真空热实验中热电偶测温系统不确定度的评定

摘要

Thermocouple measurement system is widely used in vacuum thermal test. Temperature measurement sys-tem cannot be calibrated,because it uses a large number of thermocouple,and the temperature result is affected by temper-ature field changes of built-in referenced device. Uncertainty analysis and evaluation of thermocouple measurement sys-tem is given,according to the principle and the computational formula. Through experimentation with RTD(Resistance Temperature Detector),uncertainty evaluation of thermocouple measurement system is confirmed.%热电偶测温系统是真空热试验中最常用的温度测量系统.该测温系统使用热电偶数量多,同时受内置参考点温度场变化的影响,不适合对其系统进行校准.文章依据热电偶测温系统的工作原理和计算公式,对该测温系统的不确定度进行了分析和评定,对某一批次热电偶的不确定度进行了计算.通过试验与铂电阻测温的比对,对热电偶测温系统的不确定评价进行了验证.