基于红外差分吸收的矿井瓦斯浓度分布式监测系统

Distributed Monitoring System of Mine Gas Concentration Based on Differential Infrared Absorption

为了实现矿井瓦斯气体浓度的实时监测和预警,设计了一套基于近红外差分吸收光谱原理的矿井瓦斯浓度分布式光纤监测系统。选用中心波长为1650nm的DFB激光器作为光源。选择Newport公司生产的325型号温控器和525型号驱动器,将激光器输出波长稳定在1653.7nm处。采用光分束器将激光分为两路信号,分别连接气体吸收室和参考气室。以PIN光电二极管为光电探测器,设计了光电转换电路,进行了瓦斯浓度测量实验,并得到瓦斯气体浓度的计算表达式。实验结果表明该系统能够准确地测量瓦斯浓度。

In order to realize the real time monitoring and early warning of the gas concentration in mines,a distributed optical fiber monitoring system based on the differential infrared absorption was developed.A DFB laser diode with 1650 nm as central wavelength was adopted.The 325 type of temperature controller and 525 type of driver were both selected to make the output wavelength of the laser stable at 1653.7nm.A beam splitter was used to split the laser into two beams.One was connected with a gas absorption chamber while the other one was connected with a gas reference chamber.Two photoelectric transformation circuits were designed with the PIN photodiodes as detectors.Several experiments were conducted to measure the mine gas concentration,and the computational expression of gas concentration was obtained.The results show that this system can perform measurements accurately and reliably.