Capacitance Standards At Low Frequencies

1 Page 1 isurementServices: REFEBENCE NIST PUBLICATIONS NISTCalibrationServicefor CapacitanceStandardsat LowFrequencies NIST Special Publication 250^7 )C 00 J57 ).250-47 998 U.S.DepartmentofCommerce TechnologyAdministration Natio... Open at page → 2 Page 2 fhe NationalInstituteofStandardsandTechnologywasestablished in1988byCongressto"assistindustryin thedevelopmentoftechnology ...neededtoimproveproductquality,tomodernizemanufacturingprocesses,to ensureproductreliability...... Open at page → 3 Page 3 NISTSpecialPublication250-47 NISTMEASUREMENTSERVICES: NISTCalibrationServiceforCapacitance StandardsatLowFrequencies Y.MayChangandSummerfield B.Tillett ElectricityDivision ElectronicsandElectricalEngineeringLaboratory Na... Open at page → 4 Page 4 NationalInstituteofStandardsandTechnologySpecialPublication250-47 Natl.Inst.Stand.Technol.Spec.Publ.250-47,79pages(Apr.1998) CODEN:NSPUE2 U.S.GOVERNMENTPRINTINGOFFICE WASHINGTON: 1998 ForsalebytheSuperintendent ofDocumen... Open at page → 5 Page 5 TABLEofCONTENTS page LISTofTABLES v LISTofFIGURES vi ABSTRACT 1 1. INTRODUCTION 1 2. DESCRIPTIONOFSERVICE 2 2.1Fused-Silica-Dielectric CapacitanceStandards 2 2.2Nitrogen-Dielectric CapacitanceStandards 3 2.3Three-Termina... Open at page → 6 Page 6 5.4Customer'sStandards 17 6. REPORTEDVALUEANDMEASUREMENTUNCERTAINTY 17 7. CONCLUSION 18 8. REFERENCES 18 TABLES 20 FIGURES 31 APPENDIX 54 Al. GeneralInformationonFused-Silica-Dielectric StandardCapacitors 55 A2. TypicalR... Open at page → 7 Page 7 ListofTables Table 1.SummaryofStandardCapacitorsAcceptableforCalibrations 20 Table2.SummaryofReferenceandCheckStandardsoftheType-2Bridge 21 Table3.NISTCalibrationDesignforFused-Silica-Dielectric StandardCapacitors ...22... Open at page → 8 Page 8 ListofFigures Figurela.SchematicDiagramoftheNISTType-2CapacitanceBridge 31 Figurelb.SimplifiedCircuitDiagramoftheNISTType-2CapacitanceBridge 32 Figure2a.SchematicDiagramoftheNISTType-12CapacitanceBridge 33 Figure2b.Simpl... Open at page → 9 Page 9 NISTCalibrationServiceforCapacitanceStandardsatLowFrequencies Y.MayChangandSummerfield B.Tillett ABSTRACT -ThisdocumentdescribesthecapacitancecaUbrationserviceprovidedbyNIST, includingmeasurementproceduresandsystemsusedt... Open at page → 10 Page 10 2.DESCRIPTIONOFSERVICE NISToffersacalibrationserviceforcapacitancestandardsinawiderangeofcapacitancevaluesand geometricalconfigurationsintheaudio-frequency range.Three-terminal fused-silica-,nitrogen-,and air-dielectrics... Open at page → 11 Page 11 ModelGR1408isatypicalcommercialair-bathtype,fused-silica-dielectric capacitancestandard withnominalvaluesof10pFand100pF,thatisacceptedforcalibrationsatfrequenciesof100Hz, 400Hz,and1kHz.Sincetheexacttemperaturecoefficient... Open at page → 12 Page 12 2.3Three-Terminal Air-DielectricCapacitanceStandards Atypicalexampleofathree-terminal air-dielectriccapacitancestandardisthemodelGR1403with nominalvaluesthatrangefrom0.001pFto1000pF.Anotherexample,themodelGR1615-P1,has a... Open at page → 13 Page 13 2.6CapacitanceMeasurementAssuranceProgram(C-MAP) Thisisarecentlyre-establishedmeaisurementserviceimplementedusingacommercialmeter(based onfused-silicareferencecapacitors)asatransportstandardtomeasurecapacitancestandardsw... Open at page → 14 Page 14 capacitors,andthevalueofthereferencestandard. Inaddition,theType-2bridgehasaconductancebalEincecircuit,alsodescribedin[8],tomeasure theconductancecomponentoftheunknowncapacitor.AsshowninFig.la,theconductance balanceiscon... Open at page → 15 Page 15 isconnectedtoarmADand/orarmCD,accordingtothemeasurementconfigurations. RjandR2 areresistorswitharatioof1: 1 , isthevalueofC^,and and aretheeffectivecapacitance fromthedifferentialaircapacitors, ,onarmsADandCD,respectivel... Open at page → 16 Page 16 typestandard,independentlyconnectedtoarmsADandCDsuchthatthesumofconductanceof botharmsisaconstant.Figure3isasimplifieddiagramofType-12bridgethatincludesthe conductancecomponentsineacharm,andadividerresistor,R^,(seeFig.2a... Open at page → 17 Page 17 3.3.2DigitalImpedanceMeter ThistypeofDigitalImpedanceMeteremployedintheICL(hereafterreferredtoasDIM)uses standardacresistorsasinternalreferencesandmeasuresstandardcapacitors,inductors,andac resistors,overafrequencyrangef... Open at page → 18 Page 18 ThecalibrationdesignusedintheICLissimilartotheexperimentaldesignsforgroupsof3,4,and 5standards,describedbyEickeandCameron[14].Forexample,thedesignforagroupof3 standards istoperformintercomparisonofthesestandardssixtimesb... Open at page → 19 Page 19 Forcapacitorshavingnominalvaluesof100pFand1000pF,atwo-stepprocessisperformed. First, thesecondaryreference#131isusedtomeasuretheNISTcheckstandards#493and#517(or#171 7 and#1865)ofnominalvaluesof100pF(or1000pF)ataratioof1:... Open at page → 20 Page 20 referenceadapterusedforHFcoaxialcapacitormeasurements.Thecapacitanceofthereference adapterwasdeterminedbyusinganotheradapterwithaninnerterminalconnectedtoground. Measurementswereperformedbymatingtheadjustableadapter,whic... Open at page → 21 Page 21 isthereadingofairdialswhen isconnectedtothebridge,and CfQ isthereadingofairdialswhen isdisconnectedfromthebridge. Therelationshipofairdialsreading,Cj.andvaluesofthedifferentialaircapacitors wasgivenin Section3.2,and,acco... Open at page → 22 Page 22 C^=(l/2)(Q2-Cri), (7) whereC^2 thereadingofairdialswhen isconnectedtothearmCDofthebridge,and isthereadingofairdialswhen isconnectedtothearmADofthebridge. Forcapacitorsofnominalvaluesfromhigherthan0.005|liFto0.5|aF,acerta... Open at page → 23 Page 23 5.QUALITYCONTROLINTHEIMPEDANCECALIBRATIONLABORATORY Inordertoachievehighqualityinthemeasurement results, itisimportanttoestablishprocedures toassurethatthemeasuringsystemsandreferenceandcheckstandardsareinastateofstatist... Open at page → 24 Page 24 confidencelevel)andenclosuretemperatures,datingfrom1990.Thesesecondaryreferencesare utilizedtocalibratethecheckstandardswhichareusedasworidngstandardstocalibratecustomer's capacitancestandardswithdielectricsotherthanflis... Open at page → 25 Page 25 Type-12bridge.Dataobtainedfromthesemeasurementsshowthatthedifferencesinmeasurements amongthesethreesystemsvaryinaccordancetothenominalvaluesofthecapacitors.Figure 19is anexampleillustratingthedatafrommeasurementsusingall... Open at page → 26 Page 26 TheTypeAstandarduncertaintycontainserrorcomponentsthatcanbeevaluatedbystatistical methodsandisexpressedfromeachknownsourceoferrorasastatisticalstandarddeviation.The TypeBstandarduncertaintycontainsthoseerrorsthatareevalu... Open at page → 27 Page 27 4. "NISTCalibrationServicesUsersGuide,"Natl.Inst.Stand.Tech.SpecialPublication250, 1991edition,U.S.GovernmentPrintingOffice,Washington,DC20402. 5. B.N.TaylorandC.E.Kuyatt,"GuidelinesforEvaluatingandExpressingtheUncertain... Open at page → 28 Page 28 Table1.SummaryofStandardCapacitorsAcceptableforCalibrations Manufacturer anaiviouei NorminalValues TerminalConfiguration Frequency(Hz) GeneralRadioCo.* GR1403 0.001pF to1000pF 3-TCoaxial 100400&1000 GR1404 10pF to1000pF... Open at page → 29 Page 29 Table2.SummaryofReferenceandCheckStandardsoftheType-2Bridge SerialNo. Values(pF) Dielectric Control Temperature(°C) Pnmary #121 10 Fused-Silica Oil-Bath 25 Reference #181 10 #183 10 #184 10 Secondary #102 10 Fused-Silica... Open at page → 30 Page 30 Table3.NISTCalibrationDesignforFused-Silica-Dielectric StandardCapacitors Standards Used Primary Reference SecondaryReference Customer's Capacitors (GR-1408andAHllA) SerialNo. #121 #102 #131 Cxoi Cxii Cx21 Nominal Value... Open at page → 31 Page 31 Table4a.NISTCalibrationDesignfor10pFNitrogen-Dielectric StandardCapacitors Standards Secondary CheckStandard Customer'sCapacitor Used Reference (GR-1404withouttrimmers) (GR-1404 ) Sena!No. #102 #871 Cxi2 Nominal Value 10... Open at page → 32 Page 32 Table4d.NISTCalibrationDesignforOne100pF(or1000pF)Nitrogen-Dielectric StandardCapacitor Standards WorkingStandards OneCustomer'sCapacitor Used (GR-1404withouttrimmers ) (GR-1404&ESISC-1000 ) SerialNo. #493(or#1717) #517(... Open at page → 33 Page 33 Table5.NISTLargeUncertaintyCalibrationDesignforNitrogen-andAir-Dielectric StandardCapacitors Standards Used Working Standards Customer's Capacitors Working Standard Customer's Capacitor NominalValue 1pFto10000pF 1pFto100... Open at page → 34 Page 34 Table6.SummaryofCheckStandardsoftheType-12Bridge SerialNo. Nominal Model Value GR1409 Primary Secondary Set Set Tvne W1O1o 0.001 F ffj4/ -W11nA1 ff11/41 0.002 G #4VO ffl1/Do 0.005 K ft21ozU 0.01 L ff1juy ff11loU 0.02 M #... Open at page → 35 Page 35 Table7.CalibrationUncertaintiesofFused-Silica-andNitrogen-Dielectric StandardCapacitors Expanded Uncertainties (ppm) DielectricType Fused-Silica Nitrogen TestType SmallUncertainty LargeUncertamty 100 400 1000 100 400 100... Open at page → 36 Page 36 Table8.CalibrationUncertaintiesofAir-DielectricandTwo-TerminalHFCoaxialConnector StandardCapacitors Expanded Uncertainties (ppm) Configuration Three-TerminalCoaxial Two-TerminalHFCoaxial DielectricType Air AirandMica Fre... Open at page → 37 Page 37 Table9.CalibrationUncertaintiesofCapacitanceValuesofTwo-andThree-Terminal Mica-DielectricStandardCapacitors Expanded Uncertainties ofCapacitance (ppm) Configuration Two-Terminal Three-Terminal Frequency(Hz) 66,100,400,an... Open at page → 38 Page 38 Table10.CalibrationUncertaintiesofConductanceValuesofTwo-and Three-TerminalMica-DielectricStandardCapacitors Expanded UncertaintiesofConductance (jj,S) Frequency(Hz) 66&100 400&1000 10000 NominalValue(\iF) 0.001 0.0003 0... Open at page → 39 Page 39 31 Open at page → 40 Page 40 gurelb.SimplifiedCircuitDiagramoftheNISTType-2CapacitanceBridge. 32 Open at page → 41 Page 41 ^GROONDSHIELD NOTE-.SOMESWITCHESANDANCILLARYeLEMfrMTSHAVE:BEEIjX OMITTEDTOS/MPLlr"y THISSCHEMATICDIAGRAM. Ca:aircapacitor (0>^(IOOO,ioo,|o}PF+|0PFDIFFERENTIAL CONT/KiUOUS- Ck-DIVIOE-BV-T^N CAPACITOR:' 600PFOR100PF{SeR-NO... Open at page → 42 Page 42 ure2b.SimplifiedCircuitDiagramoftheNISTType-12CapacitanceBridge. (GenerallyShowingonlytheCapacitanceComponents) 34 Open at page → 43 Page 43 35 Open at page → 44 Page 44 #121(orotherPrimaryRefeence) (10pF) #102(or#254) (10pF) Customer's Nitrogen(orAir) CapStds Cxi2(10pF) Customer's AirCapStds Cxo2(>PF) Customer's FusedSilica CapStds Cxoi(1 Cxii(lOpF) #871 (10pF) #89790 (1pF) Customer's A... Open at page → 45 Page 45 NISTREFERENCEADAPTER Open at page → 46 Page 46 UNKNOWNCAPAOTOR OR TERMINATION Figure6.ConnectionofReferenceAdapterandHFCoaxialConnectorCapacitors 38 Open at page → 47 Page 47 39 Open at page → 49 Page 49 ASS SHING CC3 mCD nil MM 41 Open at page → 50 Page 50 42 Open at page → 51 Page 51 % t I— < (U o -C. -o c o U -On- ON oo ON ON OS ON in ON ON in ON ON H-^ (N >n oo On •n CMm in in in in in in in »n in in »n in in in m m mmm 1mmm (U > ;-< <U & S H (U o C • CI, I— > P3 O Cu o CO a c *-> <L) O c <L) o IX,... Open at page → 52 Page 52 PrimaryStandardsLab ReferenceBank 4xlOpFOilBath FusedSilicaCapStds ImpedanceCalibrationLab TransferStandard 10pFAirBath FusedSilicaCapStds PrimaryReference 4xlOpFOilBath FusedSilicaCapStds Customer's FusedSilica CapStds... Open at page → 53 Page 53 (3^) sjnjmaduiaxamsopug 0''^o>no>riO</^o<^ oooooooooooooooooooo 0\ 0^ ON CTv CJN On On On On On qo (N CNl (N <N (N <N (N <N r^l <Non O W-1 O m O W-» O O >nooT^OOONONOOOOr~;r-;NO 3n\T3\90ireji0BdB3|BUTmojs[uioijuidd 45 Open at page → 54 Page 54 (3^) 3jnjBJ3dui9xamsopug o</^o<oo«ooioo»o oooooooooooooooooooo 0\ On OS ON 0\ On Os On On Onqo CN< <N <N (N (N <N CM <N PnI 46 Open at page → 55 Page 55 anjByviBuiiuo]s[uiojjuidd 47 Open at page → 56 Page 56 oo ON i tT) o in OS >n oo IT) ^ d ^ o\ od K 3n|By\|euiuio]\[uiojjuidd 48 Open at page → 57 Page 57 ' I I I ' I ' I ' I I I I csoooooooo o Oh I I I I ' (Nm «n^ ooooo ' I I oo oo ON o oo On I 49 Open at page → 58 Page 58 oo ON On -.-o On ON ON +?^ CD ON ON ON CM On ON I ' I I ' I I I I ' I I ONoo r~-^»o ooooo mfN ooo I I I I I I I O (NCO oooo B ' ' ' ' a, a, ddd ooON dd m ON CNl 0) GO 50 Open at page → 59 Page 59 J I I ' I I I I I I ' I I ooooooooo I ' I I I I I I O^CN<^ c5oo I I I s a, Oh o »n ooOS ooooo oo OS so Os --O HOS so OS so OS + OS OS (N OS SO (N OS <N OS OS 3 51 Open at page → 60 Page 60 (Srl)snp/^9oirepnpuo3 «n <o V-) ir> «n >o m (N CS ~0^ I I I I— I— I— I—r— I— 1—1—I— I— I— I—I I I—I— I—I I I— I — i— I—r— I—I i I I I I I I—r— 1— i— I- r-; lo CTs w-i 00 >n r~- >o ^ loiTi tinosoooooor-oovooomOOOvOOOsOOON... Open at page → 61 Page 61 (SrI)anjB/^aoirepnpuo^ «o >o lo >n W-) ooosooonooonooonoo ^ On 0\ OS On Open at page → 62 Page 62 APPENDIX Al . GeneralInformationonFused-Silica-Dielectric StandardCapacitors. A2. TypicalREPORTOFCALIBRATION forFused-Silica-Dielectric StandardCapacitors. A3. GeneralInformationonNitrogen-Dielectric StandardCapacitors.... Open at page → 63 Page 63 UNITEDSTATESDEPARTMENTOFCOMMERCE NationalInstituteofStandardsandTechnology Gaithersburg.Man/land20899-CXXD1 GENERALrNFORMATIONONFUSED-SILICA-DIELECTRIC CAPACITORS 1.RepresentationoftheUnitofCapacitance Asaresultofnewabso... Open at page → 64 Page 64 standarddeviationofthemeasuredcapacitancebyanorderofmagnitudeormore. Thereportedvalueofcapacitance isintermsoftheNISTunitofcapacitancemaintainedwitha groupofstablestandards[4].Theexpandeduncertaintiesincludeallowanceforb... Open at page → 65 Page 65 UNITEDSTATESDEPARTMENTOFCOMMERCE NationalInstituteofStandardsandTechnology Gaithersburg,Maryland2D899-0001 REPORTOFCALIBRATION StandardCapacitor GeneralRadioCompany Type1408-A,SerialNo.UM# EnclosureSerialNo.MM Submittedb... Open at page → 67 Page 67 UNITEDSTATESDEPARTf/IErVITOFCOMMERCE NationalInstituteofStandardsandTechnology Gaithersburg.Maryland20899-OO01 GENERALINFORMATIONONNITROGEN-DIELECTRICSTANDARDCAPACITORS 1.RepresentationoftheUnitofCapacitance Asaresultofn... Open at page → 68 Page 68 TypeBuncertaintiesinthechainofmeasurements,andareassignedtothecapacitancevaluesusing thecoveragefactor/:=2[6].Thesedonotincludeanyuncertaintiesthatmaybeassociatedwith longterminstability,temperaturehysteresis,andchangesd... Open at page → 69 Page 69 UNITEDSTATESDEPARTMENTOFCOMMERCE NationalinstituteofStandardsandTechnology Gaithersburg,Marvland20899-O001 REPORTOFCALIBRATION StandardCapacitor GeneralRadioCompany Type1404-A,SerialNo.MM Submittedby: Temperatune CO Capa... Open at page → 71 Page 71 UNITEDSTATESDEPARTMENTOFCOMMERCE NationalInstituteofStandardsandTechnology Gaidiersburg.Mar/land20899-OO01 DESCRIPTIONOFTESTSUSEDTODETEEIMFNETHEEFFECTOFSMALL MECHANICALSTRESSESONHIGHSTABILITY,NITROGEN-DIELECTRIC STANDARD... Open at page → 72 Page 72 ofthesedifferences isgivenastheresultofthistest. KNOCKSOFTTEST-Inthistestthecapacitorisstruckbyarubbertippedpendulum.Theforce generatedbythependulum isroughlyequivalenttothatgeneratedbyamildwristmotionblowof thehumanhand... Open at page → 73 Page 73 UNITEDSTATESDEPARTMENTOFCOMMERCE NationalinstituteofStandardsandTechnology Gaithersburg,MarYland20a99-CXXi1 REPORTOFCALIBRATION StandardCapacitor GeneralRadioCompany Type1404-A SerialNo.UMU Submittedby: Orientation (Maxi... Open at page → 74 Page 74 i Open at page → 75 Page 75 UNITEDSTATESDEPARTMENTOFCOMMERCE NationalInstituteofStandardsandTechnology Gaithersburg.Maryland20899-OCXD1 GENERALINFORMATIONONTHREE-TERMINALSTANDARDCAPACITORS 1.RepresentationoftheUnitofCapacitance Asaresultofnewabsolu... Open at page → 76 Page 76 Measurementsofthree-terminalcoaxialstandardcapacitorsarenotmadeatfrequenciesexceeding 1kHzduetolimitations inthepresentNISTmeasurementapparatus. Dependinguponthe constructionandpresenceoffilms,thefrequencydependenceofthe... Open at page → 77 Page 77 UNITEDSTATESDEPARTMENTOFCOMMERCE NationalInstituteofStandardsandTechnology Gaithersburg,Maryland20899-0001 REPORTOFCALIBRATION StandardCapacitor GeneralRadioCompany Type1403-D,SerialNo.#### Submittedby: Frequency (Hz) 10... Open at page → 79 Page 79 UNITEDSTATESDEPARTMENTOFCOMMERCE NationalInstituteofStandardsandTechnology Gaithersburg.Man/land20899-aX)1 GENERALINFORMATIONONTWO-TERMINALSTANDARDCAPACITORS WITHPRECISIONCOAXIALCONNECTORS 1.RepresentationoftheUnitofCapa... Open at page → 80 Page 80 Thereportedvalueofcapacitance isintermsoftheNISTrepresentationofthefarad.Theexpanded uncertaintiesincludeallowanceforbothTypeAandTypeBuncertaintiesinthechainofcalibration measurements,andareassignedtothecapacitancevalues... Open at page → 81 Page 81 UNITEDSTATESDEPARTMENTOFCOMMERCE NationalInstituteofStandardsandTechnology Gaithersburg,Maryland20899-0(X)1 REPORTOFCALIBRATION StandardCapacitor GeneralRadioCompany Type1406-A,SerialNo.MM Submittedby: Expanded Frequency... Open at page → 83 Page 83 UNITEDSTATESDEPARTIVIEIMTOFCOIVir/JERCE NationalInstituteofStandardsandTechnology Gaithersburg,Maryland20899-CO01 c GENERALINFORMATIONONMICA-DIELECTRICSTANDARDCAPACITORS WITHBINDINGPOSTCONNECTORS 1.RepresentationoftheUni... Open at page → 84 Page 84 ThereportedvaluesofcapacitanceareintermsoftheNISTrepresentationofthefarad.The capacitancecahbrationuncertaintiesareexpandeduncertaintiesandincludeallowancesforboth TypeAandTypeBuncertaintiesinthechainofcalibrationmeasure... Open at page → 85 Page 85 UNITEDSTATESDEPARTMENTOFCOMMERCE NationalInstituteofStandardsandTechnology Gaithersburg.Maryland20899-0001 REPORTOFCALIBRATION StandardCapacitor GeneralRadioCompany Type1409-Y,SerialNo.MM Submittedby: Typeof Capacitance... Open at page → 86 Page 86 I r Open at page → 87 Page 87 THESP250SERIESONNISTMEASUREMENTSERVICES* SP250-1 SpectralRadianceCalibrations PB87179883 SP250-2 FarUltravioletDetectorStandards PB87227609 SP250-3 RadiometricStandards intheVacuum Ultraviolet PB87227625 SP250-4 FrickeDo... Open at page → 88 Page 88 u u § o55 *^"7; co E3 0.1-- <u_ og .o o o o I ON OS 00 o 2P ' c> Ob 3a. ,P PZ§OO£ Open at page →