電阻溫度計的檢定-基礎(chǔ)附錄3

1、電阻溫度計的檢定電阻溫度計的檢定2一般的檢定步驟一般的檢定步驟Start New Record開始新的記錄Visual Inspection視覺檢查uClean?, bent?干凈？彎曲？Generic Checks普通檢查uInsulation resistance, Self-heating & Immersion assessmentsu絕緣電阻，自熱和浸入深度的估計Conditioning and Adjustment處理和調(diào)整uAnnealing & Stability tests退火和穩(wěn)定性測試Comparison比較uSPRTs and very best partially s

2、upported PRTs Fixed PointsuSPRT和非常好的部分支撐的PRT固定點(diǎn)uPrecision PRTs Comparison in bathsu精密PRT在恒溫槽中使用比較法uIndustrial PRTs Comparison in Dry-Wellsu工業(yè)PRT在干井爐中使用比較法Analysis分析uCalculation of coefficients or R vs. T table系數(shù)的計算或生成分度表Uncertainties不確定度uReference thermometer, heat source stability & uniformity, pro

3、be specific errorsu參考溫度計，熱源穩(wěn)定性和均勻性，探頭特有誤差Complete Records完整的記錄3Calibrating PRTs檢定檢定PRT Characterization標(biāo)定uThermometer resistance is measured at several temperature points and the data is fitted to a mathematical formula (mathematical model).u在幾個點(diǎn)測量溫度計的電阻，通過這些數(shù)據(jù)得到數(shù)學(xué)公式（數(shù)學(xué)模型） Tolerance Testing誤差測試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在幾個點(diǎn)測量溫度計的電阻，數(shù)據(jù)與相應(yīng)的溫度點(diǎn)的定義值比較。4Characterization or Tolerance Testing?標(biāo)定或誤差測量標(biāo)定或誤差測量 Characterization標(biāo)定uMost common for precision PRTs, provides best

5、uncertaintyu對精密PRT是最常用的方法，具有最好的不確定度uResult is unique to probe, requires unique compensation or linearization in readout to take full advantage of calibration datau結(jié)果只對單獨(dú)的探頭，需要在測溫儀進(jìn)行單獨(dú)的補(bǔ)償或線性化以充分利用檢定數(shù)據(jù)uRequire at least 5 data points and substantial mathematics for reasonable resultsu需要至少5個點(diǎn)的數(shù)據(jù)和數(shù)學(xué)計算以獲得

6、合理的結(jié)果 Tolerance Testing誤差測量uMost common for industrial grades of PRTs, only provides for standardized uncertaintyu對工業(yè)級PRT最常用的方法。只提供已經(jīng)標(biāo)準(zhǔn)化的不確定度uResult classifies probe into an accuracy grade, allowing non-probe specific compensation to be usedu結(jié)果按準(zhǔn)確度等級分類，允許使用補(bǔ)償uCan be completed with a few as 1 or 2 da

7、ta pointsu使用1或2個數(shù)據(jù)即可完成。5Example Configuration配置配置舉例舉例Precision Thermometer Readout / DMM Method精密測溫儀萬用表方法ReferenceProbeDigital MultimeterProbes Under Test6Example Data Set測試數(shù)據(jù)測試數(shù)據(jù)舉例舉例4個點(diǎn)水三相點(diǎn)個點(diǎn)水三相點(diǎn)溫度溫度測量值測量值7Calculate Coefficients using ITS-90 Deviation Functions使用使用ITS90溫標(biāo)偏差函數(shù)計算系數(shù)溫標(biāo)偏差函數(shù)計算系數(shù)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逆函數(shù)驗證逆函數(shù)驗證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逆函數(shù)計算殘差逆函數(shù)計算殘差9Procedures - Tolerance Testing步驟誤差測量步驟誤差測量 Typical approach for medium to low accuracy and industrial applications 主要應(yīng)用于中等或低準(zhǔn)確度的工業(yè)應(yīng)用 Resistance at temper

10、ature T is compared to defined (table) values 在溫度T時的電阻與分度表的值比較 Internationally DIN 43760, IEC-751, or ASTM 1137 standards and defined limits of error are common 國際上常用的DIN43760, IEC-751,或 ASTM 1137 標(biāo)準(zhǔn)10PRT分類誤差分類誤差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類= 0.13 + 0.0017|t|C 100 C = 0.13 + 0.0017|100| = 0.30 CIEC 751 class B IEC751 B類= 0.25 + 0.0042|t|C 100 C = 0.25 + 0.0042|100| = 0.67 C12工業(yè)允差測試的例子工業(yè)允差測試的例子 Basic system基本系統(tǒng)uFluke-744 Documenting Process Calibrator福祿克744校準(zhǔn)器uHart Field Dry-Well哈特現(xiàn)場干井爐9103 for -25 to 140 (9103干井爐）9141 for 50 to 650

12、（9141干井爐）uHart 5614 Secondary Reference PRTu哈特5614二等標(biāo)準(zhǔn)溫度計 Approximate system uncertainty 0.34C (rss method)近似的系統(tǒng)不確定度0.34u744 PRT measurement accuracy 0.3Cu744測量PRT準(zhǔn)確度為0.3Cu9141 combined stability and uniformity u9141的穩(wěn)定性及均勻性綜合指標(biāo)u0.16 420Cu5614 PRT 0.023C13精密精密PRT的系統(tǒng)舉例的系統(tǒng)舉例 Basic System基本系統(tǒng)u1529 CHUB

13、-E4 Readout1529測溫儀u5626 Secondary SPRT5626二等標(biāo)準(zhǔn)uDeep Immersion Compact Bath深井臺式槽u9938 MET/TEMP II Software9938軟件 Approximate uncertainty 0.03C 近似不確定度0.03Cu1529 CHUB 0.012C 200Cu5626 SPRT 0.009C 420Cu6331 combined stability and uniformity u6331穩(wěn)定性和均勻性綜合指標(biāo)u0.03C 300C14標(biāo)準(zhǔn)溫度計系統(tǒng)舉例標(biāo)準(zhǔn)溫度計系統(tǒng)舉例 Basic equipment

14、基本系統(tǒng)u1590 SuperThermometer超級電阻測溫儀u5681 Quartz SPRT石英護(hù)管一等標(biāo)準(zhǔn)溫度計u9114 Freeze-Point Furnace固定點(diǎn)爐u590X Fixed Point Cells固定點(diǎn)容器u9938 MET/TEMP II Software軟件 Approximate uncertainty 3mK to 5mK 近似不確定度3mK to 5mKu1590 1.5mKu5681 SPRT 1mKu5906 Zinc Point 1mK15Conclusion/結(jié)論結(jié)論 PRTs are truly remarkable instruments PRT是非常實(shí)用的儀器 With proper care and attention to detail the