傅里叶变换红外光谱(FTIR)非线性多点定标方法研究

Study on the Method of FTIR Spectrum Non Linear Multiple Point Calibration

给出了线性定标和非线性多点定标的具体算法,并且应用加拿大BOMEM公司的MR-154傅里叶变换红外光谱仪,液氮制冷型中红外MCT探测器测量了中国科学院上海技术物理研究所研制的HFY-300A型黑体在几种不同温度下的辐射谱,其中的一些辐射谱用于定标,用其中的一个特定温度下的辐射谱来检验定标结果。结果表明这种非线性多点定标方法非常可靠,理论辐射谱与定标后辐射谱相对偏差集中在0.2%附近,最大相对偏差仍小于0.4%。

FTIR Technique has developed rapidly since 1980s, and has become increasingly important. It has been used in a variety of fields. In order to make sure the result is of nicety, the authors should manipulate the FTIR spectrometer accurately and study its instrument response function and calibration arithmetic. Because the instrument response of the detector of FTIR spectrometer is different at different wave band, the no-calibrated spectrum was ruleless. Without calibration, we can not obtain the absolute intensity, even relative intensity. There are two calibration arithmetics： Linear calibration arithmetic corresponding linear detector and non-calibration arithmetic corresponding non-linear detector. The present paper gave the arithmetic of linear calibration and non-linear multiple point calibration. The authors measured several blackbody spectra at some different temperatures. Some of them were used for calibration and one was used to test the result of calibration. The result indicated that this method of non-linear multiple point calibration was very good. The relative arbitrary between calibrated blackbody spectrum and standard blackbody spectrum was near 0.2%, while the maximum was still lower than 0.4%.