Document ID: chunk:federal_register_of_legislation:F2012C00283:reg:21:p14
Version: federal_register_of_legislation:F2012C00283
Segment Type: reg
Provision Reference: reg 21 (pt 14/39)
Character Range: 295059–298207

sampling rate for the dilution air shall be comparable to that used in the case of the dilute exhaust gases.
              1.2.7.  The materials used for the sampling operations shall be such as not to change the pollutant concentration.
              1.2.8.  Filters may be used in order to extract the solid particles from the sample.
              1.2.9.  The various valves used to direct the exhaust gases shall be of a quick-adjustment, quick-acting type.
              1.2.10.  Quick-fastening gas-tight connections may be used between the three-way valves and the sampling bags, the connections sealing themselves automatically on the bag side. Other systems may be used for conveying the samples to the analyser (three-way stop valves, for example).
              1.2.11.  Storage of the sample
                The gas samples shall be collected in sampling bags of sufficient capacity not to impede the sample flow; 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 20 minutes (for instance: laminated polyethylene/polyamide films, or fluorinated polyhydrocarbons).
              1.2.12.  Hydrocarbon Sampling System – Diesel Engines
              1.2.12.1. The hydrocarbon sampling system shall consist of a heated sampling probe, line, filter and pump. The sampling probe shall be installed at the same distance from the exhaust gas inlet as the particulate sampling probe, in such a way that neither interferes with samples taken by the other. It shall have a minimum internal diameter of 4 mm.
              1.2.12.2. All heated parts shall be maintained at a temperature of 463 K (190 °C) 10 K by the heating system.
              1.2.12.3. The average concentration of the measured hydrocarbons shall be determined by integration.
              1.2.12.4. The heated sampling line shall be fitted with a heated filter (FH) 99 per cent efficient with particles ≥ 0.3 μm, to extract any solid particles from the continuous flow of gas required for analysis.
              1.2.12.5. The sampling system response time (from the probe to the analyser inlet) shall be no more than four seconds.
              1.2.12.6. The HFID shall be used with a constant flow (heat exchanger) system to ensure a representative sample, unless compensation for varying CFV or CFO flow is made.
              1.3.  Gas Analysis Requirements
              1.3.1.  Carbon monoxide (CO) and carbon dioxide (CO2) analyses:
                Analysers shall be of the non-dispersive infra-red (NDIR) absorption type.
              1.3.2.  Total Hydrocarbons (THC) analysis - spark-ignition engines:
                The analyser shall be of the flame ionisation (FID) type calibrated with propane gas expressed equivalent to carbon atoms (C1).
              1.3.3.  Total Hydrocarbons (THC) analysis - compression-ignition engines:
                The analyser shall be of the flame ionisation type with detector, valves, pipework, etc., heated to 463 K (190 °C) 10 K (HFID). It shall be calibrated with propane gas expressed equivalent to carbon atoms