一种改进型高灵敏红外CO浓度检测方法  

An Improved Highly Sensitive Infrared Detection Method for CO Concentration

作　　者：李明勇[1] 兰江[1] 石俊杰[1] 黄启勇[1] 白丽丽[1] 

机构地区：[1]中国船舶重工集团公司第七一〇研究所,湖北宜昌443003

出　　处：《自动化仪表》2016年第9期71-74,共4页Process Automation Instrumentation

基　　金：湖北省科技支撑计划基金资助项目(编号:2014BEC088)

摘　　要：针对CO气体对红外光谱吸收系数低、低浓度CO检测难度大的问题,采用非散射红外光谱吸收法,通过电学调制方式,设计了一种改进型高灵敏红外CO浓度检测装置,并给出了光学模块和电路结构设计方法。针对检测信号频率低、噪声大的问题,设计了一种性能良好的选频器以及能抑制其温度漂移的拓扑结构,提高了检测信号的信噪比,并减小了温度变化对CO浓度检测的影响。此外,还给出了CO浓度的计算方法。试验结果表明,仪器检测灵敏度可达0.3×10-6。Aiming at the problem that the infrared spectrum absorption coefficient of CO is low, and the difficulty of low CO concentration detection, an improved highly sensitive infrared CO concentration detector is designed based on non - dispersive infra - red （ NDIR） method and electrical modulation mode; the design method of optical module and electrical circuit is presented. Due to the detection signal of low frequency and large noise, an excellent frequency selector and the topological structure for suppressing the temperature drift are designed to improve the signal/noise ratio of detection signal and decrease the influence of temperature drift on CO concentration detection. In addition, the calculating method of CO concentration is given. The experimental results show that the detection sensitivity of the instrument is up to 0. 3 × 10 ^-6.

关 键 词：CO 浓度检测 光谱吸收 温漂抑制 温度补偿 选频器 滤波 数据拟合 

分 类 号：TH89[机械工程—仪器科学与技术] TP29[机械工程—精密仪器及机械]