHODS 6 AND 7 - 1977
6. PERFORMING ORGANIZATION CODE
8. PERFORMING ORGANIZATION REPORT NO.
R. G. Fuerst, R. L. Denny, and M. R. Midgett
9. PERFORMING ORGANIZATION NAME AND ADDRESS
10. PROGRAM ELEMENT NO.
Quality Assurance Branch
Environmental Monitoring and Support Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
1AD800
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
Environmental Monitoring and Support Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA 600/08
15. SUPPLEMENTARY NOTES
To be published as an Environmental Monitoring Series Report.
16. ABSTRACT
This report summarizes the 1977 results of a source methods survey program
conducted by the Quality Assurance Branch of the Environmental Monitoring and
Support Laboratory, U.S. Environmental Protection Agency. As part of these surveys,
test solutions prepared as internal quality control samples were sent to interested
participants in May and November for analysis by EPA Source Method 6 for S02 and
EPA Source Method 7 for NO . Each participant returned the analytical results to
the Quality Assurance Branch for evaluation; an individual report was returned to
each participant after processing.
This report contains a summary_of the survey results for the analytical portion
of these two source methods.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Performance Survey
Reference Methods
EPA Source Method 6
EPA Source Method 7
Sulfur Dioxide
Nitrogen Dioxide
43F
68A
N STATEMENT
Release to Public
19. SECURITY CLASS I This Report!
Unclassified
21. NO. OF PAGES
51
20, SECURITY CLASS (Tillspage)
Unclassified
22. PRICE
Form 2220-1 (9-73)
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