8 Interference effects with CO, CO2, NOx and O2 analysers
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Statutory Documents - IMO Publications and Documents - International Codes - NOx Technical Code - Technical Code on Control of Emission of Nitrous Oxides from Marine Diesel Engines - Appendix 4 - Calibration of the analytical instruments - 8 Interference effects with CO, CO2, NOx and O2 analysers

8 Interference effects with CO, CO2, NOx and O2 analysers

 Gases present in the exhaust other than the one being analysed may interfere with the reading in several ways. Positive interference may occur in NDIR and PMD instruments where the interfering gas gives the same effect as the gas being measured, but to a lesser degree. Negative interference may occur in NDIR instruments by the interfering gas broadening the absorption band of the measured gas, and in CLD instruments by the interfering gas quenching the radiation. The interference checks in 8.1 and 8.2 below shall be performed prior to an analyser's initial use and after major service intervals.

Parent topic: Appendix 4 - Calibration of the analytical instruments
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