针对煤层自然发火特征气体种类多、 检测限低、 现场监测仪器安全要求高等特点， 提出采用傅里叶变换红外光谱分析实现气体的在线分析。 并结合气体的吸收光谱特征与分析要求， 从光谱仪参数选择、 样气制备、 特征变量提取与分析模型建立方面， 介绍了一套行之有效的特征气体光谱分析方法， 然后给出了CH4， C2H6， C3H8， iC4H10， nC4H10， C2H4， C3H6， C2H2， SF6， CO和CO2的测试结果。 结果表明， 采用Tensor 27光谱仪在光谱分辨率为1 cm-1， 光程为10 cm情况下， 所有气体的分辨率优于2×10-6， 满足煤层自然发火气体检测要求。 这表明， 红外光谱分析是一种潜在的煤层自然发火特征气体分析技术， 所采用的方法可以用来进行煤层自然发火特征气体的在线分析。

Aimed at the characteristics of spontaneous combustion gas such as a variety of gases, lou limit of detection, and critical requirement of safety, Fourier transform infrared (FTIR) spectral analysis is presented to analyze characteristic gases of spontaneous combustion. In this paper, analysis method is introduced at first by combing characteristics of absorption spectra of analyte and analysis requirement. Parameter setting method, sample preparation, feature variable abstract and analysis model building are taken into consideration. The methods of sample preparation, feature abstraction and analysis model are introduced in detail. And then, eleven kinds of gases were tested with Tensor 27 spectrometer. CH4, C2H6, C3H8, iC4H10, nC4H10, C2H4, C3H6, C3H2, SF6, CO and CO2 were included. The optical path length was 10 cm while the spectra resolution was set as 1 cm-1. The testing results show that the detection limit of all analytes is less than 2×10-6. All the detection limits fit the measurement requirement of spontaneous combustion gas, which means that FTIR may be an ideal instrument and the analysis method used in this paper is competent for spontaneous combustion gas measurement on line.