Monitoring NO and CO in Aircraft Jet Exhaust by a Gas-Filter Correlation Technique.

摘要

The exhaust from jet engines contains many pollutant gas species. At the present time a convenient, reliable method is needed to monitor their concentrations. There are many different methods available for determining concentrations of pollutant gases in the effluent from smokestacks, aircraft, automobiles and other pollutions sources. Each method has its merits and its difficulties depending on the application. A class of instruments employing gas-cell correlation spectroscopy to provide good sensitivity and specificity at relatively low cost has been developed for a variety of applications. An infrared instrument using a gas-filter correlation technique was used to in-situ monitor NO and CO in the exhaust plume of a T56 jet engine combustor. The instrument, built previously by Aeronutronic Ford for EPA to monitor pollutant gases in smokestack exhausts, was modified for use on the combustor. Temperatures and concentrations ranged from 300 to 930K and up to 130 ppm for NO; for CO from 300 to 550K and up to 220 ppm. Optical results were obtained simultaneously by withdrawing the sample using probe techniques and analyzing the gas with a conventional gas analyzer.