Proposal to improve FTIR/QCL Analyser Examination (Para. 9.3.2.8.1, 9.3.2.9.1, 9.3.2.10, Appendices 10–11), including expanding the examination authority to include type-approval authorities and technical services, requiring witnessing of the testing at the instrument manufacturer’s facility, and introducing new appendices providing an examiner template and a verification certificate format, and to permit other techniques for the water quench check (Para. 9.3.2.9.9) to address the adverse effects of H₂O and CO₂ on the CLD’s NOx response and align with the provisions of 40 CFR 1065.750(e)(5).