基于TDLAS的乙炔吸收光谱模拟与实验检测

Simulation and Experimental Measurement of Acetylene Absorption Spectrum Based on TDLAS

可调谐二极管激光吸收光谱技术(tunable diode laser absorption spectroscopy,TDLAS)是开发气体传感系统最有吸引力的分析技术之一。基于TDLAS技术开展了6523.879 cm^(-1)处乙炔(C_(2)H_(2))近红外吸收光谱的模拟与实验测试研究。首先,利用LabVIEW软件模拟了Voigt线型条件下的乙炔吸收谱线并与HITRAN2020数据库中的标准吸收谱线进行对比分析,结果显示基于LabVIEW模拟的吸收谱线与标准谱具有良好一致性,证明基于LabVIEW自行建立的吸收谱线模拟程序可直接应用于在线浓度探测系统,具有更加便捷和可操作性强的优势。其次,实验搭建了一套乙炔吸收光谱探测系统,通过检测乙炔在2.5 kPa以内的低压吸收谱线并进行计算分析,测得乙炔谱线强度和自展宽系数与数据库参数相对误差分别为2.5%和1.201%。最后,建立了基于LabVIEW的实时在线检测程序,能够实现C_(2)H_(2)浓度的准确实时快速反演。

Tunable Diode Laser Absorption Spectroscopy(TDLAS)is a prominent analytical technique for developing gas sensing systems.The near infrared absorption spectroscopy of acetylene(C_(2)H_(2))at 6523.879cm^(-1) was simulated and tested based on TDLAS technology.First of all,acetylene absorption spectroscopy under different pressures is simulated based on Lab-VIEW software and compared with the standard absorption spectroscopy in HITRAN2020database.The results show that the absorption spectral line simulated based on LabVIEW is in good agreement with the standard spectrum,which is very suitable for the on-line gas detection system,and has the advantages of convenient operation and strong operability.Secondly,a set of acetylene absorption spectroscopy detection system was successfully established.The relative errors of acetylene absorption line strength and self-broadening coefficient with database parameters are 2.5%and 1.201%,respectively,by measuring and calculating the absorption line of acetylene within 25mbar gas pressure.Finally,a real-time online detection program based on LabVIEW is established,which can realize accurate real-time and fast inversion of C_(2)H_(2)concentration.