ASTM_E_2038_-_99_2004.pdf

Designation:E 2038 99(Reapproved 2004)Standard Test Method forTemperature Calibration of Dielectric Analyzers1This standard is issued under the fixed designation E 2038;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(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method describes the temperature calibrationof dielectric analyzers over the temperature range from 100 to300 C and is applicable to commercial and custom-builtapparatus.The calibration is performed by observing themelting transition of standard reference materials havingknown transition temperatures within the temperature range ofuse.1.2 Electronic instrumentation or automated data analysisand data reductions systems or treatment equivalent to this testmethod may be used.1.3 The values stated in SI units are to be reported as thestandard.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and to determine theapplicability of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E 473 Terminology Relating to Thermal AnalysisE 1142 Terminology Relating to Thermophysical Properties3.Terminology3.1 DefinitionsSpecific technical terms used in this testmethod are defined in accordance with Terminologies E 473and E 1142.4.Summary of Test Method4.1 A test specimen of known solid-solid or solid-liquid(melting)transition temperature is characterized for its dielec-tric properties in a dielectric analyzer of interest as a functionof temperature.At the transition,a sharp change in thedielectric properties is observed.The temperature observed forthe transition by the apparatus is recorded.Using a linearequation,for one or more transitions,the temperature scale orreadout of the apparatus is calibrated based upon the knownand observed transition temperatures.5.Significance and Use5.1 This test method permits interlaboratory comparisonand intralaboratory correlation of instrumental temperaturescale data.5.2 Dielectric analyzers are used to characterize a broadrange of materials that possess dielectric moments.One of thedesired values to be assigned by the measurement is thetemperature at which significant changes occur in the proper-ties of the test specimen.In order to obtain consistent resultsfrom one period of time to another and from one laboratory toanother,the temperature signal from the apparatus must becalibrated accurately over the temperature range of interest.6.Interferences6.1 Because the specimen size usually is small,care must betaken to ensure that each specimen is homogeneous andrepresentative of the sample as a whole.6.2 This test method measures dielectric properties underspecific experimental conditions.Should those experimentalconditions change,there may be an effect on the calibration ofthe apparatus.6.3 Contact or adhesion of the specimen to the sensorshould not be lost during the course of the measurement,otherwise erroneous values will be recorded.7.Apparatus7.1 Dielectric Analyzer,consisting of the following items:7.1.1 Sensors,electrodes for imparting the alternating elec-tric field and measuring the induced current and phasing in thespecimen.These usually are solid platforms that also serve tohold the specimen.These may be either two parallel plateelectrodes or a single plate containing a series of interdigitatedelectrodes.NOTE1When using parallel plate electrodes,provision shall be madeto prevent the electrodes from contacting each other upon the melting ofthe test specimen.7.1.2 Temperature Sensor,for measuring the specimen tem-perature to within 6 0.1 C.1This test method is under the jurisdiction ofASTM Committee E37 on ThermalMeasurements and is the direct responsibility of Subcommittee E37.01 on TestMethods and Recommended Practices.Current edition approved Sept.10,1999.Published November 1999.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandardsvolume information,refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.7.1.3 Specimen Container,for containing the test specimenin liquid form(after it melts).7.1.4 Temperature Programmer and Furnace,capable oftemperature programming the test specimen from 100 to300 C at a rate of at least 1C/min,or performing isothermaltemperature operation at temperatures over the range of interestto 6 1 C.7.1.5 Cooling Device and Supplies,to provide operatingtemperatures below ambient temperatures.This may be amechanical refrigerator or other coolant such as liquid nitro-gen.7.1.6 Specimen Atmos