【摘要】 为了提高气体差分传感系统的信噪比,基于微弱信号的相关检测原理,设计了以锁相放大器为核心的微弱信号处理电路。实验表明:电路输出电压与检测气体体积分数呈线性关系,电路对气体体积分数的检测极限为150×10-6,检测系统对检测气体体积分数的误差为1%,具有较好的重复性及选择性。更多还原

【Abstract】 In order to improve signal to noise ratio（SNR） of the differential absorption gas sensor system,based on the correlation detection principle,a faint signal processing circuit is designed centering around lock-in amplifier.Experimental results indicate that the output voltage of detective circuit is linear with the gas volume fraction,the limit value is 150×10^-6.The error of the whole detection system to the gas volume fraction is 1 %,the repeatability and selectivity of the system is better.更多还原