Proposal to replace para. 9.3.2.1., replace paras. 9.3.2.8.1. and 9.3.2.9.1., amend paras. 9.3.9.2.2. and 9.3.9.6., and insert new Appendices 10 and 11. The replacements clarify measurement principles, specify that analyser assessment may be conducted by type-approval authorities, designated technical services, or metrological institutes preferably via witnessed testing at the instrument manufacturer premises, and provide protocols and certificate models for analyser assessment. Amendments to para. 9.3.9.2.2. permit alternative humidification techniques and clarify that test gas shall be humidified to a water concentration approximately equal to the maximum water concentration expected during emission testing for all fuels. Amendment to para. 9.3.9.6. specifies that spectral resolution shall have a nominal value ≤0.5 cm⁻¹ to minimise cross interference.