The digital oscilloscope is widely used in thermocouple response time calibrations.Taking K-type thermo-couple 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 tem-perature.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
Key words
K-type thermocouple/response time/digital oscilloscope/data acquisition system
维普
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