Design Of Atmospheric Aerosol Detection Based On Ultraviolet Fluorescence Method

With the rapid development of modern industry, environmental problems are getting worse. More people are aware of the atmospheric environmental pollution problems. An important aspect of air pollution is aerosol. Aerosols have an impact not only on air pollution, but also in agriculture, climate change, and so on. Even in the greenhouse effect it can also play some negative reaction. But the current understanding of the degree of aerosol is still shallow, so the aerosol research has become a very meaningful research direction. It is important to have a deeper understanding of the natural environment.In this paper, a set of UV-based fluorescence measurement system was designed.The important data carrier of this measurement method was mixed cellulose grease microporous membranes. Through the mixed cellulose grease microporous membranes to collect 0-8 different sizes of aerosol particles. The fluorescence spectrum and transmission spectra of the mixed cellulose grease microporous membranes were collected by the system. Then, the collected signal was denoised and the concentration distribution was analyzed by using a fluorescent column reduction light source problem.The experimental results show that the aerosol requires high energy ultraviolet light to stimulate. In the measurement system design process, at 355 nm, 5000 Hz laser excitation, the aerosols do not fluoresce. At 266 nm, 5000 Hz laser excitation the aerosols emit significant fluorescence signals. And it proved that the membrane itself does not exist fluorescence phenomenon at 266 nm. There are two obvious fluorescence peaks in the aerosol-containing membrane. According to the calculation of the fluorescence source, the distribution of the fluorescent substance content in the particle size of different aerosols is obtained. The experiments show that the fluorescent substances in the aerosol mainly distributed in small particle size. The content in the large particle size is very low, mainly distributed in the range of PM2.5 and 3.3 ?m. And at different floor heights, concentration depends on the overall aerosol concentration. In different weather,the difference is huge, severe haze and general sunny and rainy days compared to the overall content was significantly larger,and in the rain after the weather,the content of the various particle was significantly reduced.