Detection technology of unpowered dust concentration based on light scattering method

Aiming at the problems of easy clogging and difficult maintenance of the current coal mine light scattering dust concentration sensor, a light scattering unpowered dust concentration detection technology with the characteristics of no clogging and easy maintenance was proposed, and a light scattering unpowered dust concentration sensor was developed. Firstly, by analyzing the basic principle of light scattering dust concentration detection and the structural characteristics of the current light scattering dust concentration sensor, a light scattering non-dynamic dust concentration detection unit composed of laser, photodiode, light shield and other parts was designed. With the addition of ultra-low signal processing circuits, etc., a light scattering unpowered dust concentration sensor was designed. By analyzing the influence of external natural light on the sensor, a data processing algorithm for the dynamic detection of sensor point was designed, which eliminates the interference of external nature. Then, by analyzing the distribution characteristics of the light scattering signal of the light-scattering unpowered dust concentration sensor, the mathematical relationship between the initial detection value of the light- scattering unpowered dust concentration sensor and the actual dust concentration was determined. When the dust concentration was lower than 120 mg/m³, the quadratic polynomial curve was used for fitting, and the linear fitting method was used for the dust concentration higher than 120 mg/m³, which realizes the accurate calibration of the non-dynamic light scattering dust concentration sensor. Finally, it was proved by experiments that the low concentration error of the dust concentration sensor based on the unpowered light scattering method was less than 15%, and the high concentration error was less than 10%. The detection accuracy of dust concentration detection technology by non-dynamic light scattering method meets the standard requirements. With the advantages of non-clogging and easy maintenance, the adaptability of the light scattering dust concentration sensor to harsh environments is increased, and a new idea is proposed for the development of accurate online detection technology of coal mine dust concentration.