傅里叶变换红外吸收光谱的温度修正方法研究

Temperature Correction Method of Absorption Spectrum with FTIR

利用HITRAN数据库中常温下的线强参数修正到了测量温度,利用算法得到合成校准光谱.将合成校准光谱和实验得到的光谱进行非线性最小二乘拟合,从而得到不同温度下的标准CH_4浓度.这种反演算法在常温下具有很高的精度,但随着温度的升高,浓度反演的误差逐渐增大.因此,有必要通过傅里叶变换红外光谱(FTIR)技术,对高温气体反演进行温度修正,利用分区间给出温度修正系数的方法,结合HITRAN数据库,得到了较好的合成校准光谱.

In the HITRAN database, the temperature of the line is modified to the temperature, and then the synthetic calibration spectra are obtained. The synthetic calibration spectra and the spectra obtained by the experiments were performed by nonlinear least squares fitting, and thus the standard of CH4 concentrations was obtained at different temperatures. This inversion algorithm has a high accuracy at room temperature, but with the increase of temperature, the error of the concentration gradually increased. The high-temperature gas temperature correction is carried out by FTIR for the correction of high temperature spectral parameters, better synthetic calibration spectra can be obtained by using partition given temperature correction coefficient method, and combining HITRAN database.