Research And Experiment On Correlation Between Aerosol Extinction Coefficient And Mass Concentration

Aerosol is a multi-phase system composed of solid and liquid particles suspended in the atmosphere.Its existence directly affects climate change and changes the energy balance of the geogas system.With the rapid growth of the national economy,environmental pollution has grad-ually increased,especially in the vicinity of industrial sites.Productive soot aerosols have always been present in the site environment under stable conditions,directly affecting the normal oper-ation of instruments and equipment,and bringing great hazards.At present,the measurement of aerosol mass concentration usually uses the point measurement method,and the mass concentra-tion of aerosol is obtained through the method of weighing particles at a fixed station,and the spatial distribution information cannot be obtained.Optical remote sensing technology can obtainaerosol spatial distribution information to make up for the lack of point measurement,but this method can only obtain aerosol extinction information,and can not directly obtain aerosol distri-bution.Therefore,this article will carry out research on the correlation between the aerosol ex-tinction coefficient and the mass concentration under laboratory conditions,and strive to obtain the empirical formula of the two,and use this relationship to realize a new method for obtainingthe aerosol mass concentration distribution by optical remote sensing,for the determination Pol-lution sources,monitor industrial environmental emissions,study pollutant transport laws and analysis of pollutant source lists to provide methods and technical support.In this paper,first,based on the light transmission theory and Mie scattering theory,the measurement method of aerosol extinction coefficient and mass concentrstion is constructed.Ac-cording to the measurement method,a simultaneous measurement system of aerosol extinction coefficient and mass concentration is designed and constructed under laboratory conditions.It consists of light monitoring unit,gas chamber detection cavity unit,transmitted light monitoring unit,scattered light monitoring unit and signal acquisition unit.Complete the system construction and verify the feasibility of the system.The verification results show that the system can achieve the simultaneous measurement of the aerosol extinction coefficient and mass concentration.Combined with the calculation of the system parameters,the detection sensitivity of the experi-mental system to the aerosol mass concentration is 4.6 mg/m3.Finally,the experimental results are analyzed in detail.It can be seen that the aerosol extinction coefficient and mass concentration linear model and the exponential correlation model have co-efficients above 0.98,indicating that both models can describe the relationship between the two.The two models were de-verified through experiments,and the extinction coefficients measured by the experimental system were calculated using linear models and exponential models respec-tively.The resulting mass concentration was compared with the mass concentration measured by the experimental system,with an error of about 10%Fluctuations indicate that the empirical for-mulas obtained by experiments can describe the correlation between extinction coefficient and mass concentration.This result is helpful to obtain the extinction coefficient using lidar and thus provide a theoretical basis for studying the spatial distribution of aerosols,expand the detection field of lidar,make up for the shortcomings that the point measurement cannot obtain regional information,and can also study the regional transportation law of pollutants for lidar And to provide technical means to obtain the emissions of pollution sources in the detection area.