United States

Environmental Protection

Agency

Air and Radiation EPA420-P-00-004

July 2000

Acceleration Simulation

Mode Test Procedures,

Emission Standards,

Quality Control

Requirements, and

Equipment Specifications

Technical Guidance

 Printed on Recycled Paper

DRAFT
EPA420-P-00-004

July 2000

Acceleration Simulation Mode Test Procedures,

Emission Standards, Quality Control Requirements,

and Equipment Specifications

Technical Guidance

DRAFT

Transportation and Regional Programs 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 the exchange of

technical information and to inform the public of technical developments which

may form the basis for a final EPA decision, position, or regulatory action.
§85.1

Page 2 Test Standards and Calculations

TECHNICAL GUIDANCE.......................................................................................................................................................1

§85.1 TEST STANDARDS AND CALCULATIONS .........................................................................................................3

(a) EMISSIONS STANDARDS..................................................................................................................................................3

(b) TEST SCORE CALCULATION..........................................................................................................................................12

§85.2 TEST PROCEDURES...............................................................................................................................................15

(a) GENERAL REQUIREMENTS............................................................................................................................................15

(b) VEHICLE PRE-INSPECTION AND PREPARATION..............................................................................................................15

(c) EQUIPMENT PREPARATION AND SETTINGS....................................................................................................................17

(d) TEST PROCEDURES.......................................................................................................................................................19

(e) SECOND CHANCE TESTS...............................................................................................................................................23

§85.3 TEST EQUIPMENT SPECIFICATIONS...............................................................................................................27

(a) DYNAMOMETER SPECIFICATIONS. ................................................................................................................................27

(b) EMISSION SAMPLING SYSTEM.......................................................................................................................................33

(c) ANALYTICAL INSTRUMENTS. ........................................................................................................................................35

(d) AUTOMATED TEST PROCESS SOFTWARE AND DISPLAYS. .............................................................................................39

§85.4 QUALITY CONTROL REQUIREMENTS ............................................................................................................41

(a) GENERAL REQUIREMENTS............................................................................................................................................41

(b) DYNAMOMETER ...........................................................................................................................................................41

(c) EMISSION SAMPLING SYSTEM.......................................................................................................................................46

(d) ANALYTICAL INSTRUMENTS. ........................................................................................................................................47

§85.5 TEST RECORD INFORMATION ..........................................................................................................................56

(a) GENERAL INFORMATION...............................................................................................................................................56

(b) AMBIENT TEST CONDITIONS.........................................................................................................................................56

(c) ASM MODE OR MODES................................................................................................................................................56

(d) DIAGNOSTIC/QUALITY ASSURANCE INFORMATION.......................................................................................................56
§85.1

Page 3 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 crossreferenced by the number in the column in §85.1(a)(3), as noted in the column

headings:

(i) Light Duty Vehicles.

Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen

Table §85.1 (a)(3)(i) Table §85.1 (a)(3)(ii) Table §85.1 (a)(3)(iii)

1996+4+ Tier 1 1 21 41

1991-1995 2 22 42

1983-1990 4 23 43

1981-1982 4 26 43

1980 4 26 48

1977-1979 11 30 48

1975-1976 11 30 50

1973-1974 13 34 50

1968-1972 13 34 51

(ii) High-Altitude Light Duty Vehicles.

Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen

Table §85.1 (a)(3)(i) Table §85.1 (a)(3)(ii) Table §85.1 (a)(3)(iii)

1983-1984 4 26 43

1982 4 29 43

(iii) Light Duty Trucks 1 (less than 6000 pounds GVWR).

Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen

Table §85.1 (a)(3)(i) Table §85.1 (a)(3)(ii) Table §85.1 (a)(3)(iii)

1996+4+ Tier 1

<3750 LVW 1 21 41

1996+4+ Tier 1

>3750 LVW 2 22 42

1991-1995 5 26 43

1988-1990 7 29 44

1984-1987 7 29 49

1979-1983 11 31 49

1975-1978 12 32 50

 §85.1 Test Standards and Calculations
§85.1

Page 4 Test Standards and Calculations

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)(3)(i) Table §85.1 (a)(3)(ii) Table §85.1 (a)(3)(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)(3)(i) Table §85.1 (a)(3)(ii) Table §85.1 (a)(3)(iii)

1996+

4+ Tier 1 <5750 LVW 2 22 42

1996+4+ Tier 1

>5750 LVW 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)(3)(i) Table §85.1 (a)(3)(ii) Table §85.1 (a)(3)(iii)

1991+ 6 28 46

1988-1990 9 30 47

1984-1987 9 30 49

1982-1983 12 33 49

(2) Final ASM Standards.

At this time, EPA recommends programs implement Final Standards cautiously and

monitor the failure rate closely to ensure excessive failure rates do not negatively

impact the program.

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)(1). 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)(3), as noted in the column headings:
§85.1

Page 5 Test Standards and Calculations

(i) Light Duty Vehicles.

Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen

Table §85.1 (a)(3)(i) Table §85.1 (a)(3)(ii) Table §85.1 (a)(3)(iii)

1996+4+ Tier 1 1 21 41

1983-1995 1 21 41

1981-1982 1 23 41

1980 1 23 45

1977-1979 6 27 45

1975-1976 6 27 48

1973-1974 10 32 48

1968-1972 10 32 49

(ii) High-Altitude Light Duty Vehicles.

Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen

Table §85.1 (a)(3)(i) Table §85.1 (a)(3)(ii) Table §85.1 (a)(3)(iii)

1983-1984 2 23 41

1982 2 23 41

(iii) Light Duty Trucks 1 (less than 6000 pounds GVWR).

Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen

Table §85.1 (a)(3)(i) Table §85.1 (a)(3)(ii) Table §85.1 (a)(3)(iii)

1996+4+ Tier 1 1 21 41

1988-1995 3 24 42

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

(iv) High-Altitude Light Duty Trucks 1 (less than 6000 pounds GVWR).

Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen

Table §85.1 (a)(3)(i) Table §85.1 (a)(3)(ii) Table §85.1 (a)(3)(iii)

1988+ 4 26 42

1984-1987 4 26 46

1982-1983 9 30 46

(v) Light Duty Trucks 2 (greater than 6000 pounds GVWR).

Model Years Hydrocarbons Carbon Monoxide Oxides of Nitrogen

Table §85.1 (a)(3)(i) Table §85.1 (a)(3)(ii) Table §85.1 (a)(3)(iii)

1996+4+ Tier 1 1 21 41

1988-1995 3 24 44
§85.1

Page 6 Test Standards and Calculations

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)(3)(i) Table §85.1 (a)(3)(ii) Table §85.1 (a)(3)(iii)

1988+ 4 26 44

1984-1987 4 26 46

1982-1983 9 30 46
§85.1

Page 7 Test Standards and Calculations

(3) ASM 2525 and 5015 Concentration Tables

(i) ASM2525 and ASM5015 Hydrocarbon (ppm C6) Table

Column # 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10 11 11 12 12 13 13

ETW 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525

1750 142 136 224 216 257 249 291 282 324 315 374 364 390 381 407 397 457 447 706 694 774 761 843 828 1118 1098

1875 134 129 212 205 243 236 275 266 306 297 353 344 368 359 384 375 431 421 665 653 729 717 794 780 1052 1034

2000 127 123 201 194 230 223 260 252 289 281 333 325 348 339 363 354 407 398 627 616 688 676 749 736 992 975

2125 121 116 191 184 219 212 246 239 274 267 316 308 329 321 343 335 385 376 592 582 650 638 707 695 938 921

2250 115 111 182 175 208 201 234 227 260 253 299 292 312 305 325 318 365 357 560 551 615 604 669 658 887 872

2375 109 106 173 167 198 192 223 216 247 241 284 277 297 290 309 302 346 339 531 522 583 573 635 624 841 827

2500 105 101 166 160 189 183 212 206 236 230 271 264 283 276 294 288 329 322 505 496 554 544 603 593 800 786

2625 100 97 159 153 181 175 203 197 225 219 259 252 270 263 281 274 314 307 481 472 528 518 574 564 761 748

2750 96 93 152 147 173 168 194 189 216 210 247 241 258 252 269 262 300 294 459 451 503 495 548 539 726 714

2875 92 89 146 141 167 161 187 181 207 201 237 231 247 241 257 251 287 281 439 431 481 473 524 515 695 683

3000 89 86 141 136 160 155 180 174 199 194 228 222 237 232 247 241 276 270 420 413 461 453 502 493 666 654

3125 86 83 136 132 155 150 173 168 191 186 219 214 228 223 238 232 265 260 404 397 443 435 482 474 639 628

3250 83 80 132 127 149 145 167 162 185 180 211 206 220 215 229 224 256 250 388 382 426 419 464 456 615 604

3375 81 78 128 123 145 140 162 157 179 174 204 199 213 208 221 216 247 241 374 368 411 404 447 440 593 583

3500 78 76 124 120 140 136 157 152 173 169 198 193 206 201 214 209 239 234 362 355 397 390 432 424 573 563

3625 76 74 120 117 136 132 152 148 168 164 192 187 200 195 207 203 231 226 350 344 384 377 418 411 554 544

3750 74 72 117 114 133 129 148 144 163 159 186 182 194 189 201 197 224 220 339 333 372 365 405 398 537 527

3875 72 70 114 111 129 125 144 140 159 155 181 177 188 184 196 191 218 213 329 323 361 355 393 386 521 512

4000 71 68 112 108 126 122 140 137 155 151 176 172 183 179 191 186 212 208 320 314 351 345 382 375 506 497

4125 69 67 109 106 123 119 137 133 151 147 172 168 179 175 186 181 206 202 311 305 341 335 371 365 492 484

4250 67 65 107 103 120 117 134 130 147 143 167 164 174 170 181 177 201 197 303 297 332 326 361 355 479 471

4375 66 64 104 101 118 114 131 127 144 140 164 160 170 166 177 173 196 192 295 290 323 318 352 346 467 459

4500 65 63 102 99 115 112 128 124 141 137 160 156 166 162 172 169 192 188 287 282 315 310 343 337 455 447

4625 63 61 100 97 113 109 125 122 137 134 156 152 162 159 169 165 187 183 280 275 308 302 335 329 444 436

4750 62 60 98 95 110 107 122 119 134 131 153 149 159 155 165 161 183 179 273 269 300 295 327 321 433 425

4875 61 59 96 93 108 105 120 117 132 128 149 146 155 152 161 157 179 175 267 262 293 288 319 313 423 415

5000 60 58 94 92 106 103 117 114 129 126 146 143 152 148 157 154 175 171 260 256 286 281 311 305 412 405

5125 58 57 93 90 104 101 115 112 126 123 143 139 148 145 154 150 171 167 254 250 279 274 304 298 402 395

5250 57 56 91 88 102 99 112 110 123 120 140 136 145 142 150 147 167 163 248 244 272 267 296 291 393 386

5375 56 55 89 86 100 97 110 107 121 118 137 133 142 139 147 144 163 159 242 238 266 261 289 284 383 376

5500 55 54 87 85 98 95 108 105 118 115 134 130 139 136 144 141 159 156 236 232 259 255 282 277 374 367

5625 54 53 86 83 96 93 106 103 116 113 131 128 136 133 141 138 156 152 231 226 253 248 276 271 365 359

5750 53 52 84 82 94 91 104 101 113 111 128 125 133 130 138 135 152 149 225 221 247 243 269 264 357 350

5875 52 51 83 80 92 90 102 99 111 108 125 122 130 127 135 132 149 146 220 216 241 237 263 258 348 342

6000 51 50 81 79 90 88 100 97 109 106 123 120 127 124 132 129 146 143 215 211 236 232 257 252 341 334

6125 50 49 80 78 89 86 98 95 107 104 120 118 125 122 129 126 143 140 210 206 231 227 251 247 333 327

6250 50 48 79 76 87 85 96 94 105 102 118 115 123 120 127 124 140 137 206 202 226 222 246 242 326 320

6375 49 48 77 75 86 84 95 92 103 101 116 113 120 118 125 122 138 135 202 198 222 218 242 237 320 314

6500 48 47 76 74 85 83 93 91 102 99 114 112 119 116 123 120 136 133 199 195 218 214 238 233 315 309

6625 48 46 76 74 84 82 92 90 101 98 113 110 117 114 121 119 134 131 196 192 215 211 234 230 310 304

6750 47 46 75 73 83 81 91 89 100 97 112 109 116 113 120 117 132 129 194 190 213 209 232 227 307 301

6875 47 46 75 73 83 81 91 89 99 97 111 109 115 113 119 117 132 129 193 189 211 207 230 225 305 299

7000 47 46 74 72 83 80 91 88 99 96 111 108 115 112 119 116 131 128 192 188 211 207 229 225 304 298

7125 47 46 74 72 82 80 90 88 98 96 111 108 115 112 119 116 131 128 192 188 211 206 229 225 304 298
§85.1

Page 8 Test Standards and Calculations

7250 47 46 74 72 82 80 90 88 98 96 111 108 115 112 119 116 131 128 192 188 211 206 229 225 304 298

7375 47 46 74 72 82 80 90 88 98 96 111 108 115 112 119 116 131 128 192 188 211 206 229 225 304 298

7500 47 46 74 72 82 80 90 88 98 96 111 108 115 112 119 116 131 128 192 188 211 206 229 225 304 298
§85.1

Page 9 Test Standards and Calculations

(ii) ASM2525 and ASM5015 Carbon Monoxide (%CO) Table

Column # 21 21 22 22 23 23 24 24 25 25 26 26 27 27 28 28 29 29 30 30 31 31 32 32 33 33 34 34

ETW 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525

1750 0.80 0.77 1.26 1.22 1.64 1.83 2.02 2.43 2.21 2.73 2.78 3.64 2.97 3.94 3.16 4.24 3.54 4.85 3.92 5.45 4.31 6.06 5.07 7.26 5.26 7.44 8.02 9.90

1875 0.75 0.73 1.19 1.16 1.55 1.72 1.91 2.29 2.09 2.58 2.63 3.43 2.81 3.71 2.98 4.00 3.34 4.57 3.70 5.14 4.06 5.70 4.78 6.84 4.96 7.05 7.56 9.90

2000 0.71 0.69 1.13 1.09 1.47 1.63 1.81 2.17 1.97 2.43 2.48 3.24 2.65 3.51 2.82 3.77 3.16 4.31 3.49 4.85 3.83 5.38 4.51 6.45 4.68 6.68 7.14 9.90

2125 0.68 0.66 1.07 1.04 1.39 1.54 1.71 2.05 1.87 2.30 2.35 3.06 2.51 3.32 2.67 3.57 2.99 4.08 3.31 4.58 3.63 5.09 4.26 6.10 4.43 6.34 6.75 9.66

2250 0.64 0.62 1.02 0.99 1.32 1.47 1.62 1.94 1.77 2.18 2.23 2.90 2.38 3.14 2.53 3.38 2.83 3.86 3.13 4.34 3.44 4.82 4.04 5.78 4.20 6.00 6.40 9.14

2375 0.61 0.59 0.97 0.94 1.26 1.39 1.54 1.85 1.69 2.07 2.12 2.76 2.26 2.98 2.40 3.21 2.69 3.66 2.98 4.12 3.26 4.57 3.83 5.48 3.98 5.69 6.07 8.67

2500 0.59 0.57 0.93 0.90 1.20 1.33 1.47 1.76 1.61 1.97 2.02 2.62 2.15 2.84 2.29 3.05 2.56 3.48 2.83 3.91 3.10 4.35 3.65 5.21 3.79 5.41 5.78 8.25

2625 0.56 0.54 0.89 0.86 1.15 1.27 1.41 1.68 1.53 1.88 1.92 2.50 2.05 2.70 2.18 2.91 2.44 3.32 2.70 3.73 2.96 4.14 3.48 4.96 3.61 5.15 5.51 7.85

2750 0.54 0.52 0.85 0.82 1.10 1.21 1.34 1.60 1.47 1.80 1.84 2.39 1.96 2.58 2.09 2.78 2.33 3.17 2.58 3.56 2.83 3.95 3.32 4.73 3.45 4.92 5.26 7.50

2875 0.52 0.50 0.82 0.79 1.05 1.16 1.29 1.54 1.41 1.72 1.76 2.29 1.88 2.47 2.00 2.66 2.23 3.03 2.47 3.41 2.71 3.78 3.18 4.53 3.30 4.70 5.03 7.17

3000 0.50 0.48 0.79 0.76 1.01 1.12 1.24 1.48 1.35 1.66 1.69 2.19 1.80 2.37 1.92 2.55 2.14 2.91 2.37 3.27 2.60 3.62 3.05 4.34 3.17 4.51 4.83 6.87

3125 0.48 0.46 0.76 0.73 0.98 1.08 1.19 1.42 1.30 1.59 1.63 2.11 1.74 2.28 1.84 2.45 2.06 2.79 2.28 3.14 2.50 3.48 2.93 4.17 3.04 4.33 4.64 6.60

3250 0.46 0.45 0.73 0.71 0.94 1.04 1.15 1.37 1.26 1.53 1.57 2.03 1.67 2.20 1.78 2.36 1.99 2.69 2.20 3.02 2.40 3.35 2.82 4.01 2.93 4.17 4.47 6.35

3375 0.45 0.43 0.71 0.69 0.91 1.00 1.11 1.32 1.21 1.48 1.52 1.96 1.62 2.12 1.72 2.28 1.92 2.60 2.12 2.91 2.32 3.23 2.72 3.87 2.83 4.02 4.31 6.13

3500 0.44 0.42 0.69 0.67 0.88 0.97 1.08 1.28 1.17 1.43 1.47 1.89 1.56 2.05 1.66 2.20 1.86 2.51 2.05 2.82 2.24 3.12 2.63 3.74 2.73 3.88 4.17 5.92

3625 0.42 0.41 0.67 0.65 0.86 0.94 1.05 1.24 1.14 1.39 1.42 1.84 1.52 1.98 1.61 2.13 1.80 2.43 1.99 2.73 2.17 3.02 2.55 3.62 2.65 3.76 4.04 5.73

3750 0.41 0.40 0.65 0.63 0.83 0.92 1.02 1.20 1.11 1.35 1.38 1.78 1.47 1.92 1.56 2.07 1.74 2.36 1.93 2.64 2.11 2.93 2.47 3.51 2.57 3.64 3.91 5.55

3875 0.40 0.39 0.63 0.61 0.81 0.89 0.99 1.17 1.08 1.31 1.34 1.73 1.43 1.87 1.52 2.01 1.69 2.29 1.87 2.57 2.05 2.85 2.40 3.40 2.49 3.54 3.80 5.39

4000 0.39 0.38 0.62 0.60 0.79 0.87 0.96 1.14 1.05 1.28 1.31 1.68 1.39 1.82 1.48 1.95 1.65 2.22 1.82 2.49 1.99 2.77 2.33 3.31 2.43 3.44 3.70 5.24

4125 0.38 0.37 0.60 0.58 0.77 0.85 0.94 1.11 1.02 1.24 1.27 1.64 1.36 1.77 1.44 1.90 1.61 2.16 1.77 2.43 1.94 2.69 2.27 3.22 2.36 3.34 3.60 5.09

4250 0.37 0.36 0.59 0.57 0.75 0.83 0.92 1.08 1.00 1.21 1.24 1.60 1.32 1.72 1.40 1.85 1.56 2.11 1.73 2.36 1.89 2.62 2.21 3.13 2.30 3.25 3.51 4.96

4375 0.36 0.35 0.58 0.56 0.74 0.81 0.89 1.06 0.97 1.18 1.21 1.56 1.29 1.68 1.37 1.81 1.53 2.06 1.68 2.31 1.84 2.55 2.16 3.05 2.24 3.17 3.42 4.83

4500 0.36 0.35 0.57 0.55 0.72 0.79 0.87 1.03 0.95 1.16 1.18 1.52 1.26 1.64 1.34 1.76 1.49 2.01 1.64 2.25 1.80 2.49 2.11 2.98 2.19 3.09 3.34 4.71

4625 0.35 0.34 0.55 0.54 0.70 0.77 0.85 1.01 0.93 1.13 1.15 1.48 1.23 1.60 1.30 1.72 1.46 1.96 1.61 2.19 1.76 2.43 2.06 2.90 2.14 3.02 3.26 4.60

4750 0.34 0.33 0.54 0.53 0.69 0.76 0.84 0.99 0.91 1.10 1.13 1.45 1.20 1.57 1.28 1.68 1.42 1.91 1.57 2.14 1.72 2.37 2.01 2.83 2.09 2.95 3.18 4.49

4875 0.34 0.33 0.53 0.52 0.67 0.74 0.82 0.97 0.89 1.08 1.10 1.42 1.17 1.53 1.25 1.64 1.39 1.87 1.53 2.09 1.68 2.32 1.96 2.77 2.04 2.87 3.11 4.38

5000 0.33 0.32 0.52 0.51 0.66 0.73 0.80 0.95 0.87 1.05 1.08 1.38 1.15 1.49 1.22 1.60 1.36 1.82 1.50 2.04 1.64 2.26 1.92 2.70 1.99 2.81 3.03 4.28

5125 0.32 0.31 0.51 0.50 0.65 0.71 0.78 0.92 0.85 1.03 1.05 1.35 1.12 1.46 1.19 1.57 1.33 1.78 1.46 2.00 1.60 2.21 1.87 2.64 1.95 2.74 2.97 4.18

5250 0.32 0.31 0.50 0.49 0.63 0.70 0.77 0.90 0.83 1.01 1.03 1.32 1.10 1.43 1.16 1.53 1.30 1.74 1.43 1.95 1.56 2.16 1.83 2.58 1.90 2.68 2.90 4.08

5375 0.31 0.30 0.49 0.48 0.62 0.68 0.75 0.89 0.81 0.99 1.01 1.29 1.07 1.39 1.14 1.50 1.27 1.70 1.40 1.90 1.53 2.11 1.79 2.51 1.86 2.61 2.83 3.98

5500 0.30 0.30 0.48 0.47 0.61 0.67 0.73 0.87 0.80 0.97 0.99 1.26 1.05 1.36 1.11 1.46 1.24 1.66 1.37 1.86 1.49 2.06 1.75 2.46 1.82 2.55 2.77 3.89

5625 0.30 0.29 0.47 0.46 0.59 0.65 0.72 0.85 0.78 0.94 0.97 1.24 1.03 1.33 1.09 1.43 1.21 1.62 1.34 1.82 1.46 2.01 1.71 2.40 1.77 2.49 2.70 3.80

5750 0.29 0.29 0.46 0.45 0.58 0.64 0.70 0.83 0.76 0.92 0.94 1.21 1.01 1.30 1.07 1.40 1.19 1.59 1.31 1.78 1.43 1.96 1.67 2.34 1.74 2.43 2.64 3.71

5875 0.29 0.28 0.45 0.44 0.57 0.63 0.69 0.81 0.75 0.91 0.92 1.18 0.98 1.27 1.04 1.37 1.16 1.55 1.28 1.74 1.40 1.92 1.63 2.29 1.70 2.38 2.59 3.62

6000 0.28 0.28 0.44 0.44 0.56 0.62 0.67 0.80 0.73 0.89 0.91 1.16 0.96 1.25 1.02 1.34 1.14 1.52 1.25 1.70 1.37 1.88 1.60 2.24 1.66 2.33 2.53 3.54

6125 0.28 0.27 0.44 0.43 0.55 0.61 0.66 0.78 0.72 0.87 0.89 1.13 0.94 1.22 1.00 1.31 1.11 1.49 1.23 1.66 1.34 1.84 1.57 2.19 1.63 2.28 2.48 3.47

6250 0.27 0.27 0.43 0.42 0.54 0.60 0.65 0.77 0.71 0.85 0.87 1.11 0.93 1.20 0.98 1.28 1.09 1.46 1.20 1.63 1.31 1.80 1.54 2.15 1.60 2.23 2.43 3.40

6375 0.27 0.26 0.42 0.42 0.53 0.59 0.64 0.76 0.69 0.84 0.86 1.09 0.91 1.18 0.96 1.26 1.07 1.43 1.18 1.60 1.29 1.77 1.51 2.11 1.57 2.19 2.39 3.34

6500 0.26 0.26 0.42 0.41 0.52 0.58 0.63 0.74 0.68 0.83 0.84 1.08 0.90 1.16 0.95 1.24 1.06 1.41 1.16 1.57 1.27 1.74 1.48 2.07 1.54 2.15 2.35 3.28

6625 0.26 0.26 0.41 0.41 0.52 0.57 0.62 0.73 0.67 0.82 0.83 1.06 0.88 1.14 0.94 1.23 1.04 1.39 1.15 1.55 1.25 1.72 1.46 2.04 1.52 2.12 2.32 3.23

6750 0.26 0.26 0.41 0.41 0.51 0.57 0.61 0.73 0.67 0.81 0.82 1.05 0.88 1.13 0.93 1.21 1.03 1.37 1.14 1.54 1.24 1.70 1.45 2.02 1.50 2.10 2.29 3.20

6875 0.26 0.25 0.40 0.40 0.51 0.56 0.61 0.72 0.66 0.80 0.82 1.04 0.87 1.12 0.92 1.20 1.02 1.36 1.13 1.52 1.23 1.68 1.44 2.00 1.49 2.08 2.28 3.17
§85.1

Page 10 Test Standards and Calculations

7000 0.25 0.25 0.40 0.40 0.51 0.56 0.61 0.72 0.66 0.80 0.82 1.04 0.87 1.12 0.92 1.20 1.02 1.36 1.12 1.52 1.23 1.68 1.43 2.00 1.49 2.08 2.27 3.17

7125 0.25 0.25 0.40 0.40 0.51 0.56 0.61 0.72 0.66 0.80 0.81 1.04 0.87 1.12 0.92 1.20 1.02 1.36 1.12 1.52 1.22 1.68 1.43 2.00 1.49 2.08 2.27 3.17

7250 0.25 0.25 0.40 0.40 0.50 0.56 0.61 0.72 0.66 0.80 0.81 1.04 0.86 1.12 0.92 1.20 1.02 1.36 1.12 1.52 1.22 1.68 1.43 2.00 1.49 2.08 2.27 3.17

7375 0.25 0.25 0.40 0.40 0.50 0.56 0.61 0.72 0.66 0.80 0.81 1.04 0.86 1.12 0.92 1.20 1.02 1.36 1.12 1.52 1.22 1.68 1.43 2.00 1.49 2.08 2.27 3.17

7500 0.25 0.25 0.40 0.40 0.50 0.56 0.61 0.72 0.66 0.80 0.81 1.04 0.86 1.12 0.92 1.20 1.02 1.36 1.12 1.52 1.22 1.68 1.43 2.00 1.49 2.08 2.27 3.17
§85.1

Page 11 Test Standards and Calculations

(iii) ASM2525 and ASM5015 Nitric Oxide (ppm NO) Table

Column # 41 41 42 42 43 43 44 44 45 45 46 46 47 47 48 48 49 49 50 50 51 51

ETW 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525 5015 2525

1750 1212 1095 1819 1642 2272 2114 2725 2587 3178 3060 3631 3532 4084 4005 4990 4950 4990 4960 4990 4980 4990 4990

1875 1142 1031 1713 1547 2181 1991 2649 2435 3117 2879 3586 3323 4054 3767 4990 4655 4990 4738 4990 4906 4990 4990

2000 1077 973 1616 1460 2058 1877 2499 2295 2941 2713 3383 3131 3824 3548 4707 4384 4778 4535 4919 4838 4990 4990

2125 1018 920 1527 1380 1944 1774 2360 2167 2776 2561 3192 2955 3609 3348 4441 4136 4578 4349 4853 4776 4990 4990

2250 964 871 1446 1307 1839 1678 2232 2050 2625 2422 3018 2794 3411 3165 4197 3909 4395 4179 4792 4720 4990 4990

2375 915 827 1372 1240 1744 1592 2115 1943 2487 2295 2859 2646 3231 2998 3974 3701 4228 4024 4736 4668 4990 4990

2500 869 786 1304 1179 1657 1512 2009 1845 2361 2179 2714 2512 3066 2845 3771 3512 4076 3881 4685 4620 4990 4990

2625 828 749 1242 1123 1577 1440 1912 1756 2246 2073 2581 2389 2916 2706 3585 3339 3936 3752 4639 4577 4990 4990

2750 791 715 1186 1072 1504 1374 1823 1675 2142 1976 2460 2277 2779 2579 3416 3181 3809 3579 4596 4374 4990 4772

2875 756 684 1134 1026 1438 1313 1742 1601 2046 1888 2350 2175 2654 2463 3261 3037 3669 3417 4484 4176 4892 4556

3000 725 656 1088 984 1378 1258 1668 1533 1959 1808 2249 2082 2539 2357 3120 2906 3510 3270 4290 3996 4680 4359

3125 696 630 1045 945 1323 1208 1601 1471 1879 1734 2157 1997 2435 2260 2992 2787 3366 3135 4114 3832 4488 4180

3250 670 607 1006 910 1273 1163 1539 1415 1806 1667 2073 1920 2340 2172 2874 2677 3234 3012 3952 3681 4311 4016

3375 647 585 970 878 1227 1121 1483 1363 1740 1606 1997 1849 2253 2092 2767 2577 3113 2899 3804 3544 4150 3866

3500 625 566 937 848 1184 1082 1432 1316 1679 1550 1926 1784 2174 2018 2668 2486 3002 2796 3669 3418 4002 3728

3625 605 547 907 821 1146 1047 1384 1273 1623 1498 1862 1724 2100 1950 2578 2401 2900 2701 3544 3302 3867 3602

3750 586 531 879 796 1110 1014 1340 1233 1571 1451 1802 1669 2033 1887 2494 2323 2806 2614 3429 3195 3741 3485

3875 569 515 853 773 1077 984 1300 1195 1523 1407 1747 1618 1970 1829 2417 2251 2719 2533 3323 3096 3625 3377

4000 553 501 829 751 1046 956 1262 1161 1479 1365 1695 1570 1912 1775 2345 2184 2638 2457 3224 3003 3517 3276

4125 538 487 807 731 1017 930 1227 1128 1437 1327 1647 1526 1857 1724 2277 2122 2562 2387 3131 2917 3416 3182

4250 524 475 786 712 990 905 1194 1098 1398 1291 1602 1484 1806 1677 2214 2063 2490 2320 3044 2836 3321 3094

4375 510 463 766 694 964 882 1162 1069 1360 1257 1559 1444 1757 1632 2154 2007 2423 2258 2961 2759 3230 3010

4500 498 451 747 677 939 859 1132 1042 1325 1224 1518 1406 1711 1589 2096 1953 2359 2198 2883 2686 3145 2930

4625 486 440 728 661 916 838 1104 1015 1291 1193 1479 1370 1666 1548 2042 1903 2297 2140 2807 2616 3063 2854

4750 474 430 711 645 893 818 1076 990 1259 1163 1441 1336 1624 1508 1989 1854 2238 2085 2735 2549 2983 2780

4875 463 420 694 630 872 798 1049 966 1227 1134 1405 1302 1583 1470 1938 1806 2180 2032 2665 2483 2907 2709

5000 452 410 677 615 850 778 1023 942 1196 1106 1369 1269 1542 1433 1889 1760 2125 1980 2597 2420 2833 2640

5125 441 400 661 600 830 760 998 919 1167 1078 1335 1237 1503 1397 1840 1715 2070 1930 2530 2359 2760 2573

5250 431 391 646 586 810 741 974 896 1138 1051 1301 1206 1465 1362 1793 1672 2017 1881 2466 2298 2690 2507

5375 420 382 631 573 790 723 950 874 1109 1025 1269 1176 1428 1327 1747 1629 1966 1833 2403 2240 2621 2443

5500 410 373 616 559 771 706 926 853 1082 1000 1237 1147 1392 1294 1703 1587 1916 1786 2341 2183 2554 2381

5625 401 364 601 546 752 689 904 832 1055 975 1206 1118 1357 1261 1659 1547 1867 1740 2282 2127 2489 2321

5750 391 356 587 534 734 673 882 812 1029 951 1176 1090 1323 1230 1617 1508 1820 1697 2224 2074 2426 2262

5875 383 348 574 522 717 657 860 793 1004 928 1147 1064 1290 1199 1577 1471 1774 1654 2168 2022 2366 2206

6000 374 340 561 510 701 642 840 774 980 906 1120 1039 1259 1171 1539 1435 1731 1614 2116 1973 2308 2152

6125 366 333 549 499 685 628 822 757 958 886 1094 1015 1230 1144 1503 1401 1690 1577 2066 1927 2254 2102

6250 359 326 538 489 671 615 804 741 937 867 1070 993 1203 1119 1469 1371 1653 1542 2020 1884 2204 2056

6375 352 320 528 480 658 604 788 727 919 850 1049 973 1179 1096 1439 1343 1619 1510 1979 1846 2159 2014

6500 346 315 519 473 647 593 775 714 902 835 1030 956 1158 1077 1413 1318 1590 1483 1943 1813 2119 1977

6625 341 311 512 466 638 585 763 704 889 823 1014 941 1140 1060 1391 1298 1565 1460 1913 1785 2087 1947

6750 338 307 507 461 631 578 755 696 879 813 1003 931 1127 1048 1374 1283 1546 1443 1890 1764 2062 1924

6875 335 305 503 458 626 574 749 691 872 807 995 924 1118 1040 1364 1273 1534 1432 1875 1750 2046 1909

7000 335 305 502 457 624 573 747 689 870 805 992 921 1115 1037 1360 1269 1530 1428 1870 1745 2040 1904

7125 335 305 502 457 625 573 747 689 870 805 992 921 1115 1037 1360 1269 1531 1428 1874 1745 2045 1904
§85.1

Page 12 Test Standards and Calculations

7250 335 305 502 457 625 573 747 689 870 805 992 921 1115 1037 1360 1269 1531 1428 1874 1745 2045 1904

7375 335 305 502 457 625 573 747 689 870 805 992 921 1115 1037 1360 1269 1531 1428 1874 1745 2045 1904

7500 335 305 502 457 625 573 747 689 870 805 992 921 1115 1037 1360 1269 1531 1428 1874 1745 2045 1904

 (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 100%) 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 gram per second 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

HC(j), CO(j), and NO(j) are the raw (uncorrected) tailpipe concentrations.

10

HC(j)*DCF(j)

(A) AvgHC

10

1j

∑= =

10

CO(j) *DCF(j)

(B) AvgCO

10

1j

∑= =

10

NO(j) *DCF(j)

(C) AvgNO

10

1j

∑= =

(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.
§85.1

Page 13 Test Standards and Calculations

2 measured measured

2 measured

[CO ] [CO]

[CO ] (A) X 

+ =

Where [CO2]measured and [CO]measured are the instantaneous ASM

emissions test readings.

(B) Calculate [CO2]adjusted using the following formulas.

(1) For Gasoline:

*100

4.644 1.88X

X [CO ] 2 adjusted + =

(2) For Methanol or Ethanol: 

100*

4.73 1.88X

X [CO ] 2 adjusted + =

(3) For Compressed Natural Gas (CNG): 

*100

6.64 1.88X

X [CO ] 2 adjusted + =

(4) For Liquid Propane Gas (LPG): 

*100

5.39 1.88X

X [CO ] 2 adjusted + =

(C) Calculate the DCF using the following formula:

2 measured

2 adjusted

[CO ]

[CO ] DCF =

(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

-1.0 0.0047(H - 75)

1 Kh =

(B) H = Absolute humidity in grains of water per pound of dry air.

-P (P R* /100)

(43.478)R P*

adB

da =
§85.1

Page 14 Test Standards and Calculations

(C) Ra = Relative humidity of the ambient air, percent.

(D) Pd = Saturated vapor pressure, mm Hg at the ambient dry bulb

temperature. If the temperature is above 86o

F, then it shall

be used in lieu of the higher temperature, until EPA

supplies final correction factors.

(E) PB = Barometric pressure, mm Hg.(F) 

(F) Revised method1

KH = e[0.004977(H 75) 0.004447(T 75)] −− −

(G) H = Absolute humidity in grains of water per pound of dry

air.

(H) 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 §85.1(b)(1)(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.

 

1 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.
§85.2

Page 15 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

vehicles brakes are applied during testing the mode timer shall be reset to zero (tt = 0).

(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 (4WD). Vehicles with traction control systems

that cannot be turned off shall not be tested on two wheel drive dynamometers.

Vehicles with 4WD that cannot be turned off shall only be tested on 4WD

dynamometers. If the 4WD function can be disabled, then 4WD vehicles may be tested

on two wheel drive dynamometers.

§85.2 Test Procedures
§85.2

Page 16 Test Procedures

It is the responsibility of all vehicle OEMs to notify TRPD of any vehicles that can't be

tested on 2WD dynamometers.

(4) 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.

(5) Fluid Leaks. The vehicle shall be inspected for fluid leaks. Vehicles with leaking

engine oil, transmission fluid, or coolant shall be rejected from testing.

(6) 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.

(7) 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.

(8) 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 side wall pressure, or vehicle manufacturer's

recommendation. Alternatively, vehicles with apparent low tire pressure may be

rejected from testing.

(9) 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.

(10) 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.

 (11) 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.

(12) 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
§85.2

Page 17 Test Procedures

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 monitiored 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 warmedup 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. (this does not require

span gas verification of warm-up, but provides a quality assurance method for

checking).

(2) Emission Sample System Purge. While a lane is in operation, the sample system shall

be continuously purged after each test for at least 15 minutes if not taking

measurements. The system purge should consist of flowing fresh air through the

complete system for 5 minutes or until the HC reading is less than 15 ppm C6.

(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.

(4) Multiple exhaust pipes. Exhaust gas concentrations from vehicle engines equipped

with functionally independent multiple exhaust pipes shall be sampled simultaneously.

(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.
§85.2

Page 18 Test Procedures

(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, CO2, 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.

(iv) 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 sample through probe has less than 15 ppm HC, 0.02% CO, and

25 ppm NO; and,

(2) The residual HC in the sampling system (probe sample - ambient air

reading) is less than 7 12 ppm.

(6) Cooling System. The use of a cooling system is optional when testing at temperatures

below 50(F. Furthermore, the hood may be opened at the state's discretion. If a

cooling system is in use, testing shall not begin until the cooling system 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.

Cooling System. When ambient temperatures exceed 72°F, testing shall not begin until

the cooling system blower is positioned and activated. The cooling system blower shall

be positioned to direct air to the vehicle cooling system, but shall not be directed at the

catalytic converter.

(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 it

is 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)(1) 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.

Dynamometers with temperature compensation may be warmed-up per the

manufacturers recommendation.

(8) Dynamometer Settings. Dynamometer power absorption and inertia weight settings

shall be automatically chosen from an EPA-supplied electronic look-up table which will

be referenced based upon the vehicle identification information obtained in §85.2(a)(1).

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.
§85.2

Page 19 Test Procedures

Load Setting. Prior to each mode, the system shall automatically select the load setting

of the dynamometer from a look-up table supplied by EPA or the state.

(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. Starting in 1998, the SAEstandardized OBD plug shall be used on 1996 and newer vehicles. 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)(1) and (2), and may be performed in either order (with appropriate change in

transition requirements in §85.2(d)(1)(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. 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)(1) or §85.2(d)(2). The test sequence shall have an

overall maximum test time of 290 seconds (tt=290). Approximate test times for various test

scenarios are described in §85.2 (e)(2)(v) below. The test shall be immediately terminated or

aborted upon reaching the overall maximum test time.

(1) ASM5015 Mode.

(vi) 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. If the inertia simulation error exceeds the tolerance

specified in §85.3(a)(3)(ii)(A) (or §85.3(a)(3)(ii)(B) if used) for more than 3

consecutive seconds after the mode timer is started, the test mode timer shall be

set to mt=0. Should this happen a second time, the test shall be aborted. The

dynamometer shall apply the correct torque for 15.0 mph for the torque at any

testing speed within the tolerance of 15±1.0 miles per hour (i.e., constant torque

load over speed range). The torque tolerance shall be ± 5% of the correct torque

at 15 mph.

NOTE: Some comments suggested widening the speed tolerance to ±1.5 mph.

However, other studies have shown that a ±0.5 mph tolerance is possible.

Therefore, we have kept the original ±1.0 mph tolerance.

(vii) 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)(1). Vehicles not listed in the look-up table

and for which ETW is not available shall be tested using the following default

settings:
§85.2

Page 20 Test Procedures

Default ASM5015 Actual Horsepower Settings

For 8.6" Dynamometers HP50158

Number of Cylinders

Vehicle Type

3 4 5 & 6 8 > 8

Sedans 7.9 11.4 13.8 16.4 16.0

Station Wagons 8.1 11.7 13.8 16.1 16.1

Mini-vans 10.2 14.1 15.8 17.9 18.2

Pickup Trucks 9.6 13.1 16.4 19.2 21.1

Sport/Utility 10.1 13.4 15.5 19.4 21.1

Full Vans 10.3 13.9 17.7 19.6 20.5

Default ASM5015 Actual Horsepower Settings

For 20" Dynamometers HP501520

Number of Cylinders

Vehicle Type

3 4 5 & 6 8 > 8

Sedans 8.1 11.8 14.3 16.9 16.6

Station Wagons 8.3 12.1 14.2 16.6 16.6

Mini-vans 10.4 14.5 16.3 18.5 18.7

Pickup Trucks 9.8 13.4 16.8 19.8 21.7

Sport/Utility 10.5 13.8 15.9 19.9 21.7

Full Vans 10.8 14.4 18.2 20.2 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

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 0.51.0 mph (absolute drop, not cumulative). If the speed

at the end of the 10 second period is more than 0.51.0 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
§85.2

Page 21 Test Procedures

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 second, i.e. emissions

for all pollutants are 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)(1)(iii)(A) are not satisfied by an

elapsed time of 90 seconds (mt=90).

Failing vehicles shall undergo a speed variation consisting of an

acceleration to 20 mph in approximately 2-4 seconds, a deceleration with

braking to 10 mph in approximately 4-6 seconds, and a final acceleration

to 15 mph in approximately 4-8 seconds. The times here should be taken

as general guidelines as all vehicles will respond differently to this

procedure. This procedure is performed to reduce pattern failures in

vehicles with emission control systems that

(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. If the inertia simulation error exceeds the tolerance

specified in §85.3(a)(3)(ii)(A) (or §85.3(a)(3)(ii)(B) if used) for more than 3

consecutive seconds after the mode timer is started, the test mode timer shall be

set to mt=0. Should this happen a second time, the test shall be aborted. The

dynamometer shall apply the correct torque for 25.0 mph for the torque at any

testing speed within the tolerance of 25±1.0 miles per hour (i.e., constant torque

load over speed range). The torque tolerance shall be ± 5% of the correct torque

at 25 mph.
§85.2

Page 22 Test Procedures

(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)(1). Vehicles not listed in the look-up table

and for which ETW is not available shall be tested using the following default

settings:

Default ASM2525 Actual Horsepower Settings

For 8.6" Dynamometers HP25258

Vehicle Type Number of Cylinders

3 4 5 & 6 8 > 8

Sedans 6.7 9.5 11.5 13.7 13.3

Station Wagons 6.8 9.7 11.5 13.4 13.3

Mini-vans 8.8 11.7 13.2 14.9 15.3

Pickup Trucks 8.0 10.9 13.6 16.0 17.8

Sport/Utility 8.8 11.2 12.9 16.1 17.8

Full Vans 9.0 11.6 14.7 16.3 17.2

Default ASM2525 Actual Horsepower Settings

For 20" Dynamometers HP252520

Vehicle Type Number of Cylinders

3 4 5 & 6 8 > 8

Sedans 6.9 10.1 12.3 14.5 14.3

Station Wagons 7.0 10.4 12.2 14.2 14.4

Mini-vans 8.9 12.5 14.0 15.9 16.3

Pickup Trucks 8.1 11.4 14.4 16.9 18.8

Sport/Utility 8.9 11.8 13.6 17.1 18.8

Full Vans 9.1 12.5 15.5 17.3 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 0.51.0 mph (absolute drop, not cumulative). If the speed

at the end of the 10 second period is more than 0.51.0 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.
§85.2

Page 23 Test Procedures

(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)(1)(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 second, 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).

 (e) Second Chance Tests.

(1) If the vehicle fails the first-chance test, the test timer shall reset to zero (tt=0) 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 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. an overall maximum test time of 145

seconds (tt=145) if one mode is repeated, an overall maximum time of 290 seconds

(tt=290) if two modes are repeated.

(2) Repetition or extension of failed modes for two mode ASM tests. Except in the case of

vehicles subject to preconditioning specified in §85.2(b)(12)(i), if at least 90 seconds of

loaded preconditioning is performed, as specified in §85.2(b)(12)(ii), then the secondchance 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)(1) except that

the provisions of §85.2(d)(1)(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.
§85.2

Page 24 Test Procedures

(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.
§85.2

Page 25 Test Procedures

(iv) The four possible outcomes described above are illustrated below for an ASM2

test procedure. Each testing mode, which excludes preconditioning, has a

maximum time of 90 seconds.

Outcome 1- Vehicle Passes Both Modes (Total Max Time Approximately 180s)

Outcome 2- Vehicle Fails 5015, Passes 2525 (Total Max Time Approximately 270s)

Outcome 3- Vehicle Passes 5015, Fails 2525 (Total Max Time Approximately 270s)

Outcome 4- Vehicle Fails Both Modes 5015 (Total Max Time Approximately 360s)

NOTE: It has been recommended that Outcome 4 be made optional since if a vehicle

fails both modes of the ASM test, additional testing will not likely improve emissions

performance. It was also suggested that a Two Speed Idle test be added after the ASM

mode testing is completed as some states have found vehicles to fail an idle test

although they passed the ASM test. EPA is seeking comments on these options from the

state programs.

2nd Chance 5015

End

Pass 2525 Mode

Fail 5015 Mode Pass 2525 Mode

End

Pass 5015 Mode

Speed Variation Speed Variation

2nd Pass 5015 Mode Fail 2525 Mode Chance 2525

End

Speed Variation

Fail 5015

Mode

End

Speed

Variation

Fail 2525

Mode

2nd Chance

5015

Speed

Variation

2nd Chance

2525
§85.2

Page 26 Test Procedures

(3) Repetition of failed modes for single mode ASM tests.

(i) If the vehicle is failing at the end of the mode then the test mode shall not end at

90 seconds but shall continue for up to 180 seconds, following a speed variation

phase described in §85.2(d)(1)(iii)(C). Mode and test timers shall not reset but

rather continue up to 180 seconds. The provisions of §85.2(d)(1) or §85.2(d)(2)

shall continue to apply throughout the 180 second test period. The figure below

illustrates the test sequence.

End

2nd Chance 5015

or 2525 Mode

Fail 5015 or

2525 Mode Speed Variation
§85.3

Page 27 Test Equipment Specifications

(These sections have been re-ordered to match the order used in the IM240 Guidance. Any

actual changes to the text are highlighted in red.)

 (a) Dynamometer Specifications.

(1) General Requirements

(i) Only one diameter of dynamometer shall be used in a program.

(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.

(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) 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.

(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) IHP = THP - PLHP - GTRL

HP = IHP + PLHP

Where:

HP = 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. The actual

horsepower is the sum of the indicated horsepower and the

parasitic losses (PLHP)

§85.3 Test Equipment Specifications
§85.3

Page 28 Test Equipment Specifications

IHP = Indicated Horsepower value set on the dynamometer.

THP = Total Horsepower for an ASM test includes indicated, tire losses,

and parasitics. This value is independent of roll size.

GTRL = Generic Tire/Roll Interface Losses at the specified speed (15 or 25

mph) on a dynamometer with the specified diameter rollers.

PLHP = Parasitic Losses Horsepower due to internal dynamometer friction.

A value is specific to each individual dynamometer and speed.

Indicated Horsepower. At constant velocity, the power absorber shall load the

vehicle according the following equations:

IHP = 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 the dynamometer parasitic loss horsepower.

GTRL is the generic tire/roll loss of a vehicle on the

dynamometer.

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

IM240 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 up to 8500 pounds GVWR. The power

absorber shall absorb, at 14 mph and above, a minimum of 25 horsepower

continuously for a steady-state test of at least 5 minutes, with 3 minutes between

each test.

 (iv) Power Absorber. Only electric power absorbers shall be used unless alternatives

are proposed by the state and approved by the Administrator. The power
§85.3

Page 29 Test Equipment Specifications

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% 3% 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 of the start of the

test, and shall have an accuracy of ±0.25 horsepower within 30 seconds of the

start of the test. 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) Base Inertia. The dynamometer shall be equipped with mechanical flywheel(s)

or with full inertia simulation providing a total base 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. Any

deviation from the stated inertia shall be quantified and the inertia simulation

shall be corrected accordingly. The actual inertia weight shall be marked on the

ID plate required in §85.3(a)(1)(iv).

(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

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
§85.3

Page 30 Test Equipment Specifications

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 100 200 milliseconds after

a step change is commanded by the dynamometer control system,

and shall be within 2% of the commanded torque by 300

milliseconds after the command is issued. Any overshoot of the

commanded torque value shall not exceed 25% of the torque value.

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 1% 2% of the

inertia weight selected (IWs) for the vehicle under test.

(C) Inertia Simulation Error Calculation.

ISE = [(IWs - It) / (IWs)] * 100

∫ −+=

t

0

mt m rl (F )dtF V

1 II

Where:

ISE = Inertia Simulation Error

IWs = Inertia Weight Selected

It = Total inertia being simulated by the dynamometer (kg)

It (lb force) = It (kg) * 2.2046

Im = Base (mechanical inertia of the dynamometer (kg)

V = Measured roll speed (m/s)

Fm = Force measured by the load cell (translated to the roll

surface) (N)

Frl = Road load force (N) required by IHP at the measure roll

speed (V)

t = Time (sec)

(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
§85.3

Page 31 Test Equipment Specifications

dynamometer calibration. The parasitic power losses shall be determined as

indicated in §85.4(b)(2).

(5) Rolls.

(i) Size and Type. The dynamometer shall be equipped with twin rolls. The rolls

shall be electrically or mechanically coupled side-to-side and front-to-rear. 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)(3)(ii) to

within 0.5 inches and -0.25 inches of the calculated value. Fixed dynamometer

rolls shall have an inside track width of no more than 30 inches and outside

track width of at least 100 inches. Rolls moveable from side-to-side may be

used if adequate measures are taken to prevent tire damage from lateral vehicle

movement and the dynamometer sufficiently accommodates track widths of the

full range of vehicles to be tested on the dynamometer. Alternative track

widths, roll sizes, and number of rolls may be used if approved by the state and

the Administrator and if adequate measures are taken to prevent tire damage

from lateral vehicle movement and the dynamometer sufficiently accommodates

track widths of the full range of vehicles to be tested on the dynamometer.

(ii) Roll Spacing = (24.375+D) * Sin 31.5153

 D = dynamometer roll diameter.

 Roll spacing and roll diameter are expressed in inches.

(ii) Design. The roll size, surface finish, and hardness shall be such that tire

slippage is minimized under all weather conditions; that water removal is

maximized; that the specified accuracy of the distance and speed measurements

are maintained; and that tire wear and noise are minimized.

(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

within ±5 8 degrees of horizontal.

(iii) Roll Spacing. The spacing between the roll centers shall comply with the

following equation to within +0.5 inches and -0.25 inches.
§85.3

Page 32 Test Equipment Specifications

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

(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 Cell (if equipped)

(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 cell 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.

(7) 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. The vehicle shall be restrained during the driving cycle. The

restraint system shall be designed to insure that vertical and horizontal force on

the drive wheels does not significantly affect emission levels. The restraint

system shall allow unobstructed vehicle ingress and egress and shall be capable

of safely restraining the vehicle under all reasonable operating conditions

without damaging the suspension system.
§85.3

Page 33 Test Equipment Specifications

(iii) Vehicle Cooling. The test system shall provide for a method to prevent

overheating of the vehicle. The test shall be conducted with the hood open and

the cooling system activated when ambient temperature exceeds 72°F. The

cooling method used shall direct air to the test vehicle's cooling system. The

cooling system capacity shall be at least 3000 SCFM within 12 inches of the

intake to the vehicle's cooling system. The cooling system shall avoid improper

cooling of the catalytic converter. 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. Either in-floor or above ground installations of the dynamometer

are acceptable. In all cases, installation must be performed so that the test

vehicle is approximately level (±5°) while on the dynamometer during testing.

In 85.3(a)(5)(ii).

(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.

 (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 290 seconds.

(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 or to an

appropriately ventilated area in compliance with Occupational Safety and Health

Regulations. 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 point 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.
§85.3

Page 34 Test Equipment Specifications

(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 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 1,100o

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, noncorrosive, 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
§85.3

Page 35 Test Equipment Specifications

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

the station to maintain HC, CO, CO2 and NO levels below 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, (O2 optional) and digital displays for exhaust concentrations of

HC, CO, NO, and CO2, and for vehicle speed.

(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 accuracies, repeatabilities,

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)(1)(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.
§85.3

Page 36 Test Equipment Specifications

(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 35o

F to 110oF. 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 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 CO2 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).

(v) 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.

(vi) 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.

(vii) 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.

(v) 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.
§85.3

Page 37 Test Equipment Specifications

(vi) 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. 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

NOTE: It has been suggested that today’s analyzers use variable PEF values that

make this requirement unnecessary and it should be removed.

(x) 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 nondispersive 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. 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). Note: It has been suggested that the

HC range be changed to 0-2000 ppm hexane minimum.

(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). Note: It has

been suggested that the CO range be changed to 0-10%.

(iii) Carbon Dioxide Analysis. Carbon dioxide analysis shall be determined by nondispersive 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
§85.3

Page 38 Test Equipment Specifications

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).

(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 §85.1(b)(1)(vi)).

(i) Relative Humidity. The relative humidity measurement device shall cover the

range from 5% to 95% RH, between 35oF - 110oF, 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 0oF - 140oF with a minimum accuracy of 3oF.
§85.3

Page 39 Test Equipment Specifications

(iii) Barometric Pressure. The barometric pressure measurement device shall cover

the range from 610 mm Hg - 810 mm Hg absolute (24-32 inches), and 35oF -

110o

F, 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. Starting in 1998, 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 basis is based.

(6) OBD Fault Code Retrieval. Starting in 19982001 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 EPAprovided 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.

(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.
§85.3

Page 40 Test Equipment Specifications

(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

Load 0.1 hp

Relative Humidity 1 % RH

Dry Bulb Temperature 1 oF

Barometric Pressure 1 mm HG
§85.4

Page 41 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 coastdown check. Speed windows smaller than ± 5 mph may be used provided that

they show the same calibration capabilities.

(ii) The base dynamometer inertia (2000 pounds) shall be checked at two random

horsepower settings for each speed range. The two random horsepower settings

shall be between 8.0 and 18.0 horsepower. 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) ±7%

then it shall be locked out for official testing purposes until recalibration allows

a passing value.

(A) Randomly select an IHP2525 value that is between 8.0 hp and 18.0 hp and

set dynamometer PAU to this value.

§85.4 Quality Control Requirements
§85.4

Page 42 Quality Control Requirements

Coast-down dynamometer from 30-20 mph.

*550 (IHP PLHP )

*(V )V 32.2

*0.5 DIW

CCDT

2525 25

2

20

2

30

@25mph +

−

=

Where:

DIW = Dynamometer Inertia Weight. Total "inertia" weight

of all rotating components in dynamometer.

V30 = Velocity in feet/sec at 30 mph.

V20 = Velocity in feet/sec at 20 mph.

IHP2525 = Randomly selected ASM2525 indicated horsepower.

PLHP25 = Parasitic Horsepower for specific dynamometer at 25

mph.

(B) Randomly select an IHP5015 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.

*550 (IHP PLHP )

*(V )V 32.2

*0.5 DIW

CCDT

5015 15

2

10

2

20

@15mph +

−

=

Where:

DIW = Dynamometer Inertia Weight. Total "inertia" weight

of all rotating components in dynamometer.

V20 = Velocity in feet/sec at 20 mph.

V10 = Velocity in feet/sec at 10 mph.

IHP5015 = Randomly selected ASM5015 indicated horsepower.

PLHP15 = Parasitic Horsepower for specific dynamometer at 15

mph.

(2) Parasitic Value Calculations.

(i) Parasitic losses shall be calculated using the following equations at 25 and 15

mph whenever a coast-down check is performed. The indicated horsepower

(IHP) shall be set to zero for these tests. This is only necessary if the coastdown values do not verify in §85.4(b)(1)(iii) above.
§85.4

Page 43 Quality Control Requirements

(ii) Parasitic losses at 25 mph for a dynamometer with specified diameter rollers.

*550 (ACDT)

*(V )V 32.2

*0.5 DIW

PLHP

2

20

2

30

25

−

=

Where:

DIW = Dynamometer Inertia Weight. Total "inertia" weight

of all rotating components in dynamometer.

V30 = Velocity in feet/sec at 30 mph.

V20 = Velocity in feet/sec at 20 mph.

ACDT = Actual coast-down time required for dynamometer to

coast from 30 to 20 mph.

(iii) Parasitic losses at 15 mph for a dynamometer with specified diameter rollers.

*550 (ACDT)

* (V )V 32.2

*0.5 DIW

PLHP

2

10

2

20

15

−

=

Where:

DIW = Dynamometer Inertia Weight. Total "inertia" weight

of all rotating components in dynamometer.

V20 = Velocity in feet/sec at 20 mph.

V10 = Velocity in feet/sec at 10 mph.

ACDT = Actual coast-down time required for dynamometer to

coast from 20 to 10 mph.

(3) Roll Speed. Roll speed and roll counts shall be checked at least once per week by an

independent means (e.g., photo tachometer). Deviations greater than ±0.2 mph or a

comparable tolerance in roll counts shall require corrective action. Alternatively, a

redundant roll speed transducer independent of the primary transducer may be used in

lieu of the weekly comparison. Accuracy of redundant systems shall be checked

bimonthly.

(4) Load Measuring Device. If the dynamometer fails a coast-down check or requires a

recalibration for any other reason, 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
§85.4

Page 44 Quality Control Requirements

dynamometer shall provide an automatic load measuring device calibration and

verification feature.

(5) Acceptance Check 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) Set dynamometer speed to 15 mph. Independently measure and record

dynamometer speed. Repeat at 25 mph.

(B) Acceptance Criteria: The difference for each reading from set

dynamometer speed shall not exceed 0.2 mph.

(iii) Parasitics Verification. Parasitic losses shall be calculated using the following

equations at 25 and 15 mph . The indicated horsepower (IHP) shall be set to

zero for these tests. Using time versus speed data from the system, calculate

PLHP for 25 mph and 15 mph.

(A) Parasitic losses at 25 mph for a dynamometer with specified diameter

rollers.

*550 (CDT)

*(V )V 32.2

*0.5 DIW

PLHP

2

20

2

30

25

−

=

Where:
§85.4

Page 45 Quality Control Requirements

DIW = Dynamometer Inertia Weight. Total "inertia" weight

of all rotating components in dynamometer.

V30 = Velocity in feet/sec at 30 mph.

V20 = Velocity in feet/sec at 20 mph.

CDT = Coast-down time required for dynamometer to coast

from 30 to 20 mph.

(B) Parasitic losses at 15 mph for a dynamometer with specified diameter

rollers.

*550 (CDT)

* (V )V 32.2

*0.5 DIW

PLHP

2

10

2

20

15

−

=

Where:

DIW = Dynamometer Inertia Weight. Total "inertia" weight

of all rotating components in dynamometer.

V20 = Velocity in feet/sec at 20 mph.

V10 = Velocity in feet/sec at 10 mph.

CDT = Coast-down time required for dynamometer to coast

from 20 to 10 mph.

(C) Acceptance Criteria: The difference between the externally calculated

value and the machine calculated value shall not exceed 0.25 HP.

(iv) Verify Coast-Down. The coast-down procedure shall use a vehicle offdynamometer 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)(1)(iii)(A).

(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.

CCDT@25 mph = F(BBC((F(0.5 * DIW,32.2)) * (V30

2

 - V20

2

), 550 * (IHP2525yy +

PLHP25-yy))

Where:

DIW = Dynamometer Inertia Weight. Total "inertia" weight

of all rotating components in dynamometer.
§85.4

Page 46 Quality Control Requirements

V30 = Velocity in feet/sec at 30 mph.

V20 = Velocity in feet/sec at 20 mph.

IHP2525 = Randomly selected ASM2525 indicated horsepower.

PLHP25 = Parasitic Horsepower for specific dynamometer at 25

mph.

(B) To verify the coast-downs at 15 mph, use the procedure and equations

described in §85.4(b)(1)(iii)(B).

(B) Randomly select an IHP5015 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.

CCDT@15 mph = F(BBC((F(0.5 * DIW,32.2)) * (V20

2

 - V10

2

), 550 * (IHP5015yy +

PLHP15-yy))

Where:

DIW = Dynamometer Inertia Weight. Total "inertia" weight

of all rotating components in dynamometer.

V20 = Velocity in feet/sec at 20 mph.

V10 = Velocity in feet/sec at 10 mph.

IHP5015 = Randomly selected ASM5015 indicated horsepower.

PLHP15 = Parasitic Horsepower for specific dynamometer at 15

mph.

(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) ± 7%.

 (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.
§85.4

Page 47 Quality Control Requirements

(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).

(v) 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.

 (d) Analytical 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.

NOTE: It has been suggested that that the low vs high volume criteria be

removed and replaced with requiring a low and high calibration done every 72

hours in all stations. This calibration check would include measuring the NO

cell response to ensure it is < 15 seconds with a warning displayed when the

response exceeds 7 seconds. EPA is requesting comment on this proposed

change.

(ii) Gas Calibration and Check Procedure. Gas calibration shall be accomplished by

introducing span 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
§85.4

Page 48 Quality Control Requirements

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 introduce the low-range check

calibration gas specified in §85.4(d)(2)(iii) for 60 seconds. If the lowrange check 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 ±2%, 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. Audit gas ± tolerances are

also listed. The tolerances are based on a 5% blend tolerance, accurate to 1%. It

is recommended that NIST traceable standards accurate to 1% be used to verify

all bottle names.

NOTE: Comments were received suggesting expanding the tolerances on the 2

point and 5 point calibrations. However, comments were also received

indicating that a properly functioning analyzer should be able to read a gas

bottle with a 5% blend tolerance accurate to ±1% whose name is verified with a

±1% NIST traceable standard to meet the old tolerances. The tolerances for the

2 point calibration have been expanded from the old ±2%.

(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 ± 8 ppm propane

CO = 0.5 % ± 0.02%

CO2 = 6.0 % ± 0.30%

NO = 300 ppm ± 25 ppm

N2 = Balance 99.99 % pure

(C) High-Range Calibration Gas

HC = 3200 ppm ± 134 ppm propane

CO = 8.0 % ± 0.34%
§85.4

Page 49 Quality Control Requirements

CO2 = 12.0 % ± 0.50%

NO = 3000 ppm ± 158 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 zero 5% blend tolerance. Stations that use large

capacity gas bottles (size B or larger) and that provide a quality control check to

insure proper entry of gas values, may use gases with a blend tolerance of up to

5%. Gases with a 5% blend tolerance may also be used by any station if the

analyzer system reads the bar-coded calibration gas bottle specifications and

adjusts the calibration accordingly.

(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.

(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

readings have stabilized (no less than 20 seconds of gas flow) record them

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.

Tolerance % = 

True Cylinder Value

(Reading True Cylinder Value) *100 −

(F) If the tolerance 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.
§85.4

Page 50 Quality Control Requirements

(iv) The following gases shall be used for the five-point calibration audit. Audit gas

± tolerances are also listed. The tolerances are based on using a 5% blend

tolerance, accurate to ±1%. It is recommended that NIST traceable standards

accurate to ±1% be used to verify all bottle names.

(A) Zero Audit Gas

O2 = 20.7% (if O2 span is desired)

HC < 0.1 ppm THC

CO < 0.5 ppm

CO2 < 1 ppm

NO < 0.1 ppm

N2 = Balance 99.99 % pure

(B) Low Range Audit Gas

HC = 200 ppm ± 8 ppm propane

CO = 0.5 % ± 0.02%

CO2 = 6.0 % ± 0.30%

NO = 300 ppm ± 25 ppm

N2 = Balance 99.99 % pure

(C) Low-Middle Range Audit Gas

HC = 960 ppm ± 40 ppm propane

CO = 2.4 % ± 0.10%

CO2 = 3.6 % ± 0.30%

NO = 900 ppm ± 47 ppm

N2 = Balance 99.99 % pure

(D) High-Middle Range Audit Gas

HC = 1920 ppm ± 81 ppm propane

CO = 4.8 % ± 0.20%

CO2 = 7.2 % ± 0.30%

NO = 1800 ppm ± 95 ppm

N2 = Balance 99.99 % pure

(E) High Range Audit Gas

HC = 3200 ppm ± 134 ppm propane

CO = 8.0 % ± 0.34%

CO2 = 12.0 % ± 0.50%

NO = 3000 ppm ± 158 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 zero 5% 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
§85.4

Page 51 Quality Control Requirements

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) Acceptance Testing Certification Testing. 

NOTE: EPA is requesting comments on the usefulness of this section regarding

acceptance or certification testing. We recognize the need for this procedure but also

believe there may be better procedures available. If there are more appropriate

methods, please provide details so we can consider incorporating them into this

document.

(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 full scale for the analyzers. Full

scale is defined in §85.3(c)(3).

(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) Calculations:

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.)
§85.4

Page 52 Quality Control Requirements

3. For each concentration, calculate the difference between the

candidate mean and the standard average.

4. For each concentration, compute the following:

(i) Y1 = 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) U1 = concentration value - Y1

(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, (U1 and U2) shall be

no greater than the accuracy tolerances required in

§85.3(c)(3).

(ii) Analyzer System Repeatability. This test characterizes the ability of the

instrument to give consistent readings when repeatedly sampling the same gas

concentration.

(A) Using an 80% full scale 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.
§85.4

Page 53 Quality Control Requirements

(B) Using a solenoid valve or equivalent selector system, remotely introduce

an 80% full scale 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). Note: It has been requested that this last sentence be deleted.

(iv) Analyzer Interference Effects. The following acceptance test procedure shall be

performed at 45oF, 75oF, and 105oF 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.

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 122oF ± 9oF. This test shall be performed at only the 75oF,

and 105o

F conditions.

(D) Acceptance Criteria: The interference effects shall not exceed the limits

specified in §85.3(c)(2)(iii).
§85.4

Page 54 Quality Control Requirements

(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.

(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.
§85.4

Page 55 Quality Control Requirements

(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).
§85.5

Page 56 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 (o

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

§85.5 Test Record Information
§85.5

Page 57 Test Record Information

(7) CO concentration (%) for each second of the test, not corrected for dilution

(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)