ASTM C729-05
(Test Method)Standard Test Method for Density of Glass by the Sink-Float Comparator
Standard Test Method for Density of Glass by the Sink-Float Comparator
SIGNIFICANCE AND USE
The sink-float comparator method of test for glass density provides the most accurate (yet convenient for practical applications) method of evaluating the density of small pieces or specimens of glass. The data obtained are useful for daily quality control of production, acceptance or rejection under specifications, and for special purposes in research and development.
Although this test scope is limited to a density range from 1.1 to 3.3 g/cm3, it may be extended (in principle) to higher densities by the use of other miscible liquids (Test Method F 77) such as water and thallium malonate-formate (approximately 5.0 g/cm3). The stability of the liquid and the precision of the test may be reduced somewhat, however, at higher densities.
SCOPE
1.1 This test method covers the determination of the density of glass or nonporous solids of density from 1.1 to 3.3 g/cm. It can be used to determine the apparent density of ceramics or solids, preferably of known porosity.
1.2 This 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 appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:C729–05
Standard Test Method for
1
Density of Glass by the Sink-Float Comparator
This standard is issued under the fixed designation C729; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope solution. The temperature of the system is raised at a uniform
rate. Because the volumetric expansion coefficient of the
1.1 Thistestmethodcoversthedeterminationofthedensity
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solution is much higher than those of the glass pieces, its
of glass or nonporous solids of density from 1.1 to 3.3 g/cm .
density decreases more rapidly and eventually both the stan-
It can be used to determine the apparent density of ceramics or
dard and the specimen will sink (settle) in the solution. The
solids, preferably of known porosity.
temperatures at which the specimen and standard reach the
1.2 This standard does not purport to address all of the
mid-pointofthetesttubearenotedandbyuseofspecialtables,
safety concerns, if any, associated with its use. It is the
the density of the specimen is obtained.
responsibility of the user of this standard to establish appro-
3.2 Range of a Given Density Solution— A given density
priate safety and health practices and determine the applica-
solution can be used to measure specimens whose density is
bility of regulatory limitations prior to use.
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within60.0200g/cm ofthedensityofthesolutionat35°C,by
2. Referenced Documents operating the comparator bath in the range 25 to 45°C.
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2.1 ASTM Standards:
4. Significance and Use
D1217 Test Method for Density and Relative Density (Spe-
4.1 The sink-float comparator method of test for glass
cific Gravity) of Liquids by Bingham Pycnometer
densityprovidesthemostaccurate(yetconvenientforpractical
E77 Test Method for Inspection and Verification of Ther-
applications) method of evaluating the density of small pieces
mometers
or specimens of glass. The data obtained are useful for daily
F77 Test Method for Apparent Density of Ceramics for
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quality control of production, acceptance or rejection under
Electron Device and Semiconductor Application
specifications, and for special purposes in research and devel-
3. Summary of Method opment.
4.2 Although this test scope is limited to a density range
3.1 The specimen of unknown density is compared with a
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from 1.1 to 3.3 g/cm , it may be extended (in principle) to
reference standard of known density. The specimen to be
higher densities by the use of other miscible liquids (Test
measured is placed in a test tube containing a solution whose
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Method F77) such as water and thallium malonate-formate
density at 35°C is within 0.0200 g/cm of the density of the
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(approximately 5.0 g/cm ). The stability of the liquid and the
specimen at 25°C. The solution is prepared using miscible
precision of the test may be reduced somewhat, however, at
liquids of known densities bracketing the desired range. The
higher densities.
tube also contains a glass density reference standard whose
densityat35°Cisclosetothatofthesolutionat35°C;thetube
5. Apparatus
is immersed in a variable-temperature comparator bath. Ini-
5.1 Single Tube and Multiple-Tube Comparators (Method
tiallythesolutions,specimen,andstandardareatatemperature
E77)— A single-tube comparator can be constructed from
near 25°C, and both the standard and the specimen float in the
materials readily available in a typical laboratory, and useful if
one wishes to measure the density of materials within a fairly
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This test method is under the jurisdiction of ASTM Committee C14 on Glass
narrow range, or if only a few tests need to be run each day.
and Glass Products and is the direct responsibility of Subcommittee C14.04 on
The multiple-tube comparator can be purchased commercially.
Physical and Mechanical Properties.
It is useful if materials with a wide range of density must be
Current edition approved Sept. 15, 2005. Published October 2005. Originally
approvedin1972.Lastpreviouseditionapprovedin2000asC729–75(2000).DOI:
tested or if many specimens must be tested each day. The
10.1520/C0729-05.
comparators shall consist of the following:
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For referenced ASTM standards, visit the ASTM website, www.astm.org, or
5.1.1 Single-Tube Comparator (Fig. 1):
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
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5.1.1.1 Circulating Water Bath, consisting of a 4000-cm
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
beaker, a cover plate supporting test tubes and thermometer, a
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Withdrawn. The last approved version of this historical standard is referenced
cooling water coil made from copper tubing, an electri
...
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