Textual Amendments
The test shall be carried out with a PEMS, composed of components specified in points 3.1.1 to 3.1.5. If applicable, a connection with the vehicle ECU may be established to determine relevant engine and vehicle parameters as specified in point 3.2.
Test parameters as specified in Table 1 of this Annex shall be measured, recorded at a constant frequency of 1,0 Hz or higher and reported according to the requirements of Appendix 8. If ECU parameters are obtained, these should be made available at a substantially higher frequency than the parameters recorded by PEMS to ensure correct sampling. The PEMS analysers, flow-measuring instruments and sensors shall comply with the requirements laid down in Appendices 2 and 3 of this Annex.
Test parameters
| Notes: | ||
| a To be measured on a wet basis or to be corrected as described in point 8.1 of Appendix 4. | ||
| b To be determined only if indirect methods are used to calculate exhaust mass flow rate as described in paragraphs 10.2 and 10.3 of Appendix 4. | ||
| c The method to determine vehicle speed shall be chosen according to point 4.7. | ||
| d Parameter only mandatory if measurement required by Annex IIIA, Section 2.1. | ||
| e To be determined only if necessary to verify the vehicle status and operating conditions. | ||
| f May be calculated from THC and CH 4 concentrations according to point 9.2 of Appendix 4. | ||
| g May be calculated from measured NO and NO 2 concentrations. | ||
| h Multiple parameter sources may be used. | ||
| i The preferable source is the ambient pressure sensor. | ||
| Parameter | Recommended unit | Source h |
|---|---|---|
| THC concentration a d | ppm | Analyser |
| CH 4 concentration a d | ppm | Analyser |
| NMHC concentration a d | ppm | Analyser f |
| CO concentration a d | ppm | Analyser |
| CO 2 concentration a | ppm | Analyser |
| NO X concentration a d | ppm | Analyser g |
| PN concentration d | #/m 3 | Analyser |
| Exhaust mass flow rate | kg/s | EFM, any methods described in point 7 of Appendix 2 |
| Ambient humidity | % | Sensor |
| Ambient temperature | K | Sensor |
| Ambient pressure | kPa | Sensor |
| Vehicle speed | km/h | Sensor, GPS, or ECU c |
| Vehicle latitude | Degree | GPS |
| Vehicle longitude | Degree | GPS |
| Vehicle altitude e i | M | GPS or Sensor |
| Exhaust gas temperature e | K | Sensor |
| Engine coolant temperature e | K | Sensor or ECU |
| Engine speed e | rpm | Sensor or ECU |
| Engine torque e | Nm | Sensor or ECU |
| Torque at driven axle e | Nm | Rim torque meter |
| Pedal position e | % | Sensor or ECU |
| Engine fuel flow b | g/s | Sensor or ECU |
| Engine intake air flow b | g/s | Sensor or ECU |
| Fault status e | — | ECU |
| Intake air flow temperature | K | Sensor or ECU |
| Regeneration status e | — | ECU |
| Engine oil temperature e | K | Sensor or ECU |
| Actual gear e | # | ECU |
| Desired gear (e.g. gear shift indicator) e | # | ECU |
| Other vehicle data e | unspecified | ECU |
The preparation of the vehicle shall include a general technical and operational check.
The installation of the PEMS shall follow the instructions of the PEMS manufacturer and the local health and safety regulations. The PEMS should be installed as to minimise during the test electromagnetic interferences as well as exposure to shocks, vibration, dust and variability in temperature. The installation and operation of the PEMS shall be leak-tight and minimise heat loss. The installation and operation of PEMS shall not change the nature of the exhaust gas nor unduly increase the length of the tailpipe. To avoid the generation of particles, connectors shall be thermally stable at the exhaust gas temperatures expected during the test. It is recommended not to use elastomer connectors to connect the vehicle exhaust outlet and the connecting tube. Elastomer connectors, if used, shall have a minimum exposure to the exhaust gas to avoid artefacts at high engine load.
The installation and operation of the PEMS shall not unduly increase the static pressure at the exhaust outlet. If technically feasible, any extension to facilitate the sampling or connection with the exhaust mass flow meter shall have an equivalent, or larger, cross-sectional area as the exhaust pipe.
Whenever used, the exhaust mass flow meter shall be attached to the vehicle's tailpipe(s) according to the recommendations of the EFM manufacturer. The measurement range of the EFM shall match the range of the exhaust mass flow rate expected during the test. The installation of the EFM and any exhaust pipe adaptors or junctions shall not adversely affect the operation of the engine or exhaust after-treatment system. A minimum of four pipe diameters or 150 mm of straight tubing, whichever is larger, shall be placed either side of the flow-sensing element. When testing a multi-cylinder engine with a branched exhaust manifold, it is recommended to combine the manifolds upstream of the exhaust mass flow meter and to increase the cross section of the piping appropriately as to minimise backpressure in the exhaust. If this is not feasible, exhaust flow measurements with several exhaust mass flow meters shall be considered. The wide variety of exhaust pipe configurations, dimensions and expected exhaust mass flow rates may require compromises, guided by good engineering judgement, when selecting and installing the EFM(s). If measurement accuracy requires, it is permissible to install an EFM with a diameter smaller than that of the exhaust outlet or the total cross-sectional area of multiple outlets, providing it does not adversely affect the operation or the exhaust after-treatment as specified in point 3.4.2.
The GPS antenna should be mounted, e.g. at the highest possible location, as to ensure good reception of the satellite signal. The mounted GPS antenna shall interfere as little as possible with the vehicle operation.
If desired, relevant vehicle and engine parameters listed in Table 1 can be recorded by using a data logger connected with the ECU or the vehicle network following standards, e.g. ISO 15031-5 or SAE J1979, OBD-II, EOBD or WWH-OBD. If applicable, manufacturers shall disclose parameter labels to allow the identification of required parameters.
Vehicle speed sensors, temperature sensors, coolant thermocouples or any other measurement device not part of the vehicle shall be installed to measure the parameter under consideration in a representative, reliable and accurate manner without unduly interfering with the vehicle operation and the functioning of other analysers, flow-measuring instruments, sensors and signals. Sensors and auxiliary equipment shall be powered independently of the vehicle.
[F2It is permitted to power any safety-related illumination of fixtures and installations of PEMS components outside of the vehicle's cabin by the vehicle's battery.]
Textual Amendments
Emissions sampling shall be representative and conducted at locations of well-mixed exhaust where the influence of ambient air downstream of the sampling point is minimal. If applicable, emissions shall be sampled downstream of the exhaust mass flow meter, respecting a distance of at least 150 mm to the flow sensing element. The sampling probes shall be fitted at least 200 mm or three times the diameter of the exhaust pipe, whichever is larger, upstream of the vehicle's exit of the exhaust outlet, which is the point at which the exhaust exits the PEMS sampling installation into the environment. If the PEMS feeds back a flow to the tail pipe, this shall occur downstream of the sampling probe in a manner that does not affect during engine operation the nature of the exhaust gas at the sampling point(s). If the length of the sample line is changed, the system transport times shall be verified and if necessary corrected.
If the engine is equipped with an exhaust after-treatment system, the exhaust sample shall be taken downstream of the exhaust after-treatment system. When testing a vehicle with a multi-cylinder engine and branched exhaust manifold, the inlet of the sampling probe shall be located sufficiently far downstream so as to ensure that the sample is representative of the average exhaust emissions of all cylinders. In multi-cylinder engines, having distinct groups of manifolds, such as in a ‘ V ’ engine configuration, the manifolds shall be combined upstream of the sampling probe. If this is technically not feasible, multi-point sampling at locations of well-mixed exhaust free of ambient air shall be considered. In this case, the number and location of sampling probes shall match as far as possible that of the exhaust mass flow meters. In case of unequal exhaust flows, proportional sampling or sampling with multiple analysers shall be considered.
If particles are measured, the exhaust shall be sampled from the centre of the exhaust stream. If several probes are used for emissions sampling, the particle sampling probe shall be placed upstream of the other sampling probes.
If hydrocarbons are measured, the sampling line shall be heated to 463 ± 10 K (190 ± 10 °C). For the measurement of other gaseous components with or without cooler, the sampling line shall be kept at a minimum of 333 K (60 °C) as to avoid condensation and to ensure appropriate penetration efficiencies of the various gases. For low pressure sampling systems, the temperature can be lowered corresponding to the pressure decrease provided that the sampling system ensures a penetration efficiency of 95 % for all regulated gaseous pollutants. If particles are sampled, the sampling line from the raw exhaust sample point shall be heated to a minimum of 373 K (100 °C). The residence time of the sample in the particle sampling line shall be less than 3 s until reaching first dilution or the particle counter.]