差动吸收式光纤气体传感器研究

Study on Differential Absorption Gas Sensor with Optical Fiber

本文基于甲烷和乙炔气体的光谱吸收特性,设计了一种差动吸收式光纤气体监测仪。根据被测气体的吸收峰值波长选择LED作为光源。采用不同频率的光源驱动电路实现多种气体浓度的实时检测。为保证测量精度,采用测量信号与参考信号的比值作为输出信号,以及相敏检测技术。对甲烷和乙炔气体浓度的检测实验表明,该系统具有较好的检测灵敏度和测量精度。该系统稍加改变结构参数,也可测量其它气体的浓度。

The differentialabsorption gas monitor with optical fiber is proposed based on the characteristic of spectrum absorption of the methane and acetylene. The LED of driving light source is selected by the absorptive peak wavelength of measured gas. The light source driving circuit with the different frequency is used to detect the varied gas in real time. The techniques of phase-sensitive detecting technique and ratio between measured signal and reference signal is used to ensure measurement accuracy. The experiment result of methane and acetylene intensity indicates that the system has higher detection sensitivity and accuracy. Theinstrument and system can also measure other gas intensity under the structure parameter is changed.