In Situ Measurements of CO in Combustion Gases Based on TDLAS and Analysis on Relevant Influencing Factors

Spectral parameters of CO absorption line were measured under different combustion conditions using a 2.3 μm diode laser by scanned-wavelength direct absorption(DA) strategy based on tunable diode laser absorption spectroscopy(TDLAS),so as to study the influence of pressure and temperature on the width and intensity of absorption line.Results show that the line width increases gradually with the rise of pressure,which requires the laser to have a wide scanning range;spectral line R(30) is highly independent at high pressures,without superimposition with other interference lines,therefore is suitable for measurement of CO absorption line;the influence of particles on measurement precision can be reduced by background elimination method;the intensity of lines in selected band is strong enough at high temperatures(1 000 K),so that direct absorption signals can be obtained,and the complexity of modulation technique can be avoided,which therefore may serve as a reference for study of relevant influencing factors.