1.3 Accuracy of analytical instruments
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 - 1 Introduction - 1.3 Accuracy of analytical instruments

1.3 Accuracy of analytical instruments

Parent topic: 1 Introduction

1.3.1 Permissible deviation of instruments for measurements on a test bed

 The calibration of all measuring instruments shall comply with the requirements as set out in tables 1 and 2 and shall be traceable to national or international standards.

Table 1 Engine-related permissible deviations for measurements on a test bed

No. Item Permissible deviation

(± % values based on engines' maximum values)

 Calibration intervals

(months)
1 Engine speed 2% 3
2 Torque 2% 3
3 Power 2% not applicable
4 Fuel consumption 2% 6
5 Air consumption 2% 6
6 Exhaust gas flow 4% 5

Table 2 Permissible deviations of essential measured parameters for measurements on a test bed

No. Item Permissible deviation

(± absolute values)

 Calibration intervals

(months)
1 Coolant temperature 2 K 3
2 Lubricant temperature 2 K 3
3 Exhaust gas pressure 5% of maximum 3
4 Inlet manifold depressions 5% of maximum 3
5 Exhaust gas temperature 15 K 3
6 Air inlet temperature (combustion air) 2 K 3
7 Atmospheric pressure 0.5% of reading 3
8 Intake air humidity (relative) 3% 1
9 Fuel temperature 2 K 3

1.3.2 Permissible deviation of instruments for measurements on board a ship for verification purposes

 The calibration of all measuring instruments shall comply with the requirements as set out in tables 3 and 4 and shall be traceable to national or international standards.

Table 3 Permissible deviation of instruments for engine-related parameters for measurements on board a ship

No. Item Permissible deviation

(± % based on maximum engines' values)

 Calibration intervals

(months)
1 Engine speed 2 % 3
2 Torque 5 % 3
3 Power 5 % not applicable
4 Fuel consumption 4%/6% diesel/residual 6
5 Specific fuel consumption not applicable not applicable
6 Air consumption 5% 6
7 Exhaust gas flow 5% calculated 6

Table 4 Permissible deviations of instruments for other essential parameters for measurements on board a ship

No. Item Permissible deviation


(± % absolute values or "of reading")

 Calibration intervals

(months)
1 Coolant temperature 2 K 3
2 Lubricating oil temperature 2 K 3
3 Exhaust gas pressure 5% of maximum 3
4 Inlet manifold depressions 5% of maximum 3
5 Exhaust gas temperature 15 K 3
6 Air inlet temperature 2 K 3
7 Atmospheric pressure 0.5 % of reading 3
8 Intake air humidity (relative) 3% 1
9 Fuel temperature 2 K 3
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.