Infrared Absorption Coefficients for Certain Pollutant Gases

Abstract

Quantitative analysis of gas mixtures by infrared spectroscopy requires a knowledge of the absorption coefficients,: kν−, as a function of optical path length and temperature. For the majority of pollutant gases, information is scarce or incomplete. The objective of this work was to determine absorption coefficients for CH4, C2H4, CO2, CO, SO2, NO2, NO, and H2S. Measurements were made at room temperature and elevated temperatures for certain wave lengths, and kν− was determined over a very wide range of optical path length, x. The validity of the Bouguer-Beer law was confirmed for a limiting range of x, and for larger values of x, kν− decreased and was correlated as a function of x and T.