Sun Ming-guo, Ma Hong-liang, Cao Zhen-song, Liu Qiang, Wang Gui-shi, Chen Wei-dong
Guang Pu Xue Yu Guang Pu Fen Xi. 2014 Nov;34(11):2881-6.
The accuracy of absorption spectral parameters is very important for the trace gas measurement based on absorption spectroscopy techniques, especially for the isotopic abundance measurement of gas molecules. For some of the applications, spectral parameters listed in HITRAN database were used to retrieve the trace gas concentration. However, these parameters have uncertainty, in order to validate spectroscopic parameters near 2.0 μm of CO2 lines, which are to be used in detecting the CO2 concentration and isotopic abundance, spectra of those lines were recorded at room temperature using a distributed feed-back (DFB) diode laser. The recorded absorption spectra were fitted to Voigt profile. Line position, intensity, self-broadening coefficient and N2-broadening coefficient were deduced from those data. The results show a good consistency in comparison with those listed in HITRAN2012 database. The discrepancy of most line intensities and self-broadening coefficients are less than 2%. The CO2 concentration and Δ(13 CO2 ) in real atmosphere inside laboratory are 440 ppm and -9 per hundred respectively. These results provide a reliable basis for real time and on line detecting the CO2 concentration and Δ(13 CO2) in the wavelength range.
吸收光谱参数的准确性对于基于吸收光谱技术的痕量气体测量非常重要,特别是对于气体分子的同位素丰度测量。对于某些应用,使用HITRAN数据库中列出的光谱参数来反演痕量气体浓度。然而,这些参数存在不确定性,为了验证将用于检测二氧化碳浓度和同位素丰度的二氧化碳谱线在2.0μm附近的光谱参数,使用分布反馈(DFB)二极管激光器在室温下记录了这些谱线的光谱。将记录的吸收光谱拟合到洛伦兹线型。从这些数据中推导出谱线位置、强度、自展宽系数和N2展宽系数。结果表明,与HITRAN2012数据库中列出的数据具有良好的一致性。大多数谱线强度和自展宽系数的差异小于2%。实验室内部真实大气中的二氧化碳浓度和Δ(13CO2)分别为440ppm和-9‰。这些结果为在该波长范围内实时在线检测二氧化碳浓度和Δ(13CO2)提供了可靠的依据。