Standard Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement

SIGNIFICANCE AND USE
The specific gravity or density of a solid is a property that can be measured conveniently to identify a material, to follow physical changes in a sample, to indicate degree of uniformity among different sampling units or specimens, or to indicate the average density of a large item.  
Changes in density of a single specimen may be due to changes in crystallinity, loss of plasticizer, absorption of solvent, or to other causes. Portions of a sample may differ in density because of difference in crystallinity, thermal history, porosity, and composition (types or proportions of resin, plasticizer, pigment, or filler).  
Note 6—Reference is made to Test Method D 1622.  
Density is useful for calculating strength-weight and cost-weight ratios.
SCOPE
1.1 These 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.
1.2 Two test methods are described:
1.2.1  Test Method A --For testing solid plastics in water, and
1.2.2 Test Method B--For testing solid plastics in liquids other than water.
Note 1--Alternatively, Test Method D1505 may be applied to many such forms, as well as to films and sheeting.
1.3 The values stated in SI units are to be regarded as the standard.
1.4 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Note 2--This standard is not equivalent to ISO 1183 Method A.

General Information

Status
Historical
Publication Date
09-Dec-2000
Technical Committee
Drafting Committee
Current Stage
Ref Project

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ASTM D792-00 - Standard Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D 792 – 00
Standard Test Methods for
Density and Specific Gravity (Relative Density) of Plastics
1
by Displacement
This standard is issued under the fixed designation D 792; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) 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* D4968 Guide for Annual Review of Test Methods and
2
Specifications for Plastics
1.1 These test methods describe the determination of the
5
E1 Specification for ASTM Thermometers
specific gravity (relative density) and density of solid plastics
E12 Terminology Relating to Density and Specific Gravity
in forms such as sheets, rods, tubes, or molded items.
6
of Solids, Liquids, and Gases
1.2 Two test methods are described:
E380 Practice for Use of the International System of Units
1.2.1 Test MethodA—Fortestingsolidplasticsinwater,and
7
(SI) (the Modernized Metric System)
1.2.2 Test Method B—For testing solid plastics in liquids
E691 Practice for Conducting an Interlaboratory Study to
other than water.
7
Determine the Precision of a Test Method
NOTE 1—Alternatively, Test Method D1505 may be applied to many
such forms, as well as to films and sheeting.
3. Terminology
1.3 The values stated in SI units are to be regarded as the
3.1 General—Theunits,symbols,andabbreviationsusedin
standard.
these test methods are in accordance with Practice E380.
1.4 This standard does not purport to address all of the
3.2 Definitions:
safety concerns, if any, associated with its use. It is the
3.2.1 specific gravity (relative density)—the ratio of the
responsibility of the user of this standard to establish appro-
mass in air of a unit volume of the impermeable portion of the
priate safety and health practices and determine the applica-
material at 23°C to the mass in air of equal density of an equal
bility of regulatory limitations prior to use.
volume of gas-free distilled water at the same temperature; the
form of expression shall be:
NOTE 2—This standard is not equivalent to ISO 1183 Method A.
Specificgravity ~relativedensity!23/23°C
2. Referenced Documents
~orspgr23/23°C!
2.1 ASTM Standards:
NOTE 3—This definition is essentially equivalent to the definition for
D618 Practice for Conditioning Plastics and Electrical
apparent specific gravity and apparent density in Terminology E12,
2
Insulating Materials for Testing because the small percentage difference introduced by not correcting for
the buoyancy of air is insignificant for most purposes.
D891 Test Methods for Specific Gravity, Apparent, of
3
Liquid Industrial Chemicals
3.2.2 density—the mass in air in kilograms per cubic metre
D1505 Test Method for Density of Plastics by the Density-
of impermeable portion of the material at 23°C. The form of
2
Gradient Technique
expression shall be:
D1622 TestMethodforApparentDensityofRigidCellular
23 3
2 D ,kg/m ~Notes3-5!
Plastics
4 3
D1898 Practice for Sampling of Plastics NOTE 4—The SI unit of density, as defined in Practice E380 is kg/m .
3 3
To convert density in g/cm to density in kg/m , multiply by 1000.
NOTE 5—Specific gravity 23/23°C can be converted to density 23°C,
1 3
These test methods are under the jurisdiction of ASTM Committee D20 on
kg/m , by use of the following equation:
Plastics and are the direct responsibility of Subcommittee D20.70 on Analytical
23C 3
D ,kg/m 5spgr23/23°C 3997.5
Methods (Section D20.70.01).
Current edition approved Dec. 10, 2000. Published March 2001. Originally
published as D792–44. Last previous edition D792–98.
2 5
Annual Book of ASTM Standards, Vol 08.01. Annual Book of ASTM Standards, Vol 14.03.
3 6
Annual Book of ASTM Standards, Vol 15.05. Discontinued. See 1995 Annual Book of ASTM Standards, Vol 15.05.
4 7
Discontinued. See 1998 Annual Book of ASTM Standards, Vol 08.01. Annual Book of ASTM Standards, Vol 14.02.
*A Summary of Changes section appears at the end of this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D 792–00
4. Summary of Test Method 9. Apparatus
4.1 Determine the mass of a specimen of the solid plastic in 9.1 Analytical Balance—A balance with a precision within
air. It is then immersed in a liquid, its apparent mass upon 0.1 mg, accuracy within 0.05% relative (that is, 0.05% of the
immersion is determined, and its specific gravity (relative mass of the specimen in air), and equipped with a stationary
density) calculated. support for the immersion vessel above the balance pan (“pan
straddle”).
5. Significance and Use
NOTE 7—Assuran
...

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