热电阻及其数字显示仪表的现场校准  

Field Calibration of RTDs and Their Digital Display Instruments

作　　者：曹广鹏 CAO Guang-peng(Dezhou Institute of Product Quality Standard Measurement)

机构地区：[1]德州市产品质量标准计量研究院

出　　处：《中国标准化》2024年第24期213-216,226,共5页China Standardization

摘　　要：本研究探讨了热电阻及其数字显示仪表的现场校准技术,旨在确保仪表测量的准确性与可靠性。校准过程中,选择Pt100型热电阻作为标准传感器,其示值误差控制在0.4%以内,适用温度范围为-80℃至400℃。现场测温仪要求具有高精度(±0.0025%)和分辨率(0.001℃),并通过RS-232接口与计算机连接,实现数据的自动采集和处理。校准方法包括比对实际测量值与标准值,调整仪表参数以确保输出信号一致。整体校准时,需检查热电阻的外观、连接及工作温度范围,同时测量仪表的绝缘电阻以确保安全性。自动校准需设置多个校准点以评估热电阻性能,实时监测温度变化以提高校准准确性。通过对不确定度的计算,得出标准不确定度范围为0.18℃~0.35℃,最终校准结果满足仪表的精度要求。校准过程中发现显示仪表存在误差,通过调整温度补偿值以提高测量准确性,并考虑温度场波动对结果的影响,确保校准结果的可靠性和稳定性。This paper explores thefield calibration technologies of RTDs and their digital display instruments,aiming to ensure the accuracy and reliability of instrument measurement.In the calibration process,Pt100 RTD is selected as the standard sensor,and its display value error is controlled within 0.4%,and the applicable temperature range is from-80°C to 400°C.The on-site pyrometer is required to have high accuracy(±0.0025%)and resolution(0.001°C),and is connected to the computer through the RS-232 interface to realize automatic data acquisition and processing.The calibration method includes comparing the actual measured value with the standard value and adjusting the instrument parameters to ensure consistent output signals.The overall calibration requires checking the appearance,connection and operating temperature range of the RTD,and measuring the insulation resistance of the instrument to ensure safety.Automatic calibration involves setting multiple calibration points to assess RTD performance and monitoring temperature changes in real time to improve calibration accuracy.Through the calculation of uncertainty,the standard uncertainty range is 0.18°C~0.35°C,and thefinal calibration result meets the accuracy requirements of the instrument.During the calibration process,the display meter is found to have errors,and the temperature compensation value is adjusted to improve the measurement accuracy,and the effect of temperature field fluctuation on the results is considered to ensure the reliability and stability of the calibration results.

关 键 词：热电阻 数字显示仪表 现场校准 

分 类 号：TH811[机械工程—仪器科学与技术]