2.2 Calibration and span gases
Clasification Society 2024 - Version 9.40
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 - 2 Calibration gases - 2.2 Calibration and span gases

2.2 Calibration and span gases

  2.2.1 Mixtures of gases having the following chemical compositions shall be available:

  • .1 CO and purified nitrogen;

  • .2 NOx and purified nitrogen (the amount of NO2 contained in this calibration gas must not exceed 5% of the NO content);

  • .3 O2 and purified nitrogen; and

  • .4 CO2 and purified nitrogen.

Note Other gas combinations are allowed provided the gases do not react with one another.

  2.2.2 The true concentration of a calibration and span gas shall be within ± 2% of the nominal value. All concentrations of calibration gas shall be given on a volume basis (volume percent or volume ppm).

  2.2.3 The gases used for calibration and span may also be obtained by means of a gas divider, diluting with purified N2 or with purified synthetic air. The accuracy of the mixing device shall be such that the concentration of the diluted calibration gases may be determined to within ± 2%.

Parent topic: 2 Calibration gases
Copyright 2022 Clasifications Register Group Limited, International Maritime Organization, International Labour Organization or Maritime and Coastguard Agency. All rights reserved. Clasifications Register Group Limited, its affiliates and subsidiaries and their respective officers, employees or agents are, individually and collectively, referred to in this clause as 'Clasifications Register'. Clasifications Register assumes no responsibility and shall not be liable to any person for any loss, damage or expense caused by reliance on the information or advice in this document or howsoever provided, unless that person has signed a contract with the relevant Clasifications Register entity for the provision of this information or advice and in that case any responsibility or liability is exclusively on the terms and conditions set out in that contract.