Optimal static light scattering detection angle for particulate matter size and concentration measurement

Abstract

The serious pollution of particulate matter (PM) causes many adverse effects on human health and industrial production. High-precision, real-time monitor of atmospheric particulate concentration is becoming increasingly important. In this study, a method to find the optimal detection angle to measure the mass concentration of PM is proposed. To find an optimal angle, a motorized rotary system is used to measure the light scattering signal of particles from 0° to 180°. The new method obtains parameters such as mass concentration factor, deviation, mass concentration coefficient and deviation coefficient, which can be measured more accurately. Through theoretical calculation and experimental analysis, the optimal detection angle is 45°. At the optimal angle, the correlation between the scattered light intensity and the mass concentration of spherical SiO2 particles reaches 0.9836. Then, the mass concentration of PM is inverted and calculated at the optimal angle. The results showed that the correlation coefficient R2 of different particle sizes is larger than 0.952, and the measurement results were highly correlated.