差分红外型甲烷浓度光纤网络传感系统的研究

基于甲烷气体在其特征吸收波长下光的吸收程度随浓度变化的机理和差分吸收测量方法,结合空分复用技术和长光程吸收池技术,并考虑煤矿矿井中环境的特点,复用多个气体吸收型光纤传感器.介绍了利用差分红外光谱方法测量矿井中甲烷浓度的光纤网络传感系统的工作原理,给出了系统的结构框图.实验表明,吸收气室光程长为20 cm时,该传感器的检测限为4.278 mg/m3,精确度和稳定性可以满足实际要求,可在不同场合进行多点在线测量.

Research on Differential Infrared Optic-Fiber Network Sensor System for Monitoring Methane Concentration

Taking advantages of the principle of optic absorption varied with methane concentration at its characteristic absorbent wavelength and differential absorption measurement,combining space division multiple access technology(SDMAT) and long optical path absorbent pool technology,and considering the circumstance characteristic of the coal mine,this paper proposes to adopt multiple gas absorption optic-fiber sensors to monitor methane concentration.After introducing the principle of optic-fiber sensor system for monitoring methane concentration in coal mine by differential infrared,this paper has presented the block diagram of the monitoring system.It is shown that the minimal detect limit of the sensor reaches 4.274 mg/m~3,and that the precision and stability satisfy practical application.The instrument can be used for on-line measurement with multiple points on different spots.