Design And Experimental Research Of Atmospheric Fine Particle Mass Concentration Collection System Based On Light Scattering Method

With the changes in human production and lifestyles,atmospheric particulate matter and its pollutants have a huge impact on global atmospheric circulation,climate,environment,hydrology and soil,etc.Therefore,online monitoring of particulate matter is of great significance.Based on the light scattering method,the paper designs an atmospheric fine particle mass concentration collection system.Through parameter calibration and data inversion,in a smoke box environment,the atmospheric fine particle mass concentration collection system is used to conduct experimental observations on the mass concentration of atmospheric fine particles at a specific concentration and result analysis.The atmospheric fine particulate matter concentration measurement system consists of a particulate matter generation module,a particulate matter collection module and a scattered light collection module.First,based on the light scattering method,an inversion model for measuring the mass concentration of particulate matter is deduced.Based on the theoretical model,an atmospheric fine particulate matter concentration acquisition system is designed and constructed,which mainly completes the design of the particulate matter scattered light acquisition module,data processing module and parameter calibration module.According to the characteristics of the scattered light signal of the particles,a low dark current photodiode and an integrated operational amplifier with low input bias current and low input offset voltage are selected to design the scattered light collection module to realize the collection of the scattered light of the particles.Then the design of the data processing module is completed.The maximum value of the pulse voltage in a single cycle and the voltage distribution function are obtained through adaptive filtering,maximum value filtering,and inter-zone counting inversion,and inversion,and the mass concentration measurement value including the system parameters K and a is obtained.In the parameter calibration module,the Gauss-Newton method is used to calibrate the system parameters through the comparison of multiple sets of measured values with the standard values,according to the theoretical model,the inversion algorithm program is programmed,and the feasibility of the system software design is verified by observation experiments.the inversion algorithm program is written based on the theoretical model,and the feasibility of the system software design is verified by observation experiments.Finally,in the smoke box environment,a variety of PM2.5 and PM10 standard particles were systematically measured and calibrated using the atmospheric fine particle mass concentration measurement system,and the characteristics of the scattered light intensity in a specific direction were obtained,based on the scattered light and mass concentration.The relationship inverts the mass concentration and calculates the relative deviation between the measured value and the standard value.The result shows that the relative deviation is less than 10%,which preliminarily verifies the effectiveness of the system.