电阻温度计的检定-基础附录3

1、电阻温度计的检定电阻温度计的检定2一般的检定步骤一般的检定步骤Start New Record开始新的记录Visual Inspection视觉检查uClean?, bent?干净？弯曲？Generic Checks普通检查uInsulation resistance, Self-heating & Immersion assessmentsu绝缘电阻，自热和浸入深度的估计Conditioning and Adjustment处理和调整uAnnealing & Stability tests退火和稳定性测试Comparison比较uSPRTs and very best partially s

2、upported PRTs Fixed PointsuSPRT和非常好的部分支撑的PRT固定点uPrecision PRTs Comparison in bathsu精密PRT在恒温槽中使用比较法uIndustrial PRTs Comparison in Dry-Wellsu工业PRT在干井炉中使用比较法Analysis分析uCalculation of coefficients or R vs. T table系数的计算或生成分度表Uncertainties不确定度uReference thermometer, heat source stability & uniformity, pro

3、be specific errorsu参考温度计，热源稳定性和均匀性，探头特有误差Complete Records完整的记录3Calibrating PRTs检定检定PRT Characterization标定uThermometer resistance is measured at several temperature points and the data is fitted to a mathematical formula (mathematical model).u在几个点测量温度计的电阻，通过这些数据得到数学公式（数学模型） Tolerance Testing误差测试uTher

4、mometer resistance is measured at several temperature points and the data is compared to defined values at those temperatures. No fitting is performed.u在几个点测量温度计的电阻，数据与相应的温度点的定义值比较。4Characterization or Tolerance Testing?标定或误差测量标定或误差测量 Characterization标定uMost common for precision PRTs, provides best

5、uncertaintyu对精密PRT是最常用的方法，具有最好的不确定度uResult is unique to probe, requires unique compensation or linearization in readout to take full advantage of calibration datau结果只对单独的探头，需要在测温仪进行单独的补偿或线性化以充分利用检定数据uRequire at least 5 data points and substantial mathematics for reasonable resultsu需要至少5个点的数据和数学计算以获得

6、合理的结果 Tolerance Testing误差测量uMost common for industrial grades of PRTs, only provides for standardized uncertaintyu对工业级PRT最常用的方法。只提供已经标准化的不确定度uResult classifies probe into an accuracy grade, allowing non-probe specific compensation to be usedu结果按准确度等级分类，允许使用补偿uCan be completed with a few as 1 or 2 da

7、ta pointsu使用1或2个数据即可完成。5Example Configuration配置配置举例举例Precision Thermometer Readout / DMM Method精密测温仪万用表方法ReferenceProbeDigital MultimeterProbes Under Test6Example Data Set测试数据测试数据举例举例4个点水三相点个点水三相点温度温度测量值测量值7Calculate Coefficients using ITS-90 Deviation Functions使用使用ITS90温标偏差函数计算系数温标偏差函数计算系数Set of eq

8、uations 等式Solving for a and b using example data:求解方程a = -5.3581671E-04b = 2.0307049E-05 Wa Wb WTTT111211()() Wa Wb WTTT222211()() Wa Wb WTTT333211()() Wa Wb WTTT444211()()8Check Curve Fit Using ITS-90 Inverse Functions使用使用ITS90逆函数验证逆函数验证Calculate residuals usingITS-90 inverse functionsCalculatedTem

9、p (K)Actual Temp(K)Residuals(K)429.7494429.7490 0.0004595.0770595.0780-0.0010573.1509573.1500 0.0009692.6768692.6770-0.0002使用使用ITS90逆函数计算残差逆函数计算残差9Procedures - Tolerance Testing步骤误差测量步骤误差测量 Typical approach for medium to low accuracy and industrial applications 主要应用于中等或低准确度的工业应用 Resistance at temper

10、ature T is compared to defined (table) values 在温度T时的电阻与分度表的值比较 Internationally DIN 43760, IEC-751, or ASTM 1137 standards and defined limits of error are common 国际上常用的DIN43760, IEC-751,或 ASTM 1137 标准10PRT分类误差分类误差11Example of Limits of error using IEC Tolerances使用使用IEC允差的例子允差的例子IEC 751 class AIEC 751

11、 A类= 0.13 + 0.0017|t|C 100 C = 0.13 + 0.0017|100| = 0.30 CIEC 751 class B IEC751 B类= 0.25 + 0.0042|t|C 100 C = 0.25 + 0.0042|100| = 0.67 C12工业允差测试的例子工业允差测试的例子 Basic system基本系统uFluke-744 Documenting Process Calibrator福禄克744校准器uHart Field Dry-Well哈特现场干井炉9103 for -25 to 140 (9103干井炉）9141 for 50 to 650

12、（9141干井炉）uHart 5614 Secondary Reference PRTu哈特5614二等标准温度计 Approximate system uncertainty 0.34C (rss method)近似的系统不确定度0.34u744 PRT measurement accuracy 0.3Cu744测量PRT准确度为0.3Cu9141 combined stability and uniformity u9141的稳定性及均匀性综合指标u0.16 420Cu5614 PRT 0.023C13精密精密PRT的系统举例的系统举例 Basic System基本系统u1529 CHUB

13、-E4 Readout1529测温仪u5626 Secondary SPRT5626二等标准uDeep Immersion Compact Bath深井台式槽u9938 MET/TEMP II Software9938软件 Approximate uncertainty 0.03C 近似不确定度0.03Cu1529 CHUB 0.012C 200Cu5626 SPRT 0.009C 420Cu6331 combined stability and uniformity u6331稳定性和均匀性综合指标u0.03C 300C14标准温度计系统举例标准温度计系统举例 Basic equipment

14、基本系统u1590 SuperThermometer超级电阻测温仪u5681 Quartz SPRT石英护管一等标准温度计u9114 Freeze-Point Furnace固定点炉u590X Fixed Point Cells固定点容器u9938 MET/TEMP II Software软件 Approximate uncertainty 3mK to 5mK 近似不确定度3mK to 5mKu1590 1.5mKu5681 SPRT 1mKu5906 Zinc Point 1mK15Conclusion/结论结论 PRTs are truly remarkable instruments PRT是非常实用的仪器 With proper care and attention to detail the