Document ID: chunk:federal_register_of_legislation:F2023C00229:reg:10:p21
Version: federal_register_of_legislation:F2023C00229
Segment Type: reg
Provision Reference: reg 10 (pt 21/30)
Character Range: 577954–580880

instantaneous exhaust gas mass flow is as follows:

              with:

where:
A/Fst   =  stoichiometric air to fuel ratio, kg/kg
λ       =  excess air ratio
cCO2    =  dry CO2 concentration, %
cCO     =  dry CO concentration, ppm
cHC     =  HC concentration, ppm

              Note: β can be 1 for fuels containing carbon and 0 for hydrogen fuel.

              The air flowmeter shall meet the accuracy specifications of section 2.2 of Appendix 4 to this Annex, the CO2 analyser used shall meet the specifications of section 3.3.2 of Appendix 4 to this Annex and the total system shall meet the accuracy specifications for the exhaust gas flow.

              Optionally, air to fuel ratio measurement equipment such as a zirconia type sensor may be used for the measurement of the excess air ratio which meets the specifications of section 3.3.6 of Appendix 4 to this Annex.'

       (iii)   Sections 4 and 5 are replaced by the following:

        '5.  CALCULATION OF THE GASEOUS EMISSIONS

        5.1.  Data evaluation

              For the evaluation of the gaseous emissions in the diluted exhaust gas, the emission concentrations (HC, CO and NOx) and the diluted exhaust gas mass flow rate shall be recorded according to section 3.8.2.1 and stored on a computer system. For analogue analysers the response shall be recorded, and the calibration data may be applied online or offline during the data evaluation.

              For the evaluation of the gaseous emissions in the raw exhaust gas, the emission concentrations (HC, CO and NOx) and the exhaust gas mass flow rate shall be recorded according to section 3.8.2.2 and stored on a computer system. For analogue analysers the response shall be recorded, and the calibration data may be applied online or offline during the data evaluation.

        5.2.  Dry/wet correction

              If the concentration is measured on a dry basis, it shall be converted to a wet basis according to the following formula. For con- tinuous measurement, the conversion shall be applied to each instantaneous measurement before any further calculation.

              The conversion equations of section 5.2 of Appendix 1 to this Annex shall apply.

        5.3.  NOx correction for humidity and temperature

              As the NOx emission depends on ambient air conditions, the NOx concentration shall be corrected for ambient air temperature and humidity with the factors given in section 5.3 of Appendix 1 to this Annex. The factors are valid in the range between 0 and 25 g/kg dry air.

        5.4.  Calculation of the emission mass flow rates

              The emission mass over the cycle (g/test) shall be calculated as follows depending on the measurement method applied. The mea- sured concentration shall be converted to a wet basis according to section 5.2 of Appendix 1 to this Annex, if not already measured on a wet basis. The respective values