基于有限元分析的粉末介电常数测试装置研制  

Development of device for measuring powder's dielectric constant based on finite element analysis

作　　者：邹大军[1] 李锡文[1] 何锐波[1] 詹小斌[1] 张嘉琪[1] 

机构地区：[1]华中科技大学机械学院,武汉430074

出　　处：《仪器仪表学报》2013年第2期423-427,共5页Chinese Journal of Scientific Instrument

基　　金：国家重大科学仪器设备开发专项(2011YQ160002);中央高校基本科研业务费(HUST:2010MS090)资助项目

摘　　要：针对固体粉末的特点,研制了一种测试其介电常数的装置。设计了电容传感器,采用有限元方法对其进行仿真,得出了传感器的电场矢量图,分析了传感器的等效电路;以AD7746芯片为核心,搭建了电容测试电路及电容输入范围扩展电路;采用屏蔽线、屏蔽罩提高测试系统的稳定性及精度。装置所能测试的电容值达到fF量级,应用所设计装置测试了不同密度下二氧化硅粉末的相对介电常数,实验结果表明:本装置能够稳定、准确地测试固体粉末的相对介电常数。According to the characters of solid powder, a device for measuring the dielectric constant of solid powder is proposed in this paper. A capacitance sensor is designed and simulated using finite element method to acquire its electric field vector. The equivalent circuit of the capacitance sensor is analyzed. The capacitance measurement circle and its input range extension circuit are designed based on the chip AD7746. The shielding wires and case are involved in the instrument to improve the stability and the precision. The ranging precision of the capacitance measured by the device can reach the order of fF. The dielectric constants of silicon dioxide powder tested under different density indicate that this instrument can measure the dielectric constant of solid power stably and precisely.

关 键 词：介电常数 固体粉末 电容传感器 有限元 

分 类 号：TP212.1[自动化与计算机技术—检测技术与自动化装置]