1、Designation:D61813Standard Practice forConditioning Plastics for Testing1This standard is issued under the fixed designation D618;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 indic
2、ates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1.Scope*1.1 In general,the physical and electrical properties ofplastics are influenced by tempe
3、rature and relative humidity ina manner that materially affects test results.In order to makereliable comparisons between different materials and betweendifferent laboratories,it is necessary to standardize the humid-ity conditions,as well as the temperature,to which specimensof these materials are
4、subjected prior to and during testing.Thispractice defines procedures for conditioning plastics(althoughnot necessarily to equilibrium)prior to testing,and the condi-tions under which they shall be tested.1.2 For some materials,it is possible that a material speci-fication exists that requires the u
5、se of this practice,but withsome procedural modifications.The material specificationtakes precedence over this practice.Refer to the materialspecification before using this practice.Table 1 in Classifica-tion D4000 lists the ASTM material specifications that cur-rently exist.1.3 This standard does n
6、ot 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 determine the applica-bility of regulatory limitations prior to use.NOTE1This standard and ISO 291 address the
7、 same subject matter,but differ in technical content.ISO 291 describes only two temperatureand humidity conditions for conditioning or testing,or both.2.Referenced Documents2.1 ASTM Standards:2D709 Specification for Laminated Thermosetting MaterialsD756 Practice for Determination of Weight and Shape
8、Changes of Plastics UnderAccelerated Service Conditions(Withdrawn 1998)3D4000 Classification System for Specifying Plastic Materi-alsD5032 Practice for Maintaining Constant Relative Humidityby Means of Aqueous Glycerin SolutionsE104 Practice for Maintaining Constant Relative Humidityby Means of Aque
9、ous Solutions2.2 ISO Standard:ISO 291 PlasticsStandard Atmospheres for Conditioningand Testing43.Terminology3.1 Definitions:3.1.1 room temperaturea temperature in the range from 20to 30C(68 to 86F).3.1.2 standard laboratory atmospherean atmosphere hav-ing a temperature of 23C(73.4F)and a relative hu
10、midity of50%with standard tolerances as specified in Section 8 shall bethe standard laboratory atmosphere.3.1.3 standard laboratory temperaturea temperature of23C(73.4F)with standard tolerance as specified in Section 7shall be the standard laboratory temperature.4.Significance and Use4.1 Conditionin
11、g of specimens is typically conducted:(1)for the purpose of bringing the material into equilibrium withnormal or average room conditions,(2)simply to obtainreproducible results,regardless of previous history ofexposure,or(3)to subject the material to abnormal conditionsof temperature or humidity in
12、order to predict its servicebehavior.4.2 The conditioning procedures prescribed in this practiceare designed to obtain reproducible results and have thepotential to give physical values somewhat higher or somewhatlower than values under equilibrium at normal conditions,1This practice is under the ju
13、risdiction ofASTM Committee D20 on Plastics andis the direct responsibility of Subcommittee D20.50 on Durability of Plastics.Current edition approved June 1,2013.Published July 2013.Originally approvedin 1941.Last previous edition approved in 2008 as D618-08.DOI:10.1520/D0618-13.2For referenced ASTM
14、 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.3The last approved version of this historical standard is referenced onwww.astm.org.4A
15、vailable from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 depend
16、ing upon the particular material and test.Depending onthe thickness,type of material and its previous history,it ispossible that it would take 20 to 100 days or more to ensuresubstantial equilibrium under normal conditions of humidityand temperature.Consequently,conditioning for reproducibil-ity must of necessity be used for general purchase specifica-tions and product control tests.5.Sampling5.1 Sampling shall be in accordance with the ASTM testmethods for the specific properties to be determin
