Document ID: chunk:federal_register_of_legislation:F2024L00446:reg:16:p47
Version: federal_register_of_legislation:F2024L00446
Segment Type: reg
Provision Reference: reg 16 (pt 47/108)
Character Range: 1016262–1019301

and shall not exceed 0.3 per cent of the flow rate of the dilute exhaust gases, unless the diluted exhaust bag fill volume is added to the integrated CVS volume.
              4.1.2.3. A sample of the dilution air shall be taken near the dilution air inlet (after the filter if one is fitted).
              4.1.2.4. The dilution air sample shall not be contaminated by exhaust gases from the mixing area.
              4.1.2.5. The sampling rate for the dilution air shall be comparable to that used for the dilute exhaust gases.
              4.1.2.6. The materials used for the sampling operations shall be such as not to change the concentration of the emissions compounds.
              4.1.2.7. Filters may be used in order to extract the solid particles from the sample.
              4.1.2.8. Any valve used to direct the exhaust gases shall be of a quick-adjustment, quick-acting type.
              4.1.2.9. Quick-fastening, gas-tight connections may be used between three-way valves and the sample bags, the connections sealing themselves automatically on the bag side. Other systems may be used for conveying the samples to the analyser (e.g. three-way stop valves).
              4.1.2.10. Sample storage
              4.1.2.10.1. The gas samples shall be collected in sample bags of sufficient capacity so as not to impede the sample flow.
              4.1.2.10.2. The bag material shall be such as to affect neither the measurements themselves nor the chemical composition of the gas samples by more than ±2 per cent after 30 minutes (e.g., laminated polyethylene/polyamide films, or fluorinated polyhydrocarbons).
              4.1.3. Sampling systems
              4.1.3.1. Hydrocarbon sampling system (heated flame ionisation detector, HFID)
              4.1.3.1.1. The hydrocarbon sampling system shall consist of a heated sampling probe, line, filter and pump. The sample shall be taken upstream of the heat exchanger (if fitted). The sampling probe shall be installed at the same distance from the exhaust gas inlet as the particulate sampling probe and in such a way that neither interferes with samples taken by the other. It shall have a minimum internal diameter of 4 mm.
              4.1.3.1.2. All heated parts shall be maintained at a temperature of 190 °C ±10 °C by the heating system.
              4.1.3.1.3. The arithmetic average concentration of the measured hydrocarbons shall be determined by integration of the second-by-second data divided by the phase or test duration.
              4.1.3.1.4. The heated sampling line shall be fitted with a heated filter FH having a 99 per cent efficiency for particles ≥ 0.3 μm to extract any solid particles from the continuous flow of gas required for analysis.
              4.1.3.1.5. The sampling system delay time (from the probe to the analyser inlet) shall be no more than 4 seconds.
              4.1.3.1.6. The HFID shall be used with a constant mass flow (heat exchanger) system to ensure a representative sample, unless compensation for varying CVS