基于THz光谱技术的1,3-二硝基苯挥发气体检测方法研究

针对工业生产过程中1,3-二硝基苯挥发气体突发性泄露等情况的发生,设计了一种基于太赫兹(THz)特征光谱吸收技术的检测方法,该方法可通过1,3-二硝基苯在THz波段的特征波长对痕量剧毒有害气体进行检测。系统设计了双气室结构,为THz波提供差分数据,一组为标准空气,另一组为待测样气。由1,3-二硝基苯在THz波段的四个主吸收带0.635,0.912,1.095和1.435THz可根据对应吸收带吸收系数的比例关系得到对应波长上的吸收幅值,最终反演气体浓度。经过对两种传统检测方法的实验分析和对THz吸收检测方法的仿真研究可知,色谱法检测速度无法实现实时检测,红外吸收法对环境湿度要求很高,需经干燥处理,而THz吸收法对环境湿度要求较低,且具备实时性,更适合于实际应用。

Based on THz spectroscopy detection method for the concentration of 1,3-dinitrobenzene volatile gas

For the unexpected situations occur that 1,3-dinitrobenzene volatile gas leaks in industrial production process, designed the differential characteristics absorption detection system for 1,3-dinitrobenzene volatile gas based on THz spectrum technique. The method can detect the concentration of trace 1,3-dinitrobenzene toxic gases through the THz characteristic wavelengths differential absorption method. System dealt with THz characteristics wavelengths of the two chambers, which provide difference dates, a group is standard air, and the other group tested the sample gas. Four main absorption bands of 1,3-dinitrobenzene is at 0.635, 0.912, 1.095 and 1.435 THz nearby in detection results, and according to the ratio of absorption coefficient in the corresponding absorption band it calculated the accurate amplitude from the corresponding wavelengths, at last the gas concentration was inversed. After the two traditional methods (chromatography and infrared absorption method) of experimental analysis and THz absorption detection method of the simulation study shows, precision of the detection capabilities of chromatography is high and error is small. But the chromatography separation time varies with the material, long cycle, slow; chromatography can not achieve real-time detection speed to realize real-time detection. Infrared absorption of environmental humidity is high, subject to drying. At the same time, THz absorption of environmental humidity is low; THz absorption method also has important characteristics of real time, strong anti-jamming, especially the water vapor, so it is more suitable for practical application.