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ASTM D792-13 用位移法测定塑料密度和比重的标准试验方法

ASTM D792-13 用位移法测定塑料密度和比重的标准试验方法

Designation:D792−13

Standard Test Methods for

Density and Specific Gravity(Relative Density)of Plastics by Displacement1

This standard is issued under thefixed designation D792;the number immediately following the designation indicates the year of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript 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*

1.1These test methods describe the determination of the specific gravity(relative density)and density of solid plastics in forms such as sheets,rods,tubes,or molded items.

1.2Two test methods are described:

1.2.1Test Method A—For testing solid plastics in water,and 1.2.2Test Method B—For testing solid plastics in liquids other than water.

1.3The values stated in SI units are to be regarded as the standard.

1.4This standard does not purport to address all of the safety concerns,if any,associated with its use.It is the responsibility 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.

N OTE1—This standard is not equivalent to ISO1183–1Method A.This test method provides more guidelines on sample weight and dimension. ISO1183-1allows testing at an additional temperature of2762°C. 2.Referenced Documents

2.1ASTM Standards:2

D618Practice for Conditioning Plastics for Testing

D891Test Methods for Specific Gravity,Apparent,of Liquid Industrial Chemicals

D4968Guide for Annual Review of Test Methods and Specifications for Plastics

D6436Guide for Reporting Properties for Plastics and Thermoplastic Elastomers

E1Specification for ASTM Liquid-in-Glass Thermometers E12Terminology Relating to Density and Specific Gravity

of Solids,Liquids,and Gases(Withdrawn1996)3

E691Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method

IEEE/ASTM SI-10Practice for Use of the International System of Units(SI)(the Modernized Metric System) 3.Terminology

3.1General—The units,symbols,and abbreviations used in these test methods are in accordance with IEEE/ASTM SI-10.

3.2Definitions:

3.2.1specific gravity(relative density)—the ratio of the mass of a given volume of the impermeable portion of the material at23°C to the mass of an equal volume of gas-free distilled or de-mineralized water at the same temperature;the form of expression shall be:

Specific gravity~relative density!23/23°C

~or sp gr23/23°C!

N OTE2—This definition is essentially equivalent to the definition for apparent specific gravity and apparent density in Terminology E12, because the small percentage difference introduced by not correcting for the buoyancy of air is insignificant for most purposes.

3.2.2density—cubic metre of impermeable portion of the material at23°C.The form of expression shall be:

D23,kg/m3

N OTE3—The SI unit of density,as defined in IEEE/ASTM SI-10,is kg/m3.To convert density in g/cm3to density in kg/m3,multiply by1000.

N OTE4—To convert specific gravity23/23°C to density23°C,kg/m3, use the following equation:

D23C,kg/m35sp gr23/23°C3997.5

Where997.5kg/m3is the density of water at23°C.

4.Summary of Test Method

4.1Determine the mass of a specimen of the solid plastic in air.It is then immersed in a liquid,its apparent mass upon immersion is determined,and its specific gravity(relative density)calculated.

1These test methods are under the jurisdiction of ASTM Committee D20on Plastics and are the direct responsibility of Subcommittee D20.70on Analytical Methods(Section D20.70.01).

Current edition approved Nov.1,2013.Published November2013.Originally approved http://www.wendangku.net/doc/355839baddccda38366baf50.html st previous edition approved in2008as D792-08.DOI: 10.1520/D0792-13.

2For referenced ASTM standards,visit the ASTM website,http://www.wendangku.net/doc/355839baddccda38366baf50.html ,or contact ASTM Customer Service at service@http://www.wendangku.net/doc/355839baddccda38366baf50.html .For Annual Book of ASTM

Standards volume information,refer to the standard’s Document Summary page on the ASTM website.

3The last approved version of this historical standard is referenced on http://www.wendangku.net/doc/355839baddccda38366baf50.html .

*A Summary of Changes section appears at the end of this standard Copyright©ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA19428-2959.United States

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Copyright ASTM International

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