銅-康銅熱電偶的標定與誤差分析

陳良[1,2] 侯予[1] 習蘭[1,2]
[1]西安交通大學動力工程多相流國家重點實驗室,西安710049 [2]西安交通大學能源與動力工程學院,西安710049
摘　要:開發(fā)了基于Labview的溫度測量系統(tǒng)，對銅．康銅熱電偶在-70℃至10℃范圍內進行了標定，并且進行了誤差分析。比較了不同焊接工藝和不同參考端補償方式對熱電偶性能的影響，分別對標定結果進行了線性、二次、三次和四次最小二乘擬合，并且分析了擬合誤差。最后對使用冰點槽、Keithley自動補償模塊和Aglient自動補償模塊的熱電偶標定裝置進行了分析。分析結果表明：若焊接質量得到保證，錫焊和對焊工藝對熱電偶性能影響不大，可滿足對測量精度的要求；與采用冰點槽作為補償端相比，線路板內置的溫度補償系統(tǒng)使用方便，但精度較差，不宜在熱電偶的標定中使用。[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