ASTM_D_2149_-_13.pdf

Designation:D214913Standard Test Method forPermittivity(Dielectric Constant)And Dissipation Factor OfSolid Dielectrics At Frequencies To 10 MHz AndTemperatures To 500C1This standard is issued under the fixed designation D2149;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the determination of the relativepermittivity(dielectric constant)and dissipation factor of soliddielectrics from 50 Hz to 10 MHz over a range of temperaturesfrom 80 to 500C.2,3Two procedures are included as follows:1.1.1 Procedure AUsing Micrometer Electrode.1.1.2 Procedure BUsing Precision Capacitor.NOTE1In common usage the word“relative”is frequently dropped.1.2 This standard does not purport to address the safetyconcerns,if any,associated with its use.It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use.2.Referenced Documents2.1 ASTM Standards:4D150 Test Methods for AC Loss Characteristics and Permit-tivity(Dielectric Constant)of Solid Electrical InsulationD1711 Terminology Relating to Electrical InsulationE197 Specification for Enclosures and Servicing Units forTests Above and Below Room Temperature(Withdrawn1981)53.Terminology3.1 Definitions:3.1.1 Permittivity and dissipation factor are fully defined inTerminology D1711.Briefly,the permittivity of an insulatingmaterial is the ratio of the capacitance between two conductorswhen embedded in the material to the capacitance between thesame configuration of conductors in a vacuum(or air).Thedissipation factor is the ratio of the resistive to capacitivecurrents in the dielectric.The product of the permittivity anddissipation factor is the loss index.4.Significance and Use4.1 Permittivity and dissipation factor are sensitive tochanges in chemical composition,impurities,and homogene-ity.Measurement of these properties is,therefore,useful forquality control and for determining the effect of environmentssuch as moisture,heat,or radiation.5.Apparatus5.1 Measuring CircuitsSuitable measuring circuits aredescribed in Test Methods D150.For measurements from 50Hz to 100 kHz a substitution method using a low-voltagecapacitance bridge is recommended.For measurements at 1MHz and above,a resonant-circuit susceptance variationmethod is recommended.The Q of the circuit has to be at least200 except for very low loss materials,for which a Q of 500 orhigher is desirable.5.2 TestEnclosureUnlesstestingonlyatroomtemperature,it is necessary to adapt a Hartshorn-Ward typespecimen holder to a temperature-controlled test enclosure.Where applicable,use the requirements for a gradeAenclosureas in Specification E197.A suggested arrangement is shown inFig.1.This arrangement provides terminal connections awayfrom the temperature zone.5.3 Specimen HolderThe suggested arrangement shownin Fig.1 incorporates the following requirements:5.3.1 The selection of the metals is of utmost importance.The metal has to be of good thermal and electrical conductivityand yet be oxidation resistant and have sufficient strength tomaintain its mechanical dimensions after repeated heating.1This test method is under the jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and is the direct responsibility ofSubcommittee D09.12 on Electrical Tests.Current edition approved May 1,2013.Published June 2013.Originallyapproved in 1963.Last previous edition approved in 2004 as D2149 97(2004),which was withdrawn in January 2013 and reinstated in May 2013.DOI:10.1520/D2149-13.2R.Bartnikas,Chapter 2,“Alternating-Current Loss and PermittivityMeasurements,”Engineering Dielectrics,Vol IIB,Electrical Properties of SolidInsulating Materials,Measurement Techniques,R.Bartnikas,Editor,ASTM STP926,ASTM,Philadelphia,1987.3R.Bartnikas,Chapter 1,“Dielectric Loss in Solids,”Engineering Dielectrics,Vol IIA,Electrical Properties of Solid Insulating Materials:Molecular Structure andElectrical Behavior,R.Bartnikas and R.M.Eichorn,Editors,ASTM STP 783,ASTM Philadelphia,1983.4For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.5The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 AISI Stainless No.316 fulfills these requirements except forthe thermal conductivity.The time required for a specimen toreach equilibrium in a holder made from this material is quitelong.Precious metal alloys such as type B silver-magnesium-nickel have bett