基于微波的粮食水分检测系统设计

针对粮食水分快速检测的特点和要求，研制了基于微波的粮食水分检测系统，采用微波无损检测方法实现了对粮食水分含量的实时、连续检测。微波发生器产生10．5GHz的微波信号，经基于自由空间传输检测技术的微波传感器，与粮食非接触作用，信号采集电路对微波信号进行放大滤波，再经A／D转换器AD7806将微波模拟信号转化为数字信号．微控制器PIC18F6527通过采集到的微波信号推算出粮食的水分含量。实验表明该系统水分检测范围为8％～20％，测量精度为0．5％。在粮食收购、储藏、加工等过程中水分含量的检测是可行有效的。

Design of grain moisture content measurement system based on microwave

According to the peculiarities of grain moisture rapid measurement and the demand of application,this paper suggests and develops a grain moisture detection system based on microwave. It can real-time and continuous detect grain moisture content by the microwave non-destructive detection method. The microwave source operates at a single frequency of 10.5 GHz. The microwave sensor is based on the free-space-transmission measurement technique that can be performed without physical contact with the grain. The microwave signal is amplified and filtered by the signal collect, circuit. The AD7806 transformed analog signals into digital signals. The microprocessor PICISF6527 can calculate the moisture of the grain according to the microwave signal gathered. The analysis of satisfactory results illustrates that the moisture detection range of the system is 8%-20%. The measurement accuracy of the system is 0.5% .The performance and validity of the system that can satisfy the need of moisture measurement in the harvesting, storage, marketing, and processing of grain.