A Novel Coal Mine Dust Measurement System and Experimental Analysis.

To facilitate the prediction and early warning of coal dust explosions in mines, a real-time online detection system that employs photoelectric diodes as light sources and narrow beam transmission technology based on the extinction statistical method is proposed. The study establishes a coal dust test model using the extinction statistical method, derives the extinction statistical test equations, and numerically analyzes the relationship between the average and standard deviation of transmittance using beams of varying thicknesses based on the theory of light transmission. The experimental devices of the test system and signal acquisition circuit are designed, and the interference of the original background light measure and light signal in the test is eliminated by prism splitting. Subsequently, coal dust measurement experiments are conducted using beams of diameters 0.05, 0.24, 0.72, and 1 mm. The experimental results indicate that selecting an appropriate beam thickness can enhance the accuracy of coal dust testing. The proposed system is capable of real-time online detection of coal dust particle size and concentration, demonstrating the practicality and feasibility of the system.