Design and optimization of a fine particle detector based on forward and lateral light scattering measurement

Abstract

Inhalable particulate matter has been widely concerned due to its serious harm to human health in China. Real time, rapid and high-resolution monitoring of particle concentration change is the first step to prevent and control inhalable particle pollution. In this paper we present a method for detecting fine particle mass concentration based on forward and lateral light scattering measurement. Based on Mie light scattering theory, we design and establish the experimental platform of multi-angle light scattering measurement. Moreover, a portable multi-angle light scattering detection particle mass concentration prototype is developed by using computer modeling, 3D printing and weak photoelectric signal detection technology. Through theoretical numerical simulation and experimental analysis of optical platform, 20° forward and 45° lateral are selected as the optimal detection angles with the advantages of simple structure and high efficiency. Finally, we obtain the pulse reference voltage of different particle size segments is to realize the particle size segment detection. A specific case of our nonlinear regression algorithm is used to calibrate parameters of the detection system. The feasibility of the proposed detection method is verified by the comparative detection experiments in the laboratory and the outdoor atmospheric environment.