EPA-600/4-83-026
June 1983
A SUMMARY OF THE 1981 EPA NATIONAL PERFORMANCE AUDIT PROGRAM
ON SOURCE MEASUREMENTS
by
E. W. Streib, R. G. Fuerst and M. R. Midgett
Quality Assurance Division (MD-77)
Environmental Monitoring Systems Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
ENVIRONMENTAL MONITORING SYSTEMS LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
RESEARCH TRIANGLE PARK, NC 27711
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NOTICE
This document has been reviewed in accordance with
U.S. Environmental Protection Agency policy and
approved for publication. Mention of trade names
or commercial products does not constitute endorse-
ment or recommendation for use.
11
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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 Systems Laboratory, Research Triangle
Park, North Carolina, has responsibility for: assessment of environmental
monitoring technology and systems; implementation of agency-wide quality
assurance programs for air pollution measurement systems; and supplying
technical support to other groups in the Agency including the Office of
Air, Noise and Radiation, the Office of Toxic Substances, and the Office of
Enforcement.
The major task of this study was to report the results of the national
quality assurance audit program for stationary source test methods. Audits
were designed to estimate the minimal analytical and computational accuracy
that can be expected with EPA Method 5 (dry gas meter only), Method 6 (sul-
fur dioxide), Method 7 (nitrogen oxides), and Method 19 (coal). Statistical
analysis was used to characterize the data.
Thomas R. Mauser, Ph.D.
Director
Environmental Monitoring Systems Laboratory
Research Triangle Park, North Carolina
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ABSTRACT
In the spring and fall of 1981 the Quality Assurance Division (QAD)
conducted its semi-annual National Audits for certain Stationary Source
Test Methods. The audit materials consisted of a critical orifice for
Method 5 (dry gas meter only), five simulated, liquid samples each for
Method 6 (SO,) and Method 7 (NO ), and two coal samples for Method 19.
£ A
Laboratories participating in the audits sent their data to the Source
Branch and later received written reports comparing their results to EPA's.
In the Method 5 spring audit, the mean for all participants differed
by 13.6% from the true (EPA) value. For the fall audit, the participants'
mean was 4.3% from the true value. In the two Method 6 audits, the median
values measured for 9 of 10 samples differed by less than 1% from the true
value, whereas the median values for all 10 samples used in the two
Method 7 audits were within 2% of the true value.
This was the first coal audit conducted by QAD. For the sulfur, ash,
and moisture analysis, the participants' accuracy were consistently better
for the higher concentration samples than for the lower concentration
samples.
IV
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CONTENTS
Foreword iii
Abstract iv
Figures vi
Tables vii
Acknowledgments viii
1. Introduction 1
2. Summary 2
3. Dry Gas Meter Audit 6
4. Method 6 Audit 12
5. Method 7 Audit 15
6. Coal Audit 19
References 22
Appendices
A. Frequency distributions 23
B. Instructions for EPA audit materials 28
C. Coal audit statistics 33
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FIGURES
Number Page
1 Cumulative accuracy for the participants
in the Method 5 audits, 0381 and 0981 8
2 Previous results of Method 5 audits 9
3 Results of the Method 5 Audit, 0381 10
4 Results of the Method 5 Audit, 0981 11
5 Previous results of Method 6 audits 14
6 Previous results of Method 7 audits 18
vi
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TABLES
Number Page
I Participants' Results for Method 5 Audit
(All data - no outliers removed) 2
2 Participants' Results for Methods 6 and 7 Audits
(All data - no outliers removed 3
3 Participants' Results for Method 19 Audit
(All data - no outliers removed 5
4 Method 5 Audit Participants 6
5 Method 6 Audit Participants 13
6 Summary of Source SOp Audits 13
7 Method 7 Audit Participants 16
8 Summary of Source NO Audits 16
/\
9 Coal Audit Participants 20
10 Source Coal Audit - 0781 21
vii
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ACKNOWLEDGMENTS
We wish to express our appreciation to the laboratories that partici-
pated in our audits. Thanks also to the Standards Laboratory (EPA/EMSL,
Performance Evaluation Branch) who did our Acceptance Testing on the audit
samples and to the programmers of the Data Management and Analysis
Division, EMSL, for providing the data systems for storing and evaluating
the data.
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SECTION 1
INTRODUCTION
In 1977, the Environmental Monitoring Systems Laboratory (EMSL) of
EPA established a performance audit program to evaluate the performance
of companies that conduct compliance testing using EPA Reference Methods.
The audits verify the analytical accuracy of EPA Reference Methods 6, 7
and 19 and the calibration accuracy of the Method 5 control console (1).
By participating in this free and voluntary program, testing companies
can compare their performance to other laboratories conducting similar
measurements.
In 1981, two audits each were conducted for Methods 5, 6, and 7 and
one audit was conducted for Method 19. Each participating laboratory
received an audit package consisting of the audit sample, a data card,
instructions, and an envelope for returning the data to EPA. For the
Method 5 audits, a label was also included for returning the audit device.
Participants had eight weeks to return data to EPA. At the end of this
period, all data received were statistically analyzed to determine the
participants' precision and accuracy.
This report summarizes the results of the 1981 source audits.
Individual coal results reported by each participant are contained in the
appendices to this report.
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SECTION 2
SUMMARY
In the spring and fall of 1981, EPA's Environmental Monitoring Systems
Laboratory, Research Triangle Park, North Carolina, conducted National
Quality Assurance Audits for Stationary Source Test Methods 5 (dry gas
meter only), 6 (S02), 7 (N0x), and 19 (coal). Industrial laboratories,
contractors, universities, foreign countries, and local, state, and Federal
agencies participated.
Two Method 5 audits were conducted in 1981. The overall results
(no outliers removed) are summarized in Table 1. In the spring and fall
audits, the means for all participants were 13.6% and 4.3%, respectively,
from the true value. After correcting for outliers, the means for spring
and fall audits were 2.9% and 2.7% from the true value. The participants'
performances were not significantly different statistically from previous
national audits (2, 3, 4).
TABLE 1. PARTICIPANTS' RESULTS FOR METHOD 5 AUDIT
(all data - no outliers removed)
Type of
sample
Orifice
Audit
Parameter date
Volume 0381
0981
No. of
analyses
738
723
Mean
(percent
13.6
4.3
Median
from EPA Values)
2.7
2.5
Std.
dev.
110.2
9.7
Table 2 presents the data (no outliers removed) from the two 1981
Method 6 audits. This audit procedure requires the participants to deter-
mine the sulfate content in five aqueous solutions by the Method 6 titra-
tion procedure. For each sample, the participants' means were 7%-25%
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higher than the true value, but in contrast the median value in 9 out of
10 differed from the true value by less than 1%. The participants'
accuracy was lowest for the lowest concentration sample, i.e., only 47% of
the participants in the first audit and 36% in the second audit measured
within 2% of the true value. For the four higher concentration samples,
55%-60% of the participants achieved this level of accuracy in both audits.
As in the 1981 Method 5 audits, the results from the 1981 Method 6 audits do
not differ significantly from those obtained in previous audits (2, 3, 4).
TABLE 2. PARTICIPANTS' RESULTS FOR METHODS 6 AND 7 AUDITS
(all data - no outliers removed)
Type
of
sample Parameter
Aqueous S0?
sulfate
(Method 6)
Aqueous NO
nitrate x
(Method 7)
Audit
date
0281
0881
0281
0881
0281
0881
0281
0881
0281
0881
0481
1081
0481
1081
0481
1081
0481
1081
0481
1081
No. of
analyses
120
98
120
98
120
98
121
98
120
98
89
75
86
74
88
75
89
75
87
76
EPA
(true)
value
305.0
190.7
762.6
610.1
1334.6
1296.4
1830.3
1792.1
2287.8
2402.2
119.5
159.3
298.6
378.3
497.7
557.4
696.8
776.4
895.9
955.6
Participant results
Mean
331.9
245.9
819.6
770.7
1424.2
1614.8
1997.9
2235.8
2448.6
3011.2
147.1
164.2
383.5
377.0
625.4
566.1
888.5
777.2
1108.8
961.5
Median
306
193.4
757.9
608.3
1326.0
1285.9
1823.8
1779.0
2267.9
2385.8
118.0
162.0
301.8
383.3
502.9
562.3
710.2
781.0
900.0
961.3
Std. dev.
269.9
406.5
668.9
1294.6
1179.6
2677.8
1613.7
3744.0
2009.2
5090.5
165.6
56.8
436.7
96.3
706.0
150.9
1095.8
285.4
1211.2
414.1
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Table 2 also presents the data (no outliers removed) from the two
Method 7 audits in 1981. This audit procedure requires the participants to
determine the nitrate content in five aqueous solutions. The overall posi-
tive bias observed in Method 6 for the mean was also observed in Method 7,
but the median value differed from the true value by less than 2% for all
10 samples. In contrast, the mean value for some samples was 28% higher
than the true value. The participants' level of accuracy was consistent
for all five samples in both audits; 31-40% of the testers measured with-
in 3% of the true value on all samples. The participants' performance on
the lowest concentration sample improved slightly compared to the previous
national audits (2, 3, 4), but was not significantly different for the other
four samples. On an absolute basis the accuracy for the lowest concentra-
tion sample was approximately the same as for the four higher concentration
samples.
The results of the first coal audit conducted by QAD are summarized in
Table 3. Participants analyzed each coal sample twice for BTU content and
percent sulfur, moisture, and ash. The participants achieved results that
agreed closely with the true value for sulfur and BTU determinations. How-
ever, the mean values for moisture and ash content in the low-concentration
samples were as much as 11% and 20%, respectively, from the true values.
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TABLE 3. PARTICIPANTS' RESULTS FOR METHOD 19 AUDIT
(all data - no outliers removed)
Type
of Audit
sample date Parameter
Coal 0781 %S
%S
%H20
%H20
%Ash
%Ash
BTU/lb
BTU/lb
No. of
analyses
98
83
97
81
97
81
96
80
98
81
97
81
93
77
92
77
Replicate
1
2
1
2
1
2
1
2
1
2
1
2
1
2
1
2
EPA
(true)
value
1.62
1.62
0.32
.32
1.42
1.42
18.42
18.42
22.14
22.14
4.78
4.78
11339
11339
12084
12084
Participants
Mean
1.55
1.55
0.34
.34
1.58
1.56
17.63
17.50
22.65
22.73
5.73
5.67
11397
11088
11684
11685
Median
1.57
1.59
0.35
0.35
1.69
1.67
18.47
18.57
22.08
22.09
4.70
4.69
11269
11265
11981
11987
' results
Std. dev.
0.16
0.14
0.09
0.09
0.50
0.45
3.74
3.12
5.68
6.22
9.40
10.00
741.2
731.1
870.9
904.1
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SECTION 3
DRY GAS METER AUDIT
In the Method 5 audit procedure, participants use a critical orifice
to check the calibration of the dry gas meter in their EPA Method 5 control
console (meter box). They insert the orifice in the Method 5 meter box,
allow the box to warm up, and then make three 15-min volume measurements.
Using Equation 5-1 of Method 5, they convert each of the three volumes to
cubic meters at standard conditions, record the volumes on the data card,
and mail the device and the data card to EPA for statistical analysis.
In the spring audit (0381), 77% of the 170 laboratories that received
the audit package returned data. In the fall audit (0981), 75% of the
180 laboratories returned data. These percentages are similar to those
encountered in previous audits (2, 3, 4). Table 4, which classifies the
participants into general categories, shows the number of laboratories that
requested to participate in the Method 5 audit and the number that actually
returned data.
TABLE 4. METHOD 5 AUDIT PARTICIPANTS
Contractors
Industry
Foreign
Federal
State
Local
No. requesting
0381
92
40
4
3
24
7
samples
0981
89
52
5
4
22
8
No. returning
0381
67
34
4
2
19
5
data
0981
62
43
5
3
16
6
TOTAL
170
180
131
135
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Figure 1, a cumulative histogram, shows the absolute accuracy
obtained by participants in the 0381 and 0981 Method 5 audits, expressed
as the percentage of participants whose measurements agree with the
true (EPA) value at various levels of accuracy. The Code of Federal
Regulations (1) requires that the dry gas meter be calibrated with an
accuracy of ± 2 percent. Figure 1 shows that only 42% of the reporting
laboratories in the 0381 audit and 44% in the 0981 audit obtained this
accuracy. These results are similar to those reported in previous audits
(Figure 2). One hundred and one laboratories participated in both audits.
The histograms in Figures 3 and 4 show how the individual results of
the 0381 and 0981 audits compared to the mean and the median values for
all participants. The majority of the laboratories reported values lower
than the EPA value. The standard deviation of the triplicate analyses
(precision) by each laboratory indicated that for the 0381 audit, 65% of
the standard deviations for each set were within 0.3%. For the 0981 audit,
68% of the standard deviations were within 0.3%. Six percent of the 0381
data and 5% of the 0981 data were identified as outliers using Chauvenet's
Criterion (5). Before the outliers were removed, the mean values for the
0381 and 0981 data differed by 13.6% and 4.3% from the true value,
respectively. After deletion of outliers, these values were reduced to 2.9%
and 2.7%, respectively.
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LABORATORIES ACHIEVING SPECIFIED ACCURACY, CUMULATIVE, percent
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-------
50
1 1 T
DEGREE OF ACCURACY = 2 PERCENT
I
oc
o
00
40
30
0379/342 0879/523 0280/662 0880/725
AUDIT/NUMBER OF SAMPLES
0381/738
0981/723
Figure 2. Previous results of Method 5 audit
9
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20
I I I I
NUMBER OF VOLUMES = 738
15
S.
CO*
10
OUTLIERS
REMOVED
i i r
MEAN,-1.4 MEDIAN,-1.2
I
rJl
I
I
I
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OUTLIERS
REMOVED
<13 -13 -10 -8 -6 4 -2 0 2 4 6
DIFFERENCE FROM EPA VALUE, percent
10 >10
Figure 3. Results of the Method 5 Audit 0381
10
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LABORATORIES, percent
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SECTION 4
METHOD 6 AUDIT
This audit checks the participants' ability to analyze a Method 6
sample for sulfate. The audit set consists of five dilutions of 10 N
sulfuric acid (H^SO.) in 25-ml sealed glass ampoules. These five ampoules
contained different concentrations, ranging from 0 to 3000 mg SO^ per dry
standard cubic meter (DSCM). The analyst withdraws 5.0 ml from each
ampoule, adds 30 ml of 3% hydrogen peroxide, and dilutes the sample to
100 ml with distilled water. A 20-ml aliquot is then withdrawn from the
diluted sample, 80 ml of 100% isopropanol and thorin indicator are added,
and the sample is titrated with barium perchlorate (BaCClO,]^) to a pink
endpoint. To calculate the results, the participants assume they had an
original sample volume of 100 ml, and that they had sampled 21 x 10 DSCM
of stack gas.
In the spring audit (0281), 79% of the 154 laboratories that received
the audit package returned data. In the fall audit (0881), 62% of the
157 laboratories returned data. These percentages are similar to those
encountered in previous audits (2, 3, 4). Table 5, which classifies the
participants into general categories, shows the total number of labora-
tories requested to participate in the Method 6 audit and the number that
returned data. Seventy-three laboratories participated in both audits and
returned data.
Table 6 presents the percent of laboratories that achieved 2% and 5%
accuracy for each of the five different concentrations in the two 1981
Method 6 audits. In the 0281 audit, 47% of the reporting laboratories
achieved an accuracy within 2% for the lowest concentration and in the 0881
audit, 36% of the laboratories achieved an accuracy within 2%. However, in
12
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both audits, approximately 58% of the participants achieved an accuracy
within 2% for the four higher concentration samples. The poor accuracy
obtained for the lowest sample likely results from the difficulty in deter-
mining the thorin endpoint. Approximately 80% of the laboratories were
able to achieve an accuracy level within 5%.
TABLE 5. METHOD 6 AUDIT PARTICIPANTS
Contractors
Industry
Foreign
Federal
State
Local
TOTAL
No. requesting
0281
87
37
4
1
16
9
154
samples
0881
84
42
2
2
18
9
157
No. returning
0281
69
27
1
1
14
8
121
data
0881
55
26
1
1
8
7
98
TABLE 6.
SUMMARY OF SOURCE S02 AUDITS
Concentration
0 -
501 -
1001 -
1501 -
2001 -
500 mg/DSCM
1000 mg/DSCM
1500 mg/DSCM
2000 mg/DSCM
3000 mg/DSCM
n
0281
±2%
47%
55%
55%
58%
58%
121
±5%
77%
81%
82%
80%
79%
±2%
36%
58%
60%
59%
57%
0881
±5%
64%
79%
87%
86%
88%
98
The results obtained in the 1981 Method 6 audit do not differ signifi-
cantly from those obtained in previous audits (Figure 5).
13
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90
80
70
60
CO
1 50
§ 40
30
20
10
DEGREE OF ACCURACY = 2 PERCENT
SAMPLE RANGE, mg S02/OSCM
O 0-500
D 2001 - 3000
I
I
0379/83 0979/92 0380/102 0980/101
AUDIT/NUMBER OF SAMPLES
0281/121
0881/98
Figure 5. Previous results of Method 6 audits
14
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SECTION 5
METHOD 7 AUDIT
This audit checks the participants' ability to analyze a Method 7
sample for nitrate. The NO audit set consists of five dilutions of
X
potassium nitrate (KNO_) stock solution in 25-ml glass ampoules that are
autoclaved after sealing to destroy bacteria that might attack the nitrate.
The five samples in the set simulate source samples ranging from 0 to
1000 mg NO?/DSCM. The analyst withdraws 5.0 ml from an ampoule, adds this
and 25 ml of the Method 7 absorbing solution to a flask, adjusts the pH to
9-12 with NaOH, and then dilutes the solution to 50.0 ml with distilled
water. Then the analyst withdraws a 25-ml aliquot from the diluted sample,
places it in an evaporating dish, and treats it as described in Section 4.3
of Method 7. After the treatment is completed, the absorbance is measured
at 410 nm. For the concentration calculations, the participant assumes that
2000 ml of stack gas has been sampled.
In the spring audit (0481), 72% of the 124 laboratories that received
the audit package returned data. In the fall audit (1081), 60% of the 126
laboratories returned data. These percentages are similar to those
encountered in previous audits (2, 3, 4). Table 7 shows the total number
of laboratories requesting participation and the number that returned data
for Method 7 audits 0481 and 1081.
15
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TABLE 7. METHOD 7 AUDIT PARTICIPANTS
Contractors
Industry
Foreign
Federal
State
Local
TOTAL
No. requesting
0481
75
26
3
1
11
7
124
samples
1081
78
26
4
1
10
7
126
No. returning
0481
50
22
2
1
8
6
89
data
1081
48
13
2
0
7
6
76
Table 8 shows the percentages of laboratories that achieved 3% and 7%
accuracy for each of the five concentrations. For the 0481 and 1081 audits,
31% and 36% of the reporting laboratories achieved accuracy within 3% for
the lowest concentration samples. Sixty percent of the laboratories were
able to achieve accuracy within 7% for all samples in both audits.
TABLE 8. SUMMARY OF SOURCE N0x AUDITS
0481 1081
Concentration ±3% ±7% ±3% ±7%
0 - 200 mg/DSCM 31% 57% 36% 55%
201 - 400 mg/DSCM 40% 64% 39% 58%
401 - 600 mg/DSCM 36% 64% 34% 59%
601 - 800 mg/DSCM 35% 67% 38% 59%
801 - 1000 mg/DSCM 33% 60% 34% 58%
n 89 76
16
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Figure 6 compares the results of the 1981 audit to those of the past
six audits. For the four highest concentrations, the percentage of labora-
tories obtaining 3% accuracy was between 30% and 35%. The percentage of
laboratories obtaining 3% accuracy for the lowest concentration has varied
widely from audit to audit, but seems to have improved in the 1981 audits.
17
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50
DEGREE OF ACCURACY = 3 PERCENT
SAMPLE RANGE, mg NOX/DSCM
O 0-200
Q BOM 000
40
+*
i
aa
o.
V)
IU
p 30
ec
o
20
10
I
I
0379/68 0979/59 0480/71 1080/71
AUDIT/NUMBER OF SAMPLES
0481/89
1081/76
Figure 6. Previous results of Method 7 audit
18
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SECTION 6
COAL AUDIT
Method 19 of Appendix A in Part 60, Title 40 of the Code of Federal
Regulations (CFR) allows coal sampling and analysis to serve as an accept-
able method to determine the scrubber inlet sulfur emission rate for new
large coal-fired power plants. The coal audit checks the participant's
ability to analyze a coal sample for sulfur, ash, moisture, and BTU content.
Acceptance Testing on the NBS-supplied audit samples was done by an EPA
contractor using the following instrumentation: LECO SC132 (sulfur),
Fisher Model 490 (ash and moisture), and Parr Model 1241 Calorimeter (BTU
content). This was the first coal audit conducted by QAD.
Each set of coal samples consisted of two bottles containing 13 grams
of 60 mesh coal. Participants measured sulfur, moisture, ash, and gross
calorific value of each sample. The following American Society for Testing
and Materials (ASTM) procedures were recommended, but not necessarily
mandated (6).
ASTM D-3177 (Standard Test Method for Total Sulfur in the Analysis
of Coal and Coke);
ASTM D-3174 (Standard Test Method for Ash in the Analysis Sample
of Coal and Coke);
ASTM D3173 (Test for Moisture in the Analysis Sample of Coal); and
ASTM D-2015 (Standard Test Method for Gross Calorific Value of Solid
Fuel by the Adiabatic Bomb Method) (9).
The participants reported their results for moisture (%) on an as
received basis, and their results for sulfur (%), ash (%), and gross
calorific value (BTU/lb) on a dry basis.
19
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Table 9 shows the total number of laboratories requesting samples and
the number that returned data (83%). Due to the high cost of shipping coal
samples outside of the United States, no foreign laboratories were able to
participate.
TABLE 9. COAL AUDIT PARTICIPANTS
Contractors
Industry
Foreign
Federal
State
Local
TOTAL
No. requesting samples
0781
28
32
0
2
11
4
77
No. returning data
0781
22
28
0
1
11
2
64
Table 10 summarizes the coal audit results. The numbers of analyses
in Table 10 are greater than the number of participants because some
companies had more than one laboratory participating. In this case, each
laboratory received its own set of samples and each was asked to analyze
the samples in duplicate. However, some laboratories exhausted their
sample set on the first analysis. Therefore, accuracies of 5% and 10% were
chosen for the precision criterion for each of the four parameters.
Only 20% of the laboratories were able to analyze the sulfur and mois-
ture content of the low level samples within 10% of the NBS value. In
contrast, more than 85% of the laboratories were able to analyze the higher
concentration sample within 10% of the NBS moisture and sulfur values.
For the ash analysis, 77% and 98% of the participants achieved an
accuracy within 10% for the lower and higher ash samples, respectively.
Ninety-five percent of the participants analyzed the lower BTU sample with-
in 10% and 90% analyzed the higher BTU sample within 10% of the NBS value.
20
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Table 10 also shows that the participant's accuracy was consistently
better for the higher concentration samples for the sulfur, ash, and
moisture analysis than for the lower concentration samples. For those that
did duplicate analyses, the within-laboratory precision showed no correla-
tion with concentration. Therefore, the standard deviation (precision) was
independent of the sample concentration for all four parameters.
TABLE 10. SOURCE COAL AUDIT - 0781
Expected
Value
0.32%
1.62%
1.42%
18.42%
4.78%
22.14%
11339 BTU/lb
12084 BTU/lb
Laboratories
Number of accurate
analyses within ±5%
(1)
(2)
(1)
(2)
(1)
(2)
(1)
(2)
(1)
(2)
(1)
(2)
(1)
(2)
(1)
(2)
bULrUK
97
81
98
83
-. MHTCTMDC
MUiblUKt
97
81
96
80
ACU -
Aon
97
81
98
81
-- roncc rt\\ ODTCTT
uKUoo LMLUKlriL.
93
77
92
77
15%
17%
57%
65%
15%
17%
76%
83%
55%
54%
97%
99%
90%
94%
84%
86%
Laboratories
accurate
within ±10%
21%
20%
82%
87%
21%
20%
87%
91%
76%
78%
98%
99%
95%
96%
90%
90%
21
-------
REFERENCES
1. U.S. Environmental Protection Agency. Standards of Performance
for New Stationary Sources. Appendix A. Title 40, Part 60, Code
of Federal Regulations.
2. Fuerst, R. G., R. L. Denny and M. R. Midgett. A Summary of the
Interlaboratory Source Performance Surveys for EPA Reference Methods 6
and 7 - 1977. EPA-600/4-79-045, U.S. Environmental Protection Agency,
Research Triangle Park, NC 27711, August 1979. 50 pp.
3. Fuerst, R. G., and M. R. Midgett. A Summary of the Interlaboratory
Performance Surveys for EPA Reference Methods 5, 6, and 7 - 1978.
EPA-600/4-80-029, U.S. Environmental Protection Agency, Research
Triangle Park, NC 27711, May 1980. 48 pp.
4. Fuerst, R.G., E. W. Streib and M. R. Midgett. A Summary of the EPA
National Source Performance Audit Program - 1979. EPA-600/4-81-029,
U.S. Environmental Protection Agency, Research Triangle Park, NC 27711,
April 1981. 53 pp.
5. 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, PA, 1863. pp. 558-565.
6. Annual Book of ASTM Standards - 1979. Part 26. 01-026079-13, American
Society for Testing and Materials, Philadelphia, PA.
22
-------
APPENDIX A
FREQUENCY DISTRIBUTIONS
23
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-------
SOURCE NOX FREQUENCY DISTRIBUTION OF PERCENT DIFFERENCE WITH OUTLIERS REMOVED 0481
LEVEL (MG/DSCM)
.1 - 200.0
200.1 - 400.0
400.1 - 600.0
600.1 - 800.0
800.1 - 1000.0
NOBS
73
67
73
75
71
MIN
.42
.03
.06
.04
.12
10%
.42
.20
.30
.75
.90
20%
1.92
.54
1.08
1.81
1.33
30%
2.68
1.24
1.89
2.05
1.83
40%
3.77
2.08
2.73
2.76
2.58
50%
4.94
2.85
3.46
3.46
3.64
60%
5.44
3.82
4.26
4.28
4.79
70%
6.78
4.19
5.49
5.05
5.93
80%
8.70
5.89
7.49
6.92
7.23
90%
19.46
7.50
9.60
9.07
11.62
MAX
15.48
11.19
13.52
12.54
16.08
AVE
5.51
3.53
4.35
4.34
4.92
STD
3.98
3.00
3.47
3.21
4.15
ro
cr>
SOURCE NOX FREQUENCY DISTRIBUTION OF PERCENT DIFFERENCE WITH OUTLIERS REMOVED 1081
LEVEL (MG/DSCM)
.1 - 200.0
200.1 - 400.0
400.1 - 600.0
600.1 - 800.0
800.1 - 1000.0
NOBS
62
58
67
62
62
MIN
.19
.08
.07
.04
.06
10%
.69
.29
.43
.30
.83
20%
1.44
.69
1.00
.59
1.25
30%
2.26
1.51
2.19
1.08
1.97
40%
2.70
1.93
2.76
2.20
2.45
50%
3.95
2.83
3.98
3.54
3.89
60%
5.40
3.52
5.40
4.89
5.63
70%
7.97
4.49
7.32
6.13
6.45
80%
8.66
5.21
11.71
8.57
8.68
90%
12.99
6.16
13.89
12.70
14.61
MAX
18.39
10.79
21.10
17.10
18.99
AVE
5.64
3.45
6.11
5.09
5.69
STD
4.82
2.83
5.60
4.93
5.21
-------
ro
NATIONAL COAL AUDIT FREQUENCY DISTRIBUTION
OF ABSOLUTE PERCENT DIFFERENCES OF EXPECTED AND REPORTED VALUES - 0781
SAMPLE
2000
5000
2000
5000
2000
5000
2000
5000
NO.
181
178
178
176
179
178
170
169
MIN
.00
.00
.00
.00
.00
.00
.01
.01
10X
.62
3.13
2.11
.43
.09
.63
.21
.12
20%
1.23
6.25
9.15
1.03
.14
1.26
.37
.31
30X
1.85
9.38
15.49
1.36
.27
1.88
.51
.41
40X
2.47
12.50
19.72
1.85
.41
2.72
.59
.67
BOX
3.70
12.50
23.94
2.55
.54
4.18
.69
.89
60X
4.94
15.63
28.17
2.99
.68
5.65
SS CALOROFIC
.86
1.18
70%
6.79
18.75
33.10
3.53
.86
7.11
1.28
1.94
80%
8.64
31.25
38.73
5.05
1.22
12.34
1.84
3.91
90%
16.05
43.75
47.89
13.14
2.26
18.83
3.37
9.99
MAX
45.06
93.75
164. 08
95.49
252.08
1876.78
46.76
45.86
MEAN
6.49
19.95
27.15
7.32
3.76
30.61
2.38
3.56
STO. DEV.
8.04
19.66
22.36
17.70
26.55
200.52
6.31
7.19
-------
APPENDIX B
INSTRUCTIONS FOR EPA AUDIT MATERIALS
28
-------
INSTRUCTIONS FOR USE OF ENVIRONMENTAL PROTECTION AGENCY
METHOD 5 DRY GAS METER PERFORMANCE TEST DEVICE
NOTE: All procedure* referrred to are from revised Method 5 published in the Federal Register, Vol. 12,
No. 160, Pert II, Thursday, August 18,1977, pp. 41776-41782 and references contained therein. This
revised method should be adhered to in all details in the use of this quality assurance performance
device.
EQUIPMENT: The participant in this study should possess the following equipment, including
the performance test device supplied by EPA.
Quantity Item
1 Method 5/Source Sampling Meter Box
1 Stopwatch, preferably calibrated in decimal minutes
1 Thermometer, ambient range
1 Barometer. If unavailable, call nearest National Weather Service and request the
ABSOLUTE barometric pressure. (Corrected for temperature and acceleration due to
gravity, but not corrected for altitude.)
1 Performance Test Device. A calibrated flow orifice housed in a quick-connect
coupling and identified with an engraved three-digit serial number.
WARNING: THE DEVICE MUST NOT BE DISASSEMBLED UNDER ANY CIR-
CUMSTANCES. Use these devices at room temperature.
PROCEDURE:
1. Remove the performance test device from its case and insert it into the gas inlet quick-
connect coupling on the source sampling meter box.
2. Turn the power to the meter box on and start the pump.
3. Adjust the coarse flow rate control valve and the fine flow rate control valve to give a maxt
mum vacuum reading. CAUTION: A vacuum reading of less than 17 inches Hg will result
in flow rate errors.
4. Allow the orifice and source sampling meter box to warm up for 45 minutes with flow con-
trols adjusted as described in Step 3 before starting quality assurance runs.
5. Make triplicate quality assurance runs. For each run, record initial and final dry gas meter
volumes, dry gas meter inlet and outlet temperatures, internal orifice pressure drop (AH),
ambient temperature, and barometric pressure. Run duration should be slightly greater
than 15 minutes. The following procedure is recommended. Fifteen minutes after a run is
started, the participant watches the dry gas meter needle closely. As the needle reaches the
zero (12 o'clock) position, the pump and stopwatch are stopped simultaneously. The dry
gas meter volume and time are recorded.
This complete run procedure is performed three times to provide the required triplicate
quality assurance runs.
6. Calculate the corrected dry gas volume for each run using equation 5.1 of the above-refer
enced Method 5. For each replicate, record the corrected dry gas volume in dry standard
cubic meters, the sampling time in decimal minutes, the barometric pressure in mm Hg, and
the ambient temperature in degrees Celcius on the enclosed data card. Be sure to record the
performance test device serial number on the data card in the column headed "Orifice
Number."
NOTE 1: If you calculate dry gas volume in English Units, use the conversion factor of 0.02832 rr)3 ft3
to obtain the volume in metric units.
NOTE 2: If your stopwatch is not in decimal minutes, be sure to convert (e.g. 15 minutes 20 seconds is
reported as 15.33 minutes).
7. After recording the requested data on the enclosed data form, return the data form and the
performance test device to:
Quality Assurance Division (MD-77)
Environmental Monitoring Systems Laboratory
Environmental Protection Agency
Research Triangle Park, North Carolina 27711
Attention: Robert G. Fuerst
A postpaid return envelope and label are enclosed for this purpose.
29
-------
INSTRUCTIONS FOR USE OF ENVIRONMENTAL PROTECTION AGENCY STATIONARY
SOURCE QUALITY ASSURANCE SO2 REFERENCE SAMPLES
Note: All Method 6 procedures referred to are from the amended method published in the Federal
Register Vol. 42, No. 160, Part II. Thursday, August 18, 1977, pp 41782-41784. This amend-
ed method should be adhered to in all details in the analysis of these reference standards.
1. Prepare 3-percent hydrogen peroxide according to Section 3.1.3 of the method (30 ml is required
for each sample and each blank).
2. Prepare each reference sample for analysis as follows: Wrap a paper towel around the ampule and
with the ampule in an upright position break off the top at the prescored mark by exerting pres-
sure sideways. From the ampule pipette exactly 5 ml of the reference sample into a 100-ml volu-
metric flask. Add 30 ml of 3-percent hydrogen peroxide solution. Dilute exactly to the mark
with deionized, distilled water. Analyze the sample in accordance with the procedure detailed in
Section 4.3 of the method, beginning with "Pipette a 20-ml aliquot of this solution...." (Note:
If more than 50 ml of barium perchlorate titrant is required for any sample analysis, a smaller
aliquot should be selected to allow titration with less than 50-ml titrant.)
3. Calculate the concentration, C$09 ' concentration of *u!fur dioxide, dry bests, corrected to fttndard con-
ditions, mg/dscm), using Equation 6-2. A value of 21 X 10'3 dscm should be used for Vm(stcj)>
in the equation. A value of 100 ml should be used for Vsc.|n in the equation.
4. Record the reference standard sample numbers and their corresponding SC>2 concentrations in
mg/dscm on the enclosed data form. Return the form to:
Quality Assurance Division (MD 77)
Environmental Monitoring Systems Laboratory
Environmental Protection Agency
Research Triangle Park, N.C. 27711
Ann: Robert G. Fuerst
If other than EPA Method 6 is used for your analyses, please explain in detail your analytical pro-
cedure on the back of the enclosed data form.
30
-------
INSTRUCTIONS FOR USE OF ENVIRONMENTAL PROTECTION AGENCY STATIONARY
SOURCE QUALITY ASSURANCE NOX REFERENCE SAMPLES
Note: All Method 7 procedures referred to are from the amended method published in the Federal
Register Vol. 42, No. 160, Part II, Thursday, August 18, 1977, pp 41784-41786. This amend-
ed method should be adhered to in all details in the analysis of these reference standards.
1. Prepare absorbing solution according to Section 3.1 of the method.
2. Prepare each reference sample for analysis as follows: Wrap a paper towel around the ampule and
with the ampule in an upright position break off the top at the prescored mark by exerting pres-
sure sideways. From the ampule pipette exactly 5 ml of the reference sample into a 100-ml beak-
er. Add 25 ml absorbing solution to the beaker; adjust the pH to 9-12 (using pH paper as indi-
cated in Section 4.2 of the method) by dropwise addition of sodium hydroxide (IN). Quanti-
tatively transfer the contents of the beaker to a 50-ml volumetric flask and dilute exactly to the
mark with deionized, distilled water. Mix thoroughly and pipette a 25-ml aliquot of the diluted
sample into a porcelain evaporating dish. Beginning with the evaporation step in Section 4.3,
complete the sample analysis.
3. Calculate total HQ N02 per sample using Equation 7-3. Calculate the sample concentration, C
(concentration of NOX as NO2, dry basis, corrected to standard conditions, mg/dscm), using
Equation 7-4. A value of 2000 ml should be used for Vx in Equation 7-4.
4. Record the reference sample numbers and their corresponding concentrations, C, in mg/dscm
on the enclosed data form. Return the form to:
Quality Assurance Division (MD 77)
Environmental Monitoring Systems Laboratory
Environmental Protection Agency
Research Triangle Park, N.C. 27711
Attn: Robert G. Fuerst
If other than EPA Method 7 is used for your analyses, please explain in detail your analytical pro-
cedure on the back of the enclosed data form.
31
-------
COAL AUDIT PROGRAM INFORMATION
1. There 1s approximately 13 grams of 60 mesh coal per bottle.
2. Analyze the coal samples for moisture and on a dry basis for ash,
sulfur and gross calorific value. Report moisture, ash, and sulfur
1n weight percent with gross calorific value reported as BTU/lb.
3. All methods used In the analysis of these coal samples should follow
American Society for Testing and Materials (ASTM) recommended procedures
or an accepted automatic analytical device.
4. Suggested procedures are:
Moisture D-3173
Ash D-3174
Sulfur D-3177
Gross Calorific Value ... D-2015
Please note on the data card (columns 17-32) the ASTM method number.
If an ASTM method was not used for analysis note that on the back of
the data card. Be parameter specific.
5. If you cannot analyze the coal sample for all four parameters, analyze
for what you can. Analysis of moisture 1s necessary to calculate on
a dry basis any of the other three parameters. Analysis of sulfur Is
also necessary for the calculation of gross calorific value.
6. Analyze each sample 1n duplicate (If possible) and record results as
analysis 1 and analysis 2 for each parameter.
7. Most laboratories will use site number 001. Multiple site numbers
are used by laboratories that receive more than one set of samples.
These central laboratories have requested auditing of their satellite
laboratories.
8. After recording the requested data on the enclosed data card, return the
data card to:
Mr. Robert G. Fuerst
Quality Assurance Division (MD-77)
Environmental Monitoring Systems Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
A postpaid return envelope Is enclosed for this purpose.
9. If you have any questions concerning this or any source method audit,
please call (919/541-2220).
32
-------
APPENDIX C
COAL AUDIT STATISTICS
33
-------
NATIONAL COAL AUDIT STATISTICS - 0781
Parameter: Sul
Sample Number:
Analysis: 1
Number of OBS:
.89
1.25
1.37
1.46
1.48
1.51
1.53
1.54
1.56
1.57
1.58
1.60
1.60
1.61
1.62
1.63
1.65
1.69
1.71
1.86
fur
2000
98
1.02
1.26
1.39
1.47
1.49
1.51
1.53
1.54
1.56
1.57
1.58
1.60
1.61
1.61
1.63
1.64
1.65
1.69
1.74
1.88
Parameter: Sulfur
Sample Number:
Analysis: 2
Number of OBS:
.91
1.33
1.46
1.49
1.51
1.54
1.55
1.58
1.59
1.59
1.60
1.61
1.62
1.64
1.65
1.67
1.72
2000
83
1.00
1.33
1.46
1.50
1.52
1.54
1.56
1.58
1.59
1.60
1.60
1.62
1.63
1.64
1.65
1.68
1.72
Expected Value: 1.62
Mean: 1.55
Median: 1.57
Variance: .03
._- HATA TW Acpcwnikip nonco
Unlft IN /OLtNUlNb UKUhK
1.13
1.28
1.39
1.47
1.50
1.53
1.54
1.55
1.56
1.57
1.59
1.60
1.61
1.61
1.63
1.64
1.66
1.70
1.76
2.00
Expected Value: 1.62
Mean: 1.55
Median: 1.59
Variance: .02
.__ nATA TM ACfCkinTUP DDRCD _
UMIM IN AoLhNUlNb UKUtK
1.14
1.33
1.48
1.50
1.52
1.54
1.57
1.58
1.59
1.60
1.61
1.62
1.63
1.64
1.65
1.68
1.85
34
Std. Dev.: .16
Coef. Var.: 10.53
Skewness: -1.14
Accuracy: -2.78
1.15
1.34
1.45
1.48
1.50
1.53
1.54
1.56
1.56
1.57
1.59
1.60
1.61
1.62
1.63
1.65
1.67
1.71
1.78
Std. Dev.: .14
Coef. Var.: 9.15
Skewness: -2.15
Accuracy: -1.85
1.30
1.43
1.48
1.51
1.52
1.54
1.57
1.58
1.59
1.60
1.61
1.62
1.64
1.64
1.66
1.69
1.25
1.35
1.46
1.48
1.50
1.53
1.54
1.56
1.56
1.58
1.59
1.60
1.61
1.62
1.63
1.65
1.67
1.71
1.86
1.31
1.44
1.49
1.51
1.53
1.55
1.57
1.59
1.59
1.60
1.61
1.62
1.64
1.64
1.67
1.71
-------
NATIONAL COAL AUDIT STATISTICS - 0781
Parameter: Sulfur
Sample Number: 5000
Analysis: 1
Number of DBS: 97
Expected Value:
Mean: .34
Median: .35
Variance: .01
.32
Std. Dev.: .09
Coef. Var.: 25.29
Skewness: -.48
Accuracy: 9.38
.05
.22
.26
.28
.29
.30
.31
.32
.33
.34
.35
.36
.36
.37
.37
.38
.40
.43
.47
.54
Parameter: Sulfur
Sample Number: 5000
Analysis: 2
Number of OBS: 81
.05
.24
.27
.30
.31
.32
.34
.34
.35
.35
.36
.37
.38
.40
.43
.45
.62
.07
.23
.26
.28
.29
.31
.32
.33
.34
.34
.35
.36
.36
.37
.38
.38
.41
.46
.47
.60
.07
.25
.27
.30
.31
.32
.34
.34
.35
.35
.36
.37
.38
.40
.43
.49
UMIfl IN «5LtNUlNl3 UKlJtK
.07
.24
.27
.28
.30
.31
.32
.33
.34
.34
.35
.36
.37
.37
.38
.38
.42
.46
.47
Expected Value: .32
Mean: .34
Median: .35
Variance: .01
._ HATA Tkl AC^CMHTIIP ftDnCD _.
UAIA IN AbLtNUlNb UKUtK
.08
.26
.28
.31
.32
.33
.34
.34
.35
.36
.36
.37
.38
.40
.43
.49
.19
.25
.28
.29
.30
.31
.32
.33
.34
.35
.35
.36
.37
.37
.38
.39
.42
.46
.49
Std. Dev.: .09
Coef. Var.: 25.50
Skewness: -.56
Accuracy: 9.38
.18
.26
.29
.31
.32
.33
.34
.34
.35
.36
.37
.37
.38
.42
.43
.51
.21
.25
.28
.29
.30
.31
.32
.33
.34
.35
.36
.36
.37
.37
.38
.40
.43
.46
.52
.22
.27
.29
.31
.32
.33
.34
.35
.35
.36
.37
.38
.38
.42
.45
.53
35
-------
NATIONAL COAL AUDIT STATISTICS - 0781
Parameter:
Moisture
Sample Number: 2000
Analysis:
Number of
.03
.65
1.00
1.21
1.35
1.42
1.45
1.53
1.62
1.65
1.69
1.73
1.77
1.81
1.84
1.87
1.92
2.00
2.07
2.21
Parameter:
1
DBS: 97
.03
.82
1.03
1.21
1.36
1.43
1.47
1.55
1.64
1.68
1.70
1.74
1.78
1.82
1.84
1.88
1.96
2.01
2.07
3.75
Moisture
Sample Number: 2000
Analysis:
Number of
.03
.85
1.15
1.39
1.43
1.45
1.58
1.64
1.67
1.73
1.76
1.79
1.86
1.91
1.94
1.97
2
OBS: 81
.04
.86
1.20
1.40
1.43
1.46
1.60
1.65
1.69
1.73
1.77
1.80
1.87
1.92
1.95
1.98
Expected Value: 1.42
Mean: 1.58
Median: 1.69
Variance: 31.48
- DATA TW AcrcwniMp nonco
UrtIM IN AoLtNUINU UKUtK
.10
.87
1.10
1.29
1.38
1.44
1.47
1.57
1.65
1.69
1.71
1.75
1.79
1.82
1.85
1.89
1.97
2.01
2.10
Expected Value: 1.42
Mean: 1.56
Median: 1.67
Variance: .20
._« HATA Tkl A CCCUnTM/* flDftCD
DAI A IN AbutNUlNb UKUtK
.12
.91
1.24
1.40
1.44
1.47
1.61
1.65
1.69
1.74
1.78
1.82
1.88
1.92
1.95
2.05
Std. Dev.: .50
Coef. Var. : 31.48
Skewness: -.30
Accuracy: 19.01
.54
.87
1.12
1.30
1.41
1.44
1.49
1.60
1.65
1.69
1.71
1.75
1.79
1.82
1.85
1.89
1.97
2.02
2.18
Std. Dev.: .45
Coef. Var.: 28.88
Skewness: -1.65
Accuracy: 17.61
.44
.93
1.34
1.41
1.44
1.53
1.61
1.65
1.71
1.74
1.79
1.83
1.91
1.93
1.96
2.10
.63
.91
1.20
1.33
1.41
1.44
1.51
1.61
1.65
1.69
1.71
1.76
1.81
1.83
1.86
1.89
1.99
2.04
2.19
.61
.96
1.36
1.42
1.45
1.57
1.64
1.66
1.71
1.75
1.79
1.83
1.91
1.93
1.96
2.18
2.19
36
-------
NATIONAL COAL AUDIT STATISTICS - 0781
Parameter: Moisture
Sample Number: 5000
Analysis: 1
Number of DBS: 96
.83
11.39
17.03
17.43
17.66
17.95
18.15
18.26
18.39
18.47
18.49
18.59
18.74
18.77
18.82
18.96
19.00
19.12
19.42
23.00
Parameter: Moi
Sample Number:
Analysis: 2
Number of DBS:
.85
16. 6Q
17.47
17.93
18.09
18.20
18.26
18.42
18.61
18.66
18.68
18.78
18.91
18.97
19.00
19.24
.85
15.74
17.22
17.58
17.83
17.95
18.15
18.29
18.39
18.47
18.50
18.64
18.74
18.77
18.84
18.97
19.01
19.17
19.44
sture
5000
80
.85
16.90
17.72
17.95
18.10
18.21
18.28
18.44
18.62
18.66
18.68
18.79
18.91
18.97
19.05
19.29
Expected Value: 18.42
Mean: 17.63
Median: 18.47
Variance: 13.99
RATA TM AcrcwnTwr ncnPR --
-- DAIA IN flbLtNUiNu UKUtK
1.66
15.82
17.28
17.60
17.83
18.03
18.17
18.29
18.39
18.47
18.50
18.67
18.76
18.82
18.93
18.98
19.06
19.19
19.46
Expected Value: 18.42
Mean: 17.90
Median: 18.57
Variance: 9.73
HAT A Tki AcpcwnTWP fiDHPD
-- DAIA IN nbLtNulNu UKUtK
10.84
17.24
17.76
17.96
18.15
18.23
18.30
18.48
18.63
18.67
18.70
18.85
18.92
18.98
19.07
19.41
Std. Dev.:
Coef. Var. :
Skewness:
Accuracy:
1.78
16.00
17.37
17.61
17.90
18.05
18.23
18.30
18.46
18.48
18.53
18.67
18.76
18.82
18.93
18.99
19.07
19.34
21.98
Std. Dev.:
Coef. Var.
Skewness:
Accuracy:
11.42
17.29
17.80
17.99
18.15
18.23
18.31
18.51
18.63
18.67
18.73
18.85
18.95
18.98
19.19
22.21
3.74
21.22
-3.51
.30
10.63
16.50
17.41
17.63
17.90
18.12
18.23
18.38
18.46
18.48
18.58
18.69
18.77
18.82
18.95
18.99
19.07
19.35
22.90
3.12
: 17.43
-4.23
.81
15.78
17.37
17.93
18.05
18.19
18.25
18.32
18.53
18.64
18.68
18.73
18.89
18.96
18.98
19.20
23.15
37
-------
NATIONAL COAL AUDIT STATISTICS - 0781
Parameter: Ash
Sample Number:
Analysis: 1
Number of OBS:
20.92
21.57
21.72
21.85
21.92
21.96
22.00
22.02
22.04
22.07
22.09
22.11
22.13
22.14
22.17
22.18
22.20
22.23
22.28
22.64
Parameter: Ash
Sample Number:
Analysis: 2
Number of OBS:
21.24
21.60
21.78
21.92
21.96
21.98
22.01
22.03
22.09
22.11
22.13
22.17
22.21
22.23
22.24
22.35
77.95
2000
98
21.18
21.58
21.72
21.86
21.92
21.96
22.00
22.02
22.05
22.07
22.11
22.12
22.14
22.16
22.17
22.19
22.20
22.24
22.29
28.00
2000
81
21.49
21.66
21.79
21.93
21.97
21.99
22.01
22.04
22.09
22.12
22.14
22.17
22.22
22.23
22.26
22.38
Expected Value: 22.14
Mean: 22.65
Median: 22.08
Variance: 32.26
_ HATA T u ACPCurvT UP r\nnnn
UAIA IN AottNUlNU ORDER
21.41
21.62
21.73
21.87
21.92
21.97
22.01
22.03
22.06
22.08
22.11
22.12
22.14
22.16
22.17
22.20
22.21
22.25
22.32
77.94
Expected Value: 22.14
Mean: 22.73
Median: 22.09
Variance: 38.64
__ HATA TW AcrckinTkip nonco _.
- UAIA IN AoLtNUiNLi UKUtK
21.51
21.68
21.87
21.94
21.97
21.99
22.02
22.05
22.10
22.12
22.14
22.19
22.22
22.24
22.28
22.40
Std. Dev.:
Coef. Var.
Skewness:
Accuracy:
21.53
21.66
21.76
21.90
21.93
21.97
22.02
22.03
22.07
22.08
22.11
22.12
22.14
22.16
22.18
22.20
22.21
22.28
22.36
Std. Dev.:
Coef. Var.
Skewness:
Accuracy:
21.51
21.74
21.87
21.95
21.97
22.00
22.02
22.06
22.11
22.12
22.15
22.20
22.23
22.24
22.29
22.43
5.68
: 25.07
9.42
-.25
21.56
21.68
21.83
21.90
21.94
21.98
22.02
22.03
22.07
22.09
22.11
22.12
22.14
22.16
22.18
22.20
22.23
22.28
22.40
6.22
: 27.34
8.65
-.23
21.54
21.75
21.90
21.95
21.98
22.00
22.03
22.08
22.11
22.12
22.16
22.21
22.23
22.24
22.31
22.80
38
-------
NATIONAL COAL AUDIT STATISTICS - 0781
4.78
Parameter: Ash
Sample Number:
Analysis: 1
Number of DBS:
2.70
3.84
3.92
4.05
4.40
4.49
4.50
4.58
4.65
4.66
4.70
4.73
4.76
4.78
4.84
4.86
4.94
5.05
5.16
27.40
Parameter: Ash
Sample Number:
Analysis: 2
Number of OBS:
2.65
3.80
3.97
4.33
4.45
4.52
4.61
4.65
4.69
4.72
4.75
4.80
4.82
4.87
4.99
5.07
5000
97
2.76
3.86
3.93
4.14
4.41
4.49
4.52
4.60
4.65
4.67
4.71
4.73
4.77
4.79
4.84
4.86
4.96
5.08
5.22
94.42
5000
81
2.80
3.92
3.98
4.38
4.46
4.53
4.62
4.66
4.69
4.73
4.77
4.81
4.82
4.89
4.99
5.08
Expected
Mean: 5.
Median:
Variance:
.__ RATA TKI A
Expected
Mean: 5.
Median:
Variance:
._ HATA TW A
UAIA IN P
Value: '
73
4.70
88.38
icrckiniijp
loLtNUlNb
3.45
3.87
3.93
4.22
4.42
4.50
4.55
4.61
4.65
4.69
4.71
4.74
4.77
4.79
4.85
4.87
4.98
5.12
5.23
Value: '
67
4.69
100.07
iCPCUr>TMf*
IbLtNUlNu
3.55
3.94
4.07
4.39
4.47
4.54
4.65
4.67
4.69
4.73
4.78
4.81
4.82
4.91
5.02
5.09
ORDER
4.78
ORDER
Std. Dev.:
Coef. Var.
Skewness:
Accuracy:
3.72
3.87
3.97
4.24
4.45
4.50
4.55
4.61
4.65
4.70
4.72
4.75
4.77
4.82
4.85
4.90
5.00
5.15
5.35
Std. Dev.:
Coef. Var.
Skewness:
Accuracy:
3.60
3.94
4.18
4.40
4.47
4.56
4.65
4.67
4.70
4.73
4.78
4.81
4.83
4.91
5.03
5.38
9.40
: 164. 04
8.78
-1.67
3.82
3.88
3.98
4.38
4.48
4.50
4.57
4.65
4.66
4.70
4.72
4.74
4.78
4.83
4.86
4.91
5.00
5.16
5.35
10.00
: 176.41
8.64
-1.86
3.77
3.96
4.19
4.44
4.51
4.60
4.65
4.67
4.71
4.74
4.79
4.81
4.86
4.98
5.04
5.52
94.49
39
-------
NATIONAL COAL AUDIT STATISTICS - 0781
Parameter: Gross Cal
Sample Number:
Analysis: 1
Number of OBS:
6048. 00
10500.00
11027.00
11101.00
11133.00
11183.00
11219.00
11238.00
11256.00
11269.00
11272.00
11278.00
11282.00
11296.00
11303.00
11315.00
11330.00
11380.00
11674. 00
2000
93
8273.00
10587. 00
11052.00
11105.00
11140.00
11206.00
11220.00
11248.00
11256.00
11269.00
11272.00
11279.00
11284.00
11297.00
11305.00
11321.00
11334.00
11381.00
11799.00
Parameter: Gross Cal
Sample Number:
Analysis: 2
Number of OBS:
6037.00
10888.00
11112.00
11149.00
11206.00
11242.00
11255.00
11263.00
11267.00
11275.00
11277.00
11285.00
11298.00
11325.00
11351.00
11510.00
2000
77
7928.00
10927.00
11130.00
11159.00
11222.00
11245.00
11257.00
11263.00
11269.00
11275.00
11279.00
11286.00
11302.00
11330.00
11352.00
11698.00
Expected Value: 11339.00
Mean: 1139.74
Median: 11269.00
Variance: 549377.38
_ DATA TKI ACPCMnTW/"' HDnCD _
DAI A in AoLtNUlNb UKUhK
9653.00
10607.00
11052.00
11113.00
11143.00
11208.00
11229.00
11250.00
11259.00
11270.00
11274.00
11281.00
11285.00
11301.00
11307.00
11324.00
11352.00
11435.00
14098. 00
Std. Dev.:
Coef. Var.
Skewness:
Accuracy:
10040.00
10957.00
11059.00
11120.00
11176.00
11209.00
11232.00
11255.00
11261.00
11270.00
11276.00
11281.00
11286.00
11302.00
11312.00
11326.00
11369.00
11484.00
Expected Value: 11339.00 Std. Dev.:
Mean: 1108.84
Median: 11265.00
Variance: 534561.68
TNATA TU Acpcwniup nonce -
DAI A IN AoutNUiNu UKUtK
9702.00
11047. 00
11147.00
11176.00
11227.00
11248.00
11259.00
11263.00
11271.00
11276.00
11280.00
11288.00
11305.00
11334.00
11352.00
Coef. Var.
Skewness:
Accuracy:
10631.00
10050.00
11148.00
11187.00
11235.00
11249.00
11261.00
11265.00
11272.00
11276.00
11281.00
11290.00
11305.00
11340.00
11385.00
741.20
: 6.65
-3.56
-.62
10287.00
11012.00
11085.00
11131.00
11181.00
11215.00
11233.00
11256.00
11263.00
11271.00
11278.00
11282.00
11290.00
11303.00
11315.00
11326.00
11380.00
11500.00
731.14
: 6.58
-5.48
-.65
10700.00
11074.00
11148.00
11201.00
11242.00
11255.00
11262.00
11265.00
11274.00
11276.00
11282.00
11292.00
11315.00
11346.00
11437.00
40
-------
NATIONAL COAL AUDIT STATISTICS - 0781
Parameter: Gross Cal
Sample Number:
Analysis: 1
Number of OBS:
6662.00
9778.00
11112.00
11515.00
11720.00
11846.00
11925.00
11946.00
11969.00
11981.00
12003.00
12022. 00
12031.00
12042.00
12059.00
12073.00
12086.00
12117.00
12379.00
5000
92
8701.00
9825.00
11200.00
11516. 00
11757.00
11880.00
11929.00
11954.00
11969.00
11982.00
12009.00
12024.00
12033.00
12042.00
12060.00
12075.00
12096.00
12127.00
12532.00
Parameter: Gross Cal
Sample Number:
Analysis: 2
Number of OBS:
6542.00
9855.00
11429.00
11683.00
11889.00
11924.00
11972.00
11980.00
11997.00
12018.00
12034.00
12043.00
12063.00
12074.00
12115.00
12370.00
5000
77
8763.00
10247.00
11515.00
11766.00
11899.00
11930.00
11973.00
11980.00
12001.00
12019.00
12037.00
12044.00
12068.00
12074.00
12119.00
12404. 00
Expected Value: 12084.00
Mean: 11683.64
Median: 11981.50
Variance: 758529.40
HATA TU AC^CMHTklP HDHCD _
DAI A IN AbLhNUlNb UKUtK
9519.00
9973.00
11314.00
11562.00
11770.00
11891.00
11933.00
11954.00
11972.00
11994.00
12012.00
12025.00
12034.00
12043.00
12065.00
12079.00
12097.00
12190.00
Expected Value: 12084.00
Mean: 11684.69
Median: 11986.69
Variance: 817340.62
r\ATA TM ACPCunTup nonce _
- DAI A IN AottNUlNu UKUtK
9547.00
10574.00
11562.00
11811.00
11900.00
11944.00
11973.00
11980.00
12001.00
12032.00
12038.00
12047.00
12068.00
12083.00
12123.00
Std. Dev.:
Coef. Var.
Skewness:
Accuracy:
9664.00
10510.00
11449. 00
11573.00
11825.00
11901.00
11938.00
11957.00
11977.00
11997.00
12014.00
12026.00
12037.00
12049.00
12069.00
12082.00
12115.00
12295.00
Std. Dev.:
Coef. Var.
Skewness:
Accuracy:
9727.00
10877.00
11567.00
11817.00
11902.00
11954.00
11975.00
11986.00
12003.00
12034.00
12039.00
12057.00
12070.00
12090.00
12187.00
870.94
: 7.45
-3.23
-.85
9690.00
10913.00
11471.00
11612.00
11830.00
11915.00
11941.00
11960.00
11977.00
11999.00
12015.00
12030.00
12040.00
12051.00
12070.00
12083.00
12117.00
12319.00
904.07
: 7.74
-3.38
-.81
9842.00
11159.00
11604.00
11825.00
11911.00
11971.00
11977.00
11994.00
12013.00
12034.00
12042.00
12060.00
12073.00
12096.00
12325.00
41
------- |