基于示波器的热电偶响应时间采集系统分析  

Analysis of Thermocouple Response Time Acquisition System Based on Oscilloscope

作　　者：刘波 姜盈盈[1] 邹冰妍 王志远 LIU Bo;JIANG Yingying;ZOU Bingyan;WANG Zhiyuan(Shanghai Institute of Measurement and Testing Technology,Shanghai 201203,China;School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai,200093,China)

机构地区：[1]上海市计量测试技术研究院,上海201203 [2]上海理工大学能源与动力工程学院,上海200093

出　　处：《自动化与仪表》2024年第9期106-109,共4页Automation & Instrumentation

摘　　要：鉴于数字示波器在热电偶响应时间测试中的广泛应用,以K型热电偶为例,采用校验仪模拟热电偶的输出热电势,实验研究了数字示波器测量热电势误差,分析了基于热电势瞬态变化曲线通过作图法获得热电偶响应时间的误差。结果表明,在0~100℃和0~1000℃范围内,数字示波器测量热电势的绝对值偏差较大,但是重复性和线性良好。在温度阶跃量的50%处(50℃和700℃),热电势瞬态曲线与温度曲线的偏差分别为0.5℃和2.1℃,约为温度阶跃量的1%。因而,基于热电势瞬态变化曲线通过作图法获得热电偶响应时间的方法误差较小,通常约为温度波动产生的误差。The digital oscilloscope is widely used in thermocouple response time calibrations.Taking K-type thermocouple as an example,the electromotive force(EMF)output was simulated by a calibrator,and its measurement error using a digital oscilloscope was experimentally studied.The impact on response time which was obtained through plotting method based on the transient response curve of EMF was analyzed.The results indicate that,within the range of 0~100℃ and 0~1000℃,the absolute deviation is large,but the repeatability and linearity are good of the digital oscilloscope in measuring EMF.At 50% of the step temperature(50℃ and 700℃),the deviation between the EMF transient curve and the temperature curve is 0.5℃ and 2.1℃,respectively,which is about 1% of the step temperature.Therefore,a small error of the response time of thermocouples can be obtained,usually about the error caused by temperature fluctuations.

关 键 词：K型热电偶 响应时间 数字示波器 数据采集系统 

分 类 号：TP274[自动化与计算机技术—检测技术与自动化装置]