Moisture content measurement system based on multi-infrared detection reflection bands

A sludge moisture content measurement system based on multi-infrared detection reflection bands, comprising a bearing plate (1) for carrying sludge, and further comprising:

• an infrared light source (2) configured to emit infrared light for irradiating the sludge;
• an infrared detection array comprising several infrared detectors (4), wherein each infrared detector (4) is equipped with an optical filter (5), and the optical filter (5) is configured to define a wavelength band range of infrared light received by the infrared detector (4), allowing only the infrared light within the wavelength band to pass through, and in turn enabling the infrared detector (4) to output a corresponding voltage signal;
• a signal processing module configured to receive and process the voltage signal output by the infrared detector (4);
• a model construction module configured to construct a correlation model between reflected light power and moisture content;
• and
• a moisture content calculation module configured to calculate a sludge moisture content based on the correlation model;
• wherein a quadratic polynomial model is used to fit a relationship between the reflected light power and the moisture content, and the sludge moisture content W and a voltage variation ΔV can be expressed as:
• W=a·(ΔV)2+b·(ΔV)+c, where a, b, and c are to-be-fitted model parameters, and W is an actual moisture content of the sludge;
• the sludge moisture content measurement system based on multi-infrared detection reflection bands further comprises:
• a water vapor measurement channel comprising a temperature sensor and a humidity sensor configured to measure temperature and relative humidity in the air and calculate an absolute humidity;
• wherein
• an interference of absorption by water vapor in the air on an infrared reflection signal is corrected through a value of the absolute humidity;
• and
• a correction process comprises:
• determining a coefficient of absorption by the water vapor in a specific infrared wavelength band according to the value of the absolute humidity of the water vapor, compensating for a voltage attenuation amount caused by the absorption by the water vapor in combination with a reference voltage signal from a reference band detector, and obtaining a corrected voltage signal after eliminating the interference by the water vapor;
• further comprising a focusing lens (6) disposed below the optical filter (5);
• further comprising a fixed plate (7) with an inner cavity (8) formed therein, wherein a top cylinder (11) communicating with the inner cavity (8) is fixedly installed on an edge side of a top portion of the fixed plate (7), and a bottom cylinder (12) communicating with the inner cavity (8) is fixedly installed on an edge side of a bottom portion of the fixed plate (7);
• and the infrared detector (4) is mounted in the top cylinder (11), and the focusing lens (6) is fixed in the bottom cylinder (12);
• a switching disk (9) is rotatably installed in the inner cavity (8), several mounting openings (10) for installing optical filters (5) are uniformly formed in the switching disk (9);
• a sensor fixing housing (13) is fixedly installed on an outer wall of the bottom cylinder (12), and a measurement sensor (14) is fixed in the sensor fixing housing (13);
• and
• further comprising an exhaust pipe (30) with an air jet head disposed at its end;
• wherein the air jet head at the end of the exhaust pipe (30) is inserted into the bottom cylinder (12) and faces the focusing lens (6).