光声光谱与TDLAS技术在不同气压下的特性研究

基于PAS与TDLAS的基本原理，讨论了两者之间的联系，推导了光声信号和TDLAS信号与气压的关系式，设计并构造了一个可以同时进行PAS与TDLAS气体测量的对比装置，并对两者在不同气压条件下的测量结果进行了分析和研究，为不同气压条件下的气体测量技术选择提供了参考。试验研究表明：随着气压上升，光声光谱与TDLAS信号均变大，极限检测灵敏度均提高;随着气压上升，气体吸收能量转化为光声信号的效率变低;在低压时，使用光声光谱进行气体检测具有更好的效果。

Study on Pressure Characteristics of Photoacoustic Spectroscopy and TDLAS

Based on priciples of PAS and TDLAS,relevance between them was dicussed,while the relationships of PAS and TD-LAS signal with pressure were derived.A contrast device for making PAS and TDLAS gas detection simultaneously was de-signed and constructed to test different pressure and provide a reference for the gas measurement technology selection under dif-ferent pressure conditions.Experimental studies show that:as the pressure rises,PAS and TDLAS signals become larger,and limit detection sensitivity are improved;with the rising pressure,conversion efficiency from energy absorbed by gas to PAS sig-nals becomes low;at low pressure condiction,PAS is a better choice.