Document ID: chunk:federal_register_of_legislation:F2023C00229:reg:9:p20
Version: federal_register_of_legislation:F2023C00229
Segment Type: reg
Provision Reference: reg 9 (pt 20/71)
Character Range: 265059–268171

Accuracy of measuring instruments
       Measuring instrument            Accuracy
Fuel consumption                ± 2 % of engine's maximum value
Air consumption                 ± 2 % of engine's maximum value
Temperatures ≤ 600 K (327 °C)   ± 2 K absolute
Temperatures >600 K (327 °C)    ± 1 % of reading
Atmospheric pressure            ± 0,1 kPa absolute
Exhaust gas pressure            ± 0,2 kPa absolute
Intake depression               ± 0,05 kPa absolute
Other pressures                 ± 0,1 kPa absolute
Relative humidity               ± 3 % absolute
Absolute humidity               ± 5 % of reading

2.3.                            Exhaust gas flow

              For calculation of the emissions in the raw exhaust, it is necessary to know the exhaust gas flow (see Section 4.4 of Appendix 1). For the determination of the exhaust flow either of the following methods may be used:
                a)      direct measurement of the exhaust flow by flow nozzle or equivalent metering system;

                b)      measurement of the air flow and the fuel flow by suitable metering systems and calculation of the exhaust flow by the following equation:

                           GEXHW = GAIRW + GFUEL (for wet exhaust mass)

              The accuracy of exhaust flow determination shall be ± 2,5 % of reading or better.

2.4.                            Diluted exhaust gas flow

              For calculation of the emissions in the diluted exhaust using a full flow dilution system (mandatory for the ETC), it is necessary to know the diluted exhaust gas flow (see Section 4.3 of Appendix 2). The total mass flow rate of the diluted exhaust (GTOTW) or the total mass of the diluted exhaust gas over the cycle (MTOTW) shall be measured with a PDP or CFV (Annex V, Section 2.3.1). The accuracy shall be ± 2 % of reading or better, and shall be determined according to the provisions of Annex III, Appendix 5, Section 2.4.

3.                                 DETERMINATION OF THE GASEOUS COMPONENTS

3.1.                            General analyser specifications

              The analysers shall have a measuring range appropriate for the accuracy required to measure the concentrations of the exhaust gas components (Section 3.1.1). It is recommended that the analysers be operated such that the measured concentration falls between 15 % and 100 % of full scale.

              If read-out systems (computers, data loggers) can provide sufficient accuracy and resolution below 15 % of full scale, measurements below 15 % of full scale are also acceptable. In this case, additional calibrations of at least four non-zero nominally equally spaced points are to be made to ensure the accuracy of the calibration curves according to Annex III, Appendix 5, Section 1.5.5.2.

              The electromagnetic compatibility (EMC) of the equipment shall be on a level as to minimise additional errors.

3.1.1.                        Measurement error

              The total measurement error, including the cross sensitivity to other gases (see Annex III, Appendix 5, Section 1.9), shall not exceed ± 5