Study On The Characteristics Of Aerosol Spectrum With Fiber Spectrometer

Aerosols have important influence on the Earth’s radiation balance and environmental forecast. Inhalable aerosols do great harm on the human health. To deepen the understanding of the aerosol has become an important study field. There is less research on the aerosols optical properties. Strengthening the optical characteristics of aerosols helps improving the cognition of aerosols. It has great significance of climate change and environmental forecast.Two FA-3impingement samplers for measuring aerosol particle size distribution were used to collect the information of the inhalable particles at different levels in the atmosphere. The FLA4000micro fiber spectrometer in the laboratory was considered as the core to set up a set of optical measurement system. Then this system was used to test the optical transmittance of aerosol particles. A daily spectrum change was analyzed for the optical transmittance of aerosols with different sizes. The optical transmittance spectrums of aerosols with the same size were analyzed. Conduct a numerical analysis for the optical transmittance of aerosols on different height, for the optical transmittance of aerosols with different sizes and for the optical transmittance of aerosols after the rain.The analytical results show that the aerosols ranging from PM2.5to PM10feature the low wavelength selection and relatively stable transmittance value in the time period from the appearance of the haze to its complete abreaction. For the aerosol particles less than PM2.5size, the transmittance value of some substances are the lowest in the relatively short position and their transmittance rate shows the trend of rising with the changing wave. According to the theoretical analysis, These substances are sulfate. The optical transmittance of aerosols with different sizes is a relatively independent variation process. The4-day observation says its transmittance growth rate is the biggest and comes within the scope of PM2.5, which shows the higher its position, its transmittance is much higher. Its lowest value of growth rate is out of the PM2.5range and it shows the transmittance of some large aerosols particles within certain size range will decrease. The impact of meteorological elements on the transmittance of the particulates is significant, and their transmittances change along with the meteorological elements. Among the meteorological elements, the impact of the wind is the most significant. The pollution emissions in the industry are the main contributor for the micro particles in the observation site, especially for the aerosols particles of PM2.5.