Document ID: chunk:federal_register_of_legislation:F2023C00229:reg:9:p36
Version: federal_register_of_legislation:F2023C00229
Segment Type: reg
Provision Reference: reg 9 (pt 36/71)
Character Range: 309955–313071

pressure (≡ critical flow). The CVS system shall be operated as in a normal exhaust emission test for about 5 to 10 minutes. A gas sample shall be analysed with the usual equipment (sampling bag or integrating method), and the mass of the gas calculated. The mass so determined shall be within ± 3 % of the known mass of the gas injected.

2.4.2.                        Metering by means of a gravimetric technique

              The weight of a small cylinder filled with carbon monoxide or propane shall be determined with a precision of ± 0,01 gram. For about 5 to 10 minutes, the CVS system shall be operated as in a normal exhaust emission test, while carbon monoxide or propane is injected into the system. The quantity of pure gas discharged shall be determined by means of differential weighing. A gas sample shall be analysed with the usual equipment (sampling bag or integrating method), and the mass of the gas calculated. The mass so determined shall be within ± 3 % of the known mass of the gas injected.

3.                                 CALIBRATION OF THE PARTICULATE MEASURING SYSTEM

3.1.                            Introduction

              Each component shall be calibrated as often as necessary to fulfil the accuracy requirements of this Directive. The calibration method to be used is described in this section for the components indicated in Annex III, Appendix 4, Section 4 and Annex V, Section 2.

3.2.                            Flow measurement

              The calibration of gas flow meters or flow measurement instrumentation shall be traceable to international and/or national standards. The maximum error of the measured value shall be within ± 2 % of reading.

              If the gas flow is determined by differential flow measurement, the maximum error of the difference shall be such that the accuracy of GEDF is within ± 4 % (see also Annex V, Section 2.2.1, EGA). It can be calculated by taking the Root-Mean-Square of the errors of each instrument.

3.3.                            Checking the partial flow conditions

              The range of the exhaust gas velocity and the pressure oscillations shall be checked and adjusted according to the requirements of Annex V, Section 2.2.1, EP, if applicable.

3.4.                            Calibration intervals

              The flow measurement instrumentation shall be calibrated at least every three months or whenever a system repair or change is made that could influence calibration.

4.                                 CALIBRATION OF THE SMOKE MEASUREMENT EQUIPMENT

4.1.                            Introduction

              The opacimeter shall be calibrated as often as necessary to fulfil the accuracy requirements of this Directive. The calibration method to be used is described in this section for the components indicated in Annex III, Appendix 4, Section 5 and Annex V, Section 3.

4.2.                            Calibration procedure

4.2.1.                        Warming-up time

              The opacimeter shall be warmed up and stabilised according to the manufacturer's recommendations. If