PLC控制系统温度测量补偿问题的研究

Study on Temperature Measurement Compensation in PLC Control System

本文对自动化控制系统中热电偶冷端温度补偿方式进行分析，对PLC应用的几种补偿方式优缺点进行讨论。提出利用高精度温度传感器，对PIC控制系统冷端温度进行动态补偿。通过软件开发及热电偶分度值数据庄自动查找热电偶分度值获得冷端补偿电势值，然后在PI￡控制系统程序内进行代数运算，得出实测温度。参与过程控制或输出，此种补偿方法完全用软件实现，特别适用于PLC系统的温度测量。

This article analyzed temperature compensation methods at the cold end of thermocouple in automatic control system, discussed advantages and disadvantages of several compensation methods used in PLC and put forward that dynamic temperature compensation at the cold end in PLC control system is carried out by high precision temperature sensor. Electric potential compensation at the cold end is obtained by advanced software and automatic search of division value in data debase of ther- mocouple and then changed into practical temperature by algebraic operation with programs in PLC control system. Involved in process control and output, this kind of compensation methods is realized by software and especially suitable for temperature measurement with PLC system.