Nephelometric method for measuring mass concentrations of urban aerosols and their respirable fractions
S.A. Lysenko, M.M. Kugeiko
Belarusian State University, 4, Nezavisimosti avenue, 2200301, Minsk, Republic of Belarus
Keywords: urban aerosol, mass concentration, nephelometric method, multiple regressions
Abstract
A method has been proposed for determining the mass concentration of airborne particles with sizes ≤ 1, ≤ 2.5, ≤ 10, and > 10 mm by measuring the light scattering coefficients of the investigated air at wavelengths λ1 ≤ 0.55 and λ2 ≥ 1.0 mm and scattering angles θ1 ≤ 5° and θ2 = 15 ÷ 45°. Mass concentrations of airborne particles are calculated on the basis of their stable statistical relationships with measured coefficients. Analytical expressions, approximating those statistical relationships, have been obtained on the basis of optical-microphysical model of urban aerosol, adopted by World Meteorological Organization, with varying concentrations, size distribution parameters, and complex refractive index of the particles of aerosol components (soot, water–soluble and dust). Statistical relationships obtained in the modeling approach have been compared with independent numerical and experimental data. The errors of the developed method in the overall variability of urban aerosol microphysical parameters have been evaluated.
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