铜-康铜热电偶的标定与误差分析

陈良[1,2] 侯予[1] 习兰[1,2]
[1]西安交通大学动力工程多相流国家重点实验室,西安710049 [2]西安交通大学能源与动力工程学院,西安710049
摘　要:开发了基于Labview的温度测量系统，对铜．康铜热电偶在-70℃至10℃范围内进行了标定，并且进行了误差分析。比较了不同焊接工艺和不同参考端补偿方式对热电偶性能的影响，分别对标定结果进行了线性、二次、三次和四次最小二乘拟合，并且分析了拟合误差。最后对使用冰点槽、Keithley自动补偿模块和Aglient自动补偿模块的热电偶标定装置进行了分析。分析结果表明：若焊接质量得到保证，锡焊和对焊工艺对热电偶性能影响不大，可满足对测量精度的要求；与采用冰点槽作为补偿端相比，线路板内置的温度补偿系统使用方便，但精度较差，不宜在热电偶的标定中使用。[著者文摘]

Calibration of copper-constantan thermocouple and related error analysisChen Liang, Hou Yu, Xi Lan1 State Key Laboratory of Multiphase Flow in Power Engineering,Xihn Jiaotong University,Xi＇an 710049, China;2 School of Energy and Power Engineering, Xihn Jiaotong University, Xi＇an 710049, ChinaAbstract:Copper-constantan thermocouples were calibrated from - 70 ℃ to 10 ℃ and error analysis was presented. A temperature measurement system based on Labview was developed. Effects of welding methods and reference junctions on the accuracy of thermocouples were analyzed. Then the least square fittings with one order, second order, third order and fourth order were respectively performed on the test da- ta. Error analysis on the calibration apparatus was conducted. The results show that thermoeouples fabricated through soldering had comparative accuracy as thermocouples fabricated through butt welding. Model 7 014 Multiplexer Card （Keithley Instruments, Inc. ） and Aglient 34 921A Multiplexer Module （Aglient Technologies, Inc. ） were unsuitable for the temperature measurement at the reference junction in the calibration of thermocouples.[著者文摘]

Key words:thermocouples ; calibration ; error analysis