ASTM C729-11

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 ) 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 3. 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.

General Information

• Status: Historical
• Publication Date: 30-Sep-2011
• ICS: 81.040.10 - Raw materials and raw glass
• Technical Committee: C14 - Glass and Glass Products
• Drafting Committee: C14.04 - Physical and Mechanical Properties

Relations

• Replaces: ASTM C729-05 - Standard Test Method for Density of Glass by the Sink-Float Comparator
• Effective Date: 01-Oct-2011
• Referred By: ASTM E438-92(2018) - Standard Specification for Glasses in Laboratory Apparatus
• Effective Date: 01-Oct-2011
• Referred By: ASTM F1538-03(2017) - Standard Specification for Glass and Glass Ceramic Biomaterials for Implantation
• Effective Date: 01-Oct-2011

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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 − 11
StandardTest 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 near 25°C, and both the standard and the specimen float in the
solution. The temperature of the system is raised at a uniform
1.1 Thistestmethodcoversthedeterminationofthedensity
3 rate. Because the volumetric expansion coefficient of the
of glass or nonporous solids of density from 1.1 to 3.3 g/cm .
solution is much higher than those of the glass pieces, its
It can be used to determine the apparent density of ceramics or
density decreases more rapidly and eventually both the stan-
solids, preferably of known porosity.
dard and the specimen will sink (settle) in the solution. The
1.2 This standard does not purport to address all of the
temperatures at which the specimen and standard reach the
safety concerns, if any, associated with its use. It is the
mid-pointofthetesttubearenotedandbyuseofspecialtables,
responsibility of the user of this standard to establish appro-
the density of the specimen is obtained.
priate safety and health practices and determine the applica-
3.2 Range of a Given Density Solution—A given density
bility of regulatory limitations prior to use.
solution can be used to measure specimens whose density is
3
within 6 0.0200 g/cm of the density of the solution at 35°C,
2. Referenced Documents
2 by operating the comparator bath in the range 25 to 45°C.
2.1 ASTM Standards:
D1217Test Method for Density and Relative Density (Spe-
4. Significance and Use
cific Gravity) of Liquids by Bingham Pycnometer
4.1 The sink-float comparator method of test for glass
E77Test Method for Inspection and Verification of Ther-
densityprovidesthemostaccurate(yetconvenientforpractical
mometers
applications) method of evaluating the density of small pieces
F77Test Method for Apparent Density of Ceramics for
or specimens of glass. The data obtained are useful for daily
Electron Device and Semiconductor Application (With-
3
quality control of production, acceptance or rejection under
drawn 2001)
specifications, and for special purposes in research and devel-
3. Summary of Method
opment.
3.1 The specimen of unknown density is compared with a
4.2 Although this test scope is limited to a density range
3
reference standard of known density. The specimen to be
from 1.1 to 3.3 g/cm , it may be extended (in principle) to
measured is placed in a test tube containing a solution whose
higher densities by the use of other miscible liquids (Test
3
density at 35°C is within 0.0200 g/cm of the density of the Method F77) such as water and thallium malonate-formate
3
specimen at 25°C. The solution is prepared using miscible
(approximately 5.0 g/cm ). The stability of the liquid and the
liquids of known densities bracketing the desired range. The precision of the test may be reduced somewhat, however, at
tube also contains a glass density reference standard whose
higher densities.
densityat35°Cisclosetothatofthesolutionat35°C;thetube
is immersed in a variable-temperature comparator bath. Ini- 5. Apparatus
tiallythesolutions,specimen,andstandardareatatemperature
5.1 Single Tube and Multiple-Tube Comparators (Method
E77)—A single-tube comparator can be constructed from
materials readily available in a typical laboratory, and useful if
1
This test method is under the jurisdiction of ASTM Committee C14 on Glass
one wishes to measure the density of materials within a fairly
and Glass Products and is the direct responsibility of Subcommittee C14.04 on
Physical and Mechanical Properties.
narrow range, or if only a few tests need to be run each day.
Current edition approved Oct. 1, 2011. Published October 2011. Originally
The multiple-tube comparator can be purchased commercially.
approved in 1972. Last previous edition approved in 2005 as C729–05. DOI:
It is useful if materials with a wide range of density must be
10.1520/C0729-11.
2
tested or if many specimens must be tested each day. The
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
comparators shall consist of the following:
Standards volume information, refer to the standard’s Document Summary page on
5.1.1 Single-Tube Comparator (Fig. 1):
the ASTM website.
3
3
5.1.1.1 Circulating Water Bath, consisting of a 4000-cm
The last approved version of this historical standard is referenced on
www.astm.org. beaker, a cover plate supporting test tubes and thermometer, a
Copyright © ASTM I
...

This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:C729–05 Designation:C729–11
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
3
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.
2. Referenced Documents
2
2.1 ASTM Standards:
D1217 Test Method for Density and Relative Density (Specific Gravity) of Liquids by Bingham Pycnometer
E77 Test Method for Inspection and Verification of Thermometers
3
F77 Test Method for Apparent Density of Ceramics for Electron Device and Semiconductor Application
3. Summary of Method
3.1 The specimen of unknown density is compared with a reference standard of known density. The specimen to be measured
3
is placed in a test tube containing a solution whose density at 35°C is within 0.0200 g/cm of the density of the specimen at 25°C.
The solution is prepared using miscible liquids of known densities bracketing the desired range. The tube also contains a glass
density reference standard whose density at 35°C is close to that of the solution at 35°C; the tube is immersed in a
variable-temperature comparator bath. Initially the solutions, specimen, and standard are at a temperature near 25°C, and both the
standard and the specimen float in the solution. The temperature of the system is raised at a uniform rate. Because the volumetric
expansioncoefficientofthesolutionismuchhigherthanthoseoftheglasspieces,itsdensitydecreasesmorerapidlyandeventually
both the standard and the specimen will sink (settle) in the solution. The temperatures at which the specimen and standard reach
the mid-point of the test tube are noted and by use of special tables, the density of the specimen is obtained.
3.2 Range of a Given Density Solution—A given density solution can be used to measure specimens whose density is within
3
6 0.0200 g/cm of the density of the solution at 35°C, by operating the comparator bath in the range 25 to 45°C.
4. Significance and Use
4.1 The sink-float comparator method of test for glass density provides the most accurate (yet convenient for practical
applications)methodofevaluatingthedensityofsmallpiecesorspecimensofglass.Thedataobtainedareusefulfordailyquality
control of production, acceptance or rejection under specifications, and for special purposes in research and development.
3
4.2 Although this test scope is limited to a density range from 1.1 to 3.3 g/cm , it may be extended (in principle) to higher
densities by the use of other miscible liquids (Test Method F77) such as water and thallium malonate-formate (approximately 5.0
3
g/cm ). The stability of the liquid and the precision of the test may be reduced somewhat, however, at higher densities.
5. Apparatus
5.1 Single Tube and Multiple-Tube Comparators (Method E77)—Asingle-tube comparator can be constructed from materials
readily available in a typical laboratory, and useful if one wishes to measure the density of materials within a fairly narrow range,
orifonlyafewtestsneedtoberuneachday.Themultiple-tubecomparatorcanbepurchasedcommercially.Itisusefulifmaterials
1
This test method is under the jurisdiction ofASTM Committee C14 on Glass and Glass Products and is the direct responsibility of Subcommittee C14.04 on Physical
and Mechanical Properties.
Current edition approved Sept. 15, 2005.Oct. 1, 2011. Published October 2005.2011. Originally approved in 1972. Last previous edition approved in 20002005 as
C729–75(2000).C729–05. DOI: 10.1520/C0729-05.10.1520/C0729-11.
2
ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,[e-mail] Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3
Withdrawn. The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM
...