Research On The Reflective Near Infraded Moisture Measurement Instrument Based On The Method Of Three Wave Bands And Six Beams

Near infrared moisture meter is an important branch of the infrared spectrum application.. 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. The subject’s near-infrared moisture meter which is reflectance and base on three-band six-beam,can inhibit the error which is caused by the light source disturbance and texture changes in disturbance caused the error,using both internal and external light path and the two reference bands.After carefully studied the subject in the six-beam tri-band reflective near infrared moisture meter works, on the basis of previous, for the problem which sample value is not accurate and near-infrared moisture meter can not be properly measured, fix and improve the existing hardware and soft ware, to make the near infrared moisture meter measure accurately.And on this basis,improve the performance of the instrument, and improve the function of the instrument.Design moisture meter’s power system, complete the design of each power supply unit, product power system circuit board. For the problem of PbS detector influenced by temperature, on the basis of refrigeration circuit, the structure of the detector base is re-designed,and the use of separate base effectively cut off from the heat from light source is. The cutting light disc is redesigned to improve the sampling method of AD conversion,that makes the AD sampling triggered by fix pulse,so the stability of sample position is more stable,addressing the shortcoming of the sampling location is not accurate. Changed the calculation method of water in the calculation of the ratio of water added to compensate for factors, and add compensate factors to ratio of water calculation,this handling solve the problem that attenuation of reference band light is excessive when moisture is increasing,and ensure the instrument’s sensitivity. Analysis and evaluate instrument performance through a large number of experiments, in order to further improve the performance of the instrument. Test the instrument error, reading stable, measurement repeatability and other performance.Experimental data shows that the instrument has good performance to the lowe moisture content,but when moisture content is higher,the instrument performance goes lower slightly.