可调谐半导体激光吸收光谱(tunable diode laser absorption spectroscopy,简称为TDLAS)技术具有高灵敏度、快速响应、非接触式、环境适应性强等优点,能够实现燃烧温度、组分浓度、速度等参量的实时动态在线测量。为准确测量高温下的水汽浓度,采用窄带半导体激光器作为光源,结合实验室的高温测量系统,记录了常压下1.39μm附近水汽在773~1 273K温度范围内的吸收光谱,利用多线组合非线性最小二乘法拟合得到高温吸收光谱的吸光度,找出了两条适合高温水汽浓度测量的吸收线7 154.35和7 157.73cm-1,首次提出高温水汽浓度测量的模型求解方法,该方法测得的高温下水汽浓度符合理论推理,浓度测量的标准误差低于0.2%,相对误差低于6%。通过实验验证了该测量方法的可行性。 Tunable diode laser absorption spectroscopy (TDLAS) technology has the advantages of high sensitivity, fast response, non-contact, strong environmental adaptability, and real-time performance of the combustion temperature, component concentration, Dynamic online measurement. In order to accurately measure the water vapor concentration at high temperature, a narrow-band semiconductor laser was used as the light source, combined with the laboratory high-temperature measurement system, the absorption spectra of water vapor near 1.39μm under the pressure of 773 ~ 1 273K were recorded. Linear least squares method was fitted to get the absorbance of high temperature absorption spectrum. Two absorption lines 7 154.35 and 7 157.73cm-1 which were suitable for measurement of water vapor concentration at high temperature were found. The model solution method of water vapor concentration measurement at high temperature was proposed for the first time. The water vapor concentration at high temperature conforms to the theoretical reasoning, the standard error of the concentration measurement is less than 0.2% and the relative error is less than 6%. The feasibility of this method is verified by experiments.