热电偶的正确选择及测量误差原因分析

热电偶是一种在自动化控制过程中应用非常普遍的温度传感设备。其结构简单、安装使用方便而被广泛应用于各行业自动化温度控制领域。为了保证热电偶在温度测量过程中安全、准确、长周期的运行,通过对热电偶分度号、测点位置及插入深度的正确选择,以及分析其在实际应用中出现的各种测量误差原因,提出了热电偶在选用过程中常被忽略的一些问题,以及热电偶测量误差的形成原因,希望为热电偶在正确选择及高精度测量方面起到一定帮助。

Thermocouples are a very common temperature sensor used in the automation control process. Its structure is simple,easy to install and widely applied in various industries' automatic temperature control services. In order to guarantee the thermocouples' safe,accurate and long-term operation in the temperature measurement process,the correct selection of thermocouple type,measuring point position and insertion depth,are described and also the various reasons of the thermocouples' measuring tolerance are analyzed in the practical applications. Furthermore,some problems often ignored in the selection and the causes of thermocouple measuring tolerance are putted forward. It is hoped to be useful for the thermocouple's proper selection and high precision measurement.