&EPA
United States
Environmental Protection
Agency
Office of Transportation EPA420-B-04-011
and Air Quality July 2004
Acceleration Simulation Mode
Test Procedures, Emission
Standards, Quality Control
Requirements, and Equipment
Specifications
Final Technical Guidance
-------
EPA420-B-04-011
July 2004
Acceleration Simulation Mode Test Procedures,
Emission Standards, Quality Control
Requirements, and Equipment Specifications
Final Technical Guidance
Certification and Compliance Division
Office of Transportation and Air Quality
U.S. Environmental Protection Agency
NOTICE
This Technical Report does not necessarily represent final EPA decisions or positions.
It is intended to present technical analysis of issues using data that are currently available.
The purpose in the release of such reports is to facilitate an exchange of
technical information and to inform the public of technical developments.
-------
§85.1 §85.1
§85.1 TEST STANDARDS AND CALCULATIONS 3
(a) Emissions Standards 3
(b) Test Score Calculation 11
§85.2 TEST PROCEDURES 14
(a) General Requirements 14
(b) Vehicle Pre-Inspection and Preparation 14
(c) Equipment Preparation and Settings 16
(d) Test Procedures 18
(e) Second Chance Tests 24
§85.3 TEST EQUIPMENT SPECIFICATIONS 25
(a) Dynamometer Specifications 25
(b) Emission Sampling System 32
(c) Analytical Instruments 34
(d) Automated Test Process Software and Displays 38
§85.4 QUALITY CONTROL REQUIREMENTS 40
(a) General Requirements 40
(b) Dynamometer 40
(c) Emission Sampling System 45
(d) Analytic Instruments 46
§85.5 TEST RECORD INFORMATION 54
(a) General Information 54
(b) Ambient Test Conditions 54
(c) ASM Mode or Modes 54
(d) Diagnostic/Quality Assurance Information 54
APPENDIX A: CALCULATING AUDIT TOLERANCES 56
Page 2 Test Standards and Calculations
-------
§85.1
§85.1
§85.1 Test Standards and Calculations
(a) Emissions Standards
(1) Start-up ASM Standards
Start-up standards should be used during the first cycle of the program. The exhaust
emissions standards for the following model years and vehicle types are cross-
referenced by the number in the column in §85.1(a)(4), as noted in the column
headings:
(i) Light Duty Vehicles.
Model Years
Hydrocarbons
Carbon Monoxide
Oxides of Nitrogen
1996+
1991-1995
1983-1990
1981-1982
1980
1977-1979
1975-1976
1973-1974
1968-1972
Table §85.1 (a)(4)(i)
1
2
4
4
4
11
11
13
13
(10 Hi gh- Altitude Li ght Duty
Model Years
1983-1984
1982
(iii) Light
Model Years
1996+
<3750 LVW
1996+
>3750 LVW
1991-1995
1988-1990
1984-1987
1979-1983
1975-1978
Hydrocarbons
Table §85. 1 (a)(4)(i)
4
4
Duty Trucks 1 (less
Hydrocarbons
Table §85.1 (a)(4)(i)
1
2
5
7
7
11
12
Table §85. 1 (a)(4)(ii)
21
22
23
26
26
30
30
34
34
Vehicles.
Carbon Monoxide
Table §85. 1 (a)(4)(ii)
26
29
Table §85. 1 (a)(4)(iii)
41
42
43
43
48
48
50
50
51
Oxides of Nitrogen
Table §85. 1 (a)(4)(iii)
43
43
than 6000 pounds GVWR).
Carbon Monoxide
Table §85. 1 (a)(4)(ii)
21
22
26
29
29
31
32
Oxides of Nitrogen
Table §85. 1 (a)(4)(iii)
41
42
43
44
49
49
50
Page 3
Test Standards and Calculations
-------
§85.1 §85.1
1973-1974 13 34 50
1968-1972 13 34 51
(iv) High-Altitude Light Duty Trucks 1 (less than 6000 pounds GVWR).
Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen
Table §85.1 (a)(4)(i) Table §85.1 (a)(3)(ii) Table §85.1 (a)(4)(iii)
1991+ 6 28 43
1988-1990 9 30 44
1984-1987 9 30 49
1982-1983 12 33 49
(v) Light Duty Trucks 2 (greater than 6000 pounds GVWR).
Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen
Table §85.1 (a)(4)(i) Table §85.1 (a)(4)(ii) Table §85.1 (a)(4)(iii)
1996+
<5750LVW 2 22 42
1996+
>5750LVW 5 26 45
1991-1995 5 26 46
1988-1990 7 29 47
1984-1987 7 29 49
1979-1983 11 31 49
1975-1978 12 32 50
1973-1974 13 34 50
1968-1972 13 34 51
(vi) High-Altitude Light Duty Trucks 2 (greater than 6000 pounds GVWR).
Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen
Table §85.1 (a)(4)(i) Table §85.1 (a)(4)(ii) Table §85.1 (a)(4)(iii)
1991+ 6 28 46
1988-1990 9 30 47
1984-1987 9 30 49
1982-1983 12 33 49
(2) Original Final ASM Standards
The following exhaust emissions standards are designed to achieve the emission
reduction credits issued by EPA. They should only be used after at least one cycle of
operation using the start-up standards in §85.1(a)(l). The exhaust emissions standards
for the following model years and vehicle types are cross-referenced by the number in
the column in §85.1(a)(4), as noted in the column headings.
Revised Final Standards are provided in §85.1(a)(3) below. Use of these Revised Final
Standards will provide the same emission reduction credits available as use of the
Original Final ASM Standards. It is permissible to use combinations of the Original
Page 4 Test Standards and Calculations
-------
§85.1
§85.1
Final and Revised Final Standards, e.g. a state may implement the Original Final
Standards for LDTs and the Revised Final Standards for LDVs.
(i)
Light Duty Vehicles.
Model Years
1996+
1983-1995
1981-1982
1980
1977-1979
1975-1976
1973-1974
1968-1972
Hydrocarbons
Table §85.1 (a)(4)(i)
1
1
1
1
6
6
10
10
Carbon Monoxide
Table §85.1 (a)(4)(ii)
21
21
23
23
27
27
32
32
(ii) High-Altitude Light Duty Vehicles.
Model Years
1983-1984
1982
Hydrocarbons
Table §85.1 (a)(4)(i)
2
2
Carbon Monoxide
Table §85.1 (a)(4)(ii)
23
23
Oxides of Nitrogen
Table §85.1 (a)(4)(iii)
41
41
41
45
45
48
48
49
Oxides of Nitrogen
Table §85.1 (a)(4)(iii)
41
41
(iii) Light Duty Trucks 1 (less than 6000 pounds GVWR).
Model Years
1996+
1988-1995
1984-1987
1979-1983
1975-1978
1973-1974
1968-1972
Hydrocarbons
Table §85.1 (a)(4)(i)
1
3
3
8
9
10
10
Carbon Monoxide
Table §85.1 (a)(4)(ii)
21
24
24
28
29
32
32
Oxides of Nitrogen
Table §85.1 (a)(4)(iii)
41
42
46
46
48
48
49
(iv) High-Altitude Light Duty Trucks 1 (less than 6000 pounds GVWR).
Model Years
1988+
1984-1987
1982-1983
Hydrocarbons
Table §85.1 (a)(4)(i)
4
4
9
Carbon Monoxide
Table §85.1 (a)(4)(ii)
26
26
30
Oxides of Nitrogen
Table §85.1 (a)(4)(iii)
42
46
46
Page 5
(v) Light Duty Trucks 2 (greater than 6000 pounds GVWR).
Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen
Test Standards and Calculations
-------
§85.1 §85.1
Table §85.1 (a)(4)(i) Table §85.1 (a)(4)(ii) Table §85.1 (a)(4)(iii)
1996+ 1 21 41
1988-1995 3 24 44
1984-1987 3 24 46
1979-1983 8 28 46
1975-1978 9 29 48
1973-1974 10 32 48
1968-1972 10 32 49
(vi) High-Altitude Light Duty Trucks 2 (greater than 6000 pounds GVWR).
Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen
Table §85.1 (a)(4)(i) Table §85.1 (a)(4)(ii) Table §85.1 (a)(4)(iii)
1988+ 4 26 44
1984-1987 4 26 46
1982-1983 9 30 46
(3) Revised Final ASM Standards
The following exhaust emissions standards are designed to achieve the emission
reduction credits issued by EPA. They should only be used after at least one cycle of
operation using the start-up standards in §85.1(a)(l). The Revised Final Standards are
of the form depicted below.
Vehicle Engine Displacement (1) * Avg Emission <= Revised Standard
The Avg Emission is defined in §85.1(b)(l)(iv) and the vehicle shall pass the
appropriate ASM test if the product of Engine Displacement and the respective Avg
Emission is less than or equal to the Revised Standard for all three pollutants (HC, CO
&NO).
NOTE: The only exception to the form described above is for the ASM2525 LDT1 HC
standards. In this one case, the standards listed for HC in 85. l(3)(iv) below, are to be
compared directly to the Avg HC reading as defined in §85. l(b)(l)(iv). If the Avg HC
measurement is less than the Revised Standard, the vehicle's HC emissions are to
receive a passing grade. This deviation from the procedure described above is only to
be used for the HC ASM2525 LDT1 Revised Standards.
It is permissible to use combinations of the Original Final and Revised Final Standards,
e.g. a state may implement the Original Final Standards for LDTs and the Revised Final
Standards for LDVs.
The units of the Revised Standard are (ppm * liter) for HC and NO and (%* liter) for CO.
Page 6 Test Standards and Calculations
-------
§85.1 §85.1
There are no High Altitude or Light Duty Truck 2 Revised Final Standards available at
this time.
(i) ASM5015 Light Duty Vehicles
Pollutant MY Revised Standard
HC 1980+ 275
CO 1980-1982 1.3
1983+ 1.1
NO 1980 8,500
1981+ 3,600
(ii) ASM2525 Light Duty Vehicles
Pollutant MY Revised Standard
(iii)
(iv)
HC 1980-1989
1990+
CO 1980-1982
1983+
NO 1980
1981+
500
300
2.3
1.6
4,750
3,500
ASM5015 Light Duty Trucks 1 (less than 6000 pounds GVWR)
Pollutant MY
HC 1980-1983
1984-1995
1996+
CO 1980-1983
1984-1995
1996+
NO 1980-1987
1988-1995
1996+
Revised Standard
1140
537
275
9.7
5.4
1.1
14,145
7,380
6,150
ASM2525 Light Duty Trucks 1 (less than 6000 pounds GVWR)
Pollutant MY
HC* 1980-1983
1984-1995
1996+
CO 1980-1983
1984-1995
1996+
NO 1980-1987
1988-1995
1996+
Revised Standard
340
160
82
23.28
12.96
4.4
32,200
16,800
14,000
See NOTE above in §85.1(3) regarding the application of the HC ASM2525 LDT1 Revised Standards.
Page 7 Test Standards and Calculations
-------
§85.1
§85.1
(4) ASM 2525 and 5015 Concentration Tables for Phase-In & Original Final Standards
(i) ASM2525 and ASM5015 Hydrocarbon (ppm C6) Table
Column #
ETW
1750
1875
2000
2125
2250
2375
2500
2625
2750
2875
3000
3125
3250
3375
3500
3625
3750
3875
4000
4125
4250
4375
4500
4625
4750
4875
5000
5125
5250
5375
5500
5625
5750
5875
6000
6125
6250
6375
6500
6625
6750
6875
7000
7125
7250
7375
7500
1
5015
142
134
197
191
1 15
10Q
105
100
Q6
Q9
8q
86
83
81
78
76
74
79
71
6Q
67
66
65
63
69
61
60
58
57
56
S5
54
53
59
51
50
50
4Q
48
48
47
47
47
47
47
47
A7
1
2525
136
129
193
1 16
1 1 1
106
101
Q7
Q3
8Q
86
83
80
78
76
74
79
70
68
67
65
64
63
61
60
5Q
58
57
56
S5
54
53
59
51
50
4Q
48
48
47
46
46
46
46
46
46
46
Af.
2
5015
224
212
901
1Q1
189
173
166
15Q
159
146
141
136
139
198
194
190
117
114
119
10Q
107
104
109
100
Q8
Q6
Q4
Q3
Q1
8Q
87
86
84
83
81
80
7Q
77
76
76
75
75
74
74
74
74
7A
2
2525
216
205
1Q4
184
175
167
160
153
147
141
136
139
197
193
190
117
114
111
108
106
103
101
qq
q7
q5
q3
q9
qo
88
86
85
83
89
80
7q
78
76
75
74
74
73
73
79
79
79
79
79
3
5015
257
243
930
9iq
908
iqs
isq
181
173
167
160
155
14q
145
140
136
133
19Q
196
193
190
1 18
1 15
113
110
108
106
104
109
100
qs
q6
q4
q9
qo
sq
87
86
85
84
83
83
83
89
89
89
S9
^
2525
249
236
993
919
901
iq9
183
175
168
161
155
150
145
140
136
139
19Q
195
199
i iq
1 17
1 14
1 19
ioq
107
105
103
101
qq
q7
q5
q3
qi
qo
88
86
85
84
83
89
81
81
80
80
80
80
Sfl
4
5015
291
275
960
946
934
993
919
903
194
187
180
173
167
169
157
159
148
144
140
137
134
131
198
195
199
190
117
1 15
1 19
1 10
108
106
104
109
100
98
96
95
93
99
91
91
91
90
90
90
qn
4
2525
282
266
959
93q
997
916
906
1Q7
isq
181
174
168
169
157
159
148
144
140
137
133
130
197
194
199
iiq
117
114
1 19
1 10
107
105
103
101
qq
q7
q5
q4
q9
qi
qo
sq
sq
88
88
88
88
SS
5
5015
324
306
98q
974
960
947
936
995
916
907
iqq
iqi
185
i7q
173
168
163
15q
155
151
147
144
141
137
134
139
19Q
196
193
191
1 18
116
113
111
ioq
107
105
103
109
101
100
qq
qq
qs
qs
qs
qs
5
2525
315
2q?
981
967
953
941
930
91Q
910
901
1Q4
186
180
174
i6q
164
ISQ
155
151
147
143
140
137
134
131
198
196
193
190
1 18
1 15
113
111
108
106
104
109
101
qq
qs
q7
q7
q6
q6
q6
q6
qfi
6
5015
374
353
333
316
9qq
984
971
95q
947
937
998
91Q
91 1
904
iqs
1Q9
186
181
176
179
167
164
160
156
153
14Q
146
143
140
137
134
131
198
195
193
190
1 18
1 16
1 14
113
119
111
111
1 1 1
1 1 1
1 1 1
1 1 1
6
2525
364
344
395
308
9q9
977
964
959
941
931
999
914
906
iqq
iq3
187
189
177
179
168
164
160
156
159
14Q
146
143
13q
136
133
130
198
195
199
190
1 18
1 15
1 13
1 19
110
ioq
ioq
108
108
108
108
ins
7
5015
390
368
348
399
319
997
983
970
958
947
937
998
990
913
906
900
194
188
183
179
174
170
166
169
159
155
159
148
145
149
139
136
133
130
197
195
193
190
1 19
117
116
115
115
1 15
1 15
1 15
1 1 S
7
2525
381
359
339
391
305
990
976
963
959
941
939
993
915
908
901
195
189
184
179
175
170
166
169
159
155
159
148
145
149
139
136
133
130
197
194
199
190
1 18
1 16
114
113
113
119
1 19
1 19
1 19
1 19
8
5015
407
384
363
343
395
309
994
981
969
957
947
938
999
991
914
907
901
196
191
186
181
177
179
169
165
161
157
154
150
147
144
141
138
135
139
199
197
195
193
191
190
119
119
1 19
1 19
1 19
1 iq
8
2525
397
375
354
335
318
309
988
974
969
951
941
939
994
916
909
903
197
191
186
181
177
173
169
165
161
157
154
150
147
144
141
138
135
139
199
196
194
199
190
119
117
117
116
1 16
1 16
1 16
1 Ifi
9
5015
457
431
407
385
365
346
399
314
300
987
976
965
956
947
939
931
994
918
919
906
901
196
199
187
183
179
175
171
167
163
159
156
159
149
146
143
140
138
136
134
139
139
131
131
131
131
ni
9
2525
447
421
398
376
357
339
399
307
994
981
970
960
950
941
934
996
990
913
908
909
197
199
188
183
179
175
171
167
163
159
156
159
149
146
143
140
137
135
133
131
199
199
198
198
198
198
19S
10
5015
706
665
697
599
560
531
505
481
459
439
490
404
388
374
369
350
339
399
390
31 1
303
995
987
980
973
967
960
954
948
949
936
931
995
990
915
910
906
909
199
196
194
193
199
199
199
199
iq9
10
2525
694
653
616
589
551
599
496
479
451
431
413
397
389
368
355
344
333
393
314
305
997
990
989
975
969
969
956
950
944
938
939
996
991
916
911
906
909
198
195
199
190
189
188
188
188
188
1SS
11
5015
774
729
688
650
615
583
554
598
503
481
461
443
496
41 1
397
384
379
361
351
341
339
393
315
308
300
993
986
979
979
966
959
953
947
941
936
931
996
999
918
915
913
911
911
91 1
91 1
91 1
91 1
11
2525
761
717
676
638
604
573
544
518
495
473
453
435
419
404
390
377
365
355
345
335
396
318
310
309
995
988
981
974
967
961
955
948
943
937
939
997
999
918
914
911
909
907
907
906
906
906
9flfi
12
5015
843
794
749
707
669
635
603
574
548
594
509
489
464
447
439
418
405
393
389
371
361
359
343
335
397
319
311
304
996
989
989
976
969
963
957
951
946
949
938
934
939
930
999
999
999
999
99q
12
2525
828
780
736
6q5
658
694
5q3
564
53q
515
4q3
474
456
440
494
411
3qs
386
375
365
355
346
337
39q
391
313
305
9qs
9Q1
984
977
971
964
958
959
947
949
937
933
930
997
995
995
995
995
995
99S
13
5015
111
105
qq9
q38
887
841
800
761
796
6q5
666
63q
615
5q3
573
554
537
591
506
4q9
47q
467
455
444
433
493
419
409
3q3
383
374
365
357
348
341
333
396
390
315
310
307
305
304
304
304
304
1f\A
13
T595
109
103
975
991
879
897
786
748
714
683
654
698
604
583
563
544
597
519
497
484
471
459
447
436
495
415
405
395
386
376
367
359
350
349
334
397
390
314
309
304
301
999
998
998
998
998
9q»
PageS
Test Standards and Calculations
-------
§85.1
§85.1
(ii) ASM2525 and ASM5015 Carbon Monoxide (%CO) Table
Column #
ETW
1750
1875
2000
2125
2250
2375
2500
2625
2750
2875
3000
3125
3250
3375
3500
3625
3750
3875
4000
4125
4250
4375
4500
4625
4750
4875
5000
5125
5250
5375
5500
5625
5750
5875
6000
6125
6250
6375
6500
6625
6750
6875
7000
7125
7250
7375
7500
21
5015
080
075
071
068
064
061
0 59
0 56
0 54
0 52
0 50
048
046
0 45
044
042
041
04Q
0 39
038
03?
036
036
035
0 34
0 34
033
0 32
032
031
030
030
0 99
0 99
098
098
09?
09?
096
096
096
096
095
095
095
095
n 9S
21
•>s->s
077
073
0 69
066
062
0 59
05?
0 54
0 52
0 50
048
046
045
043
042
041
04Q
0 39
038
0 3?
036
035
035
034
033
033
032
031
031
030
030
099
0 99
098
098
09?
09?
096
096
096
096
095
095
095
095
095
n 9S
22
5015
1 96
1 19
1 13
1 0?
1 02
097
093
0 89
0 85
0 82
0 79
076
073
071
069
06?
065
063
0 62
06Q
0 59
0 58
0 5?
055
0 54
0 53
0 52
0 51
0 50
049
048
04?
046
045
0 44
0 44
043
042
042
0 41
041
04Q
04Q
04Q
040
040
n An
22
2525
1 92
1 16
1 09
1 04
099
094
090
086
0 82
0 79
076
073
071
069
06?
065
063
061
06Q
0 58
05?
0 56
055
0 54
0 53
0 52
0 51
0 50
049
048
04?
046
045
0 44
0 44
043
042
042
041
041
0 41
04Q
04Q
04Q
040
040
n An
23
5015
1 64
1 55
1 4?
1 39
1 32
1 96
1 90
1 15
1 10
1 05
1 01
098
094
091
088
086
0 83
0 81
0 79
07?
075
074
072
070
0 69
0 6?
066
065
063
062
061
0 59
0 58
0 5?
0 56
0 55
0 54
053
0 52
0 52
0 51
0 51
0 51
0 51
0 50
0 50
n sn
23
2525
1 83
1 72
1 63
1 54
1 47
1 39
1 33
1 97
1 91
1 16
1 12
1 08
1 04
1 00
09?
094
0 92
0 89
0 8?
0 85
0 83
0 81
079
07?
076
074
073
071
070
068
06?
065
064
063
062
061
060
0 59
0 58
05?
0 5?
0 56
0 56
0 56
0 56
0 56
n =,f.
24
5015
902
1 91
1 81
1 71
1 62
1 54
1 4?
1 41
1 34
1 99
1 94
1 19
1 15
1 U
1 08
1 05
1 02
0 99
096
0 94
092
0 89
0 8?
0 85
0 84
0 82
0 80
078
07?
075
073
072
07Q
0 69
0 6?
066
065
064
063
062
0 61
0 61
0 61
0 61
061
061
n f.\
24
2525
943
999
9 1?
905
1 94
1 85
1 76
1 68
1 60
1 54
1 48
1 42
1 37
1 32
1 98
1 94
1 90
1 17
1 14
1 U
1 08
1 06
1 03
1 01
0 99
0 9?
095
0 92
090
0 89
0 8?
0 85
0 83
0 81
0 80
078
07?
076
074
073
073
072
072
072
072
072
n 79
25
5015
991
9 09
1 9?
1 8?
1 7?
1 69
1 61
1 53
1 4?
1 41
1 35
1 30
1 96
1 91
1 17
1 14
1 U
1 08
1 05
1 02
1 00
09?
095
093
0 91
0 89
0 8?
0 85
083
0 81
080
078
076
075
073
072
071
069
068
06?
0 6?
066
066
066
066
066
n f.f.
25
2525
973
9 58
943
930
9 18
9 0?
1 9?
1 88
1 80
1 72
1 66
1 59
1 53
1 48
1 43
1 39
1 35
1 31
1 98
1 94
1 91
1 18
1 16
1 13
1 10
1 08
1 05
1 03
1 01
099
09?
094
0 92
0 91
0 89
0 8?
0 85
0 84
0 83
0 82
0 81
0 80
0 80
0 80
080
080
n sn
26
5015
978
963
948
935
993
9 12
9 02
1 92
1 84
1 76
1 69
1 63
1 57
1 52
1 47
1 42
1 38
1 34
1 31
1 97
1 94
1 91
1 18
1 15
1 13
1 10
1 08
1 05
1 03
1 01
099
09?
0 94
0 92
0 91
0 89
0 8?
086
0 84
083
0 82
0 82
0 82
0 81
0 81
0 81
n si
26
2525
364
343
394
3 06
990
976
9 62
9 50
939
999
9 19
9 U
9 03
1 96
1 89
1 84
1 78
1 73
1 68
1 64
1 60
1 56
1 52
1 48
1 45
1 42
1 38
1 35
1 32
1 99
1 96
1 94
1 91
1 18
1 16
1 13
1 U
1 09
1 08
1 06
1 05
1 04
1 04
1 04
1 04
1 04
i ru
27
5015
997
9 81
965
9 51
938
996
9 15
905
1 96
1 88
1 80
1 74
1 6?
1 62
1 56
1 52
1 47
1 43
1 39
1 36
1 32
1 99
1 96
1 93
1 90
1 17
1 15
1 12
1 10
1 07
1 05
1 03
1 01
098
096
0 94
093
091
090
088
0 88
0 8?
0 8?
0 8?
086
086
n Kf.
27
2525
394
371
3 51
332
3 14
998
9 84
970
9 58
94?
93?
998
990
9 12
9 05
1 98
1 92
1 8?
1 82
1 77
1 72
1 68
1 64
1 60
1 57
1 53
1 49
1 46
1 43
1 39
1 36
1 33
1 30
1 97
1 95
1 92
1 90
1 18
1 16
1 14
1 13
1 12
1 12
1 12
1 12
1 12
1 19
28
5015
3 16
9 98
9 82
96?
9 53
940
9 99
9 18
9 09
9 00
1 92
1 84
1 78
1 72
1 66
1 61
1 56
1 52
1 48
1 44
1 40
1 37
1 34
1 30
1 98
1 95
1 92
1 19
1 16
1 14
1 U
1 09
1 0?
1 04
1 02
1 00
098
096
095
094
093
0 92
0 92
0 92
092
092
n Q9
28
2525
494
400
37?
3 5?
338
391
305
9 91
978
966
9 55
945
936
998
990
9 13
90?
901
1 95
1 90
1 85
1 81
1 76
1 72
1 68
1 64
1 60
1 5?
1 53
1 50
1 46
1 43
1 40
1 3?
1 34
1 31
1 98
1 96
1 94
1 93
1 91
1 90
1 90
1 90
1 90
1 90
1 9fl
29
5015
3 54
334
3 16
9 99
9 83
9 69
9 56
9 44
933
993
9 14
9 06
1 99
1 92
1 86
1 80
1 74
1 69
1 65
1 61
1 56
1 53
1 49
1 46
1 42
1 39
1 36
1 33
1 30
1 97
1 94
1 91
1 19
1 16
1 14
1 U
1 09
1 0?
1 06
1 04
1 03
1 02
1 02
1 02
1 02
1 02
1 f!9
29
2525
485
45?
431
408
3 86
366
348
332
3 1?
303
991
979
9 69
960
9 51
943
936
999
992
9 16
9 U
906
9 01
1 96
1 91
1 8?
1 82
1 78
1 74
1 70
1 66
1 62
1 59
1 55
1 52
1 49
1 46
1 43
1 41
1 39
1 37
1 36
1 36
1 36
1 36
1 36
1 If.
30
5015
3 92
3 70
349
331
3 13
998
9 83
970
9 58
94?
93?
998
990
9 12
905
1 99
1 93
1 87
1 82
1 77
1 73
1 68
1 64
1 61
1 57
1 53
1 50
1 46
1 43
1 40
1 37
1 34
1 31
1 98
1 95
1 93
1 90
1 18
1 16
1 15
1 14
1 13
1 12
1 12
1 12
1 12
1 19
30
2525
545
5 14
485
458
434
412
391
373
3 56
341
39?
3 14
3 02
9 91
9 82
973
964
9 5?
9 49
943
936
931
9 95
9 19
9 14
9 09
904
9 00
1 95
1 90
1 86
1 82
1 78
1 74
1 70
1 66
1 63
1 60
1 57
1 55
1 54
1 52
1 52
1 52
1 52
1 52
1 S9
31
5015
431
406
3 83
363
3 44
396
3 10
996
9 83
971
9 60
9 50
940
9 32
9 94
9 1?
9 U
905
1 99
1 94
1 89
1 84
1 80
1 76
1 72
1 68
1 64
1 60
1 56
1 53
1 49
1 46
1 43
1 40
1 37
1 34
1 31
1 99
1 97
1 95
1 94
1 93
1 93
1 92
1 92
1 92
1 99
31
2525
606
570
538
5 09
482
45?
435
4 14
395
3 78
362
348
335
393
3 12
3 02
993
9 85
97?
969
9 62
9 55
9 49
943
93?
932
996
991
9 16
9 U
906
9 01
1 96
1 92
1 88
1 84
1 80
1 77
1 74
1 72
1 70
1 68
1 68
1 68
1 68
1 68
1 fiS
32
5015
507
478
451
496
404
383
365
348
332
3 18
305
9 93
9 82
9 72
963
9 55
94?
940
933
99?
9 91
9 16
9 U
906
901
1 96
1 92
1 8?
1 83
1 79
1 75
1 71
1 6?
1 63
1 60
1 5?
1 54
1 51
1 48
1 46
1 45
1 44
1 43
1 43
1 43
1 43
i /n
32
2525
796
6 84
645
6 10
578
548
591
496
473
453
434
4 1?
401
38?
374
362
3 51
3 40
331
392
3 13
305
998
990
9 83
97?
970
964
9 58
9 51
946
940
934
999
994
9 19
9 15
9 U
9 0?
9 04
902
9 00
9 00
9 00
900
900
9 nn
33
5015
596
496
468
443
490
398
379
361
345
330
3 1?
3 04
993
9 83
973
965
9 5?
949
943
936
930
9 94
9 19
9 14
9 09
9 04
1 99
1 95
1 90
1 86
1 82
1 77
1 74
1 70
1 66
1 63
1 60
1 57
1 54
1 52
1 50
1 49
1 49
1 49
1 49
1 49
1 AQ
33
2525
744
705
668
634
600
569
541
5 15
492
470
451
433
41?
402
3 88
376
364
3 54
344
334
395
3 1?
3 09
3 02
995
9 8?
9 81
974
968
961
9 55
9 49
943
938
933
998
9 93
9 19
9 15
9 12
9 10
9 08
9 08
9 08
908
908
9 ftS
34
5015
802
756
7 14
675
640
60?
578
5 51
596
503
483
464
44?
431
4 1?
404
391
3 80
3 70
3 60
3 51
3 42
334
396
3 18
3 U
303
99?
990
9 83
97?
970
9 64
9 59
9 53
948
943
9 39
935
9 32
999
998
99?
99?
9 9?
9 9?
9 97
34
T^5
990
99Q
99Q
966
9 14
86?
895
785
750
7 1?
6 8?
66Q
635
6 13
5 92
573
5 55
539
594
5 09
496
483
471
460
449
438
498
4 18
408
398
3 89
3 80
371
362
3 54
34?
340
334
398
393
3 90
3 1?
3 1?
3 1?
3 1?
3 1?
•3 17
Page 9
Test Standards and Calculations
-------
§85.1
§85.1
(iii) ASM2525 and ASM5015 Nitric Oxide (ppm NO) Table
Column #
ETW
1750
1875
2000
2125
2250
2375
2500
2625
2750
2875
3000
3125
3250
3375
3500
3625
3750
3875
4000
4125
4250
4375
4500
4625
4750
4875
5000
5125
5250
5375
5500
5625
5750
5875
6000
6125
6250
6375
6500
6625
6750
6875
7000
7125
7250
7375
7500
41
5015
1212
1 149
1077
1018
Q64
915
86Q
898
7Q1
756
795
6Q6
670
647
695
605
586
56Q
553
538
594
510
4Q8
486
474
463
459
441
431
490
410
401
3Q1
383
374
366
35Q
359
346
341
338
335
335
335
335
335
T3S
41
2525
1095
1031
Q73
Q90
871
897
786
74Q
715
684
656
630
607
585
566
547
531
515
501
487
475
463
451
440
430
490
410
400
3Q1
389
373
364
356
348
340
333
396
390
315
311
307
305
305
305
305
305
™s
42
5015
1819
1713
1616
1597
1446
1379
1304
1949
1186
1 134
1088
1045
1006
970
937
907
879
853
899
807
786
766
747
798
711
694
677
661
646
631
616
601
587
574
561
549
538
598
519
519
507
503
509
509
509
509
Sfl9
42
2525
1642
1547
1460
1380
1307
1940
1179
1193
1079
1096
984
945
910
878
848
891
796
773
751
731
719
694
677
661
645
630
615
600
586
573
559
546
534
599
510
499
489
480
473
466
461
458
457
457
457
457
/LS7
43
5015
2272
9181
9058
1944
1839
1744
1657
1577
1504
1438
1378
1393
1973
1997
1184
1146
1110
1077
1046
1017
990
964
939
916
893
879
850
830
810
790
771
759
734
717
701
685
671
658
647
638
631
696
694
695
695
695
fi9S
43
2525
2114
1991
1877
1774
1678
1599
1519
1440
1374
1313
1958
1908
1 163
1191
1089
1047
1014
984
956
930
905
889
859
838
818
798
778
760
741
793
706
689
673
657
649
698
615
604
593
585
578
574
573
573
573
573
S7T
44
5015
2725
9649
9499
9360
9939
9115
9009
1919
1893
1749
1668
1601
1539
1483
1439
1384
1340
1300
1969
1997
1 194
1169
1139
1104
1076
1049
1093
998
974
950
996
904
889
860
840
899
804
788
775
763
755
749
747
747
747
747
747
44
2525
2587
9435
9995
9167
9050
1943
1845
1756
1675
1601
1533
1471
1415
1363
1316
1973
1933
1 195
1 161
1 198
1098
1069
1049
1015
990
966
949
919
896
874
853
839
819
793
774
757
741
797
714
704
696
691
689
689
689
689
fiSQ
45
5015
3178
31 17
9941
9776
9695
9487
9361
9946
9149
9046
1959
1879
1806
1740
1679
1693
1571
1593
1479
1437
1398
1360
1395
1991
1959
1997
1 196
1 167
1 138
1109
1089
1055
1099
1004
980
958
937
919
909
889
879
879
870
870
870
870
S7fl
45
2525
3060
9879
9713
9561
9499
9995
9179
9073
1976
1888
1808
1734
1667
1606
1550
1498
1451
1407
1365
1397
1991
1957
1994
1193
1163
1 134
1 106
1078
1051
1095
1000
975
951
998
906
886
867
850
835
893
813
807
805
805
805
805
sns
46
5015
3631
3586
3383
3199
3018
9859
9714
9581
9460
9350
9949
9157
9073
1997
1996
1869
1809
1747
1695
1647
1609
1559
1518
1479
1441
1405
1369
1335
1301
1969
1937
1906
1176
1 147
1 190
1094
1070
1049
1030
1014
1003
995
999
999
999
999
QQ9
46
2525
3532
3393
3131
9955
9794
9646
9519
9389
9977
9175
9089
1997
1990
1849
1784
1794
1669
1618
1570
1596
1484
1444
1406
1370
1336
1309
1969
1937
1906
1176
1147
1118
1090
1064
1039
1015
993
973
956
941
931
994
991
991
991
991
Q91
47
5015
4084
4054
3894
3609
3411
3931
3066
9916
9779
9654
9539
9435
9340
9953
9174
9100
9033
1970
1919
1857
1806
1757
1711
1666
1694
1583
1549
1503
1465
1498
1399
1357
1393
1990
1959
1930
1903
1179
1158
1140
1197
1 1 18
1115
1115
1115
1115
111S
47
2525
4005
3767
3548
3348
3165
9998
9845
9706
9579
9463
9357
9960
9179
9099
9018
1950
1887
1899
1775
1794
1677
1639
1589
1548
1508
1470
1433
1397
1369
1397
1994
1961
1930
1 199
1 171
1 144
1 119
1096
1077
1060
1048
1040
1037
1037
1037
1037
im7
48
5015
4990
4990
4707
4441
4197
3974
3771
3585
3416
3961
3190
9999
9874
9767
9668
9578
9494
9417
9345
9977
9914
9154
9096
9049
1989
1938
1889
1840
1793
1747
1703
1659
1617
1577
1539
1503
1469
1439
1413
1391
1374
1364
1360
1360
1360
1360
nfifl
48
2525
4950
4655
4384
4136
3909
3701
3519
3339
3181
3037
9906
9787
9677
9577
9486
9401
9393
9951
9184
9199
9063
9007
1953
1903
1854
1806
1760
1715
1679
1699
1587
1547
1508
1471
1435
1401
1371
1343
1318
1998
1983
1973
1969
1969
1969
1969
19fiQ
49
5015
4990
4990
4778
4578
4395
4998
4076
3936
3809
3669
3510
3366
3934
3113
3009
9900
9806
9719
9638
9569
9490
9493
9359
9997
9938
9180
9195
9070
9017
1966
1916
1867
1890
1774
1731
1690
1653
1619
1590
1565
1546
1534
1530
1531
1531
1531
1ST1
49
2525
4960
4738
4535
4349
4179
4094
3881
3759
3579
3417
3970
3135
3019
9899
9796
9701
9614
9533
9457
9387
9390
9958
9198
9140
9085
9039
1980
1930
1881
1833
1786
1740
1697
1654
1614
1577
1549
1510
1483
1460
1443
1439
1498
1498
1498
1498
149S
50
5015
4990
4990
4919
4853
4799
4736
4685
4639
4596
4484
4990
41 14
3959
3804
3669
3544
3499
3393
3994
3131
3044
9961
9883
9807
9735
9665
9597
9530
9466
9403
9341
9989
9994
9168
91 16
9066
9090
1979
1943
1913
1890
1875
1870
1874
1874
1874
1S7/L
50
2525
4980
4906
4838
4776
4790
4668
4690
4577
4374
4176
3996
3839
3681
3544
3418
3309
3195
3096
3003
9917
9836
9759
9686
9616
9549
9483
9490
9359
9998
9940
9183
9197
9074
9099
1973
1997
1884
1846
1813
1785
1764
1750
1745
1745
1745
1745
174S
51
5015
4990
4990
4990
4990
4990
4990
4990
4990
4990
4899
4680
4488
431 1
4150
4009
3867
3741
3695
3517
3416
3391
3930
3145
3063
9983
9907
9833
9760
9690
9691
9554
9489
9496
9366
9308
9954
9904
9159
9119
9087
9069
9046
9040
9045
9045
9045
9fUS
51
2525
4990
4990
4990
4990
4990
4990
4990
4990
4779
4556
4359
4180
4016
3866
3798
3609
3485
3377
3976
3189
3094
3010
9930
9854
9780
9709
9640
9573
9507
9443
9381
9391
9969
9906
9159
9109
9056
9014
1977
1947
1994
1909
1904
1904
1904
1904
IQfU
Page 10
Test Standards and Calculations
-------
§85.1 §85.1
(b) Test Score Calculation
(1) Exhaust Gas Measurement Calculation.
(i) Measurement Start. The analysis and recording of exhaust gas concentrations
shall begin 15 seconds after the applicable test mode begins, or sooner if the
system response time (to 95% of full scale) is less than 15 seconds. The
analysis and recording of exhaust gas concentrations shall not begin sooner than
the time period equivalent to the response time of the slowest transducer.
(ii) Sample Rate. Exhaust gas concentrations shall be analyzed at a minimum rate
of once per second.
(iii) Negative Values. Negative concentration readings shall be integrated as zero
and recorded as such.
(iv) Emission Measurement Calculations. Partial stream (concentration) emissions
shall be calculated based on a running 10 second average. The values used for
HCG), COG), and NOG) are the raw (uncorrected) tailpipe concentrations.
]THCG)*DCFG)
(A) AvgHC = -^
10
£COG)*DCF(J)
(B)
10
10
(C)
10
(v) Dilution Correction Factor. The analyzer software shall multiply the raw
emissions values by the Dilution Correction Factor (DCF) during any valid
ASM emissions test. The DCF accounts for exhaust sample dilution (either
intentional or unintentional) during an emissions test. The analyzer software
shall calculate the DCF using the following procedure, and shall select the
appropriate vehicle fuel formula. If the calculated DCF exceeds 3.0 then a
default value of 3.0 shall be used.
(A) X =
2 J measured
2 J
2 measured measured
Page 11 Test Standards and Calculations
-------
§85.1 §85.1
Where [CO2]measured and [CO]measured are the instantaneous ASM
emissions test readings.
(B) Calculate [CO2]adjUsted using the following formulas.
(1) For Gasoline:
V
rrn 1 = _ — _ *100
L Jadjusted 4.644 + 1.88X
(2) For Methanol or Ethanol:
V
rrn 1 = _ — _ *100
L Jadjusted 4.73 + 1.88X
(3) For Compressed Natural Gas (CNG):
(4) For Liquid Propane Gas (LPG):
(C) Calculate the DCF using the following formula:
L ^ " 2 J adjusted
DCF =
[LxU2 Jmeasur
ed
(vi) NO Humidity Correction Factor. The NO measurement shall be adjusted based
on relative humidity using a correction factor Kh, calculated as follows:
(A) Standard Method
1
1.0-0.0047(H-75)
Where:
H = Absolute humidity in grains of water per pound of dry air.
= (43.478)Ra*Pd
PB-(Pd*Ra/100)
Ra = Relative humidity of the ambient air, percent.
Page 12 Test Standards and Calculations
-------
§85.1 §85.1
Pd = Saturated vapor pressure, mm Hg at the ambient dry bulb
temperature*.
= (.4.14438* 10'3) + (5.76645* 10'3 * Td) - (6.32788* 10'5 *
Td2) + (2.12294*10'6 * Td3) - (7.85415*10'9 * Td4) +
(6.55263*10'u *Td5)
Where :Td = Dry bulb temperature, °F
PB= Barometric pressure, mm Hg.
(B) Revised method*
v _ [0.004977(H-75)-0.004447(1-75)]
j^h - e
Where: H =Absolute humidity in grains of water per pound
of dry air.
T =Temperature in °F.
NOTE: If the calculated KH using either method of calculation is greater
than 2.19, the value of KH shall be set at 2.19.
(2) Pass/Fail Determination.
A pass or fail determination shall be made for each applicable test mode based on a
comparison of the applicable test standards and the measured value for HC, CO, and
NO as described in §85. l(b)(l)(iv). A vehicle shall pass the test mode if the emission
values for HC, CO, and NO are simultaneously below or equal to the applicable short
test standards for all three pollutants. A vehicle shall fail the test mode if the values for
HC, CO, or NO, or any combination of the three, are above the applicable standards at
the expiration of the test time.
* SAEJ1094, §6.1.1.3, p.38, June 1992. This equation is a least squares fit to the Keenan and Keyes "steam table." It
reproduces steam table values within 0.0001 in Hg for temperatures from 20° to 110°F.
* This revised method for calculating Kh as a function of both T and H is based on work performed by Sierra Research under
contract 68-C4-0056, Work Assignment 2-04. If the calculated value of Kh exceeds 2.19, the value of Kh shall be set to 2.19.
This analysis used the same MY69, 5-vehicle sample employed for the original Kh factor study that resulted in the current
CFR standard Kh calculation method (listed in (vi)(F) above). However, in many cases IM testing occurs outside the
temperature limits set by the CFR for the standard method; therefore, at this time EPA recommends using the revised method
when testing above 86°F. The new method makes the calculation of Kh more accurate over a wider range of temperatures.
Page 13 Test Standards and Calculations
-------
§85.2 §85.2
§85.2 Test Procedures
(a) General Requirements.
(1) Vehicle Characterization. The following information shall be determined for the vehicle
being tested and used to automatically select the dynamometer power absorption settings:
(i) Vehicle type: LDGV, LDGT1, LDGT2, HDGT, and others as needed
(ii) Chassis model year
(iii) Make
(iv) Model
(v) Number of cylinders
(vi) Cubic inch or liters displacement of the engine
(vii) Transmission type
(viii) Equivalent Test Weight.
(2) Ambient Conditions. The ambient temperature, absolute humidity, and barometric
pressure shall be recorded continuously during the test cycle or as a single set of readings
up to 4 minutes before the start of the driving cycle.
(3) Restart. If shut off, the vehicle shall be restarted as soon as possible before the test and
shall be running for at least 30 seconds prior to the start of the ASM driving cycle.
(4) Void Test Conditions. The test shall immediately end and any exhaust gas measurements
shall be voided if the instantaneous measured concentration of CO plus CO2 falls below
six percent or the vehicle's engine stalls at any time during the test sequence.
(5) Vehicle Brakes. The vehicle's brakes shall not be applied during the test modes. If the
vehicle's brakes are applied during testing the mode timer shall be reset to zero (tt = 0).
Some dynamometers do not have the ability to automatically sense if a vehicle's brakes
become engaged. In these instances, it shall be the responsibility of the Program to
implement technician training and test procedures so that a test shall be manually
restarted if the vehicle's brakes are applied.
(6) Test Termination. The test shall be aborted or terminated upon reaching the overall
maximum test time.
(b) Vehicle Pre-Inspection and Preparation.
(1) Accessories. All accessories (air conditioning, heat, defogger, radio, automatic traction
control if switchable, etc.) shall be turned off (if necessary, by the inspector).
(2) Traction Control and Four-Wheel Drive (AWD). Most vehicles with traction control
can be tested on AWD dynamometers; however, this is not true for all vehicles and
dynamometer models.
Page 14 7/28/04 Test Procedures
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§85.2 §85.2
Vehicles with traction control systems that cannot be turned off shall not be tested on
two wheel drive dynamometers. Vehicles with AWD that cannot be turned off shall
only be tested on AWD dynamometers. If the AWD function can be disabled, then
AWD vehicles may be tested on two wheel drive dynamometers.
It is the responsibility of all vehicle OEMs to notify the Certification and Compliance
Division of EPA in writing of any vehicles that can't be tested on AWD dynamometers
so that EPA may share this information with state IM programs.
(c) Exhaust Leaks. The vehicle shall be inspected for exhaust leaks. Audio assessment
while blocking exhaust flow, or gas measurement of carbon dioxide or other gases shall
be acceptable. Vehicles with leaking exhaust systems shall be rejected from testing.
(4) Fluid Leaks. The vehicle shall be inspected for fluid leaks. Vehicles with leaking
engine oil, transmission fluid, or coolant shall be rejected from testing.
(5) Mechanical Condition. Vehicles with obvious mechanical problems (engine,
transmission, brakes, or exhaust) that either create a safety hazard or could bias test
results shall be rejected from testing.
(6) Operating Temperature. The vehicle shall be at normal operating temperature prior to
the start of the test. The vehicle temperature gauge, if equipped and operating, shall be
checked to assess temperature. Vehicles in overheated condition shall be rejected from
testing.
(7) Tire Condition. Vehicles shall be rejected from testing if tread indicators, tire cords,
bubbles, cuts, or other damage are visible. Vehicles shall be rejected from testing if
they have space-saver spare tires or if they do not have reasonably sized tires on the
drive axle or axles. Vehicles may be rejected if they have different sized tires on the
drive axle or axles. In test-and-repair facilities, drive wheel tires shall be checked with
a gauge for adequate tire pressure. In test-only facilities, drive wheel tires shall be
visually checked for adequate pressure level. Drive wheel tires that appear low shall be
inflated to approximately 30 psi, or to tire sidewall pressure, or vehicle manufacturer's
recommendation. Alternatively, vehicles with apparent low tire pressure may be
rejected from testing.
(8) Gear Selection. The vehicle shall be operated during each mode of the test with the
gear selector in drive for automatic transmissions and in second (or third if more
appropriate) for manual transmissions for the loaded modes.
(9) Roll Rotation. The vehicle shall be maneuvered onto the dynamometer with the drive
wheels positioned on the dynamometer rolls. Prior to test initiation, the rolls shall be
rotated until the vehicle laterally stabilizes on the dynamometer. Vehicles that cannot
be stabilized on the dynamometer shall be rejected from testing. Drive wheel tires shall
be dried if necessary to prevent slippage.
(10) Vehicle Restraint. Testing shall not begin until the vehicle is restrained. Any restraint
system shall meet the requirements of §85.3(a)(5)(ii). In addition, the parking brake
shall be set for front wheel drive vehicles prior to the start of the test, unless parking
brake functions on front axle or if is automatically disengaged when in gear.
Page 15 Test Procedures
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§85.2 §85.2
(11) Vehicle Conditioning.
(i) Queuing Time. When a vehicle waits in a queue more than 20 minutes or when
a vehicle is shut-off for more than 5 minutes prior to the test, vehicle
conditioning shall be performed for 60 seconds, as specified in
§85.2(b)(12)(ii)(C) below. This 60 second period is in addition to the test times
described in §85.2(d). Emissions may be monitored during this cycle and if
passing readings are obtained, as specified for the ASM cycle in §85.2(d), then
the cycle may be terminated and the respective ASM mode skipped.
(ii) Discretionary Preconditioning. At the program's discretion, any vehicle may be
preconditioned using any of the following methods:
(A) Non-loaded Preconditioning. Increase engine speed to approximately
2500 RPM, for up to 4 minutes, with or without a tachometer.
(B) Loaded Preconditioning. Drive the vehicle on the dynamometer at 30
miles per hour for up to 240 seconds at road-load.
(C) ASM Preconditioning. Drive the vehicle on the dynamometer using
either mode of the ASM test as specified in §85.2(d).
(D) Transient Preconditioning. After maneuvering the vehicle onto the
dynamometer, drive a transient cycle consisting of speed, time,
acceleration, and load relationships such as the IM240.
(c) Equipment Preparation and Settings.
(1) Analyzer Warm-Up. Emission testing shall be locked out until the analyzer is warmed-
up and stable. The analyzer shall reach stability within 30 minutes from startup. If an
analyzer does not achieve stability within the allotted time frame, it shall remain locked
out from testing. The instrument shall be considered "warmed-up" when the zero and
span readings for HC, CO, NO, and CO2 have stabilized within the accuracy values
specified in §85.3(c)(3)(vi) for five minutes without adjustment.
(2) Emission Sample System Purge. While the equipment is in operation, the sample
system shall be continuously purged after each test for at least 15 minutes if not taking
measurements. If the equipment has been shut down, the system shall be purged for 5
minutes or until the HC reading is less than 15 ppm C6 prior to the start of a test.
(3) Probe Insertion. The sample probe shall be inserted into the vehicle's tailpipe to a
minimum depth of 10 inches. If the vehicle's exhaust system prevents insertion to this
depth, a tailpipe extension shall be used.
Page 16 Test Procedures
-------
§85.2 §85.2
(4) Multiple exhaust pipes. Exhaust gas concentrations from vehicle engines equipped
with functionally independent multiple exhaust pipes shall be sampled simultaneously.
The collection system shall be designed such that the flow through both probes is
within ± 10%.
(5) Analyzer Preparation. The analyzer shall perform an automatic zero, an ambient air
reading, and an HC hang-up check prior to each test. This process shall occur within
two minutes of the start of the test.
(i) Automatic Gas Zero. The analyzer shall conduct automatic zero adjustments
using the zero gas specified in §85.4(d)(2)(iii). The zero adjustment shall
include the HC, CO, CC>2, and NO channels. Bottled or generated zero air may
be used.
(ii) Ambient Air Reading. Filtered ambient air shall be introduced to the analyzer
before the sample pump, but after the sample probe, hose, and filter/water trap.
The analyzer shall record the concentrations of the four measured gases, but
shall make no adjustments.
(1) The sample through probe has less than 15 ppm HC, 0.02% CO, and
25ppmNO.
(iii) HC Hang-up Determination. The analyzer shall sample ambient air through the
probe to determine background pollution levels and HC hang-up. The analyzer
shall be locked out from testing until:
(1) The residual HC in the sampling system (probe sample - ambient air
reading) is less than 7 ppm.
(6) Cooling System. When ambient temperatures exceed 72°F, testing shall not begin until
the cooling system blower is positioned and activated. The cooling system shall be
positioned to direct air to the vehicle cooling system, but shall not be directed at the
catalytic converter. The use of a cooling system is optional when testing at
temperatures below 50°F. If a cooling system is in use, testing shall not begin until the
cooling system is positioned and activated. Furthermore, the hood may be opened at
the state's discretion.
(7) Dynamometer Warm-Up. Dynamometers that do not have temperature compensation
shall be automatically warmed-up prior to official testing and shall be locked out until
warmed-up. Dynamometers resting (not operated for at least 30 seconds and at least 15
mph) for more than 30 minutes shall pass the coast-down check specified in §85.4(b)(l)
prior to use in testing. As specified in §85.4(a)(2), control charts may be used to
demonstrate allowing a longer duration of inactivity before a required warm-up.
If the dynamometer is not warmed-up as outlined above, then the parasitic losses,
typically bearing and windage friction expressed as a function of velocity, shall be
characterized as a function of bearing temperature or some alternative parameter that
the manufacturer ca demonstrate is correlated with parasitic losses. Based on this
characterization, the dynamometer load shall be automatically adjusted to compensate
Page 17 Test Procedures
-------
§85.2 §85.2
for changes in parasitic losses as a function of dynamometer temperature in order to
ensure dynamometer load accuracy without having to perform dynamometer warm-ups.
All-wheel-drive dynamometers must characterize losses for the entire system, i.e. both
roll sets. If an all-wheel-drive dynamometer can be operated in either two- or all-
wheel-drive mode, parasitic losses must be characterized in both two- and all-wheel-
drive modes. System software shall automatically change parasitic losses depending on
how the vehicle is tested.
(8) Dynamometer Settings. Dynamometer power absorption and inertia weight settings
shall be automatically chosen from an EPA-supplied or EPA-approved electronic look-
up table which will be referenced based upon the vehicle identification information
obtained in §85.2(a)(l)*. Vehicles not listed shall be tested using default power
absorption and inertia settings in the latest version of the EPA I/M Look-up Table, as
posted on EPA's web site: www.epa.gov/orcdizux/im.htm. At a minimum the look-up
table on the ASM host computer should be updated once per year.
(9) Engine Speed. Engine speed measurement equipment shall be attached on all 1996 and
newer light duty vehicles and trucks, and in test-and-repair programs, engine speed
shall also be monitored on all pre-1996 vehicles. On vehicles equipped with OBD
systems (1996 and newer), it is recommended that the SAE-standardized OBD-plug be
used. Engine speed measurement equipment shall meet the requirements of
§85.3(c)(5).
(d) Test Procedures.
The test sequence shall consist of either a single ASM mode or both ASM modes described in
§85.2(d)(l) and (2), and may be performed in either order (with appropriate change in
transition requirements in §85.2(d)(l)(iv)). Vehicles that fail the first-chance test described in
§85.2(d) shall receive a second-chance test if the conditions in §85.2(e) apply. An Alternative
ASM mode is described in §85.2(d)(3). This new procedure was designed to improve vehicle
throughput by reducing the likelihood of failing a vehicle because it had locked into a non-
representative high emitting mode of operation. Vehicles that fail the Alternative ASM Test
Procedure may be granted a second-chance test at the state's discretion.
The test timer shall start (tt=0) when the conditions specified in §85.2(b) and §85.2(c) are met
and the mode timer initiates as specified in §85.2(d)(l), §85.2(d)(2), or §85.2(d)(3). Maximum
test times for various test scenarios are described in §85.2 (e)(l) below. The test shall be
immediately terminated or aborted upon reaching the overall maximum test time.
EPA last updated the look-up table on September 10, 1998 (I/M LOOK-UP TABLE, RELEASE 1.6.1). Since that time the
table has been updated by states, contractors and consulting firms.
Page 18 Test Procedures
-------
§85.2
§85.2
(1) ASM5015Mode.
(i) The mode timer shall start (mt=0) when the dynamometer speed (and
corresponding power) is maintained within 15±1.0 miles per hour for 5
continuous seconds. The dynamometer shall apply the constant torque over the
duration of the ASM mode. Torque shall be set to the correct torque necessary
to generate the required horsepower at 15.0 mph. If actual torque applied
deviates by more than 2% from the target torque for more than two consecutive
seconds, the test mode timer shall be set to mt=0.
(ii) The dynamometer power shall be automatically selected from an EPA-supplied
or EPA-approved look-up table, based upon the vehicle identification
information described in §85.2(a)(l). If a vehicle is not specifically listed in the
EPA-approved table, default values from the same table shall be used. If an
appropriate default value is not available in the EPA-approved table, ASM
loading should be taken from the following table:
Default ASM5015 Actual Horsepower Settings
For 8.6" Dynamometers HP50158
Vehicle Type
Sedans
Station Wagons
Mini-vans
Pickup Trucks
Sport/Utility
Full Vans
Number of Cylinders
3
7.9
8.1
10.2
9.6
10.1
10.3
4
11.4
11.7
14.1
13.1
13.4
13.9
5&6
13.8
13.8
15.8
16.4
15.5
17.7
8
16.4
16.1
17.9
19.2
19.4
19.6
>8
16.0
16.1
18.2
21.1
21.1
20.5
Default ASM5015 Actual Horsepower Settings
For 20" Dynamometers HP501520
Vehicle Type
Sedans
Station Wagons
Mini-vans
Pickup Trucks
Sport/Utility
Full Vans
Number of Cylinders
3
8.1
8.3
10.4
9.8
10.5
10.8
4
11.8
12.1
14.5
13.4
13.8
14.4
5&6
14.3
14.2
16.3
16.8
15.9
18.2
8
16.9
16.6
18.5
19.8
19.9
20.2
>8
16.6
16.6
18.7
21.7
21.7
21.1
If the dynamometer speed or torque falls outside the speed or torque tolerance
for more than 2 consecutive seconds, or for more than 5 seconds total, the mode
Page 19
Test Procedures
-------
§85.2 §85.2
timer shall reset to zero and resume timing. The minimum mode length shall be
determined as described in §85.2(d)(iii). The maximum mode length shall be
90 seconds elapsed time (mt=90).
During the 10 second period used for the pass decision, the dynamometer speed
shall not fall more than 0.5 mph (absolute drop, not cumulative). If the speed at
the end of the 10 second period is more than 0.5 mph less than the speed at the
start of the 10 second period, testing shall continue until the speed stabilizes
enough to meet this criterion.
The ten second emissions window shall be matched to the corresponding
vehicle speed trace time window. This shall be performed by subtracting the
nominal response time for the analyzers from the mode time to determine the
time for the corresponding vehicle speed.
(iii) The pass/fail analysis shall begin after an elapsed time of 25 seconds (mt=25).
A pass/fail determination shall be made for the vehicle and the mode shall be
terminated as follows:
(A) The vehicle shall pass the ASM5015 mode and the mode shall be
immediately terminated if, at any point between an elapsed time of 25
seconds (mt=25) and 90 seconds (mt=90), the 10 second running average
measured values for each pollutant are simultaneously less than or equal
to the applicable test standards described in §85.1 (a).
(B) Pass/Fail determinations may be made at mt=15 seconds if a 50% safety
margin in cutpoints is applied from mt=15 to mt=25 seconds, i.e.
emissions for all pollutants are simultaneously 50% below the appropriate
ASM standards.
(C) The vehicle shall fail the ASM5015 mode and the mode shall be
terminated if the requirements of §85.2(d)(l)(iii)(A) are not satisfied by an
elapsed time of 90 seconds (mt=90).
(iv) Upon termination of the ASM5015 mode, the vehicle shall immediately begin
accelerating to the speed required for the ASM2525 mode. The dynamometer
torque shall smoothly transition during the acceleration period and shall
automatically reset to the load required for the ASM2525 mode as specified in
§85.2(d)(2)(i) once the roll speed specified in §85.2(d)(2)(i) is achieved.
(2) ASM2525 Mode.
(i) The mode timer shall start (mt=0) when the dynamometer speed (and
corresponding power) are maintained within 25±1.0 miles per hour for 5
continuous seconds. The dynamometer shall apply the constant torque over the
duration of the ASM mode. Torque shall be set to the correct torque necessary
to generate the required horsepower at 25.0 mph. If actual torque applied
deviates by more than 2% from the target torque for more than two consecutive
seconds, the test mode timer shall be set to mt=0.
Page 20 Test Procedures
-------
§85.2
§85.2
(ii) The dynamometer power shall be automatically selected from an EPA-supplied
or EPA-approved look-up table, based upon the vehicle identification
information described in §85.2(a)(l). If a vehicle is not specifically listed in the
EPA-approved table, default values from the same table shall be used. If an
appropriate default value is not available in the EPA-approved table, ASM
loading should be taken from the following table:
Default ASM2525 Actual Horsepower Settings
For 8.6" Dynamometers HP25258
Vehicle Type
Sedans
Station Wagons
Mini-vans
Pickup Trucks
Sport/Utility
Full Vans
Number of Cylinders
3
6.7
6.8
8.8
8.0
8.8
9.0
4
9.5
9.7
11.7
10.9
11.2
11.6
5&6
11.5
11.5
13.2
13.6
12.9
14.7
8
13.7
13.4
14.9
16.0
16.1
16.3
>8
13.3
13.3
15.3
17.8
17.8
17.2
Default ASM2525 Actual Horsepower Settings
For 20" Dynamometers HP252520
Vehicle Type
Sedans
Station Wagons
Mini-vans
Pickup Trucks
Sport/Utility
Full Vans
Number of Cylinders
3
6.9
7.0
8.9
8.1
8.9
9.1
4
10.1
10.4
12.5
11.4
11.8
12.5
5&6
12.3
12.2
14.0
14.4
13.6
15.5
8
14.5
14.2
15.9
16.9
17.1
17.3
>8
14.3
14.4
16.3
18.8
18.8
18.3
If the dynamometer speed or torque falls outside the speed or torque tolerance
for more than two consecutive seconds, or for more than 5 seconds total, the
mode timer shall reset to zero and resume timing. The minimum mode length
shall be determined as described in §85.2(d)(2)(iii). The maximum mode length
shall be 90 seconds elapsed time (mt=90).
During the 10 second period used for the pass decision, the dynamometer speed
shall not fall more than 0.5 mph (absolute drop, not cumulative). If the speed at
the end of the 10 second period is more than 0.5 mph less than the speed at the
start of the 10 second period, testing shall continue until the speed stabilizes
enough to meet this criterion.
Page 21
Test Procedures
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§85.2 §85.2
(iii) The pass/fail analysis shall begin after an elapsed time of 25 seconds (mt=25).
A pass or fail determination shall be made for the vehicle and the mode shall be
terminated as follows:
(A) The vehicle shall pass the ASM2525 mode if, at any point between an
elapsed time of 25 seconds (mt=25) and 90 seconds (mt=90), the 10-
second running average measured values for each pollutant are
simultaneously less than or equal to the applicable test standards
described in §85.1 (a). If the vehicle passed the ASM5015 mode, as
described in §85.2(d)(l)(iii), the ASM2525 mode shall be terminated
upon obtaining passing scores for all three pollutants. If the vehicle
failed the ASM5015 mode, the ASM2525 mode shall continue for an
elapsed time of 90 seconds (mt=90).
(B) Pass/Fail determinations may be made at mt=15 seconds if a 50% safety
margin in cutpoints is applied from mt=15 to mt=25 seconds, i.e.
emissions for all pollutants are 50% below the appropriate ASM
standards.
(C) The vehicle shall fail the ASM2525 mode and the mode shall be
terminated if the requirements of §85.2(d)(2)(iii)(A) are not satisfied by
an elapsed time of 90 seconds (mt=90).
(3) Alternative ASM2525 (ASM5015) Test Procedure
(i) The Alternative ASM2525 (ASM5015) test cycle consists of three modes as
depicted qualitatively below. (The same figure may be applied to the
Alternative ASM5015 test if one simply recognizes that the y-axis speed value
in this case should be 15 mph rather than 25 mph.) Mode 1 is 30 seconds in
duration at 25 mph (15 mph), Mode 2 is a short duration speed variation, and
Mode 3 is 135 seconds at 25 mph (15 mph).
(ii) The timers for Mode 1 and Mode 3 shall start when the vehicle speed,
dynamometer loading and dilution are within the test limits specified above in
§85.2(d) (specifically §85.2(d) (l)(i) and §85.2(d)(l)(ii) for the ASM5015 or
§85.2(d) (2)(i) and §85.2(d)(2)(ii) for the ASM2525) for 2 continuous seconds
and no low flow error is recorded.
(iii) In Mode 1, the vehicle shall pass the test and the test shall be terminated
immediately if at any point between 15 and 30 seconds the 10 second running
average measured values for each pollutant are simultaneously less than or
equal to 50% of the applicable standards.
(iv) If the 10 second running average measured values for each pollutant are not
simultaneously less than or equal to 50% of the applicable standards, a speed
variation up to 30 mph in 2 seconds, down to 20 mph in 4 seconds and back to
25 mph in 2 seconds shall be performed. During the speed variation there are
no acceleration or speed limits; however, the target speeds must be reached.
Page 22 Test Procedures
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§85.2
§85.2
(v) For the ASM5015 test, the speed variation is from 15 mph to 20 mph, down to
10 mph and back to 15 mph in the same time increments outlined above for the
ASM2525.
(vi) When the vehicle has returned to 25 mph (15 mph) for 2 seconds, Mode 3 shall
begin.
(vii) The vehicle shall pass the test and the test shall be terminated immediately if at
any point between 15 and 30 seconds the 10 second running average measured
values for each pollutant are simultaneously less than or equal to 50% of the
applicable standards.
(viii) Starting at Second 31 in Mode 3, the vehicle shall pass the test and the test shall
be terminated immediately if the 10 second running average measured values
for each pollutant are simultaneously less than or equal to the applicable
standards.
Q.
E 20
0)
5 -
Qualitative Illustration of Alternative ASM Test Procedure
Model
30 sec.
Mode 2
ModeS
135 sec.
I I
Time (s)
(e) Second Chance Tests.
(1) If the vehicle fails the first-chance test, the test timer shall reset to zero and a second-
chance test shall be performed, except as noted below. If the vehicle is not tested
within 20 minutes of failing the test it shall be preconditioned by driving the vehicle at
the designated test speed and appropriate inertia weight settings for an additional 60
seconds prior to the start of the retest. The second-chance test shall be of the same
maximum duration as the first chance test. As each test mode is roughly 90 seconds
long, the total maximum test time can vary accordingly depending on whether a one or
two mode ASM test is implemented. A retest on only one mode would increase the
Page 23
Test Procedures
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§85.2 §85.2
total test time to roughly 180 seconds, while performing a retest for each mode on a
vehicle that failed both modes would extend the total test time to approximately 360
seconds.
Depending on the length of time it takes to perform the speed wiggle in the Alternative
ASM Test Procedure, the maximum time for a single mode should be roughly 170-180
seconds. Retesting a failed vehicle could double this time to 340-360 seconds.
Therefore, although the Alternative ASM Test Procedure is designed to improve a
vehicle's chances of passing, performing retests using this procedure could double the
overall test time versus the Original ASM Test Procedure.
(2) For vehicles that fail one mode of a two mode ASM test, the failed mode may be
repeated or extended as described below. An exception to this would be in the case of
vehicles already subjected to preconditioning as specified in §85.2(b)(12)(i) or if at
least 90 seconds of loaded preconditioning were performed, as specified in
§85.2(b)(12)(ii), then the second-chance test may be omitted.
(i) If the vehicle failed only the first mode (ASM5015) of the first chance test, then
that mode shall be repeated upon completion of the second mode (ASM2525).
The repeated mode shall be performed as described in §85.2(d)(l) except that
the provisions of §85.2(d)(l)(iv) shall be omitted. The test will terminate when
the mode ends or when the vehicle passes, whichever occurs first.
(ii) If the vehicle is failing only the second mode (ASM2525) of the first chance
test, then the second mode shall not end at 90 seconds but shall continue for up
to 180 seconds. Mode and test timers shall not reset but rather continue up to
180 seconds. The provisions of §85.2(d)(2) shall continue to apply throughout
the 180 second test period.
(iii) If the vehicle failed both modes (ASM5015 and ASM2525) of the first chance
test, then the vehicle shall receive a second-chance test for the ASM5015. If the
vehicle fails the second-chance ASM5015, then the vehicle shall fail the test.
Otherwise, the vehicle shall also receive a second-chance ASM2525.
Page 24 Test Procedures
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§85.3 §85.3
§85.3 Test Equipment Specifications
(a) Dynamometer Specifications*.
(1) General Requirements
(i) While dynamometer roll diameters may range from 8.5" to 21", it is preferable
that only one diameter of dynamometer roll be used throughout each program
whenever possible.
(ii) The dynamometer structure (e.g., bearings, rollers, pit plates, etc.) shall
accommodate all light-duty vehicles and light-duty trucks up to 8500 pounds
GVWR and axle weights up to 6,000 Ibs.
(iii) Dynamometer ASM load horsepower (HP5015 or HP2525) shall be
automatically selected based on the vehicle parameters in the test record.
(iv) All dynamometers shall have an identification plate permanently affixed
showing at a minimum, the dynamometer manufacturers name, the system
provider's name, production date, model number, serial number, dynamometer
type, maximum axle weight, maximum HP absorbed, roll diameter, roll width,
base inertia weight, and electrical requirements.
(v) The dynamometer shall be designed to meet specifications at an ambient
temperature range of 35° to 110°F, and at absolute humidity values
representative of the testing location. A wider range of operating temperatures
shall be used to reflect local operating conditions if applicable.
(vi) Dynamometers shall be equipped with both torque and speed test points to be
used during audits. Test points shall be easily accessed with test clips. The
torque signal shall be a DC voltage free of electrical noise. Maximum absorbed
torque shall produce between +5 and +10 volts of signal. Maximum motored
torque shall produce between -5.0 and -10.0 volts. The speed signal shall
consist of a 5 volt pulse signal that can be counted by an external pulse counter.
Alternative designs will be considered on a case-by-case basis.
(vii) Alternative dynamometer specifications, designs or error checking may be
allowed if proposed by a state and upon a determination by the Administrator
that, for the purpose of properly conducting an approved short test, the evidence
supporting such deviations show that proper vehicle loading will be applied.
NOTE: Throughout the specification, whenever dynamometer inertia weight is used in an equation, the units should be
referenced as "Ibs" and coast-down times should be referenced in "seconds".
Page 25 7/28/04 Test Equipment Specifications
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§85.3 §85.3
(2) Power Absorption.
(i) Vehicle Loading. The vehicle loading used during the ASM driving cycles
shall follow the equation in §85.3(a)(2)(ii) at 15 and 25 mph. Unless otherwise
noted, any horsepower displayed during testing shall be expressed as HP .
(ii) Indicated Horsepower. At constant velocity, the power absorber shall load the
vehicle according the following equations:
fflP = TRLHP - PLHP - GTRL
Where: IHP is the dynamometer indicated, or set, horsepower.
TRLHP is the track, or total, horsepower for a particular vehicle.
PLHP is Parasitic Losses Horsepower due to internal
dynamometer friction. Parasitic losses are specific to each
dynamometer and are a function of speed.
GTRL is Generic Tire/Roll Interface Losses at the specified
speed. For two-wheel-drive dynamometers, values may either be
taken directly from the EPA-approved Look-up Table, or be
calculated according to the procedures outlined in the EPA's
EVI240 Equipment Specification.
TRLHP, PLHP, GTRL, and therefore IHP, are all expressed as three term
polynomials of the type:
HP = A*Obmph + B*Obmph2 + C*Obmph3
Where: HP represents individual expressions relating IHP, TRLHP,
PLHP, or GTRL as a function of velocity.
A, B, or C represent horsepower coefficients for the individual
expressions relating IHP, TRLHP, PLHP, or GTRL as a function
of velocity.
Obmph is the velocity in miles per hour.
Expressions for TRLHP, and GTRL are found in Appendices H and I of the
EVI240 Guidance
(iii) Range of Power Absorber. The range of the power absorber shall be sufficient
to simulate the load required to perform an ASM5015 and an ASM2525 on all
light-duty vehicles and light-duty trucks with ETW values up to 7,500 Ibs. And
This is the actual Horsepower value contained in the look-up table for a vehicle being tested (using the ASM5015 or 2525)
on a dynamometer with the specified diameter rollers. It is the sum of the Indicated Horsepower and the Parasitic Losses.
Page 26 Test Equipment Specifications
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§85.3 §85.3
5015 tire losses of 3.3 HP. To this end, the power absorber shall be sufficient to
absorb a peak load of 33.3 hp at 14 mph for five minutes straight. In addition,
the power absorber shall be sufficient to absorb and dissipate energy from
continuous cycles consisting of five minutes of 25 horsepower at 14 mph
followed by three minutes at rest.
(iv) Power Absorber. Only electric power absorbers shall be used unless
alternatives are proposed by the state and approved by the Administrator. The
power absorber shall be adjustable in 0.1 hp increments at both 15 MPH and 25
MPH. The accuracy of the power absorber (PAU + parasitic losses) shall be
±0.25 horsepower or ±2% of required power, whichever is greater, in either
direction of rotation. For field auditing the accuracy shall be ±0.5 horsepower.
(v) Accuracy Over the Operating Range. The dynamometer's accuracy when warm
shall not deviate more than ±0.5 horsepower over the full ambient operating
range of 35°F to 110°F. This may be accomplished by intrinsic design or by
software correction techniques. At any constant temperature, the dynamometer
shall have an accuracy of ±0.5 horsepower within 15 seconds from the time the
rolls start turning, and shall have an accuracy of ±0.25 horsepower within 30
seconds from the time the rolls start turning. For temperatures outside the
specified range, the dynamometer shall provide correction or proceed with a
manufacturer warm-up sequence until full warm condition has been reached.
(3) Inertia.
(i) Test Inertia. The dynamometer shall be equipped with mechanical flywheel(s)
or with full inertia simulation providing an inertia weight of 2000 pounds ±40
pounds. Any deviation from the 2000 pound base inertia shall be quantified and
the coast-down time shall be corrected accordingly.
For all-wheel-drive dynamometers that may be operated in either two- or four-
wheel-drive modes, the inertia in two-wheel-drive mode must comply with the
above requirements. The inertia in four-wheel-drive mode may be different,
however it shall be quantified to within 10 Ibs.
The actual test inertia weight shall be marked on the ID plate required in
§85.3(a)(l)(iv). In the case of all-wheel-drive dynamometers, the test inertia
must be displayed for both two- and all-wheel-drive operation.
(ii) Inertia/Inertia Simulation. The dynamometer shall be capable of conducting, at
a minimum, diagnostic level transient inertia simulations with an acceleration
rate between 0 and 3.3 miles per hour per second with a minimum load (power)
of 25 horsepower at 14 mph over the inertia weight range of 2000 pounds to
6000 pounds. For the diagnostic level inertia simulation, the 25 horsepower
criterion is a requirement on acceleration only, while for the full inertia
simulation option, the requirement is for both acceleration and deceleration.
Mechanical inertia simulation shall be provided in 500 pound increments;
electric inertia simulation shall be provided in 1 pound increments. Any
Page 2 7 Test Equipment Specifications
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§85.3 §85.3
deviation from the stated inertia shall be quantified and the inertia simulation
shall be corrected accordingly. Mechanical or electrical inertia simulation, or a
combination of both, may be used, subject to review and approval by the state.
(A) Diagnostic Level Simulation.
1. System Response. The torque response to a step change shall be at
least 90% of the requested change within 300 milliseconds.
2. Simulation Error. An inertia simulation error (ISE) shall be
continuously calculated any time the actual dynamometer speed is
between 10 MPH and 60 MPH. The ISE shall be calculated by the
equation in §85.3(a)(3)(ii)(C), and shall not exceed 3% of the inertia
weight selected (IWS) for the vehicle under test.
(B) Full Inertia Simulation. (Recommended Option)
1. System Response. The torque response to a step change shall be at
least 90% of the requested change within 300 milliseconds. Torque
response shall settle to within 2% of the requested change within 600
milliseconds.
2. Simulation Error. Horsepower simulation error (HPSE) shall be
continuously calculated any time the dynamometer speed is greater
than 5 mph. The HPSE is defined as the average difference between
the desired power (DP) and the achieved power (AP) in 10
measurements taken at 0.5-second sequential intervals over the
previous 5 seconds, divided by the total power (TP = inertia plus
road load). However, if augmented braking is applied or the desired
PAU power is less than or equal to zero* during any 0.5-second
measurement, then the difference between the desired and achieved
power for that 0.5-second measurement shall be set to 0. Values set
to be 0 shall be used in the 5-second moving averages. If TP is less
than 5HP over the 5-second period, set TP to 5HP.
(C) Horsepower Simulation Error Calculation.
^(DP-AP)
HPSE= '
This shall only apply to eddy current dynamometers, not full electric dynamometers.
Page 28 Test Equipment Specifications
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§85.3 §85.3
Where:
i - current 0.5-second interval, starting at second 5
DP -desired power (inertia plus road load minus GTRL and PLHP)
AP - achieved power (measured at the load cell)
TP - total power (inertia plus road load)
A violation occurs if HPSE is greater than ±0.25%.
(4) Parasitic Losses.
(i) The parasitic losses (PLHP) in each dynamometer system (including but not
limited to windage, bearing friction, and system drive friction) shall be
characterized at 15 and 25 mph upon initial acceptance, and during each
dynamometer calibration. The parasitic power losses shall be determined as
indicated in §85.4(b)(2).
00 For all-wheel-drive dynamometers that can be operated in either two or four-
wheel-drive modes, parasitic losses must be characterized in both modes.
Software controlling the dynamometer must automatically adjust programmed
parasitic losses depending upon the mode in which the dynamometer is
operating.
(5) Rolls.
(i) Size and Type. The dynamometer shall be equipped with twin rolls. The rolls
shall be coupled side to side. In addition, the front and rear rolls shall be
coupled. The dynamometer roll diameter shall be between 8.5 and 21.0 inches.
The spacing between the roll centers shall comply with the equation in
§85.3(a)(5)(iii). The dynamometer rolls shall accommodate an inside track
width of 30 inches and an outside track width of at least 100 inches.
(ii) Roll Installation. Rolls shall be installed in the floor such that vehicles will be
be reasonably level when tested. The system shall be designed and installed
such that ±8 degrees of level is achieved for vehicles having an 86" wheelbase
and 27" outer diameter tires; an 89" wheelbase and 18" outer diameter tires; and
a 170" wheelbase with 33" outer diameter tires. Either in-floor or above-
ground installations are acceptable providing they meet these criteria.
(iii) Roll Spacing. The spacing between the roll centers shall comply with the
following equation to within +0.5 inches and -0.25 inches.
Roll Spacing = (24.375 + D) * Sin 31.5
Where: Roll Spacing is the distance between the roll centerlines in inches.
D= Roll diameter in inches
Page 29 Test Equipment Specifications
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§85.3 §85.3
(iv) Roll Surface. The surface finish and hardness shall be such that tire slippage is
minimized when testing vehicles using the inertia weight and horsepower
settings found in the EPA I/M Look-up Table while following the driving
schedule, and that tire wear and noise are minimized. Knurled roll surfaces are
acceptable .
(v) Vehicle Lift. A vehicle lift system located between the dynamometer rolls shall
be provided to facilitate drive axle positioning and vehicle egress from the
dynamometer.
(vi) Vehicle Restraint System. The system shall include a system of safely
restraining the forward and side-to-side motion of front wheel drive vehicles,
and the forward motion of rear wheel drive vehicles during the driving
schedule, while allowing unobstructed ingress and egress from the
dynamometer.
(6) Load Measuring Device
(i) Torque Measurement. The dynamometer shall have a torque measurement
system accurate to within ±2% of full scale.
(ii) Dead Weights. Dead weights used to calibrate a torque meter or load measuring
device shall be traceable to NIST and be accurate to within ±0.5%. Dead
weights traceable to standards other than NIST may be used upon approval of
the Administrator.
(iii) Dynamic Calibrations. Designs using an F = MA method for calibrating the
load cell are also acceptable; however, systems using such dynamic calibrations
must provide an external means of accurately determining base inertia or
performing load cell calibrations.
(7) All-Wheel-Drive-Dynamometers.
(i) Design. The dynamometer shall meet the requirements for two-wheel-drive
vehicles and be capable of testing traction control and all-wheel-drive vehicles
in a safe manner without damaging the vehicle.
(ii) Wheelbase. The all-wheel-drive dynamometer shall be capable of testing
vehicles having wheelbases ranging from 84 to 125 inches. The separation
between the front and rear dynamometer rolls shall be automatically adjustable
in increments of 1.00" or less and shall be accurate to ±0.25" of the selected
vehicle wheelbase. Once a vehicle is positioned on the dynamometer, the
It should be noted that knurlling or altering the surface of the dynamometer will effect the CTRL coefficients. However, at
this time it is believed that the impact such alterations may have will be minimal and not affect emissions measurements.
Page 30 Test Equipment Specifications
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§85.3 §85.3
dynamometer must allow the vehicle to be centered on the dynamometer,
including fine tuning the roll separation as necessary to meet the actual
wheelbase of the vehicle within 0.1". After the roll separation matches the
vehicle, the dynamometer must automatically lock the roll separation prior to
the beginning of loaded testing. The roll separation lock must be sufficient to
maintain the roll separation to within 0.25" of the vehicle wheelbase when 1000
Ibs offeree is applied to either compress or extend the dynamometer roll
separation.
(iii) Speed Synchronization. Front and rear rolls shall maintain speed
synchronization within ±0.1 mph during steady-state operation. During
transient speed operation, secondary roll speed must be maintained within ±0.1
mph or 1% of the primary roll speed, whichever is greater. Since many traction
control vehicles will not be equipped with all-wheel drive, the secondary rolls
must have sufficient power to drive and maintain speed for the non-drive
wheels without assistance from the vehicle.
(iv) Bi-directionality. Dynamometers in which one set of rolls is considered
primary (i.e., drive wheels for non-all-wheel-drive vehicles must be place on
one set) must be bi-directional. This will allow both front- and rear-wheel-drive
vehicles to be tested in all-wheel-drive mode.
(v) Disengageable Secondary Rolls. Dynamometers may be configured so that
secondary rolls may be automatically disengaged when all-wheel-drive testing
is not required. If the secondary rolls are disengaged, the system shall
automatically compensate for the change in parasitic losses and base inertia as
well and the change in generic tire roll losses.
(vi) Base inertia. All-wheel-drive dynamometers that can be operated in either two-
or all-wheel-drive modes must account for changes in base inertia resulting
from the two different configurations.
(8) Other Requirements.
(i) Vehicle Speed. The measurement of roll speed shall be accurate within 0.1 mph
over the full operating range. The dynamometer shall accommodate vehicle
speeds of up to 60 mph.
(ii) Vehicle Restraint. In §85.2(b)(10).
(iii) Vehicle Cooling. In §85.2(c)(6).
(iv) Four-Wheel Drive. If used, four-wheel drive dynamometers shall insure the
application of correct vehicle loading as defined in §85.3(a)(2), shall not
damage the four wheel drive system of the vehicle, and shall accommodate
vehicles equipped with anti-lock brakes and/or traction control. Front and rear
wheel rolls shall maintain speed synchronization within 0.2 mph.
(v) Installation. In §85.3(a)(5)(ii).
Page 31 Test Equipment Specifications
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§85.3 §85.3
(vi) Augmented Braking. Dynamometers shall apply augmented braking on major
decelerations during transient drive cycles, if such cycles are used in the
program. The dynamometer software shall provide a signal output to inform the
operator when augmented braking is activated. Augmented braking shall be
actuated only when the negative force applied by the vehicle at the roll surface
is greater than 110 Ibs. Augmented braking shall be applied so that at least 50%
of the braking force beyond 110 Ibs required to meet the deceleration
requirements of the drive trace is absorbed by the dynamometer.
(b) Emission Sampling System.
(1) The sampling system shall be designed to insure durable, leak free operation and be
easily maintained. Materials that are in contact with the gases sampled shall not
contaminate or change the character of the gases to be analyzed, including gases from
vehicles not fueled by gasoline (except diesels). The system shall be designed to be
corrosion-resistant and be able to withstand typical vehicle exhaust temperatures when
the vehicle is driven through the ASM test cycle for the maximum test length described
in §85.2(e).
(2) The sampling system shall draw exhaust gas from the vehicle, shall remove particulate
matter and aerosols from the sampled gas, shall drain condensed water from the sample
if necessary, and shall deliver the resultant gas sample to the analyzers/sensors for
analysis and then deliver the analyzed sample directly outside the building. The
sampling system shall, at a minimum, consist of a tailpipe probe, flexible sample line,
water removal system, a particulate trap, sample pump, and flow control components.
(3) Sample Probe.
(i) Insertion. The sample probe shall allow at least a 16 inch insertion depth of the
sample probe into the vehicle's exhaust. In addition, the probe shall be inserted
at least 10 inches into the vehicle's exhaust. Use of a tailpipe extension is
permitted as long as the extension does not change the exhaust back pressure by
more than ±1.0 inch of water pressure.
(ii) Retention. The probe shall incorporate a positive means of retention to
prevent it from slipping out of the tailpipe during use. High through-put test
systems may use alternative means to insure probe retention.
(iii) Flexibility. The probe shall be designed so that the tip extends 16 inches into
the tailpipe. The probe tip shall be shielded so that debris is not scooped up by
the probe when it is inserted into the tailpipe. High through-put test systems
may use alternative means to insure adequate probe insertion.
(iv) Probe Tip. Probe tips shall be designed and constructed to prevent sample
dilution.
(v) Materials. All materials in contact with exhaust gas prior to and throughout the
measurement portion of the system shall be unaffected by and shall not affect
Page 32 Test Equipment Specifications
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§85.3 §85.3
the sample (i.e., the materials shall not react with the sample, and they shall not
taint the sample). Acceptable materials include stainless steel, Teflon, silicon
rubber, and Tedlar. Dissimilar metals with thermal expansion factors of more
than 5% shall not be used in either the construction of probes or connectors.
The sample probe shall be constructed of stainless steel or other non-corrosive,
non-reactive material which can withstand exhaust gas temperatures at the
probe tip of up to 1,100°F for 10 minutes.
(vi) System Hoses and Connections. Hoses and all other sample handling
components must be constructed of, or plated with a non-reactive, non-
corrosive, high temperature material which will not affect, or be affected by, the
exhaust constituents and tracer gases.
(vii) Dual Exhaust. The sample system shall provide for the testing of dual exhaust
equipped vehicles. When testing a vehicle with functional dual exhaust pipes, a
dual sample probe of a design certified by the analyzer manufacturer to provide
equal flow in each leg shall be used. The equal flow requirement is considered
to be met if the flow rate in each leg of the probe has been measured under two
sample pump flow rates (the normal rate and a rate equal to the onset of low
flow), and if the flow rates in each of the legs are found to be equal to each
other (within 15% of the flow rate in the leg having lower flow).
(4) Particulate Filter. The particulate filter shall be capable of trapping 97% of all
particulate and aerosols 5 microns or larger. The filter element shall not absorb or
adsorb hydrocarbons. The filter housing shall be transparent or translucent to allow the
operator to observe the filter element's condition without removing the housing. The
filter element shall be easily replaceable and shall provide for reliable sealing after
filter element changes.
(5) Water Trap. The water trap shall be sized to remove exhaust sample water from
vehicles fueled with gasoline, propane, compressed natural gas, reformulated gasoline,
alcohol blends or neat, and oxygenated fuels. The filter element, bowl and housing
shall be inert to these fuels as well as to the exhaust gases from vehicles burning these
fuels. The condensed water shall be drained from the water trap's bowl either
continuously or automatically on a periodic basis such that the following performance
requirement is maintained. Sufficient water shall be trapped, regardless of fuel, to
prevent condensation in the sample system or in the optical bench's sample cell.
(6) Low Flow Indication. The analyzer shall lock out official testing when the sample flow
is below the acceptable level. The sampling system shall be equipped with a flow
meter (or equivalent) that shall indicate sample flow degradation when measurement
error exceeds 3% of the gas value used for checking, or causes the system response
time to exceed 13 seconds to 90 percent of a step change in input (excluding NO),
whichever is less. Alternatively, the sample vacuum may be continuously monitored to
detect a low flow condition.
(7) Exhaust Ventilation System. The high quantities of vehicle emissions generated during
loaded mode testing shall be properly vented to prevent buildup of hazardous
concentrations of HC, CO, CO2 and NOx. Sufficient ventilation shall be provided in
Page 33 Test Equipment Specifications
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§85.3 §85.3
the station to maintain HC, CO, CC>2 and NO levels below recommended Occupational
Safety and Health Association (OSHA) standards*.
(i) The ventilation system shall discharge the vehicle exhaust outside the building.
(ii) The flow of the exhaust collection system shall not cause dilution of the exhaust
at the sample point in the probe.
(iii) The flow of the exhaust collection system shall not cause a change of more than
±1.0 inches of water pressure in the vehicle's exhaust system at the exhaust
system outlet.
(c) Analytical Instruments.
(1) General Requirements.
(i) Measured Gases. The analyzer system shall consist of analyzers for HC, CO,
NO, and CO2, (C>2 optional). It is recommended that the system provide digital
displays for exhaust concentrations of HC, CO, NO, and CO2, as well as for
vehicle speed; however, it is recognized that some BAR97 systems do not
provide these features.
(ii) Emission Accuracy. The system shall ensure that the analytical system provides
an accurate accounting of the actual exhaust emissions produced during the test,
taking into consideration the individual channel accuracy, repeatability,
interference effects, sample transport times, and analyzer response times.
(iii) Sample Rate. The analyzer shall be capable of measuring exhaust
concentrations of the gases specified in §85.3(c)(l)(i) at a minimum rate of once
per second.
(iv) Alternative Equipment. Alternative analytic equipment specification, materials,
designs, or detection methods may be allowed if proposed by a state and upon a
determination by the Administrator, that for the purpose of properly conducting
a test, the evidence supporting such deviations will not significantly affect the
proper measurement of emissions.
(2) Performance Requirements.
(i) Temperature Operating Range. The analyzer system and all associated
hardware shall operate within the performance specifications described in
§85.3(c)(3) at ambient air temperatures ranging from 35°F to HOT. Analyzers
shall be designed so that adequate air flow is provided around critical
components to prevent overheating (and automatic shutdown) and to prevent the
condensation of water vapor which could reduce the reliability and durability of
The following limits may be found in 29 CFR 1910.1000 Table Z-l. CO 50 ppm; CO2 5000 ppm; NO2 5 ppm; n-Hexane
500 ppm; Propane 1000 ppm.
Page 34 Test Equipment Specifications
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§85.3 §85.3
the analyzer. The analyzer system shall otherwise include necessary features to
keep the sampling system within the specified range.
(ii) Humidity Operating Range. The analyzer system and all associated hardware
shall operate within the performance specifications described in §85.3(c)(3) at a
minimum of 85% relative humidity throughout the required temperature range.
(iii) Interference Effects. The interference effects for non-interest gases shall not
exceed ±4 ppm for hydrocarbons, ±0.02% for carbon monoxide, ±0.20% for
carbon dioxide, and ±20 ppm for nitric oxide when using the procedure
specified in §85.4(d)(5)(iv). Corrections for collision-broadening effects of
combined high CO and CC>2 concentrations shall be taken into account in
developing the factory calibration curves, and are included in the accuracy
specifications.
(iv) Barometric Pressure Compensation. Barometric pressure compensation shall be
provided. Compensation shall be made for elevations up to 6000 feet (above
mean sea level). At any given altitude and ambient conditions specified in
§85.3(c)(2)(i) and (ii), errors due to barometric pressure changes of ±2 inches of
mercury shall not exceed the accuracy limits specified in §85.3(c)(3).
(iv) System Lockout During Warm-up. Functional operation of the gas sampling
unit shall remain disabled through a system lockout until the instrument meets
stability and warm-up requirements. The instrument shall be considered
"warm" when the zero and span readings for HC, CO, NO, and CO2 have
stabilized, within the accuracy values specified in §85.3(c)(3) for five minutes
without adjustment.
(v) Zero Drift Lockout. If zero or span drift cause the optical bench signal levels to
move beyond the adjustment range of the analyzer, the system shall be locked
out from testing.
(vi) Electromagnetic Isolation and Interference. Electromagnetic signals found in
an automotive service environment shall not cause malfunctions or changes in
the accuracy in the electronics of the analyzer system. The instrument design
shall ensure that readings do not vary as a result of electromagnetic radiation
and induction devices normally found in the automotive service environment,
including high energy vehicle ignition systems, radio frequency transmission
radiation sources, and building electrical systems.
(vii) Vibration and Shock Protection. System operation shall be unaffected by the
vibration and shock encountered under the normal operating conditions
encountered in an automotive service environment.
(viii) Propane Equivalency Factor. The nominal PEF range shall be between 0.490
and 0.540. For each audit/calibration point, the nominal PEF shall be
conveniently displayed for the quality assurance inspector and other authorized
personnel. Ideally, the PEF shall appear on the monitor in conjunction with the
HC reading during any audit or at the operator's request.
Page 35 Test Equipment Specifications
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§85.3 §85.3
If an optical bench must be replaced in the field, any external labels shall be
changed to correspond to the nominal PEF of the new bench. The analyzer
shall incorporate an algorithm relating PEF to HC concentration. Corrections
shall be made automatically. The corrected PEF value may cover the range of
0.470 to 0.560
(ix) System Response Requirements. The response time from the probe to the
display for HC, CO, and CO2 analyzers shall not exceed 8 seconds for 90% of a
step change in input, nor shall it exceed 12 seconds to 95% of a step change in
input. The response time for a step change in O2 from 20.9% O2 to 0.1% O2
shall be no longer than 40 seconds. For NO analyzers, the response time shall
not exceed 12 seconds for 90% of a step change in input. The response time for
a step change in NO from a stabilized reading to 10% of that reading shall be no
longer than 12 seconds.
(3) Detection Methods, Instrument Ranges, Accuracy, and Repeatability.
(i) Hydrocarbon Analysis. Hydrocarbon analysis shall be determined by non-
dispersive infrared (NDIR) analyzer. The analyzer shall cover at least the range
of 0 ppm HC to 9999 ppm HC, where ppm HC is parts per million of
hydrocarbon volume as hexane. The accuracy of the instrument from 0-2000
ppm HC shall be ±3% of point or 4 ppm C6, whichever is greater. The
accuracy of the instrument between 2001 ppm HC and 5000 ppm HC shall be at
least ±5% of point and the accuracy of the instrument between 5001 ppm HC
and 9999 ppm HC shall be at least ±10% of point. The instrument shall comply
with the quality control specifications in §85.4(d).
(ii) Carbon Monoxide Analysis. Carbon monoxide analysis shall be determined by
non-dispersive infrared (NDIR) analyzer. The analyzer shall cover at least the
range of 0.00 % CO to 14.00% CO, where % CO is % volume CO. The
accuracy of the instrument between 0.01% and 10.00% CO shall be ±3% of
point or 0.02% CO, whichever is greater. The accuracy of the instrument
between 10.01% and 14.00% shall be at least ±5% of point. The instrument
shall comply with the quality control specifications in §85.4(d).
(iii) Carbon Dioxide Analysis. Carbon dioxide analysis shall be determined by non-
dispersive infrared (NDIR) analyzer. The analyzer shall cover at least the range
of 0.0 % CO2 to 18.0% CO2. The accuracy of the instrument between 0.01%
and 16.00% CO2 shall be ±3% of point or 0.3% CO2, whichever is greater. The
accuracy of the instrument between 16.01% and 18.00% shall be at least ±5% of
point. The instrument shall comply with the quality control specifications in
§85.4(d).
(iv) Nitric Oxide Analysis. The analyzer shall cover at least the range of 0 ppm NO
to 5000 ppm NO, where ppm NO is parts per million nitric oxide. The accuracy
of the instrument between 0 and 4000 ppm shall be at least ±4% of point or 25
ppm NO, whichever is greater. The accuracy of the instrument between 4001
and 5000 ppm shall be at least ±8% of point. The instrument shall comply with
the quality control specifications in §85.4(d).
Page 36 Test Equipment Specifications
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§85.3 §85.3
(v) Oxygen Analysis, (optional) If an oxygen analyzer is included, the analyzer
shall cover at least the range of 0.0% O2 to 25.0% O2. The accuracy of the
instrument over this range shall be at least 5% of point or ±0.1% O2, whichever
is greater. The instrument shall comply with the quality control specifications
in §85.4(d).
(vi) Repeatability. The repeatability for the HC analyzer in the range of 0-1400 ppm
HC shall be 2% of point or 3 ppm HC absolute, whichever is greater. In the
range of 1400-2000 ppm HC, the repeatability shall be 3% of point. The
repeatability for the CO analyzer in the range of 0-7.00% CO shall be 2% of
point or 0.02% CO absolute, whichever is greater. In the range of 7.00% to
10.00% CO, the repeatability shall be 3% of point. The repeatability for the
CO2 analyzer in the range of 0-10.0% CO2 shall be 2% of point or 0.1% CO2
absolute, whichever is greater. In the range of 10.0% to 16.0% CO2, the
repeatability shall be 3% of point. The repeatability of the NO analyzer shall be
3% of point or 20 ppm NO, whichever is greater. The repeatability of the O2
analyzer shall be 3% of point or 0.1% O2, whichever is greater.
(vii) Rounding Rule. Rounding beyond the decimal places shown in §85.3(c)(3)
shall follow the standard mathematical practice of going to the next higher
number for any numerical value of five or more. This shall also hold true for
pass/fail decisions. For example, if 2.00% CO passes and 2.01% CO fails, and
the reading is 2.0049%, the value shall be rounded down and the decision shall
be a pass. If the reading is 2.0050, the value shall be rounded up and the
decision shall be a fail. The value displayed and printed on the test report shall
be consistent with the value used for the pass/fail decision.
(4) Ambient Conditions. The current relative humidity, dry-bulb temperature, and
barometric pressure shall be measured and recorded prior to the start of every
inspection in order to calculate Kh (nitric oxide correction factor §85. l(b)(l)(vi)).
(i) Relative Humidity. The relative humidity measurement device shall cover the
range from 5% to 95% RH, between 35°F - 110°F, with a minimum accuracy of
±3% RH. Wet bulb thermometers shall not be used.
(ii) Dry-bulb Temperature. The dry-bulb temperature device shall cover the range
from OT - 140T with a minimum accuracy of 3°F.
(iii) Barometric Pressure. The barometric pressure measurement device shall cover
the range from 610 mm Hg - 810 mm Hg absolute (24-32 inches), and 35T -
HOT, with a minimum accuracy of ±3% of point or better.
(5) Engine Speed Detection. The analyzer shall utilize a tachometer capable of detecting
engine speed in revolutions per minute (RPM) with a 0.5 second response time and an
accuracy of ±3% of the true RPM. On vehicles equipped with onboard diagnostic
(OBD) systems, it is recommended that the engine speed be taken by connecting to the
SAE standardized OBD link on 1996 and newer vehicles. RPM readings shall be
recorded on a second-by-second basis for the 10 second period upon which the pass/fail
decision is based.
Page 37 Test Equipment Specifications
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§85.3 §85.3
(6) OBD Fault Code Retrieval. Starting in 2001 the system shall include the hardware and
software necessary to access the onboard computer systems on 1996 and newer
vehicles, determine OBD readiness, and recover stored fault codes using the SAE
standardized link.
(d) Automated Test Process Software and Displays.
(1) Software. The testing process, data collection, and quality control features of the
analyzer system shall be automated to the greatest degree possible. The software shall
automatically select the emission standards and set the vehicle load based on an EPA-
provided or approved look-up table. Vehicle identification information shall be derived
from a database accessed over a real-time data system to a host computer system.
Entry of license plate and all or part of the VIN shall be sufficient to access the vehicle
record. Provision shall be made for manual entry of data for vehicles not in the host
computer system. Alternative methods for matching test records to the appropriate
vehicle and ensuring that the vehicle is tested using the proper parameters may be used
if approved by the Administrator.
(2) Test and mode timers. The analyzer shall be capable of simultaneously determining the
amount of time elapsed in a test (overall test time), and in a mode within that test (mode
time).
(3) Clocks and Timers. The clock used to check the coast-down time shall be accurate to
within 0.1% of reading between 0.5 and 100 seconds, with a resolution of 0.001
seconds. The test mode timers used shall be accurate to within 0.1% of reading
between 10 and 1000 seconds with a resolution of 0.1 seconds.
(4) Driver's Aid. The system shall be equipped with a driver's aid that shall be clearly
visible to the driver as the test is performed. The aid shall continuously display the
required speed, the number of seconds into the test mode, the driver's actual speed/time
performance (a display showing the deviation between set-point and actual driving
trace), engine RPM, the use of augmented braking, and necessary prompts and alerts. It
is recommended that an analog speed display be used as this has been demonstrated to
improve a driver's ability to maintain the ±1.0 mph tolerance. The driver's aid shall
also be capable of displaying test and equipment status and other messages as required.
Dynamic information being displayed shall be refreshed at a minimum rate of twice per
second. Emissions values shall not be displayed during official testing.
(5) Minimum Analyzer Display Resolution. The analyzer electronics shall have sufficient
resolution to achieve the following:
HC 1 ppm HC as hexane
NO 1 ppm NO
CO 0.01 % CO
CO2 0.1 %CO2
O2 0.1 % O2 (optional)
RPM 10 RPM
Speed 0.1 mph
Page 38 Test Equipment Specifications
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§85.3 §85.3
Load 0.1 hp
Relative Humidity 1 % RH
Dry Bulb Temperature 1 °F
Barometric Pressure 1 mm Hg
Page 39 Test Equipment Specifications
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§85.4 §85.4
§85.4 Quality Control Requirements
(a) General Requirements
(1) Minimums. The frequency and standards for quality control specified here are
minimum requirements, unless modified as specified in §85.4(a)(2). Greater frequency
or tighter standards may be used as needed.
(2) Statistical Process Control. Reducing the frequency of the quality control checks,
modifying the procedure or specification, or eliminating the quality control checks
altogether may be allowed if the state demonstrates and the Administrator determines,
for the purpose of properly conducting an approved short test, that sufficient Statistical
Process Control (SPC) data exist to make a determination, that the SPC data support
such action, and that taking such action will not significantly reduce the quality of the
emissions measurements. Should emission measurement performance or quality
deteriorate as a result of allowing such actions, the approval shall be suspended and the
frequencies, procedures specifications, or checks specified here or otherwise approved
shall be reinstated, pending further determination by the Administrator.
(b) Dynamometer
(1) Coast Down Check.
(i) The calibration of each dynamometer shall be automatically checked every 72
hours in low volume stations (less than 4000 tests per year) and daily in high
volume stations by a dynamometer coast-down procedure equivalent to 40 CFR
§86.118-78 (for reference see National Vehicle and Fuel Emission Laboratory's
Testing Services Division test procedure TP-302A and TP-202) between the
speeds of 30-20 mph if the ASM2525 is used and 20-10 mph if the ASM5015 is
used. All rotating dynamometer components shall be included in the coast-
down check. Speed windows smaller than ± 5 mph may be used provided that
they show the same calibration capabilities.
(ii) The dynamometer calibration shall be checked at two random horsepower
settings for each speed range using the 2000 Ib. test inertia. The two random
horsepower settings shall be between 8.0 and 18.0 horsepower. The random
selection shall be evenly distributed throughout the 8 to 18 FTP range. A shunt
resistor for a load cell performance check shall not be used.
(iii) The coast-down procedure shall use a vehicle-off-dynamometer type method or
equivalent. Using a vehicle to bring the dynamometer up to speed and
removing the vehicle before the coast-down shall not be permitted. If either the
measured 30-20 mph coast-down time or 20-10 mph coast-down time is outside
the window bounded by the Calculated Coast-Down Time (CCDT) (seconds) ±
6% then it shall be locked out for official testing purposes until recalibration
allows a passing value.
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§85.4
§85.4
If the dynamometer fails a coast-down check, a parasitic loss determination
shall be required and performed automatically.
(A) Randomly select an IHP2525 value that is between 8.0 hp and 18.0 hp and
set dynamometer PAU to this value.
Coast-down dynamometer from 30-20 mph.
0.5* DIW
32.2
:(v320-v220)
550*(IHP2525+PLHP25)
Where:
DIW
¥20
IHP2525
PLHP2s
= Dynamometer Inertia Weight. Total "inertia" weight
of all rotating components in dynamometer.
= Velocity in feet/sec at 30 mph.
= Velocity in feet/sec at 20 mph.
= Randomly selected ASM2525 indicated horsepower.
= Parasitic Horsepower for specific dynamometer at 25
mph.
(B) Randomly select an IHP50i5 value that is between 8.0 hp and 18.0 hp and
set dynamometer PAU to this value.
Coast-down dynamometer from 20-10 mph.
0.5* DIW
CCDT
32.2
72 - V2"
'20 MO-
@15mph
550*(IHP5015+PLHP15)
Where:
DIW
V20
Vio
IHP50i5
PLHPis
Dynamometer Inertia Weight. Total "inertia" weight
of all rotating components in dynamometer.
Velocity in feet/sec at 20 mph.
Velocity in feet/sec at 10 mph.
Randomly selected ASM5015 indicated horsepower.
Parasitic Horsepower for specific dynamometer at 15
mph.
Page 41
Quality Control Requirements
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§85.4 §85.4
(2) Parasitic Value Calculations. Parasitic losses should be measured any time service is
performed on a dynamometer, as the first step in diagnosing a dynamometer's inability
to pass a coast-down, or if the load measuring device is re-calibrated.
(i)
Parasitic losses shall be calculated using the following equations at 25 and 15
mph whenever a coast-down check is performed, except the indicated
horsepower (IHP) shall be set to zero for these tests. -Parasitic losses shall be
determined using the equations listed below. After new parasitic values are
calculated, the coast-down check procedure contained in §85.4(b)(l) must be
passed before the dynamometer can be returned to service.
(ii)
Parasitic losses at 25 mph for a dynamometer with specified diameter rollers.
0.5*DIW
PLHP25 =
32.2
:(v320-v220)
550*(ACDT)
Where:
DIW = Dynamometer Inertia Weight. Total "inertia" weight
of all rotating components in dynamometer.
(iii)
= Velocity in feet/sec at 30 mph.
= Velocity in feet/sec at 20 mph.
ACDT = Actual coast-down time required for dynamometer to
coast from 30 to 20 mph.
Parasitic losses at 15 mph for a dynamometer with specified diameter rollers.
0.5* DIW
PLHP15 =
32.2
2 - v
20 M
O
550* (ACDT)
Where:
DIW
V20
Vio
ACDT
Dynamometer Inertia Weight. Total "inertia" weight
of all rotating components in dynamometer.
Velocity in feet/sec at 20 mph.
Velocity in feet/sec at 10 mph.
Actual coast-down time required for dynamometer to
coast from 20 to 10 mph.
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Quality Control Requirements
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§85.4 §85.4
(3) Roll Speed. There is no need to perform roll speed checks on a regular basis, providing
the coast-down procedures are being performed and adhered to. This is because
dynamometers will not be able to pass the coast-down test with erroneous speed
readings, especially when the load is changed from coast-down to coast-down.
(4) Load Measuring Device. If the dynamometer fails a coast-down check immediately
after performing a parasitic loss determination, then the dynamometer load measuring
device may be malfunctioning or out of calibration. In this case, or in the case of the
load measuring system being serviced, the load-measuring device shall be checked
using a dead-weight method or an equivalent procedure proposed by the state and
approved by the Administrator. The check shall cover at least three points over the
range of loads used for vehicle testing. Dead weights shall be traceable to the National
Institute of Standards (NIST) and shall be accurate to within ±0.1%. Dead weights
traceable to standards other than NIST may be used upon approval of the
Administrator. The dynamometer shall provide an automatic load measuring device
calibration and verification feature.
(5) Certification Testing.
(i) Load Cell Verification (if equipped). This test confirms the proper operation of
the dynamometer load cell and associated systems. Weights in the proper range
shall be supplied by the system supplier. Weights shall be NIST traceable to
0.1% of point. Dead weights traceable to standards other than NIST may be
used upon approval of the Administrator.
(A) Calibrate the load cell according to the manufacturer's direction.
(B) Using a dead weight method, load the test cell to 20%, 40%, 60%, and
80% (in ascending order) of the range used for ASM testing. Record the
readings for each weight. Remove the weights in the same steps
(descending order) and record the results.
(C) Perform steps A through B two more times (total of three). Calculate the
average value for each weight. Multiply each average weight from E by
the length of the torque arm.
(D) Acceptance Criteria: The difference for each reading from the weight
shall not exceed 1% of full scale.
(ii) Speedometer Verification. This test confirms the accuracy of the
dynamometer's speedometer.
(A) Measure the dynamometer roll diameter to within ±0.01 inch. This may
be accomplished using a PI tape. If the dynamometer is able to motor to a
constant speed, set the dynamometer speed to 15 mph. If the dynamometer
does not have the ability to motor at constant speeds, place a vehicle on
the dynamometer and drive the vehicle at a constant speed as close to 15
mph as possible. Independently measure and record dynamometer roll
rotational frequency using a frequency counting device such as a strobe
tachometer. Mathematically convert the roll diameter to circumference
Page 43 Quality Control Requirements
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§85.4 §85.4
and multiply by the rotational frequency to obtain linear speed. Compare
this speed to the speed measured by the test system. Repeat at 25 mph.
(B) Acceptance Criteria: The difference for each reading from set
dynamometer speed shall not exceed 0.1 mph.
(iii) Parasitics Verification. Parasitic losses shall be verified at 25 and 15 mph using
the procedure in §85.4(b)(2), using time data from a system independent source
(e.g. stopwatch) and speed data from the system. The indicated horsepower
(IHP) shall be set to zero for these tests.
(A) Acceptance Criteria: The difference between the externally calculated
value and the machine calculated value shall not exceed 10% of the
independently measured value.
(iv) Verify Coast-Down. The coast-down procedure shall use a vehicle off-
dynamometer type method or equivalent. Using a vehicle to bring the
dynamometer up to speed and removing the vehicle before the coast-down shall
not be permitted.
(A) To verify the coast-downs at 25 mph, use the procedure and equations
described in §85.4(b)(2)(ii).
(B) To verify the coast-downs at 15 mph, use the procedure and equations
described in §85.4(b)(2)(iii).
(C) Acceptance Criteria: The measured 30-20 mph coast-down time and the
20-10 mph coast-down time must be inside the window bounded by
CCDT (seconds) ± 6% at both speeds.
(6) Field Auditing.
(i) Frequency. Field audits should be performed on each dynamometer at least
once per year (A) Calibrate the load cell according to the manufacturer's
direction.
(ii) Perform coast-down check to verify system does not self diagnose any
problems. Correct any problems as necessary.
(iii) Dynamometer load verification may be performed either with an existing
dynamometer tester or by reading voltage directly from the dynamometer load
cell. If an existing dynamometer tester is used, follow the directions provided
by the tester manufacturer. If voltage measurement is used, follow the
directions below:
(A) Determine the ratio for converting load cell voltage into dynamometer
load.
(B) Test a known vehicle on the ASM test while measuring voltage at the
load cell.
Page 44 Quality Control Requirements
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§85.4 §85.4
(C) Determine vehicle load by plugging known values into the loading
equation found in §85.3.a.2.ii. Determine vehicle load by plugging
known values into the loading equation found in §85.3.a.2.ii.
(D) Compare the applied load with the target load from the EPA-approved
lookup table (or the applicable table for the particular emissions
inspection program)
(c) Emission Sampling System.
(1) Leak Check. The entire sample system shall be checked for vacuum leaks on a daily
basis and proper flow on a continuous basis. This may be accomplished using a
vacuum decay method, reading a span gas, or other methods proposed by a state and
approved by the Administrator. The analyzer shall not allow an error of more than 1%
of reading using the high-range span gas described in §85.4(d)(2)(iii)(C). The analyzer
shall be locked out from testing if the leak check is not performed when due or fails to
pass the check.
(2) Dilution. The flow rate on the analyzer shall not cause more than 10% dilution during
sampling of exhaust of a 1.6 liter engine a normal idle. Ten percent dilution is defined
as a sample of 90% exhaust and 10% ambient air.
(3) Dilution Acceptance Test.
(i) Set vehicle with 1.6 liter maximum engine displacement at factory -
recommended idle speed, OEM configuration exhaust system, transmission in
neutral, hood up (a fan to cool the engine may be used if needed). Set idle
speed not to exceed 920 RPM. (Set for 900 RPM with a tolerance ± 20 RPM.)
(ii) With a laboratory grade analyzer system, sample the exhaust at 40 centimeters
depth with a flow sample rate below 320 liters per hour. Allow sufficient time
for this test. Record all HC, CO, NO, CO2, and O2 readings. A chart recorder or
electronically stored data may be used to detect the point of stable readings.
(iii) While operating the candidate analyzer system in a mode which has the same
flow rate as the official test mode, record the levels of HC, CO, NO, CO2, and
O2. Ensure that the probe is installed correctly.
(iv) Repeat step (ii).
(iv) Acceptance Criteria: If the difference of the readings between (ii) and (iv)
exceed five percent of the average of (ii) and (iv), repeat (ii), (iii), and (iv);
otherwise average (ii) and (iv) and compare with (iii). If (iii) is within 10
percent of the average of (ii) and (iv), then the equipment meets the dilution
specification.
Page 45 Quality Control Requirements
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§85.4 §85.4
(d) Analytic Instruments.
(1) General Requirements. The analyzer shall, to the extent possible, maintain accuracy
between gas calibrations taking into account all errors, including noise, repeatability,
drift, linearity, temperature, and barometric pressure.
(2) Two-Point Gas Calibration and Low-Range Audit.
(i) Analyzers shall automatically require a zero gas calibration and a high-range
gas calibration for HC, CO, NO, and CO2. The system shall also use a low-
range gas to check the calibration in the range of vehicle emission standards. In
high volume stations (4000 or more tests per year), analyzers shall be calibrated
within four hours before each test. In low volume stations (below 4000 tests per
year), analyzers shall be calibrated within 72 hours before each test. If the
system does not calibrate or is not calibrated, the analyzer shall lock out from
testing until corrective action is taken. This calibration check shall include
measuring the NO cell response to ensure it is < 15 seconds with a warning
displayed when the response exceeds 7 seconds.
(ii) Gas Calibration and Check Procedure. Gas calibration shall be accomplished
by introducing calibration gases that meet the requirements of §85.4(d)(2)(iii)
into the calibration port. The pressure in the sample cell shall be the same with
the calibration gas flowing as with the sample flowing during testing. The
analyzer channels shall be adjusted to the center of the allowable tolerance
range as a result of the calibration. The system shall record the gas reading data
from before the adjustment and other data pertinent to control charting analyzer
performance.
(A) Zero the analyzer and perform a leak check.
(B) Calibrate the analyzer using the low and high-range calibration gas as
specified in §85.4(d)(2)(iii).
(C) Purge the analyzers completely by flowing the low-range calibration gas
specified in §85.4(d)(2)(iii) for 60 seconds. If the low-range calibration
gas readings differ from the true cylinder value by more ±3% of point for
HC, ±3% of point for CO, ±3% of point for CO2, or ±25 ppm NO the
analyzer shall be locked out from testing.
(iii) The following gases shall be used for the 2-point calibration and low-range
audit. The Low- and High-Range Calibration Gases are the same concentrations
and purity as the Low- and High-Range Audit Gases.
Appendix A contains a table with sample calculations illustrating how the Low
and High Audit Limits for the Calibration Gases are to be determined. The
tolerances are based on a 2% blend tolerance, accurate to 1%. It is
Page 46 Quality Control Requirements
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§85.4 §85.4
recommended that NIST traceable standards accurate to 1% be used to verify all
bottle names*.
(A) Zero Gas
O2 = 20.7%
HC < 1 ppm THC
CO < 1 ppm
CO2 < 400 ppm
NO < 1 ppm
N2 = Balance 99.99 % pure
(B) Low-Range Calibration Gas
HC = 200 ppm propane
CO = 0.5 %
CO2 = 6.0 %
NO =300 ppm
N2 = Balance 99.99 % pure
(C) High-Range Calibration Gas
HC = 3200 ppm propane
CO = 8.0 %
CO2 = 12.0 %
NO = 3000 ppm
N2 = Balance 99.99 % pure
(iv) Traceability. The audit and span gases used for the gas calibration shall be
traceable to National Institute of Standards and Technology (NIST) standards
±1%. Gases shall have a 2% blend tolerance.
(3) Five-Point Calibration Audit.
(i) Analyzers shall automatically require and successfully pass a five point gas
audit for HC, CO, NO, and CO2. For high volume stations, audits shall be
checked monthly. In low volume stations, analyzers shall undergo the audit
procedure every six months.
(ii) Gas Audit Procedure. Calibration auditing shall be accomplished by
introducing audit gas through the probe. The pressure in the sample cell shall
be the same with the audit gas flowing as with the sample flowing during
testing.
(A) Zero the analyzer and perform a leak check.
EPA has been informed that adherence to this minimum NIST standard may not be an ironclad guarantee of accuracy.
Requiring gases to be analyzed using EPA-600/R-97-121 may be a more reliable method; however, it may also cause a
significant increase in cost.
Page 47 Quality Control Requirements
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§85.4 §85.4
(B) Flow the low range audit gas specified in §85.4(d)(3)(iii) through the
sample probe, ensuring that the tip is equal to ambient barometric pressure
±0.1 inches Hg (a balloon teed into the gas flow line is an acceptable
pressure indicator; the balloon should stand slightly erect).
(C) When the HC, CO, NO, and CO2 gases have been flowing for 60 seconds
record the readings as well as the PEF value for HC at each audit blend.
(D) Repeat steps B and C for each audit gas specified in §85.4(d)(3)(iii).
(E) Compare the readings with the audit gas values using the equation listed
below. Be sure to divide the HC reading by its PEF if this calculation is
not performed automatically in the analyzer software.
(Reading - True Cylinder Value)
Tolerance % = 100*-
True Cylinder Value
(F) If the analyzer response when reading any of the Audit Gases exceeds
±4.0% for HC/PEF, CO, and CO2, or ±5.0% for NO, then the analyzer
shall fail the gas audit and shall be locked out from testing until it passes.
(iv) The following gases shall be used for the five-point calibration audit.
(A) Zero Audit Gas
O2 = 20.7% (if O2 span is desired)
HC < O.lppmTHC
CO < 0.5 ppm
CO2 < 1 ppm
NO < 0.1 ppm
N2 = Balance 99.99 % pure
(B) Low Range Audit Gas
HC = 200 ppm propane
CO = 0.5 %
CO2 = 6.0 %
NO =300 ppm
N2 = Balance 99.99 % pure
(C) Low-Middle Range Audit Gas
HC = 960 ppm propane
CO = 2.4 %
CO2 = 3.6%
NO = 900 ppm
N2 = Balance 99.99 % pure
(D) High-Middle Range Audit Gas
HC = 1920 ppm propane
CO = 4.8 %
CO2 = 7.2 %
NO = 1800 ppm
Page 48 Quality Control Requirements
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§85.4 §85.4
N2 = Balance 99.99 % pure
(E) High Range Audit Gas
HC = 3200 ppm propane
CO = 8.0 %
CO2 = 12.0 %
NO = 3000 ppm
N2 = Balance 99.99 % pure
(iv) Traceability. These gases shall be traceable to National Institute of Standards
and Technology (NIST) standards ±1%. Gases shall have a 2% blend tolerance.
(4) Service, Repair and Modification.
(i) Each time an analyzer's emissions measurement system, sensor, or other related
electronic components are repaired or replaced, the five point calibration audit
required in §85.4(d)(3) shall be performed, at a minimum, prior to returning the
unit to service.
(ii) Each time the sample line integrity is broken, a leak check shall be performed
prior to testing.
(5) Certification Testing.
(i) Analyzer accuracy. This test confirms the ability of the candidate instruments
to read various concentrations of gases within the tolerances required by this
specification. The test compares the response of the candidate instrument with
that of standard instruments, and also estimates the uncertainty of the readings.
The analyzer shall be zeroed and gas calibrated using the high-range calibration
gas. The instrument shall be tested using propane, carbon monoxide, carbon
dioxide, and nitric oxide in nitrogen, with a certified accuracy of ±1%, in the
following concentrations: 0%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%,
90%, and 100% of the high range audit gas
(A) Introduce the gases in ascending order of concentrations beginning with
the zero gas. Record the readings of the standard and candidate
instruments to each concentration value. A gas divider may be used to
divide the high range audit gas to the concentrations described in
§85.4(d)(5)(i).
(B) After the highest concentration has been introduced and recorded,
introduce the same gases to the standard and candidate analyzers in
descending order, including the zero gas. Record the reading of analyzers
to each gas, including negatives (if any).
(C) Repeat steps A and B for the candidate only, four more times (total of five
times).
(D) Calculation Procedure:
Page 49 Quality Control Requirements
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§85.4 §85.4
1. Calculate the average value of each concentration for the readings
of the standard instruments.
2. Calculate the mean and standard deviation of each candidate's
readings for each concentration. Include both upscale and
downscale readings for the same gas concentration. (All
calculations may not be possible for zero concentrations.)
3. For each concentration, calculate the difference between the
candidate mean and the standard average.
4. For each concentration, compute the following:
(i) Yi = x + Ksd
(ii) Y2 = x - Ksd
Where
Ksd= std dev * 3.5 for zero and the highest concentration value
Ksd= std dev * 2.5 for all other concentration values
x = mean (arithmetic average) of the set of candidate readings.
5. Compute the uncertainty (U) of the calibration curve for each
concentration as follows:
(i) Ui = concentration value - YI
(ii) U2 = concentration value - Y2
6. Acceptance Criteria:
(a) For each concentration, the differences calculated in Step 3
shall be no greater than the accuracy tolerances specified in
§85.3(c)(3) for each instrument.
(b) For each concentration, the uncertainties, (Ui and U2) shall
be no greater than the accuracy tolerances required in
§85.3(c)(3).
(E) Alternative Calculation Procedure:
1. Use a gas divider readings as the standard values and compare
them to the measured values of a sample lot of instruments
2. Compute the absolute and percent of point deltas using the
equation in Section §85.4(d)(3)(ii)(E).
3. For each point, the instruments shall pass the criteria provided in
Section §85.4(d)(3)(ii)(F).
(ii) Analyzer System Repeatability. This test characterizes the ability of the
instrument to give consistent readings when repeatedly sampling the same gas
concentration.
Page 50 Quality Control Requirements
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§85.4 §85.4
(A) Using the high range span gas, introduce the gas through the calibration
port. Record the readings.
(B) Purge with ambient air for at least 30 seconds but no more than 60
seconds.
(C) Repeat steps A and B above four more times.
(D) Repeat steps A, B, and C, introducing the gas through the sample probe.
(E) Acceptance Criteria: The differences between the highest and lowest
readings from both ports shall not exceed the values specified in
§85.3(c)(3)(vi).
(iii) Analyzer System Response Time. This test determines the speed of response of
the candidate instrument when a sample is introduced at the sample probe.
(A) Gas calibrate the candidate instrument per the manufacturer's instructions.
(B) Using a solenoid valve or equivalent selector system, remotely introduce
an high range span gas to the probe. The gas pressure at the entrance to
the probe shall be equal to room ambient.
(C) Measure the elapsed time required for the instrument display to read 90%
and 95% of the final stabilized reading for HC, CO, CO2 and NO.
(Optional: Also, measure the time required for the O2 analyzer to read
0.1% O2). Alternatively the bench outputs may be recorded against a time
base to determine the response time. Record all times in seconds.
(D) Switch the solenoid valve to purge with zero air for at least 40 seconds but
no more than 60 seconds.
(E) Measure the elapsed time required for the NO instrument display to read
10% of the stabilized reading in Step C.
(F) Repeat steps A, B, and C, two more times (total three times).
(G) Acceptance Criteria: The response (drop time for O2 and NO; rise time for
HC, CO, CO2 and NO) times shall meet the requirement specified in
§85.3(c)(2)(x). The response time shall also be within ±1 second of the
nominal response time supplied by the equipment supplier for use in
§85.5(b)(5).
(iv) Analyzer Interference Effects. The following acceptance test procedure shall be
performed at 45°F, 75°F, and 105°F conditions, except as noted.
(A) Zero and span the instrument.
(B) Sample the following gases for at least one minute. Record the response
of each channel to the presence of these gases.
Page 51 Quality Control Requirements
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§85.4 §85.4
1. 16% Carbon Dioxide in Nitrogen.
2. 1600 ppm Hexane in Nitrogen.
3. 10% Carbon Monoxide in Nitrogen.
4. 3000 ppm Nitric Oxide in Nitrogen.
5. 75 ppm Sulfur Dioxide (SO2) in Nitrogen.
6. 75 ppm Hydrogen Sulfide (H2S) in Nitrogen.
(C) Water-Saturated Hot Air. Water-saturated hot air shall be drawn through
the probe from the top of a sealed vessel partially filled with water
through which ambient air will be bubbled. The water shall be
maintained at a temperature of!22°F±9°F. This test shall be performed
at only the 75°F, and 105°F conditions.
(D) Acceptance Criteria: The interference effects shall not exceed the limits
specified in §85.3(c)(2)(iii).
(v) Electromagnetic Isolation and Interference. This test shall measure the ability
of the candidate instrument to withstand electromagnetic fields which could
exist in vehicle testing and repair facilities. For all tests described below,
sample "Low-Middle Range Audit Gas" specified in §85.4(d)(3)(iii)(C), at
atmospheric pressure, through the sample probe. Record analyzer reading
during test periods.
(A) Radio Frequency Interference Test.
1. Use a test vehicle with an engine having a high energy ignition
system (or equivalent), a solid core coil wire and a 3/8" air gap.
Leave engine off.
2. Locate the candidate instrument within 5 feet of the ignition coil.
Gas calibrate the candidate instrument.
3. Sample gas specified above. Wait 20 seconds, and record analyzer
readings.
4. Start engine. With the hood open and gas flowing to the analyzer,
cycle the engine from idle through 25 mph on the dynamometer at
ASM loads and record the analyzer readings.
5. Relocate the instrument to within 6 inches of one side of the
vehicle near the engine compartment. Follow procedure described
in step 4 and record analyzer readings.
6. Relocate the instrument to within 6 inches of the other side of the
vehicle near the engine compartment. Follow procedure described
in step 4 and record analyzer readings.
7. Acceptance Criteria: The analyzer readings shall deviate no more
than 0.5% full scale.
Page 52 Quality Control Requirements
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§85.4 §85.4
(B) Induction Field Test. Use a variable speed (commutator type) hand drill
having a plastic housing and rated at 3 amps or more. While the analyzer
is sampling the gas, vary the drill speed from zero to maximum while
moving from the front to the sides of the instrument at various heights.
Acceptance Criteria: The analyzer readings shall deviate no more than
0.5% full scale.
(C) Line Interference Test. Plug the drill used in part B above into one outlet
of a #16-3 wire extension cord approximately 20 feet long. Connect the
instrument into the other outlet of the extension cord. Repeat part B
above.
Acceptance Criteria: The analyzer readings shall deviate no more than
0.5% full scale.
(D) VHF Band Frequency Interference Test. Locate both a citizens ban radio
(CB), with output equivalent to FCC legal maximum, and a highway
patrol transmitter (or equivalent) within 50 feet of the instrument. While
the analyzer is sampling the gas, press and release transmit button of the
both radios several times.
Acceptance Criteria: The analyzer readings shall deviate no more than
0.5% full scale.
(E) Ambient Conditions Instruments. Upon installation and every six months
thereafter, the performance of the ambient conditions instruments shall be
cross-checked against a master weather station.
Acceptance Criteria: The individual instruments shall be within the
tolerance specified in §85.3(c)(4).
(v) Ambient Conditions Instruments. Upon installation and every six months
thereafter, the performance of the ambient conditions instruments shall be cross
checked against a master weather station.
Acceptance Criteria: The individual instruments shall be within the tolerance
specified in §85.3(c)(4).
Page 53 Quality Control Requirements
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§85.5 §85.5
§85.5 Test Record Information
The following information shall be collected for each test performed (both passing and failing
tests), recorded in electronic form, and made available to EPA upon request.
(a) General Information.
(1) Test Record Number
(2) Inspection station and inspector numbers
(3) Test system number
(4) Dynamometer site
(5) Date of test
(6) Emission test start time and the time final emission scores are determined.
(7) Vehicle identification number
(8) License plate number
(9) Test certificate number
(10) Vehicle model year, make, and type
(11) Number of cylinders or engine displacement
(12) Transmission type
(13) Odometer reading
(14) Type of test performed (i.e., initial test, first retest, or subsequent retest)
(b) Ambient Test Conditions.
(1) Relative humidity (%)
(2) Dry-bulb temperature (°F).
(3) Atmospheric pressure (mm Hg)
(4) NO correction factor
(5) Nominal response time for each instrument (Transport + T90)
(c) ASM Mode or Modes.
The following information shall be captured separately for each test mode (ASM5015 and/or
ASM2525) performed.
(1) Final HC running average (AvgHC) (ppm)
(2) Final CO running average (AvgCO) (%)
(3) Final NO running average (AvgNO) (ppm)
(4) Total horsepower used to set the dynamometer (THP5015) (hp)
(5) Engine RPM running average corresponding to the final test score
(6) Dilution correction factor (DCF)
(d) Diagnostic/Quality Assurance Information.
(1) Test time (seconds)
(2) Mode time (seconds)
(3) Vehicle speed (mph) for each second of the test
(4) Engine RPM for each second of the test
(5) Dynamometer load (pounds) for each second of the test
(6) HC concentration (ppm) for each second of the test, not corrected for dilution
(7) CO concentration (%) for each second of the test, not corrected for dilution
Page 54 7/28/04 Test Record Information
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§85.5 §85.5
(8) NO concentration (ppm) corrected for humidity for each second of the test, not
corrected for dilution
(9) CO2 concentration (%) for each second of the test
(10) O2 concentration (%) for each second of the test (optional)
Page 55 Test Record Information
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§85.5
§85.5
Appendix A: Calculating Audit Tolerances
"Actual Cylinder" field is input by the auditor in ppm or %. Audit limits are calculated and filled in by
the spreadsheet (or the auditor). The tolerances are based on a 2% blend tolerance, accurate to 1%. It is
recommended that NIST traceable standards accurate to 1% be used to verify all bottle names.
Spreadsheet for Calculating
Range
High
Mid
High
Mid
Low
Low
Zero
Gas
HC (ppm)
CO (%)
C02 (%)
NO (ppm)
HC (ppm)
CO (%)
CO2 (%)
NO (ppm)
HC (ppm)
CO (%)
C02 (%)
NO (ppm)
HC (ppm)
CO (%)
CO2 (%)
NO (ppm)
HC (ppm)
CO (%)
C02 (%)
NO (ppm)
Gas Concentration
Recom-
mended
3200
8.00
12.00
3000
1920
4.80
7.20
1800
960
2.40
3.60
900
200
0.50
6.00
300
0
0.00
0.00
0
Actual
Cylinder
3191
8.11
11.90
2987
1918
4.83
7.15
1801
960
2.39
3.57
902
203
0.49
6.01
299
0
0.00
0.00
0
Accuracy
%of
Reading
3.0%
3.0%
3.0%
4.0%
3.0%
3.0%
3.0%
4.0%
3.0%
3.0%
3.0%
4.0%
3.0%
3.0%
3.0%
4.0%
3.0%
3.0%
3.0%
4.0%
Point
8
0.02
0.30
25
8
0.02
0.30
25
8
0.02
0.30
25
8
0.02
0.30
25
8
0.02
0.30
25
Gas
1 .0%
1 .0%
1 .0%
1 .0%
1 .0%
1 .0%
1 .0%
1 .0%
1 .0%
1 .0%
1 .0%
1 .0%
1 .0%
1 .0%
1 .0%
1 .0%
1 .0%
1 .0%
1 .0%
1 .0%
ASM Audit Tolerances
Audit Tolerance
%of
Reading
4.0%
4.0%
4.0%
5.0%
4.0%
4.0%
4.0%
5.0%
4.0%
4.0%
4.0%
5.0%
4.0%
4.0%
4.0%
5.0%
4.0%
4.0%
4.0%
5.0%
%
(as point)
128
0.32
0.48
149
77
0.19
0.29
90
38
0.10
0.14
45
8
0.02
0.24
15
0
0.00
0.00
0
Point
40
0.10
0.42
55
27
0.07
0.37
43
18
0.04
0.34
34
10
0.02
0.36
28
9
0.02
0.30
26
Applied
Tnlprflnrp
(greater of
% or point)
128
0.32
0.48
149
77
0.19
0.37
90
38
0.10
0.34
45
10
0.02
0.36
28
9
0.02
0.30
26
Audit Limits
Low
3063
7.79
11.42
2838
1841
4.64
6.78
1711
922
2.29
3.23
857
193
0.47
5.65
271
-9
-0.02
-0.30
-26
High
3319
8.43
12.38
3136
1995
5.02
7.52
1891
998
2.49
3.91
947
213
0.51
6.37
327
9
0.02
0.30
26
In the "Actual Cylinder" column, enter the gas concentrations from the audit cylinders
The audit low and high tolerances are calculated in the columns on the right
Page 56
Test Record Information
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