Aerosol Sauter mean diameter measurement based on the light scattering response of the combined particle volume-surface area

Abstract

The relationship between the numerical of Sauter mean diameter (SMD) and aerosol distribution parameters, as well as its physical significance are lacking in detailed research. Meanwhile, existing method is not widely used for SMD accurate measurement due to many restrictions on the incident light wavelengths. In this study, we analyzed the relationship between SMDs and the mean and median values of the lognormal, normal, and Weibull distributions with different parameters. It is found that SMD can be directly used to substitute the mean particle size in lognormal distributions with slight deviations. A new method for aerosol SMD measurement with no wavelength limitation based on the light scattering response of the combined volume-surface area of particles is proposed. SMD inversion results show that this method reduces the error caused by inconsistent integration of the wavelength of incident light and particle size in existing measurements, because has no limitation on the wavelength of incident light. SMDs of N-Heptane combustion smokes measured using the developed sensor indicates that our proposed SMD measurement method effectively compensates the shortcomings of the existing method and improves the measurement accuracy, with the minimum and average errors of 8.9% and 14.78%, respectively.

Embedded Spatial–Temporal Convolutional Neural Network Based on Scattered Light Signals for Fire and Interferential Aerosol Classification

“…Photoelectric smoke detection technology is based on the optical scattering theory, in which scattered light intensity is related to the size, refractive index, shape, and concentration of the particles [ 14 , 15 , 16 ]. However, to simplify the detection principle, it is often assumed that the intensity of the scattered light obtained by the receiver is approximately proportional to the concentration of aerosol particles entering the measurement area in practical applications [ 14 ].…”

“…However, to simplify the detection principle, it is often assumed that the intensity of the scattered light obtained by the receiver is approximately proportional to the concentration of aerosol particles entering the measurement area in practical applications [ 14 ]. Then, a fire is considered to have occurred when the smoke concentration increases to the point where the scattered light intensity reaches the alarm threshold [ 15 ]. In fact, non-fire interfering aerosol concentrations can also cause the scattered light intensity to reach the alarm threshold if it is high enough, thereby triggering a false fire alarm [ 17 ].…”