Influence of the Concentration Measurement of Carbon Monoxide with Temperature

In order to figure out the concentration of carbon monoxide, by measuring the second and third harmonics of the absorption spectrum line, this paper obtained results which indicate that this method can be applied to industry field. Tunable semiconductor laser of 1.58um can be used, and its wavelength is a nice window of communication in long wavelength band of fiber. The measurement optical paths can well be integrated with fiber and passive component in fiber system and it is already applied to industry field. Moreover, the 1.58um spectrum line is an absorption peak of carbon monoxide and around the spectrum line, there is a good transmission window in the background gas of atmosphere. It is very well to measure carbon monoxide concentration. Through measuring peaks of the first and second harmonic or the second and fourth harmonic of absorption spectrum lines of carbon monoxide with tunable diode laser absorption spectroscopy (TDLAS) technique, the carbon monoxide concentration can accurately be calculated by composition algebra. This paper focuses on the study that the absorption coefficient changes with temperature. As the absorption coefficient of different temperature changes, the parameters of concentration measurement will change. This is a very complicated process.