基于可调谐半导体激光吸收光谱的H2O分子光谱参数测量研究

气体分子吸收谱线的光谱参数是影响吸收光谱测量精度的重要因素，分子光谱数据库中收录的光谱参数大都具有较大的不确定度，用以测量气体温度等参数时会产生较大的测量误差。为了获得可用于燃烧场诊断的H₂O谱线的光谱参数，采用时分复用技术，在温度、压强和H₂O组分浓度可控的环境中对1.4 μm附近的吸收光谱开展了研究。对7 185.60和7 454.45 cm-1两条H₂O谱线的线强度、展宽系数及其温度指数等光谱参数进行测量，实验结果表明，两条谱线的线强度测量值与数据库中的值偏差分别小于2.61%和4.65%，不确定度都小于4%。

Measurements of H2O Spectroscopic Parameters Based on the TunableDiode Laser Absorption Spectroscopy

The spectroscopic parameters of gas absorption lines are an important factor that can influence gas parameters’measurement accuracy based on laser absorption spectroscopy technology.However,the spectroscopic parameters in the molecule spectral database exist big uncertainties,resulting in the obvious measurement errors when used in laser absorption technology measurement.To obtain the spectroscopic parameters of H₂O lines that can be used in the combustion diagnosis,time-division multiplexing technique is adopted to measure the absorption spectroscopy near 1.4μm in the environments where the temperature,pressure and H₂O concentration are known.The line strength,broadening coefficients and their temperature-dependent exponents of two H₂O lines(7185.60 and 7454.45 cm^-1)are measured,and the measured line strength of the two lines is less than 2.61%and 4.65%compared to the value in the HITRAN database.The uncertainty of the measured line strength of two lines is less than 4%.