1、Designation:E158214Standard Practice forCalibration of Temperature Scale for Thermogravimetry1This standard is issued under the fixed designation E1582;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A numbe
2、r in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice describe the temperature calibration ofthermogravimetric analyzers over the temperature range from25 to 1500C and is applicable to
3、 commercial and custom-builtapparatus.This calibration may be accomplished by the use ofeither melting point standards or magnetic transition standards.1.2 The mass change curve in thermogravimetry resultsfrom a number of influences,some of which are characteristicof the specimen holder assembly and
4、 atmosphere rather thanthe specimen.The variations from instrument to instrumentoccur in the point of measurement of the temperature,thenature of the material,its size and packing,the geometry andcomposition of the specimen container,the geometry anddesign of the furnace,and the accuracy and sensiti
5、vity of thetemperature sensor and displaying scales.These all contributeto differences in measured temperatures,which may exceed20C.In addition,some sample holder assemblies will showvariations of measured temperature with sample size orheating/cooling rate,or both.Since it is neither practical nora
6、dvisable to standardize sample holders or thermobalancegeometries,instruments may be calibrated by measurement ofthe deviation of a melting or magnetic(Curie Point)transitiontemperature from the standard reference temperature.Thisdeviation can be applied as a correction term to subsequentmeasurement
7、s.1.3 This practice assumes that the indicated temperature ofthe instrument is linear over the range defined by a two-pointcalibration and that this linearity has been verified.These twocalibration temperatures should be as close to the experimentalmeasurements to be made as possible.1.4 This practi
8、ce describes two procedures for temperaturecalibration of thermogravimetric analyzers using any typebalance.Procedure A uses melting point standards for calibra-tion.Procedure B uses magnetic transition standards forcalibration.NOTE1Since all electronic data treatments are not equivalent,the usersha
9、ll verify equivalency prior to use.1.5 The data generated by these procedures can be used tocorrect the temperature scale of the instrument by either apositive or negative amount using either a two-point tempera-ture calibration procedure or a multi-point temperature calibra-tion with best line fit
10、for the generated data.NOTE2A single-point calibration may be used where this is the onlyprocedure possible or practical.The use of a single-point procedure is notrecommended.1.6 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.
11、7 This practice is related to ISO 11358 but providesinformation and methods not found in ISO 11358.1.8 This standard does not purport to address all of thesafety problems,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health p
12、ractices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E473 Terminology Relating to Thermal Analysis and Rhe-ologyE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE967 Test Method for T
13、emperature Calibration of Differen-tial Scanning Calorimeters and Differential Thermal Ana-lyzersE1142 Terminology Relating to Thermophysical Properties2.2 Other Standards:ISO 11358 Plastics Part 4:Thermogravimetry(TG)ofPolymers General Principles33.Terminology3.1 DefinitionsTechnical terms used in
14、this document aredefined in Terminologies E473 and E1142.1This practice is under the jurisdiction of ASTM Committee E37 on ThermalMeasurements and is the direct responsibility of Subcommittee E37.01 on Calo-rimetry and Mass Loss.Current edition approved May 1,2014.Published June 2014.Originallyappro
15、ved in 1993.Last previous edition approved in 2010 as E1582 10.DOI:10.1520/E1582-14.2For 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 o
16、nthe ASTM website.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.1 magnetic reference temperaturethe observed tem-perature at which a change in the magnetic properties of amaterial in a magnetic field produces an apparent mass change.This temperature is read from the dynamic TG curve as thepoint of intersection