8.2 Hydrocarbon response factors
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Statutory Documents - IMO Publications and Documents - International Codes - NOx Technical Code (2008) - Technical Code on Control of Emission of Nitrogen Oxides from Marine Diesel Engines - Appendix 4 - Calibration of the analytical and measurement instruments - 8 Adjustment of the HFID - 8.2 Hydrocarbon response factors

8.2 Hydrocarbon response factors

  8.2.1 The analyser shall be calibrated using propane in air and purified synthetic air, according to 5.

  8.2.2 Response factors shall be determined when introducing an analyser into service and after major service intervals. The response factor (r h) for a particular hydrocarbon species is the ratio of the (H)FID ppmC reading to the gas concentration in the cylinder expressed in terms of ppmC.

  8.2.3 The concentration of the test gas must be at a level to give a response of approximately 80% of full scale. The concentration must be known to an accuracy of ± 2% in reference to a gravimetric standard expressed in volume. In addition, the gas cylinder must be preconditioned for 24 hours at a temperature of 25°C ± 5°C.

  8.2.4 The test gases to be used and the recommended relative response factor ranges are as follows:

  • – Methane and purified synthetic air 1.00 ≤ r h ≤ 1.15

  • – Propylene and purified synthetic air 0.90 ≤ r h ≤ 1.1

  • – Toluene and purified synthetic air 0.90 ≤ r h ≤ 1.1

 These values are relative to a r h of 1 for propane and purified synthetic air.

Parent topic: 8 Adjustment of the HFID
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