Procedure for Measurement of Gaseous Emissions from Aircraft Gas Turbine Engines Using Fourier Transform Infrared Analysis
This Aerospace Information Report (AIR) describes the use of FTIR analyzers for measurements of gaseous emissions from aircraft gas turbine engines and combustion rigs. The use of FTIR analyzers can be demonstrated as a suitable and cost-effective equivalent to NDIR and chemiluminescence analyzers as prescribed in ARP1256 for the measurement of CO, CO2, NO, and NO2, where NOx is closely approximated by the sum of NO and NO2 concentrations. FTIR analyzers may be proven suitable for equivalency of analyzers used in current emission testing. Additionally, FTIR analyzers have potential for equivalent measurements of “total” hydrocarbon (THC) as currently defined in ARP1256.
Fourier transform infrared (FTIR) analyzers can measure gaseous emissions from combustion sources with similar accuracy to present non-dispersive infrared (NDIR) and chemiluminescent-type analyzers recommended by ARP1256 and required by ICAO Annex 16 Vol II. This Aerospace Information Report (AIR) summarizes experience in the use of FTIR instruments in measuring aircraft gas turbine engine and combustion rig exhaust effluents by extraction. The intent of this AIR is to discuss the FTIR analysis method and document the use of FTIR gas analyzer instrumentation prior to development of a future FTIR ARP document. Adoption of FTIR instruments in a measurement system will reduce the number of analyzers currently necessary and may provide the capability to measure detailed hydrocarbon species.