Document ID: chunk:federal_register_of_legislation:F2023C00229:reg:9:p45
Version: federal_register_of_legislation:F2023C00229
Segment Type: reg
Provision Reference: reg 9 (pt 45/71)
Character Range: 338605–341634

Pressure regulator

              To control the flows of the fuel (= carrier gas), the sample, and the air, respectively.

              FC Flow capillary

              To control the rate of air flow to the FID.

              G1, G2, G3 Pressure gauge

              To control the flows of the fuel (= carrier gas), the sample, and the air, respectively.

              F1, F2, F3, F4, F5 Filter

              Sintered metal filters to prevent grit from entering the pump or the instrument.

              FL1

              To measure the sample by-pass flow rate.

1.3.2.                        Non-methane cutter method (NMC, Figure 10)

              The cutter oxidises all hydrocarbons except CH4 to CO2 and H2O, so that by passing the sample through the NMC only CH4 is detected by the FID. If bag sampling is used, a flow diverter system shall be installed at SL (see Section 1.2, Figure 8) with which the flow can be alternatively passed through or around the cutter according to the upper part of Figure 10. For NMHC measurement, both values (HC and CH4) shall be observed on the FID and recorded. If the integration method is used, an NMC in line with a second FID shall be installed parallel to the regular FID into HSL1 (see Section 1.2, Figure 8) according to the lower part of Figure 10. For NMHC measurement, the values of the two FID's (HC and CH4) shall be observed and recorded.

              The cutter shall be characterised at or above 600 K (327 °C) prior to test work with respect to its catalytic effect on CH4 and C2H6 at H2O values representative of exhaust stream conditions. The dewpoint and O2   level of the sampled exhaust stream must be known. The relative response of the FID to CH4 must be recorded (see Annex III, Appendix 5, Section 1.8.2).

        Figure 10

        Flow diagram for methane analysis with the non-methane cutter (NMC)

              Components of Figure 10

              NMC Non-methane cutter

              To oxidise all hydrocarbons except methane.

              HC

              Heated flame ionisation detector (HFID) to measure the HC and CH4 concentrations. The temperature shall be kept at 453 K to 473 K (180 °C to 200 °C).

              V1 Selector valve

              To select sample, zero and span gas. V1 is identical with V2 of Figure 8.

              V2, V3 Solenoid valve

              To by-pass the NMC.

              V4 Needle valve

              To balance the flow through the NMC and the by-pass.
              R1 Pressure regulator

              To control the pressure in the sampling line and the flow to the HFID. R1 is identical with R3 of Figure 8.

              FL1 Flowmeter

              To measure the sample by-pass flow rate. FL1 is identical with FL1 of Figure 8.

2.                                 EXHAUST GAS DILUTION AND DETERMINATION OF THE PARTICULATES

2.1.                            Introduction
              Sections 2.2, 2.3 and 2.4 and Figures 11 to 22 contain detailed descriptions of the recommended