[27 Pa.B. 5010]
[Continued from previous Web Page] 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. Engine RPM shall be measured per § 3(d)(6).
(iv) Sample probe.
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.
(v) Multiple exhaust pipes.
Exhaust gas concentrations from vehicle engines equipped with functionally independent multiple exhaust pipes shall be sampled simultaneously.
(vi) Automatic gas zero.
The analyzer shall conduct an automatic zero adjustment using the zero gas specified in § 4(d)(iii).
(vii) Automatic zero adjustment.
The zero adjustment shall include HC, CO, CO2 and NO channels.
(viii) Ambient air and HC hang-up determination.
The analyzer shall perform the automatic zeroing, O2 calibration (if included) and ambient air reading, followed by an HC hang-up check. This process shall begin after initiation of data entry into the analyzer computer. The analyzer shall be locked out from testing until: (1) the ambient air (sampled through the probe) has less than 15 PPM HC and (2) the residual HC in the sampling system (probe sample--port sample) is less than 7 PPM.
(ix) Engine speed.
For 1996 and newer vehicles equipped with Federal OBD systems or California OBD II systems, engine speed in RPM may be monitored by the standardized plug throughout the test. RPM readings shall be recorded on a second-by-second basis. In test-and-repair stations, engine speed shall also be monitored on all pre-1996 vehicles and recorded in the test record. For vehicles that are not equipped for OBD measurement, an alternative means of measuring engine speed (RPM) shall be provided.
(d) Overall test procedure.
The test timer shall start (TT=0) when the conditions specified in paragraph (c)(2) are met. The dynamometer rolls reach 1.0 MPH due to the test vehicle's initial acceleration for testing purposes, and the mode timer initiates as specified in paragraph (d)(2). The test sequence shall have an overall maximum test time of 290 seconds (TT-290). The test shall be immediately terminated or aborted upon reaching the overall maximum test time. The test mode in § 2(d)(3) may precede the test mode in § 2(d)(2).
(1) Preconditioning cycle.
Vehicle preconditioning shall be performed prior to start of an official test. The preconditioning cycle must be approved by the Department. A state may waive the preconditioning requirement if it ensures that all vehicles are adequately warmed up prior to taking the final emissions measurements as described at § 1(b)(iii). The following preconditioning cycle is approved:
(i) The preconditioning timer shall start once the dynamometer has reached a speed of 15 or 25 mph (PT=0), consistent with the speed of the first test mode. The vehicle will continue to be operated for a maximum of 30 seconds at this speed within ±5 MPH and within ±10% of the wheel force tolerance specified in § 2(d)(2). The duration of the preconditioning cycle may be adjusted if a Department determines through the use of statistical process control methods that an alternative preconditioning cycle duration is adequate to ensure that vehicles are fully warmed up prior to testing. If the speed or wheel force fall above or below the tolerance, the preconditioning timer will reset to zero. Preconditioning time shall not be included in the overall maximum test time.
(2) ASM5015 mode.
(i) Mode timer.
The mode timer shall start (MT=0) when the dynamometer speed (and corresponding wheel force) are maintained within 15±1.0 miles per hour for 5 continuous seconds. If the inertia simulation exceeds the tolerance specified in § 3(a)(4)(ii)(b) for more than 5 consecutive seconds after the mode timer is started, the test mode timer shall be set to TT=0. If this happens a second time, the test shall be aborted. The dynamometer shall apply the correct wheel force based on the required ASM horsepower load at 15 mph across the testing speed window (15±1.0 miles per hour) (that is, constant load over the speed range). The wheel force torque tolerance shall be ±5% of the correct wheel force at 15 MPH.
(ii) Look-up table.
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 § 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 ASM5015 actual horsepower settings Number of Cylinders for 8.6" dynamometers HP50158 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 Number of Cylinders for 20" dynamometers HP501520 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 wheel force falls outside the speed or wheel force 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 paragraph (d)(2)(iii). The maximum mode length shall be equal to 90 seconds elapsed time (MT = 90).
If the speed at the end of the 10 second period is more than 0.5 mph less (absolute drop, not cumulative) than the speed at the start of the 10 second period, testing shall continue until the speed stabilizes enough to meet this criterion.
(iii) Pass/fail determination.
The pass/fail analysis shall begin after an elapsed time of 22 seconds (MT = 22. 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 ASM5015 mode and the mode shall be immediately terminated if, at any point between an elapsed time of 22 seconds (MT = 22) 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 paragraph (a).
(b) The vehicle shall fail the ASM5015 mode and the mode shall be terminated if paragraph (d)(2)(iii)(a) is not satisfied by an elapsed time of 90 seconds (MT = 90).
(iv) If ASM5015 is the first test mode, upon termination of the ASM5015 mode, the vehicle shall immediately begin accelerating to the speed required for the ASM2525 mode, if applicable. The dynamometer shall smoothly transition during the acceleration period and shall automatically reset to the load required for the ASM 2525 mode, if applicable, once the roll speed is achieved.
(e) Second chance tests.
If a vehicle fails the 5015 test mode and completes all required test modes with emissions values for HC, CO and NO not greater than 150% of the applicable standard, the vehicle shall receive a second chance test for each failed test mode.
(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. The second-chance test shall have an overall maximum test time of 110 seconds (TT=110) if one mode is repeated.
NOTE: Maximum mode time: 90 sec.
+Maximum transition: 15 sec.
+DYNE stabilization: 5 sec.
110 sec.12 sec. transport and 10 sec. averaging are included in the mode time as in the initial test.
(2) 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.
§ 3. ASM short test equipment.
(a) Dynamometer specifications.
(1) General requirements
(i) Capacity
The dynamometer structure (for example, bearings, rollers, pit plates, and the like) shall accommodate all light-duty vehicles and light-duty trucks up to 9,000 pounds GVWR.
(ii) ASM load
Dynamometer ASM load horsepower (HP5015YY) shall be automatically selected based on the vehicle parameters in the test record.
(iii) Alternative design
Alternative dynamometer specification or designs may be allowed upon a determination by the Department that, for the purpose of properly conducting an approved short test, the evidence supporting these deviations will not cause improper vehicle loading.
(2) Power absorption.
(i) Vehicle loading.
The vehicle loading used during the ASM driving cycles shall follow the equation in paragraph (a)(2)(ii) of this section at 15. Unless otherwise noted, any horsepower displayed during testing shall be HP5015YY.
(ii) HP calculation
IHPXXXXYY = THPXXXX-PLHPZZ-YY -GTRL@ZZ MPH-YY- HPXXXXYY = IHPXXXXYY + PLHPZZ-YY
(iii) Range of power absorber.
The range of the power absorber shall be sufficient to test all light-duty vehicles and light-duty trucks up to 9,000 pounds GVWR, using both the ASM5015 and ASM2525. The absorption shall be adjustable in 0.1 hp increments at both 15 mph and 25 mph.
(iv) Parasitic losses.
The parasitic losses (PLHP) in each dynamometer system (such as windage, bearing friction and system drive friction) shall be characterized at 25 and 15 mph upon initial acceptance, and during each dynamometer calibration if required.
(v) Power absorber.
Only electric power absorbers shall be used unless alternatives are approved by the Department.
(vi) Power absorber accuracy.
The accuracy of the power absorber shall be 6.25 pounds of wheel force at 15 mph and 3.75 pounds of wheel force at 25 mph or ±2% of required wheel force, whichever is greater, in direction of rotation.
(3) 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 paragraph (a)(3)(ii) to within 0.5 inch and -0.25 inch of the calculated value. The parasitic power losses shall be determined as indicated in § 4(b)(1)(iv). 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 coupling methods, track widths, roll sizes and number of rolls may be used if approved by the Department and the Environmental Protection Agency 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. General tire roll interface losses must be determined for alternative roll sizes, configurations and spacing.
(ii) Roll spacing
Roll spacing = (24.375+D) *SIN 31.5153
D = Dynamometer roll diameter.
Roll spacing and roll diameter are expressed in inches.
(iii) 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.
(4) Inertia.
The dynamometer shall have a total test inertia weight of 2,000 pounds ±40 pounds. Any deviation from the 2,000 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.
(i) Mechanical inertia.
Dynamometers shall be equipped with additional flywheel weights or diagnostic level inertia simulation, for transient simulations of up to +3.3 mph/s acceleration at 500 pound increments of mechanical inertia weight or 1 pound increments of electrically simulated positive inertia, to a total of 5,500 pounds up to speeds of 57 mph with a minimum load (power) of 25 horsepower at 14 mph over the inertia weight range of 2,000 to 6,000 pounds. A 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.
(ii) Electrical inertia simulation.
Electrical inertia simulation, or a combination of electrical and mechanical simulation may be used in lieu of mechanical flywheels, provided that the performance of the electrically simulated inertia complies with the following specifications. Exceptions to these specifications may be allowed upon a determination by the Department that the exceptions would not significantly increase vehicle loading or emissions for the purpose of properly conducting an approved short test.
(a) System response. The torque response to a step change shall be at least 90% of the requested change within 300 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.
(b) 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 § 3(a)(4)(ii)(c), and shall not exceed 3% of the inertia weight selected (IWS) for the vehicle under test.
(c) ISE = [(IWS-IT)/(IVS)] * 100
(d)
Where:
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 IHPXXXXYY at the measured roll speed (v)
T = Time (sec)
(5) Other requirements.
(i) Vehicle speed and speed response.
The measurement of roll speed shall be accurate within 0.1 mph between speeds of 10 and 30 mph. The dynamometer controller shall be able to detect and resolve speed variations in less than 500 milliseconds to 0.10 mph/sec accuracy.
(ii) Vehicle restraint.
The vehicle shall be restrained during the ASM 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.
(iii) Vehicle cooling.
The test operator shall prevent overheating of the vehicle. The test shall be conducted with the hood open when the 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 3,000 SCFM within 12 inches of the intake to the vehicle's cooling system. The cooling system shall avoid improper cooling of the catalytic converter.
(iv) All-wheel drive.
If used, four-wheel drive dynamometers shall insure the application of correct vehicle loading as defined in paragraph (a)(2) and shall not damage the four wheel drive system of the vehicle. Front and rear wheel rolls shall be coupled and maintain speed synchronization within 0.2 mph. The four wheel drive system shall be able to uncouple the rear roll set so as to function as a two wheel drive system.
(v) Installation.
In all cases, installation must be performed so that the test vehicle is approximately level (±5°) while on the dynamometer during testing.
(b) Emission sampling system
(1) Materials and design.
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. 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 ASM5015 test cycle for 290 seconds.
(2) Sampling system.
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 outside the building. The sampling system shall, at a minimum, consist of a tailpipe probe, flexible sample line, water removal system, a particulate trap, sample pump and flow control components.
(3) Sample probe.
(i) Insertion.
The sample probe shall allow at least a 16 inch insertion depth of the sample 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 inch of water pressure.
(ii) Retention.
The probe shall incorporate a positive means of retention to prevent it from slipping out of the tailpipe during use.
(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.
(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 (that is, 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 noncorrosive, nonreactive material which can withstand exhaust gas temperatures at the probe tip of up to 1,100°F.
(vi) System hoses and connections.
Hoses and all other sample handling components must be constructed of, or plated with a nonreactive, non-corrosive, high temperature material which will not affect, or be affected by, the exhaust constituents and tracer gases.
(vii) Dual exhaust.
The sample system shall provide for the testing of dual exhaust equipped vehicles. When testing a vehicle with functional dual exhaust pipes, a dual sample probe of a design certified by the analyzer manufacturer to provide equal flow in each leg shall be used. The equal flow requirement is considered to be met if the flow rate in each leg of the probe has been measured under two sample pump flow rates (the normal rate and a rate equal to the onset of low flow), and if the flow rates in each of the legs are found to be equal to each other (within 15% of the flow rate in the leg having lower flow).
(4) Particulate filter.
The particulate filter shall be capable of trapping 97% of all particulate and aerosols 5 microns or larger. The filter element shall not absorb or adsorb hydrocarbons. The filter housing shall be transparent or translucent to allow the operator to observe the filter elements 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 continuously drained from the water trap's bowl. 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 be prevented from performing an emissions test 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% of a step change in input (excluding no), whichever is less.
(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) Ventilation system.
The ventilation system shall discharge the vehicle and analyzer exhaust outside the building.
(ii) Exhaust collection system.
The flow of the exhaust collection system shall not cause dilution of the exhaust at the sample point in the probe.
(iii) Exhaust collection system flow.
The flow of the exhaust collection systems shall not cause a change of more than 1.0 inch of water pressure in the vehicle's exhaust system at the exhaust system outlet.
(c) Analytical instruments.
(1) General requirements.
(i) Analyzers.
The analyzer system shall consist of analyzers for HC, CO, NO and CO2. And digital displays for exhaust concentrations of HC, CO, NO and CO2, and for vehicle speed.
(ii) Alternative analytical equipment.
Alternative analytic equipment specification, materials, designs or detection methods may be allowed upon a determination by the Department and the Environmental Protection Agency, that for the purpose of properly conducting an approved short test, the evidence supporting such deviations will not significantly affect the proper measurement of emissions.
(iii) Sample rate.
The analyzer shall be capable of measuring exhaust concentrations of gases specified in this section at a minimum rate of once per second.
(2) Performance requirements.
(i) Temperature operating range.
The analyzer system and all associated hardware shall operate within the performance specifications described in § 2 of this subpart at ambient air temperatures ranging from 41°F to 110°F. 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 § 2 of this subpart 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 § 4(d)(6)(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 6,000 feet (above mean sea level). At any given altitude and ambient conditions specified in (iv) and (v), errors due to barometric pressure changes of ±2 inches of mercury shall not exceed the accuracy limits specified in paragraph (2).
(v) System lockout during warm-up.
Functional operation of the gas sampling unit shall remain disabled through a system lockout preventing the system from performing emission tests until the instrument meets stability and warm-up requirements. 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 § 3(c)(3) for 5 minutes without adjustment. Turning on the analyzer for a time period of at least 4 times the period of time required to reach stability as demonstrated in the equipment certification (see § 7) shall constitute ''warmed-up.''
(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 prevented from performing an emissions test.
(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. Certification acceptance test is described in § 7.
(viii) 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.
(ix) Propane equivalency factor.
The PEF range shall be between 0.470 and 0.560. For each audit/calibration point, the nominal PEF shall be conveniently displayed for the quality assurance inspector and other authorized personnel, in a manner acceptable to the program. If an optical bench must be replaced in the field, the manufacturer's field service representative (FSR) shall change any external labels 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.
(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. 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 (HC) analysis shall be determined by nondispersive infrared (NDIR) analyzer. The analyzer shall cover at least the range of 0 PPM HC to 2000 PPM HC, where PPM HC is parts per million of hydrocarbon volume as hexane. The accuracy of the instrument between 1400 PPM HC and 2000 PPM HC shall be at least 5.0% of point. The accuracy of the instrument from 0-1400 PPM HC shall be ±4 PPM C6 or 3% of point, whichever is greater. The calibration curve must comply with the quality control specifications in § 4(d)(2) for calibration curve verification.
(ii) Carbon monoxide analysis.
Carbon monoxide (CO) analysis shall be determined by nondispersive infrared (NDIR) analyzer. The analyzer shall cover at least the range of 0.00% CO to 9.99% CO, where % CO is % volume CO. The accuracy of the instrument between 0.01% and 7.00% CO shall be ±3% or 0.02% CO, whichever is greater. The accuracy of the instrument between 7.01% and 10.00% shall be at least 5.0% of point. The calibration curve must comply with the quality control specifications in § 4(d)(2) for calibration curve generation.
(iii) Carbon dioxide analysis.
Carbon dioxide (CO2) analysis shall be determined by nondispersive infrared (NDIR) analyzer. The analyzer shall cover at least the range of 0.0% CO2 to 16.0% CO2. The accuracy of the instrument between 0.01% and 16% CO2 shall be at least ±0.3% CO2 or 3% of point which ever is greater. The accuracy of the instrument between 16.01% and 18% shall be at least 5.0% of point. The calibration curve must comply with the quality control specifications in § 4(d)(2) for calibration curve generation.
(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 ±4.0% of point or 25 PPM NO, whichever is greater. The accuracy of the instrument between 4001 and 5000 PPM shall be ±5.0%. The calibration curve must comply with the quality control specifications in § 4(d)(2) for calibration curve generation.
(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 calibration curve must comply with the quality control specifications in § 4(d)(2) for calibration curve generation.
(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 0-700% 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% CO 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.
(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, see § 1(b)(v)).
(i) Relative humidity.
The relative humidity measurement device shall cover the range from 5% to 95% RH, and 35°F--110°F, with a minimum accuracy of °5% RH. Wet bulb thermometers shall not be used.
(ii) Dry-bulb temperature.
The dry-bulb temperature device shall cover the range from 35°F--110°F-with a minimum accuracy of ±3°F.
(iii) Barometric pressure.
The barometric pressure measurement device shall cover the range from 610 MM HG--810 MM HG, and 35°F--110°F, with a minimum accuracy of ±3% of point.
(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 a Department-provided or approved look-up table. Vehicle identification information may 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, and in a mode within that test.
(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 ASM test mode timers used shall be accurate to within 0.1% of reading between 10 and 1,000 seconds with a resolution of 0.1 seconds.
(4) Display refresh rate.
Dynamic information being displayed shall be refreshed at a minimum rate of twice per second.
(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 C 0.01 % CO CO2 0.1 % CO2 O2 0.1 % O2 RPM 10 RPM Speed 0.1 MPH Wheel Force 0.1 LB Relative Humidity 1 %RH Dry bulb temperature 1 °F Barometric pressure 1 MM HG (6) Engine speed detection.
The system shall be 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.
(7) Display during testing.
The display during testing shall read ''test in progress'' and shall digitally display the vehicle's speed in mph. Emissions values shall not be displayed during official testing.
§ 4. ASM 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 paragraph (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 Department 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. If 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 Department.
(b) Dynamometer
(1) Coast down check.
(i) Coast down frequency.
The calibration of each dynamometer shall be automatically checked every 72 hours in low volume stations (less than 4,000 tests per year) and daily in high volume stations, when the dynamometer is in active service, by a dynamometer coast-down procedure equivalent to § 86.118-78 (for reference see EOD test procedure TP-302A and TP-202) between the speeds of 30-20 mph and 20-10 mph. All rotating dynamometer components shall be included in the coast-down check. Speed windows smaller than ±5 mph may be used provided that they show the same calibration capabilities.
(ii) Coast down HP settings.
The base dynamometer inertia (2,000 pounds) shall be checked at two random horsepower settings for each speed range. The two random horsepower settings shall be between 8.0 to 18.0 horsepower. Use of a shunt resistor for a load cell performance check is not permissible because it does not verify the performance of the actual load cell, only the signal processing portion of the system.
(iii) Coast down procedure.
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 DET (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.
Coast-down dynamometer from 30-20 mph.
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.
IHP2525YY = Randomly selected ASM2525 indicated horsepower.
PLHP25-YY = 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.
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.
IHP5015YY = Randomly selected ASM5015 indicated horsepower.
PLHP15-YY = Parasitic horsepower for specific dynamometer at 15 mph.
(iv) Parasitic value calculations.
If the coast-down values does not verify in § 2(b)(iii).
Parasitic losses shall be calculated using the following equations at 25 and 15 mph. The indicated horsepower shall be set to zero for these tests.
(a) Parasitic losses at 25 mph for a dynamometer with YY diameter rollers.
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.
CDT = Coast-down time required for dynamometer to coast from 30 to 20 mph.
(b) Parasitic losses at 15 mph for a dynamometer with YY diameter rollers.
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.
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