真空热实验中热电偶测温系统不确定度的评定

UNCERTAINTY EVALUATION OF THERMOCOUPLE MEASUREMENT SYSTEM IN VACUUM THERMAL TEST

摘要: 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。

Abstract: Thermocouple measurement system is widely used in vacuum thermal test.Temperature measurement system cannot be calibrated，because it uses a large number of thermocouple，and the temperature result is affected by temperature field changes of built-in referenced device.Uncertainty analysis and evaluation of thermocouple measurement system 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.