长程吸收光谱技术在二氧化碳检测中的应用研究

Research on application of long-path absorption spectroscopy technology in carbon dioxide detection area

矿井作业时,二氧化碳浓度超标会对人体产生危害,因此对气体的实时监测便显得尤为重要。将长程吸收光谱技术与TDLAS技术相结合,在有效光程38.4 m的条件下,利用波长调制-二次谐波法(WMS-SH),测量了0.15个大气压下1.43μm附近气体的二次谐波信号,经过线性拟合得到浓度-信号强度线性方程,并对二氧化碳浓度进行反演,评估了系统的性能。计算结果表明,低浓度下二氧化碳与二次谐波信号之间具有良好的线性关系,其相关系数为0.981 3。实现了大气中的含量探测,与实际大气中浓度的典型值一致性很好,可将该系统应用到井下二氧化碳含量监测领域。

During the mine operation, excessive carbon dioxide concentration will be harmful to the human body, so the real-time detection of carbon dioxide is so important. This paper applied the long-path absorptionspeetroscopy technology to the field of ultra-trace gas detection. With the effective length 38.4 m and the 0. 15 atmospheric pressure,by using Wavelength Modulation Spectroscopy - SeeondHarrnonie method （WMS-SH）, the carbon dioxide gas second-harmonic signal around 1.43μm was measured. After the linear fit, the concentration of carbon dioxide and evaluate the performance of this system were deduced. The result shows that there is a good linear relationship between the low concentration of carbon dioxide and the second-harmonic signal, and the correlation coefficient is 0.981 3.The detection of carbon dioxide content in the atmosphere was deduced, which is in good agreement with the typical values in real atmosphere. This system could be used in the real-time detection of carbon dioxide concentration under the pit.