(a) Scope and frequency. If you use FID analyzers for raw exhaust measurements from engines that operate in a non-stoichiometric mode of combustion (e.g., compression-ignition, leanburn), verify the amount of FID O2 interference upon initial installation and after major maintenance.
CFR 40-1065.362-2014 history
2014CFR 40-1065.362-2014 Protection of Environment. Part1065:Engine-testing procedures. Section1065.362:Non-stoichiometric raw exhaust FID O2 interference verification.