CO concentration real-time monitoring in combustion process has great significance in improving combustion efficiency and controlling combustion emissions. No CO-spectroscopy solid state sensors are available at the high temperature of 1600K–2000K in the flames. Gas sensing based on tunable diode laser absorption spectroscopy (TDLAS) with the advantages of high sensitivity, high selectivity, quick response and non-intrusiveness offers the possibility for on-line measurement in combustion environment. CO absorption line located at 2302.12nm is selected for measurement by direct absorption method in premixed C3H8/Air flat flame. Experiment results show that, when equivalence ratio is larger than one, the concentration of CO in the flame is increased with the increase of equivalence ratio. It proves that this method can be used on combustion environment.
