A Variety Of Theoretical Study Of The Photoacoustic Spectroscopy Of The Gas Composition

Waveguide CO2 laser based photoacoustic spectrometers have been one of the best tools in the detection of the ultra low concentration toxic gases, the access of atmosphere quality, and the fundamental study of biology, because of their high sensitivity, wide dynamic range, compact structure and high automaticity. The photoacoustic spectrum technology and its development are introduced in this paper. This paper makes a qualitative analysis and a further quantitative calculation on the phase delay resulting from the absorption of CO2 and H2O. The principle of simultaneous measurement of multi-gas component is discussed in detail. This paper proposes two fit approaches to multi spectrum line, one is the liner least square method, and the other is a nonlinear method based on Levenberg-Marquardt arithmetic. The former has been verified with a sample gas consisting of CO2, H2O and C2H4 which is compounded artificially. The latter is debated theoretically about it's feasibility in the analysis of multi spectrum line and need to be verified experimentally.