基于激光光谱差分法检测NO2

为了分析大气污染的主要污染气体之一的二氧化氮(NO2)的光谱与气体体积分数之间的关系,采用了中心波长位于NO2高吸收峰位置的激光作为检测光源,建立了光谱气体检测系统。根据朗伯-比尔定律,采用分时差分方法,结合权威数据库对比,并考虑光谱线宽度等因素影响,进行光谱分析,用最小二乘法进行数据拟合,取得了NO2吸收光谱与其体积分数的关系曲线数据,并进行了体积分数反演和误差分析。结果表明,实验结果与理论分析相吻合,验证了光谱检测对NO2检测的研究与应用价值。

NO2 detection based on laser spectrum differential method

In order to analyze the relationship between spectra and gas volume fractions of NO2 which is one of the main pollution gases, laser whose center wavelength was located in the peak of NO2 absorption was chosen as light source and a gas spectra detection system was built. The spectrum was analyzed according to Lambert-Beer law, using time-sharing differential method, comparing with authoritative database and considering the spectral area and other factors. The data were fitted by the least squares method and the relationship curve between NO2 absorption spectra and NO2 volume fractions was obtained. The data of volume fractions was inversed and the error was analyzed. The experimental results agree well with the theoretical analysis. The research value and the application value of the experimental system are verified.