光子学报, 2021, 50 (4): 198, 网络出版: 2021-05-11
光声光谱多组分气体分析仪的交叉干扰特性研究 下载: 823次
Cross Interference Characteristics of Photoacoustic Spectroscopy Multi-gas Analyzer
光声光谱 多组分气体检测 红外光谱 交叉干扰 测量误差 Photoacoustic spectroscopy Multi-gas detection Infrared spectroscopy Cross interference Measurement error
摘要
设计了一套基于红外热辐射光源的光声光谱多组分气体分析仪。通过分析多组分气体间交叉干扰的主要因素以及特征气体的红外吸收谱线,确定了中红外带通滤光片的参数。利用标准气体对设计的光声光谱仪进行标定,研究了待测气体之间交叉干扰的定量关系,并利用湿度发生器对装置受到水气干扰情况进行分析。实验结果表明,C2H2对CH4、CH4对C2H6的干扰水平分别达到10.49 μV/(μL/L)、18.66 μV/(μL/L),其他烃类气体间的干扰可以忽略。CO2对CO、CH4、C2H2和C2H4干扰响应度分别为1.615 μV/(μL/L)、0.055 μV/(μL/L)、0.130 μV/(μL/L)以及0.016 μV/(μL/L)。此外,水气对C2H2、CH4、C2H6、C2H4、CO和CO2都会产生一定的干扰,干扰的响应度分别为0.591 μV/(μL/L)、0.421 μV/(μL/L)、0.071 μV/(μL/L)、0.007 μV/(μL/L)、0.051 μV/(μL/L)和0.055 μV/(μL/L)。实验结果表明C2H2对CH4、CH4对C2H6、CO2对CO以及高浓度水气对其他气体的检测会产生较高水平的干扰,在测量过程中应当考虑扣除。
Abstract
A photoacoustic spectroscopy multi-gas detection system based on infrared heat radiation light source was developed. The broadband mid-infrared thermals radiation source and band-pass filter were used to generate the photoacoustic excitation light. Combined with a small-volume non-resonant photoacoustic cell, the time-sharing measurement of multi-component gas concentration was realized. The parameters of the mid-infrared bandpass filter were determined by analyzing the main factors of cross-interference among multi-component gases and the infrared absorption spectrum of target gases. To determine the quantitative relationship of cross interference among the gases to be measured, the photoacoustic spectrometer system was calibrated by using the standard gas, and a humidifier was used to analyze the interference from water vapor. The experimental results showed that the interference levels of C2H2 to CH4 and CH4 to C2H6 reached 10.49 μV/(μL/L) and 18.66 μV/(μL/L) respectively, and the interference between other hydrocarbon gases can be ignored. The responsiveness of CO2 to CO, CH4, C2H2 and C2H4 interference was 1.615 μV/(μL/L), 0.055 μV/(μL/L), 0.130 μV/(μL/L) and 0.016 μV/(μL/L), respectively. In addition, water vapor will cause certain interference to C2H2, CH4, C2H6, C2H4, CO and CO2, and the responsiveness of the interference was 0.591 μV/(μL/L), 0.421 μV/(μL/L), 0.071 μV/( μL/L), 0.007 μV/(μL/L), 0.051 μV/(μL/L) and 0.055 μV/(μL/L). The experimental results indicated that there was a high level of interference when detecting CH4 in C2H2 background, C2H6 in CH4 background, CO in CO2 background, and other target gases in high concentration water vapor background, which should be considered in the measurement process.
袁帅, 王广真, 付德慧, 陈珂, 安冉, 张博, 郭珉, 张广寅. 光声光谱多组分气体分析仪的交叉干扰特性研究[J]. 光子学报, 2021, 50(4): 198. Shuai YUAN, Guangzhen WANG, Dehui FU, Ke CHEN, Ran AN, Bo ZHANG, Min GUO, Guangyin ZHANG. Cross Interference Characteristics of Photoacoustic Spectroscopy Multi-gas Analyzer[J]. ACTA PHOTONICA SINICA, 2021, 50(4): 198.