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]