Use of Raman spectrometry in gas analysis

Abstract

The application of a commercial general purpose Raman spectrometer in gas analysis is described. The total information content of the rotational Raman spectra measured with moderate resolution in connection with the linear relationship between the concentration and the power of the scattered radiation is exploited by means of a least squares fit of a linear combination of the spectra of the components to that of the mixture for determining the composition. The feasibility of the method is demonstrated for mixtures composed of CO2, O2, N2, and CO. A relative uncertainty of 1% (2% for CO, the least favourable case) can be achieved with the present equipment. Special difficulties inherent in the method and possibilities for further improvements are discussed. © 1987 Springer-Verlag.