Document ID: chunk:federal_register_of_legislation:F2023C00229:reg:10:p28
Version: federal_register_of_legislation:F2023C00229
Segment Type: reg
Provision Reference: reg 10 (pt 28/30)
Character Range: 597918–600722

The oxides of nitrogen analyser shall be of the ChemiLuminescent Detector (CLD) or Heated ChemiLuminescent Detector (HCLD) type with a NO2/NO converter, if measured on a dry basis. If measured on a wet basis, a HCLD with converter maintained above 328 K (55 °C) shall be used, provided the water quench check (see section 1.9.2.2 of Appendix 5 to this Annex) is satisfied.

        3.3.6. Air-to-fuel measurement

              The air to fuel measurement equipment used to determine the exhaust gas flow as specified in section 4.2.5 of Appendix 2 to this Annex shall be a wide range air to fuel ratio sensor or lambda sensor of Zirconia type. The sensor shall be mounted directly on the exhaust pipe where the exhaust gas temperature is high enough to eliminate water condensation.

              The accuracy of the sensor with incorporated electronics shall be within:

              ± 3 % of reading  λ < 2
              ± 5 % of reading  2 ≤ λ < 5
              ± 10 % of reading  5 ≤ λ

              To fulfil the accuracy specified above, the sensor shall be calibrated as specified by the instrument manufacturer.

       3.4.  Sampling of Gaseous Emissions

        3.4.1. Raw exhaust gas

              The gaseous emissions sampling probes shall be fitted at least 0,5 m or 3 times the diameter of the exhaust pipe — whichever is the larger — upstream of the exit of the exhaust gas system but sufficiently close to the engine as to ensure an exhaust gas tem- perature of at least 343 K (70 °C) at the probe.

              In the case of a multi-cylinder engine with a branched exhaust manifold, the inlet of the probe shall be located sufficiently far downstream so as to ensure that the sample is representative of the average exhaust emissions from all cylinders. In multi-cylinder engines having distinct groups of manifolds, such as in a "Vee" engine configuration, it is recommended to combine the manifolds upstream of the sampling probe. If this is not practical, it is permissible to acquire a sample from the group with the highest CO2 emission. Other methods which have been shown to correlate with the above methods may be used. For exhaust emission cal- culation the total exhaust mass flow shall be used.

              If the engine is equipped with an exhaust aftertreatment system, the exhaust sample shall be taken downstream of the exhaust aftertreatment system.

        3.4.2. Diluted exhaust gas

              The exhaust pipe between the engine and the full flow dilution system shall conform to the requirements of section 2.3.1 of Annex V (EP).

              The gaseous emissions sample probe(s) shall be installed in the dilution tunnel at a point where the dilution air and exhaust gas are well mixed, and in close proximity to the particulates sampling probe.