基于无吸收谱线区域检测谐波的背景消除方法

Background Elimination Method Based on Harmonic Detection in No Absorption Spectral Region

在应用可调谐半导体激光吸收光谱(TDLAS)技术的开放和密闭式气体检测中,提出一种基于无吸收谱线区域检测谐波(HDINASR)的背景消除方法。分析了背景信号成分,设计了背景信号搜索方法和谱线选取原则,给出相邻吸收谱线之间的最小波长间距公式。以氟化氢(HF)气体为检测对象,利用TDLAS实验系统设计相应的实验,确定HF目标吸收谱线、激光器工作温度、背景搜索温度范围和采样周期。实验结果表明,使用HDINASR背景消除前后的曲线相关度提高了3.4%,体积分数精度提高的相对幅度为5.8%。HDINASR为开放和密闭式的气体检测提供一种有效的背景消除方法。

A background elimination method based on harmonic detection in no absorption spectral region （HDINASR） is proposed. It can be used in open and closed gas detection based on tunable diode laser absorption spectroscopy （TDLAS）. Background signal component is discussed, background signal searching and spectral line selection principle are designed, and the minimum wavelength spacing formula between adjacent absorption spectral lines is given. The experiment is designed to detect hydrogen fluoride （HF） using TDLAS experimental system. The HF target absorption spectral line, laser working temperature and temperature range of background searching are determined. Experimental results show that with the application of HDINASR background elimination, the curve correlation is increased by 3.4 % and the relative amplitude of volume fraction accuracy improving is increased by 5.8 %. HDINASR provides an effective background elimination method for open and closed gas detection.