非标短型无补偿导线铱铑热电偶的校准方法研究  

Research on the Calibration Method of Non⁃standard Short Uncompensated Wire Iridium⁃rhodium Thermocouple

作　　者：李可 张婷婷 李竟怡 许淑惠 卢小丰[2] LI Ke;ZHANG Tingting;LI Jingyi;XU Shuhui;LU Xiaofeng(School of Environmental and Energy Engineering,Beijing University of Civil Engineering and Architecture,Beijing 100044,China;National Institute of Metrology,Beijing 100029,China)

机构地区：[1]北京建筑大学环境与能源工程学院,北京100044 [2]中国计量科学研究院,北京100029

出　　处：《计量学报》2025年第3期340-346,共7页Acta Metrologica Sinica

基　　金：国家重点研发计划(2023YFF0615003);国家科技重大专项(J2019-V-0015-0110)。

摘　　要：非标准化又无补偿导线的短型热电偶(80~150 mm)由于其尺寸短且冷端无法外延,导致其在测量或校准过程中会产生较大偏差。以短型铱铑热电偶为例,利用干体炉及均热块装置进行校准,冷端分别采用空冷、循环水冷盘和浸没水冷3种处理方式并用K偶测温修正。对同源长型铱铑热电偶进行热电势与温度关系分度作为短型铱铑偶的参考值,发现分度值与国标偏差超过1%,与In、Sn、Zn固定点校准结果分别差0.23、0.32和0.48℃。实验结果表明短型铱铑偶在0~500℃温度范围,使用循环水冷盘控制冷端并测温修正的方法校准误差优于1%,不确定度为0.9~3.2℃。Non-standardized short thermocouples(80~150 mm)without compensating wires usually have significant deviations during measurement or calibration due to their short length and the incapability of extending the cold junction.A short iridium-rhodium thermocouple was taken as an example,calibratesd using a dry body-furnace and a thermal equalization block device.Three different cold-junction treatments methods were adopted:air cooling,using a circulating water-cooled plate,and immersion water cooling.All of these were corrected with K-type thermocouples.The thermoelectric potential-temperature relationship of a long iridium-rhodium thermocouple from the same source was taken as a reference for the short thermocouple.It was found that the deviation of the reference values from the national standard was over 1%,and the differences in the calibration results at the In,Sn,and Zn fixed points were 0.23,0.32,and 0.48°C,respectively.The experimental results show that the calibration error of the short iridium rhodium couple using a circulating water-cooled plate to control the cold junction and temperature correction method within the temperature range of 0~500℃is better than 1%,with an uncertainty of 0.9~3.2℃.

关 键 词：温度计量 短型铱铑热电偶 校准 干体炉 分度曲线 

分 类 号：TB942[一般工业技术—计量学]