Accurate measuring method and device for capacitive grain moisture sensor

Abstract

The invention discloses an accurate measuring method and device for a capacitive grain moisture sensor. The method comprises steps of A, supplying power for a sensor and a single-chip microcomputer; B, outputting a signal through an oscillation circuit; and C, calculating and obtaining a moisture value. The accurate measuring method comprises steps of S1, zero initial measurement; S2, temperaturedrift calibration; S3, consistency calibration; and S4, grain parameter calibration. The sensor comprises a casing, positive and negative electrodes and a detection circuit board, wherein a capacitivedetection end of the detection circuit board is connected with the positive and negative electrodes. As the accurate measuring method is utilized, unified algorithm calibration for diverse sampling media can be performed, a physically isolated power supply circuit is utilized to realize independent power supply, so all interference sources can be avoided in the detection process, a single bus communication scheme is further utilized, and thereby grain storage distributed layout needs can be conveniently met.

Description

technical field [0001] The invention relates to the technical field of moisture detection, in particular to a precise measurement method and equipment for a capacitive grain moisture sensor. Background technique [0002] At present, in the process of grain storage and drying, most of the methods for testing moisture are still manual sampling inspection, which is complicated and inefficient. The Chinese invention patent application with publication number CN200810055014.8 discloses a "digital sensing device for online measurement of grain temperature and moisture in grain depot", which uses capacitance method to detect grain capacitance and corrects the influence of temperature on sensing , this method uses metal sheets as electrodes; according to the finite element analysis, it can be obtained that electromagnetic interference has a great influence on the sensor, and it is difficult to obtain stable and accurate sensor data information. [0003] The Chinese invention patent...

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Problems solved by technology

[0002] At present, in the process of grain storage and drying, most of the methods for testing moisture are still manual sampling inspection, which is complicated and inefficient

The Chinese invention patent application with publication number CN200810055014.8 discloses a "digital sensing device for online measurement of grain temperature and moisture in grain depot", which uses capacitance method to detect grain capacitance and corrects the influence of temperature on sensing , this method uses metal sheets as electrodes; according to the finite element analysis, it can be obtained that electromagnetic interference has a great influence on the sensor, and it is difficult to obtain stable and accurate sensor data information

[0003] The Chinese invention patent application with the publication number CN201610331177.9 discloses "a moisture calculation method for capacitive moisture sensor components", which uses a binary function to calibrate the measured moisture, because the sensor is used for different measurement media during the measurement process, such as For rice, wheat, corn and other crops, this method cannot fully meet all test occasions

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