Document ID: chunk:federal_register_of_legislation:F2023C00229:reg:9:p41
Version: federal_register_of_legislation:F2023C00229
Segment Type: reg
Provision Reference: reg 9 (pt 41/71)
Character Range: 327766–330676

exhaust gas analysis system for CO, CO2, NOx, HC ESC only

1.2.                            Description of the analytical system

              An analytical system for the determination of the gaseous emissions in the raw (Figure 7, ESC only) or diluted (Figure 8, ETC and ESC) exhaust gas is described based on the use of:

                —    HFID analyser for the measurement of hydrocarbons;

                —    NDIR analysers for the measurement of carbon monoxide and carbon dioxide;

                —    HCLD or equivalent analyser for the measurement of the oxides of nitrogen.

              The sample for all components may be taken with one sampling probe or with two sampling probes located in close proximity and internally split to the different analysers. Care must be taken that no condensation of exhaust components (including water and sulphuric acid) occurs at any point of the analytical system.

              Figure 8

        Flow diagram of diluted exhaust gas analysis system for CO, CO2, NOx, HC ETC, optional for ESC

       1.2.1. Components of Figures 7 and 8

              EP Exhaust pipe

              Exhaust gas sampling probe (Figure 7 only)

              A stainless steel straight closed end multi-hole probe is recommended. The inside diameter shall not be greater than the inside diameter of the sampling line. The wall thickness of the probe shall not be greater than 1 mm. There shall be a minimum of three holes in three different radial planes sized to sample approximately the same flow. The probe must extend across at least 80 % of the diameter of the exhaust pipe. One or two sampling probes may be used.

              SP2 Diluted exhaust gas HC sampling probe (Figure 8 only)

              The probe shall:

                —    be defined as the first 254 mm to 762 mm of the heated sampling line HSL1;

                —    have a 5 mm minimum inside diameter;

                —    be installed in the dilution tunnel DT (see Section 2.3, Figure 20) at a point where the dilution air and exhaust gas are well mixed (i.e. approximately 10 tunnel diameters downstream of the point where the exhaust enters the dilution tunnel);

                —    be sufficiently distant (radially) from other probes and the tunnel wall so as to be free from  the  influence of any wakes or eddies;

                —    be heated so as to increase the gas stream temperature to 463 K ± 10 K (190 °C ± 10 °C) at the exit of the probe.

              SP3 Diluted exhaust gas CO, CO2, NOx sampling probe (Figure 8 only)

              The probe shall:

                —    be in the same plane as SP2;

                —    be sufficiently distant (radially) from other probes and the tunnel wall so as to be free from  the  influence of any wakes or eddies;
                —    be heated and insulated over its entire length to a minimum temperature of 328 K (55