红外吸收式光纤甲烷气体传感系统的研究

Methane Sensing System Based on Infrared Absorption

通过对甲烷气体吸收光谱的分析,结合光学器件的发展情况,提出了红外吸收式光纤甲烷气体传感测试方法。该测试系统基本工作原理是多分子气体对特征吸收波长的光吸收作用随浓度变化而变化。该系统以1.33μm波长的分布反馈式半导体激光器(DFB LD)作为光源,响应灵敏度1 nW的光功率计作为光探测器。采用单光路传输,通过实验说明红外吸收式光纤甲烷气体传感器可靠检测小于体积分数15%的甲烷体,为其进行报警等应用打下基础。

By analyzing absorption spectrum of methane gas and development trend of optical device, this paper presents a methane-sensing system based on the infrared absorption principle, which refers to that a multi-molecule gas will absorb light at its characteristic wavelength and then the changing intensity of light is the indication of the concentration of the gas. In the system, a DFB LD with wavelength 1.33 μm serves as the light power, and an optical power meter is used for detecting the intensity of light. Experiments verified that the system is reliable for detecting mathane with concentration of less than 15 % by infrared absorption, laying foundation for its real applications such as alarm.