Development and performance detection of higher precision optical sensor for coal dust concentration measurement based on Mie scattering theory

摘要

A higher precision optical sensor for coal dust concentration measurement was developed in this study, in order to overcome the deficiencies of current coal mine dust detection (such as their low precision and poor stability). Based on Mie scattering theory, the effects of the dust particle size, refractive index, and scattering angle on the distribution of the scattered light intensity were examined by using numerical simulations in MATLAB and MiePlot. Accordingly, the scattering structure was determined, and the mathematical model of the sensor was established. Then the sensor was developed after the selection and assembly of optimal devices through redesigning the circuit and control system independently and optimizing the optical structure. After calibration, the mean measured error of the developed sensor was 3.884%, 3.546%, and 3.037% in the short-term test. The relative errors in long-term detection increased to some extent, but still remained between 4% and 5%. It is firmly indicated that the developed sensor can reliably measure the dust concentration and exhibits excellent stability. This study provides a more accurate method for measuring and monitoring dust concentrations in coal mines.