搭建了一套基于LabVIEW的实时、在线气体高分辨率光谱探测系统，采用离轴入射腔增强吸收光谱技术，将外腔式二极管激光器(ECDL)作为激光光源，实现了粗细两种扫描方式的光谱测量，获得了CO2分子在6358.65 cm-1处的弱吸收谱峰、吸收光谱强度、线宽与气体浓度的关系，采用该吸收峰使整个系统的最小探测灵敏度达1.1×10-6 cm-1。在波数为6450～6530 cm-1范围内，所获得的CO2分子振动转动光谱与模拟结果基本一致。实验结果表明该系统不仅可行，而且具有较高的探测灵敏度和光谱精度，能满足气体不同光谱的探测需求。

A real-time, on-line gaseous detection system with high-resolution spectrum is built based on LabVIEW. It employs off-axis cavity enhanced absorption spectroscopy technology, and uses an external cavity diode laser (ECDL) as a laser light source. Two kinds of scan mode, one in roughness, the other in fineness for spectral measurement are achieved. A weak absorption spectrum of CO2 molecule as well as the relationship among the spectral intensity, line width and gaseous concentration is obtained at wave number of 6358.65 cm-1. The minimum detection sensitivity is 1.1×10-6 cm-1 for the entire system when using the 6358.65 cm-1 spectral line. Vibration-rotation spectra of CO2 molecule from experiment is basically consistent with the simulation results in the wave number range of 6450~6530 cm-1. Experimental results indicate that this system is not only feasibility but also has high detection sensitivity and spectral resolution, and meets the different spectral detection requirements of gas.