1.1 Emission species measurement
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Statutory Documents - IMO Publications and Documents - Resolutions - Marine Environment Protection Committee - Resolution MEPC.103(49) - Guidelines for On-Board NOx Verification Procedure - Direct Measurement and Monitoring Method - (adopted on 18 July 2003) - Annex - Guidelines for On-Board NOx Verification Procedure - Direct Measurement and Monitoring Method - 1 Analysing Equipment - 1.1 Emission species measurement

1.1 Emission species measurement

  1.1.1 On-board NOx monitoring includes, as an absolute minimum, the measurement of gaseous emission concentrations of NOx (as NO + NO2).

  1.1.2 If determination of exhaust flow is performed, utilizing the NOx Technical Code, appendix 6 (Method 2, universal, carbon/oxygen-balance), then O2 and/or CO2 should be measured and provisions in appendix 6 that assume complete combustion may be used in all cases. If the provisions in appendix 6 that do not assume complete combustion are preferred, then additionally CO and HC should be measured.

  1.1.3 The exhaust gases should be analysed with the following instruments. For non-linear analysers, the use of linearizing circuits is permitted. Other systems or analysers may be accepted, subject to the approval of the Administration, provided they yield equivalent results to that of the equipment referenced below:

  • .1 Oxides of nitrogen (NOx) analysis

    The oxides of nitrogen analyser should be of the Chemiluminescent Detector (CLD) or Heated Chemiluminescent Detector (HCLD) type. The exhaust gas sampled for NOx measurement should be maintained above its dewpoint temperature until it has passed through an NO2 to NO converter.

    Note In the case of raw exhaust gas this temperature should be greater than 333 K (60°C) if the engine is fueled with ISO 8217 DM-grade type fuel and greater than 413 K (140°C) if fueled with ISO 8217 RM-grade type fuel.

  • .2 Carbon dioxide (CO2) analysis

    When needed, the carbon dioxide analyser should be of the Non-Dispersive Infrared (NDIR) absorption type.

  • .3 Oxygen (O2) analysis

    When needed, the oxygen analyser should be of the Paramagnetic Detector (PMD), Zirconium Dioxide (ZRDO) or Electrochemical Sensor (ECS) type.

  • .4 Carbon monoxide (CO) analysis

    When needed, the carbon monoxide analyser should be of the Non-Dispersive Infrared (NDIR) absorption type.

  • .5 Hydrocarbon (HC) analysis

    When needed, the hydrocarbon analyser should be of the Heated Flame Ionization Detector (HFID) type. The exhaust gas sampled for HC measurement should be maintained at 463 K ± 10 K (190°C ±10°C) from the sample point to the detector.

Parent topic: 1 Analysing Equipment
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