1、Designation:D79220Standard Test Methods forDensity and Specific Gravity(Relative Density)of Plasticsby Displacement1This standard is issued under the fixed designation D792;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of
2、last revision.A number in parentheses indicates 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 U.S.Department of Defense.1.Scope*1.1 These test methods describe the deter
3、mination of thespecific gravity(relative density)and density of solid plasticsin forms such as sheets,rods,tubes,or molded items.1.2 Two test methods are described:1.2.1 Test Method AFor testing solid plastics in water,and1.2.2 Test Method BFor testing solid plastics in liquidsother than water.1.3 T
4、he values stated in SI units are to be regarded as thestandard.1.4 WarningMercury has been designated by many regu-latory agencies as a hazardous substance that can causeserious medical issues.Mercury,or its vapor,has beendemonstrated to be hazardous to health and corrosive tomaterials.Use caution w
5、hen handling mercury and mercury-containing products.See the applicable product Safety DataSheet(SDS)for additional information.The potential existsthat selling mercury or mercury-containing products,or both,is prohibited by local or national law.Users must determinelegality of sales in their locati
6、on.1.5 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.N
7、OTE1This standard is not equivalent to ISO 11831 MethodA.Thistest method provides more guidelines on sample weight and dimension.ISO 1183-1 allows testing at an additional temperature of 27 6 2C.1.6 This international standard was developed in accor-dance with internationally recognized principles o
8、n standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for
9、 TestingD891 Test Methods for Specific Gravity,Apparent,of LiquidIndustrial ChemicalsD4968 Practice for Annual Review of Test Methods andSpecifications for PlasticsD6436 Guide for Reporting Properties for Plastics andThermoplastic ElastomersE12 Terminology Relating to Density and Specific Gravityof
10、Solids,Liquids,and Gases(Withdrawn 1996)3E456 Terminology Relating to Quality and StatisticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE2251 Specification for Liquid-in-Glass ASTM Thermom-eters with Low-Hazard Precision LiquidsE2935 Practice for C
11、onducting Equivalence Testing inLaboratory ApplicationsIEEE/ASTM SI-10 Practice for Use of the InternationalSystem of Units(SI)(the Modernized Metric System)3.Terminology3.1 GeneralThe units,symbols,and abbreviations used inthese test methods are in accordance with IEEE/ASTM SI-10.3.1.1 For terms re
12、lating to precision and bias and associatedissues,the terms used in this test method are in accordancewith the definitions in Terminology E456.3.2 Definitions:3.2.1 specific gravity(relative density)the ratio of themass of a given volume of the impermeable portion of thematerial at 23C to the mass o
13、f an equal volume of gas-free1These test methods are under the jurisdiction of ASTM Committee D20 onPlastics and are the direct responsibility of Subcommittee D20.70 on AnalyticalMethods(Section D20.70.01).Current edition approved July 1,2020.Published July 2020.Originally approvedin 1944.Last previ
14、ous edition approved in 2013 as D792-13.DOI:10.1520/D0792-20.2For 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 onthe ASTM website.3The
15、last approved version of this historical standard is referenced onwww.astm.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 StatesThis international standard was developed in acc
16、ordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.distilled or de-mineralized water at the same temperature;theform of expression shall be:Specific gravityrelative density!23/23Cor sp gr23/23C!NOTE2This definition is essentially equivalent to the definition forapparent specific gravi