Escort 3004B, 3008B, 3016B 17.4.Accuracyclass indexofclass

17 Appendix
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Pl= + 0.25 C(accuracyofstandardisation)
Pz= + 0.25 C(zeroaccuracy)
Pd=0(nozerooffset)
Pmcalculation:
Slopecalculationat240 C:321+(301-321)x(240-200)/(400-200)so317 V/ C
Pm=210/317= + 0.66 C
Max.totalaccuracy:
Pt= + 0.25 + 0.25 + 0.66= + 1.16 C
17.4.Accuracyclass indexofclass
ThisisoneoftheessentialconceptsoftheC.E.I.recommendation:itisintendedtoalleviatethe
listingofthespecifications.Inordertodoso,itintroducestheconceptofACCURACYCLASS,
whichisdeterminedhereasCLASSCINDEX.
Thenormalisedvaluesoftheindexofclassare:C=0.1;0.25;0.5and1.
Theintrinsicerror(inthereferenceconditions)doesnotexceed C%(themanufacturercanalso
specifythislimitoftheintrinsicerrorasanabsolutevalue(forexample 5microvolts)forthefirst
ranges).
Whenoneoftheinfluencevariablevarieswithinthenominalrangeofuse,variations(ofthe
measuredvalue)donotexceed:
-C%fortheposition,forthemagneticinductionfromouteroriginandforspurious
voltages
-0.5C%forthepowersupply
-0.3C%accordingtotheclassindexfortheroomtemperature(0.15%forthe0.25class).
Moreover,therangeofinsensitivitymustnotexceed:
-C%inthereferenceconditions
-1.5C%forthemaximumresistanceoftheoutercircuitofmeasure
-2C%forthespuriousvoltages
-
Eventually,noovervalue shouldexceed2C%(4C%forthelimitsofthepowersupply).