基于CAV424的粮食含水率检测仪表设计  

Design of grain moisture content detection instrument based on CAV424

作　　者：郭伟[1] 乔丽娟[1] 刘海[1] 杜清府[1] 

机构地区：[1]山东大学(威海),山东威海264209

出　　处：《传感器与微系统》2013年第9期111-114,共4页Transducer and Microsystem Technologies

摘　　要：根据电容式湿度传感器的工作原理,传感器2个极板间的电容值随介电常数的改变而线性变化,而粮食含水率影响介电常数的大小。仪表采用电容测量专用芯片CAV424,将传感器的电容值转换为直流电压,经片上系统C8051F060单片机片内A/D转换成数字量,再进行数据处理后得到粮食的含水率。仪表通过液晶显示测量值,浏览仪表自动存储的历史数据,可利用RS—485接口将测量数据实时上传到上位机,实现远程测量。仪表采用了片上系统、专用测量集成电路,电路设计简捷、检测精度较高、且稳定可靠。According to working principle of capacitive humidity sensor,capacitance value between two plates of the sensor changes linearly with change of dielectric constant,and grain moisture content affects dielectric constant.The instrument,uses chip CAV424 for capacitance measurement which is used to convert the capacitance value to DV value.The A/D module converts into digital quantity by system-on-chip microcontroller C8051F060 and then the grain moisture content can be calculated after data processing.The instrument displays measured value through LCD and the historical data automatically stored by the instrument is browsed,the measurement data is uploaded to the host computer real-time by RS—485 interface and remote measurement is realized.Due to a system-on-chip and special measurement IC in the instrument,the whole system has characters of simple circuit design,high detection precision,stable and reliable performance.

关 键 词：电容传感器 CAV424 粮食含水率 C8051F060 检测仪表 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]