Research On The Near Infrared Moisture Measurement Instrument

Near infrared moisture detector is based on near-infrared light water characteristic absorption spectra.As the water has a strong absorption of certain specific wavelengths of near infrared light, the extent of absorption is proportional to moisture content of material, which is near infrared moisture meter works.Reflective near infrared moisture detector test speed, real-time detection of powder materials moisture content online, and a non-contact detection.Using near infrared moisture tester both inside and outside the reference light path and the two bands, the light source can effectively suppress fluctuations and changes in the interference caused by the texture.Careful study of this subject in the near infrared moisture detector works, in response to the previous near-infrared moisture detector can accurately detect the sinter mixture moisture issues, designing a new analog circuits and digital circuits and power supply system. Application of PID control algorithm, the detector temperature is stable at 15℃, improved signal to noise ratio, signal to obtain a low-noise waveform. Designed a new water calculation algorithm, and programmed the system software. After calibration and error analysis, near infrared moisture detector can more accurately detect the moisture content of sinter mixture.Hardware, Designed the main control board circuits and power systems. Control board circuit includes analog and digital sections. Wherein the analog circuit is responsible for signal filtering, amplification, digital circuitry responsible for synchronizing signal detection, signal sampling, data processing, data display and communications functions. Power system is mainly responsible for the analog circuits, digital circuits, the detector cooling, light and motors each module.Software, the interrupt detection circuit for synchronous position is not the signal waveform peak, so the problem can not be accurately sampled signal, the application of single-chip timer delay to accurately sampled signal peaks. Using incremental PID control algorithm achieved the stability of the detector temperature control. C8051F005 and C8051F340 procedures designed. Data filtering algorithm, serial communication between the microcontroller and other procedures Designed. Calculation algorithm designed to moisture, so that the light source can effectively suppress fluctuations and changes in the interference caused by the texture. Preparation of PC software, the realization of material moisture content, temperature, and moisture detectors curve real-time display, and the AD values, the detector temperature and moisture content in real-time storage.The optimized near infrared moisture detector was calibrated experiments and error analysis. Experiments show that the optimized near infrared moisture detector can more accurately detect the moisture content of sinter mixture, instrument performance is improved.