以CCD为探测器的长程差分吸收光谱系统

介绍了采用科研级面阵CCD作为探测器的长光程差分吸收光谱系统,对该系统所使用的CCD探测器的偏置、暗电流、噪音、线性响应以及光谱仪的分辨率、光谱范围等性能进行了详细的测试,并将北京外场实验DOAS系统测量SO2、NO2的结果与传统点式仪器的测量结果进行了比较.结果显示,两种方法有着很好的一致性.性能测试和对比结果表明该系统的性能较为优越,满足多种痕量气体的同时、长期监测.给出了应用该系统进行外场观测SO2、NO2和HONO的变化趋势,确定出相应光程下不同痕量气体的最低检测限.

Long Path Differential Optical Absorption Spectroscopy Based on CCD

The long path differential optical absorption spectroscopy (LP-DOAS) technique was presented.A charge coupled device (CCD) was employed as the detector.The properties of the system were described,including offset,dark current,noise,linearity of the detector and spectral resolution,wavelength range,stray light of the spectrometer.Field observations for SO2,NO2 and HONO were performed in Beijing,and time series of SO2,NO2 and HONO concentration were listed,and the detection limits of this system for SO2,NO2 and HONO over a 920 meter light path were determined.A comparison between the DOAS system and traditional point monitoring techniques for the results of SO2,NO2 showed that quite good correlation could be established,so the system is suitable for monitoring many trace gases.The results of field observations show that this system is more predominant and it allows long-term measurements of many trace gases.