激光遥测甲烷气体最低可探测浓度

Minimum Detection Limit for Methane with Single Laser Remote Sensing

对一种使用单一激光源遥感检测甲烷方案的最低可探测的路径-积分浓度进行了理论分析和实验研究,该方案主要采用了频率调制及谐波探测技术。通过理论计算得出了最低可探测甲烷的路径-积分浓度大约为8.7×10-8m。实验中测得该探测系统的探测灵敏度为8.43×10-6m/mV,甲烷最低可探测路径-积分浓度为4.2×10-7m。结果表明该探测系统具有较高的探测灵敏度,完全满足对矿井瓦斯的实时监测要求。

This article carried theoretical analysis and experimental research on the scheme of remote sensing the minimum detection limit concentration for methane gas using a single laser source. In this project, the frequency modulation （FM） and harmonic detection （HD） technologies are adopted. It is obtained through the theoretical calculation that the minimum detection limit concentration for methane gas was about 8.7 ×10^-8 m. Simultaneously the experimental sensitivity of the detection system and the minimum measurable path-integrated concentration were measured to be 8.43× 10^-6 m/mV and 4.2 × 10^-7 m respectively. This results show that the remote sensing system owns a super-high sensitivity and it can satisfy the need of monitoring methane in the coal mine.