一种新颖的电阻应变式两线制称重变送器设计  

Design of New Two-wire Resistance Strain Transmitter for Weight Measurement

作　　者：殷文志 王勇[1] 罗小月 刘学宁[1] 胡慕伊[1] YIN Wen-zhi WANG Yong LUO Xiao-yue LIU Xue-ning HU Mu-yi(College of Light Industry Science and Engineering, Nanfing Forestry Universit)

机构地区：[1]南京林业大学轻工科学与工程学院

出　　处：《化工自动化及仪表》2017年第7期637-642,共6页Control and Instruments in Chemical Industry

摘　　要：针对常用的电阻应变电桥式称重传感器输出电压信号变化极为微小(若干毫伏)、零位误差较大(与输出变化量相当,甚至大于输出电压变化量),不便于转换和传输的问题,为了将电阻应变电桥式称重传感器信号转换为两线制4~20m A电流信号进行输出,采用基于仪表放大器AD627和电流转换器XTR105的模拟电路转换方案,对信号进行放大、零位偏差补偿。通过V/I转换器,把电压信号转换成电流输出信号,有利于长距离传输。详细介绍了变送器的工作原理和硬件电路设计。通过测试实验验证了变送器的测量特性。Considering the tiny change （ several millivohs） in output voltage signals, obvious zero offset（ equal to or greater than the output voltage） and inconvenience in conversion and transmission of the commonly-used resistance strain bridge-type weighing sensor, and for purpose of converting its output signals to 4 -20mA current signals with a two-wire output form, a AD627 instrument amplifier and XTRI05 current converter-based analog circuit conversion scheme was proposed to magnify signals and implement zero offset compensation; meanwhile, through V/I converter, it has voltage signals converted into current output signals for long-distance transmission. The working principle of the transmitter and the design scheme of the hardware circuit were intro- duced in detail. The test results verify the measuring characteristics of this transmitter.

关 键 词：称重变送器 应变电桥 AD627 XTR105 V/I转换 

分 类 号：TH715[机械工程—测试计量技术及仪器]