Appendix 4 - Calibration of the Analytical Instruments (Refer to Chapter 5 of the NOx Technical Code)
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Appendix 4 - Calibration of the Analytical Instruments (Refer to Chapter 5 of the NOx Technical Code)

Parent topic: Technical Code on Control of Emission of Nitrogen Oxides from Marine Diesel Engines (NOx Technical Code)

1 Introduction

Chapter 1.1 reads as follows:

 Each analyser used for the measurement of an engine's parameters shall be calibrated as often as necessary in accordance with the requirements of this appendix.

Tables 1, 2, 3 and 4 right hand column headers read as follows:

 Calibration intervals (month).

Interpretation:

 For application of this section it should be interpreted that the calibration intervals as defined by Tables 1, 2, 3, and 4 of appendix 4 represent the duration of calibration validity applicable to the particular measurement instruments listed.

All instruments used for the measurement of an engine's parameters should be verified as being within the defined calibration validity period at the time of the measurement.

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

8.1 CO analyser interference check

8.1 reads as follows:

 Water and CO2 may interfere with the CO analyser performance. Therefore, a CO2 span gas having a concentration of 80 to 100% of full scale of the maximum operating range used during testing shall be bubbled through water at room temperature and the analyser response recorded. The analyser shall not be more than 1% of full scale for ranges greater than or equal to 300 ppm or more than 3 ppm for ranges below 300 ppm.

Interpretation:

 For application of this section the term "The analyser shall not be more than ..." should be interpreted as "The analyser response shall not be more than ..." to correctly reflect the intent of this statement and ISO 8178-1, section 8.9.1.

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