OXYGEN CONCENTRATION AND TEMPERATURE SIMULTANEOUS MEASUREMENT BASED ON TUNABLE DIODE LASER ABSORPTION SPECTROSCOPY

Tunable Diode Laser Absorption Spectroscopy (TDLAS) technology is an ideal method to detect trace gas quantitatively based on the wavelength tunable character of diode laser. It can obtain the absorption spectroscopy in the characteristic absorption region. It can be used for trace gas detection and industrial combustion control due to its advantages of high sensitivity, high selectivity, quick respond and on-line measurement. Simultaneous measurement of O(2) concentration and temperature in combustion environment has great significance for improving combustion efficiency and reducing pollutants emission. A pair of O(2) absorption lines location at 13150.19cm(-1) and 13160.34cm(-1) was selected for measuring. Absorption line in 13150.19 cm(-1) is selected for concentration measurement because of bigger line-strength. By detection of the background absorption simultaneously, the effecting of the O2 in air atmosphere can been remove. O(2) concentration and temperature is simultaneously measured on high temperature test bench in laboratory based on TDLAS. Experimental results show that when concentration of O(2) higher than 2.5%, within the temperature range from 373K to 723K, the calculation error of concentration and temperature were below 4% the results coincide with calibration value. Simultaneous measuring of O(2) concentration and temperature has been done on an oil burner, the result proves that this method can be used on combustion environment.