一种中红外差分甲烷检测仪的研制  

Development of a mid-infrared differential methane detection device

作　　者：郑悦[1] 党佩佩 叶玮琳[2] 郑传涛[1] 王一丁[1] 

机构地区：[1]吉林大学电子科学与工程学院,集成光电子学国家重点联合实验室吉林大学实验区,吉林长春130012 [2]汕头大学工学院,广东汕头515063

出　　处：《光电子．激光》2016年第4期366-373,共8页Journal of Optoelectronics·Laser

基　　金：国家自然科学基金(61307124);吉林省科技发展计划(20140307014SF);长春市科技发展计划(14KG022)资助项目

摘　　要：根据甲烷(CH4)分子在中红外波段的吸收特性并利用宽光谱红外热辐射光源(IR55),研制了一种基于中红外吸收光谱技术的双通道差分CH4检测仪。通过对双通道探测器(3.31μm和3.90μm)输出的两路信号进行差分处理,有效抑制了系统噪声。给出了系统的检测原理和结构,表征了光源和探测器的光学特性。为了提高聚光效率并增大光程,设计制作了球面反射镜开放气室,其半径约20cm。配备了16种不同浓度的CH4气体样品,开展了气体标定实验,得到了气体浓度与双通道信号幅值电压的关系表达式。误差实验结果显示,对1 6种气体样品的检测误差小于12.4%。对体积分数为5×10-4的CH4气体样品开展的长达10h的浓度测量实验表明,检测结果的相对波动范围为±10%。对测得的实验结果进行数理统计,其标准差为2.06×10-5,进而得到该检测仪的检测下限约为6.18×10-5。In this paper,a dual-channel differential methane（CH4）detection device based on min-infrared absorption spectroscopy is implemented by using the absorption characteristic of CH4 molecule in midinfrared waveband and an infrared light source（IR55）with wide emitting spectrum.Through the differential processing on the two output signals from the dual-channel detector（3.31μm and 3.9μm）,the system noise can be removed effectively.Detection principle and structure are proposed,and the optical characteristics of the light source and the detector are analyzed.In order to improve light collection efficiency and enhance absorption length,structures of spherical reflection mirror and open gas cell are optimized,whose radius is 20 cm.Sixteen CH4 samples with different concentrations were prepared,calibration experiment was carried out using the detection system,and the expression between concentration and two channel signals was derived.System error experiment indicates that the relative detection errors on the 16CH4 samples are less than 12.4%.At the same time,a 10hlong-term concentration detection on the 5×10-4 CH4 sample indicates that variation range of the detected result is±10%.Meanwhile,mathematical statistics on the 10 hresults reveals that the standard derivation is 2.06×10-4,and the limit of detection is estimated to be 6.18×10-4.

关 键 词：光电检测 红外技术与应用 甲烷(CH4)检测 气室优化 

分 类 号：TN929.1[电子电信—通信与信息系统]