光谱吸收型气体分析仪校准技术研究

Study on Calibration Technology of Spectral Absorption Gas Analyzer

光谱吸收型气体分析仪适合在开放场所应用,而可调谐半导体激光吸收光谱(TDLAS)气体分析仪具有不受粉尘、视窗、环境参数和背景气体交叉干扰,反应速度快和精度高等优点,近年来广泛地应用于恶劣工况的现场监测,但在线校准溯源技术的相关研究甚少。从TDLAS吸收光谱模型出发,分析了TDLAS分析仪测量原理和分类,提出采用标准浓度腔来校准TDLAS气体分析仪的方案。该方案提供了一种浓度均匀、量值稳定且背景单一的标准气体环境,成功对TDLAS分析仪进行了校准。经校准实例证明,方法可行,测量不确定度接近于标准气源的不确定度,最好可达1.1%。

Spectral absorption gas analyzers can be applied in open places,while TDLAS gas analyzer has the advantages of being free from cross interference of dust,window,environmental parameters and background gas,fast response speed and high accuracy.In recent years,it has been widely used in the field monitoring of severe working conditions,but there is little research on online calibration and traceability technology.Based on the TDLAS absorption spectrum model,the measuring principle and classification of TDLAS analyzers are analyzed,and scheme of calibrating TDLAS gas analyzers with standard concentration chamber is proposed.This scheme provides a standard gas environment with uniform concentration,stable quantity and single background,and successfully calibrates the TDLAS analyzer.The calibration example shows that the method is feasible,and the measurement uncertainty is close to the uncertainty of the standard gas source,and the best measurement uncertainty is 1.1%.