基于电容法的稻谷含水率检测

摘要

为快速准确测量稻谷含水率,设计了一种单一平面电容传感器探头,并应用电容数字转换芯片AD7150设计转换电路.传感器探头将稻谷含水率转换成电容,转换电路将电容模拟量转换成数字量,经单片机处理后获得稻谷含水率.对传感器进行了标定试验和温度特性试验,结果表明稻谷含水率在8％ ～ 23％的范围里,含水率预测误差为±0.8％；温度在12 ～33℃范围内,稻谷含水率为12.86％时,温度漂移量为0.2％/℃.%In order to quickly detect rice moisture content,a uniplanar capacitor probe was designed.A corresponding converting circuit was also designed for getting digital value of capacitance.The rice moisture content was converted into capacitance and digital value in turn by the capacitor probe and converting circuit.Finally,the rice moisture content was obtained by using single chip.After the calibration experiments and temperature characteristics experiments,the results showed that prediction error of moisture content was within + 0.8％ at the range of rice moisture content of 8％ ～ 23％.With the temperature of 12 ～ 33℃ and rice moisture content of 12.86％,the temperature shift value was O.2％/℃.