摘要
在粮食品质检测分级过程中,为了测量样品的含杂率和容积密度,设计了一种高精度称重系统。以PIC18F4580为主控单元,采用四臂电桥式负荷传感器,用AD7799进行模数转换及传感器微弱信号的放大。差动式输入参考电压减小电源低频漂移时带来的系统误差。实际测试表明,系统测量重复误差不超过0.005%,系统非线性度误差小于0.007%,可以满足粮食检测过程的需求。
A design of a precision weight system for testing percentage of impurities and bulk density in grain quality grading process is presented.This circuit used PIC18F4580 for signal processing,AD7799 for andlog-digital conversion and signal amplification,differential reference voltage input for decreasing the system low frequency drifting.Experimental results show that the repeatability error is less than 0.005% and the nonlinearity is less than 0.01%,which achives high precision and stablity requirement during the testing procedure.
出处
《电子设计工程》
2011年第12期175-177,180,共4页
Electronic Design Engineering
基金
国家科技支撑计划(2008BADA8B04-1)
