气体流量对石英增强型光声光谱检测精度的影响

石英增强型光声光谱(QEPAS)检测技术在痕量气体浓度检测方面具有灵敏度高、可靠性好、系统体积小等优势。以二氧化碳(CO2)为目标气体,深入研究不同气体流量对QEPAS检测系统精度的影响。通过Fluent ANSYS仿真软件对气体流场进行分析,完成对不同流量情况下气室内压强和流速的仿真。通过基于QEPAS的CO2气体检测系统的实验,研究了气室压强对气体浓度检测的影响。实验结果表明通过控制气体流量使得气室内的压强为1.08e-1~1.48e-1 Pa时,检测信号与气体浓度之间线性关系良好,相关系数R=0.99971,系统相对误差为0.5%,系统检测下限为72ppm。

Effect of gas flow rate on detection accuracy of quartz enhanced photoacoustic spectroscopy

Quartz enhanced photoacoustic spectroscopy (QEPAS) has the advantages of high sensitivity, good reliability and small system volume in the detection of trace gas concentration. Taking carbon dioxide (CO2) as the target gas, the influence of different gas flow rates on the accuracy of qepas detection system was studied. The flow field of gas is analyzed by fluent ANSYS simulation software, and the simulation of pressure and velocity in the air chamber is completed by simulation software. The influence of gas chamber pressure on gas concentration detection is studied by the experiment of CO2 gas detection system based on QEPAS. The experimental results show that when the pressure in the gas chamber is 1.08e-1~1.48e-1 Pa by controlling the gas flow, the linear relationship between the detection signal and the gas concentration is great, the correlation coefficient R = 0.99971, the relative error of the system is 0.5%, and the detection limit of the system is 72ppm.