CH_4检测系统微弱信号处理电路研究  

Design on Faint Signal Proceeding Circuit for CH_4 Detection System

作　　者：王艳菊[1] 王玉田[1] 刘静[2] 

机构地区：[1]燕山大学电气工程学院,河北秦皇岛066004 [2]河北师范大学电子系,河北石家庄050031

出　　处：《仪表技术与传感器》2006年第8期41-43,共3页Instrument Technique and Sensor

基　　金：河北省博士基金项目(03547020D);黑龙江省自然科学基金(F0312)

摘　　要：基于光谱吸收原理设计的CH4检测系统,气体吸收的信号比光源的噪声还要小,被淹没在背景噪声中。为改善检测系统的信噪比,针对非常微弱的气体吸收信号,基于微弱信号的锁定检测原理,以锁相放大器为核心,以同步积分器自动跟踪滤波,设计了检测系统的光电信号处理电路。结果表明:电路输出电压与CH4体积分数呈线性关系,电路对CH4气体体积分数的检测极限为150×10-6。In the CH4 detection system designed on the principle of spectrum absorption, the signal of gas absorption is even less than the noise of optical source, it is submerged in the background noise. In order to improve the parameter SNR of the detection system, aiming at the faint gas absorption signal, based on lock-in detection principle, taking lock-in amplifier as the core, using synchronization integrator to be automatic tracking filter, a faint photoelectricity signal processing circuit was designed. The results indicated that the output of detective circuit is linear with the gas volume fraction, the limit value is 150 × 10^-6.

关 键 词：锁相放大器 微弱信号 同步积分器 信噪改善比 

分 类 号：TP274[自动化与计算机技术—检测技术与自动化装置]