【摘要】 本文介绍了差分光学吸收光谱法(DOAS)测量大气污染气体浓度的基本原理。DOAS方法就是利用氙灯发出的紫外-可见光,经望远镜准直后再经过一段距离的传输,由望远镜来接收。在传输中,由于各种不同的分子在不同的波段对光有不同的吸收特征,使光谱具有了污染物的特征,再通过与光源发出的光进行比较,反演这些气体在大气中浓度。我们将DOAS方法应用在监测有机物上,在分析光谱的过程中,应用多项式拟合和最小二乘法,从而精确地从测量光谱中来反演出大气中污染气体的浓度。文中用DOAS方法测量了苯和甲苯的样品,并分析了结果,结果和理论吻合。可为环境中有机污染物监测提供可靠的方法。更多还原

【Abstract】 The principle of a differential optical absorption spectrometer (DOAS) is presented in this paper. UV-VIS light that emits from a high-pressure arc lamp is collimated by the telescope, reflected by the retroreflector, collected by the same telescope. In the transmission, different gases have different absorptions in different wavebands which can distinguish the different gases, and the spectra have carried the characteristics of air pollutants, so we can retrieve the concentration of air pollutants by comparing the measuring spectra and the lamp spectra. We use this method to measure the organic pollutants. In processing and analyzing the spectra, we use some mathematics algorithm, such as the polynomial of specified degree, least squares fitting algorithm, etc, so the concentration can retrieve precisely. In this paper, we use DOAS method to measure the spectra of benzene and toluene sample and analyze the results. The results anastomose with the theory. The method will be the reliable one for measuring and monitoring the atmosphere organic pollutants.更多还原