A scanning mobility particle sizer

二次有机气溶胶的形成是大气中颗粒物(如烟雾)的主要来源。二次有机气溶胶是由挥发性有机化合物氧化产生的，会影响能见度、气候以及人类和生态健康。我们最近建造了一个光反应室(“烟雾室”)，以模拟大气条件，并研究导致气溶胶形成的反应。我们仪器的一个独特之处是可以使用基于中红外半导体激光器的痕量气体传感系统。该传感器使我们能够实时监测反应物的浓度，例如BTEX化合物(苯、甲苯、乙苯、二甲苯)。我们还成功地检测了紫外光诱导氧化反应中的产物种类。

The formation of secondary organic aerosols is a major source of particulate matter (such as smog) in the atmosphere. Secondary organic aerosols are generated by the oxidation of volatile organic compounds and can affect visibility, climate, and human and ecological health. We have recently constructed a photoreaction chamber ("smog chamber") to simulate atmospheric conditions and to study the reactions that lead to aerosol formation. A unique feature of our instrument is the availability of a mid-infrared semiconductor laser based trace gas sensing system. This sensor allows us to monitor the concentrations of reactants, for example, BTEX compounds (benzene, toluene, ethylbenzene, xylene) in real time. We have also succeeded in detecting product species during the ultra-violet light induced oxidation reactions.