Hydrocarbon response factors. If hydrocarbons are measured, the hydrocarbon response factor of the FID shall be verified by following the provisions of paragraph 5.4.3. of Annex B5 to UN Regulation No. 154 on WLTP, using propane-in-air or propane-in-nitrogen as span gases and purified synthetic air or nitrogen as zero gases, respectively.
Hydrocarbon response factors. The analyser shall be calibrated using propane in air and purified synthetic air, according to paragraph 1.5. Response factors shall be determined when introducing an analyser into service and after major service intervals. The response factor (Rf) for a particular hydrocarbon species is the ratio of the FID C1 reading to the gas concentration in the cylinder expressed by ppm C1. The concentration of the test gas must be at a level to give a response of approximately 80 per cent of full scale. The concentration must be known to an accuracy of ± 2 per cent in reference to a gravimetric standard expressed in volume. In addition, the gas cylinder must be pre-conditioned for 24 hours at a temperature of 298 (25 °C) ± 5K. The test gases to be used and the recommended relative response factor ranges are as follows: Methane and purified synthetic air: 1.00 ≤ Rf ≤ 1.15 Propylene and purified synthetic air: 0.90 ≤ Rf ≤ 1.1 Toluene and purified synthetic air: 0.90 ≤ Rf ≤ 1.10 These values are relative to the response factor (Rf) of 1.00 for propane and purified synthetic air.
Hydrocarbon response factors. The analyser shall be calibrated using propane in air and purified synthetic air, according to paragraph 1.5. Response factors shall be determined when introducing an analyser into service and after major service intervals. The response factor (Rf) for a particular hydrocarbon species is the ratio of the FID C1 reading to the gas concentration in the cylinder expressed by ppm C1. The concentration of the test gas shall be at a level to give a response of approximately 80 per cent of full scale. The concentration shall be known to an accuracy of ±2 per cent in reference to a gravimetric standard expressed in volume. In addition, the gas cylinder shall be pre-conditioned for 24 hours at a temperature of 298 K (25 oC) ± 5 K. The test gases to be used and the recommended relative response factor ranges are as follows:
