一种高精度粮食水分测量传感器电路设计

Experimental study on capacitive grain moisture measurement based on MS3110

针对目前粮食水分测量精度较低的问题,根据介电常数模型分析了在交变电场下介电常数的损耗特性与电容特性、介电常数与电场变化频率的关系,设计了在确定频率的激励下将待测粮食水分转化为电容值的介电常数型的平行板电容传感器。提出了基于MS3110集成粮食水分测量电路的设计方法。相比于传统的基于交流电桥平衡原理搭建的测试电路,该系统电路具有高稳定性、集成度高、可编程控制等优点。实验表明该传感器电路测得的粮食含水量更精确。

To address the problem of low grain moisture measurement accuracy,a dielectric constant parallel plate capacitor is designed, combined with AC bridge under the excitation of a particular frequency. The design is based on the relationship between the loss characteristics and the capacitance of the dielectric constant,and the relationship between the dielectric constant and the frequency under alternating electric field. The scheme of system circuit based on MS3110 is proposed.Compared with the traditional test circuit based on the theory of AC bridge balance,it has some advantages such as high stability,programmable control and so on. Experiments show that the design is more precise in the grain moisture measurement field.