ASTM C690-09(2019)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: C690 − 09 (Reapproved 2019)
Standard Test Method for
Particle Size Distribution of Alumina or Quartz Powders by
Electrical Sensing Zone Technique
This standard is issued under the fixed designation C690; 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.
1. Scope* 3. Significance and Use
1.1 This test method, one of several found valuable for the 3.1 This test method is useful to both sellers and purchasers
measurement of particle size, covers the determination of the of alumina and quartz powders for determining particle size
particle size distribution of alumina or quartz powders (0.6 to distributions for materials specifications, manufacturing
56.0 µm) using electrical sensing zone particle size analyzers. control, and development and research.
These instruments use an electric current path of small dimen-
sions which is modulated by individual particle passage 4. Apparatus
through an aperture, and produces individual pulses of ampli-
4.1 Electrical Sensing Zone Particle Counter.
tude proportional to the particle volume.
4.2 Aperture Tubes, diameter ranging from approximately
1.2 The values stated in SI units are to be regarded as
30 to 140 µm. The diameter required is dependent upon the
standard. No other units of measurement are included in this
particle size distribution of the sample. Generally any given
standard.
tube will cover a particle size range from 2 to 60 % of its
1.3 This standard does not purport to address all of the aperture diameter.
safety concerns, if any, associated with its use. It is the
NOTE 1—In certain cases, apertures up to 300 µm are usable.
responsibility of the user of this standard to establish appro-
4.3 Sample Beaker, capable of maintaining all particles
priate safety, health, and environmental practices and deter-
uniformly in suspension (for example, round-bottom).
mine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accor- 4.4 Blender, capacity 1-L glass container. A means to control
dance with internationally recognized principles on standard-
speed is required.
ization established in the Decision on Principles for the
4.5 Beakers, 100, 500, and 1000-mL.
Development of International Standards, Guides and Recom-
4.6 Pipet.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
4.7 Wash Bottles.
4.8 Membrane Filtering Device, rated at 0.45-µm filters or
2. Summary of Test Method
finer.
2.1 A carefully dispersed, dilute suspension of the powder
in a beaker filled with an electrolyte is placed on the instrument
5. Reagents
sample stand. The suspension is forced through a restricting
5.1 Purity of Reagents—Reagent grade chemicals shall be
aperture. Each particle passing generates an electric pulse that
used in all tests. Unless otherwise indicated, it is intended that
is recorded on an electronic counter.
all reagents shall conform to the specifications of the Commit-
2.2 The instrument response is essentially related to particle
tee on Analytical Reagents of the American Chemical Society,
volume (liquid displacement). Equivalent spherical diameter is
where such specifications are available. Other grades may be
commonly used to express the particle size. (Comparisons with
used, provided it is first ascertained that the reagent is of
other techniques have been found to be good for spherical
sufficiently high purity to permit its use without lessening the
particles; for non-spherical particles results may differ.)
accuracy of the determination.
This test method is under the jurisdiction of ASTM Committee C21 on Ceramic
Whitewares and Related Productsand is the direct responsibility of Subcommittee Reagent Chemicals, American Chemical Society Specifications , American
C21.04 on Raw Materials. Chemical Society, Washington, DC. For suggestions on the testing of reagents not
Current edition approved Oct. 1, 2019. Published October 2019. Originally listed by the American Chemical Society, see Analar Standards for Laboratory
approved in 1971. Last previous edition approved in 2014 as C690 – 09 (2014). Chemicals, VWR International Ltd., U.K., and the United States Pharmacopoeia,
DOI: 10.1520/C0690-09R19. USPC, Rockville, MD.
*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
C690 − 09 (2019)
maintain a uniform particle suspension while withdrawing the sample. The
5.2 Dispersing Media—Ten percent solution of purified or
pipet should deliver all of the withdrawn slurry to ensure a representative
reagent grade sodium hexametaphosphate in distilled water
transfer of sample in the event of any size classification during the
twice filtered through the membrane filtering device.
transfer.
NOTE 2—Deionized water may be substituted for distilled water.
6.6 Place the sample beaker in position on the sample stand.
NOTE 3—This liquid should not be retained longer than 1 month and
6.7 Adjust the speed of the stirrer to furnish sufficient
should not be pH modified or heated.
agitation to maintain a uniform particle suspension, but below
5.3 Electrolyte—Dissolve 10.0 g of reagent grade sodium
air bubble generation speeds.
chloride (NaCl) in 1000 mL of distilled water and filter twice
through the membrane filtering device. 6.8 Use the apparatus control software to set the measure-
ment parameters. Make three measurements in which each
5.4 Wash Water—Distilled water twice filtered through the
measurement counts and measures at least 5000 particles.
membrane filtering device.
Average the particle size distribution from the three measure-
5.5 Calibration Particles—NIST or NIST traceable mono-
ments and report the statistical parameters from the averaged
sized particle standards.
results.
6. Procedure
6.9 Precautions:
6.9.1 Before each analysis, using wash bottle and filtered
6.1 Summary—Disperse the test powder in the electrolyte
wash water, wash all surfaces coming in contact with sample.
with a blender. Transfer a representative portion to the sample
6.9.2 Ensure that the calibration of the instrument
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM 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: C690 − 09 (Reapproved 2014) C690 − 09 (Reapproved 2019)
Standard Test Method for
Particle Size Distribution of Alumina or Quartz Powders by
Electrical Sensing Zone Technique
This standard is issued under the fixed designation C690; 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.
1. Scope*
1.1 This test method, one of several found valuable for the measurement of particle size, covers the determination of the particle
size distribution of alumina or quartz powders (0.6 to 56.0 μm) using electrical sensing zone particle size analyzers. These
instruments use an electric current path of small dimensions which is modulated by individual particle passage through an aperture,
and produces individual pulses of amplitude proportional to the particle volume.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety problems,concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and
determine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Summary of Test Method
2.1 A carefully dispersed, dilute suspension of the powder in a beaker filled with an electrolyte is placed on the instrument
sample stand. The suspension is forced through a restricting aperture. Each particle passing generates an electric pulse that is
recorded on an electronic counter.
2.2 The instrument response is essentially related to particle volume (liquid displacement). Equivalent spherical diameter is
commonly used to express the particle size. (Comparisons with other techniques have been found to be good for spherical particles;
for non-spherical particles results may differ.)
3. Significance and Use
3.1 This test method is useful to both sellers and purchasers of alumina and quartz powders for determining particle size
distributions for materials specifications, manufacturing control, and development and research.
4. Apparatus
4.1 Electrical Sensing Zone Particle Counter.
4.2 Aperture Tubes, diameter ranging from approximately 30 to 140 μm. The diameter required is dependent upon the particle
size distribution of the sample. Generally any given tube will cover a particle size range from 2 to 60 % of its aperture diameter.
NOTE 1—In certain cases, apertures up to 300 μm are usable.
4.3 Sample Beaker, capable of maintaining all particles uniformly in suspension (for example, round-bottom).
4.4 Blender, capacity 1-L glass container. A means to control speed is required.
4.5 Beakers, 100, 500, and 1000-mL.
4.6 Pipet.
4.7 Wash Bottles.
This test method is under the jurisdiction of ASTM Committee C21 on Ceramic Whitewares and Related Productsand is the direct responsibility of Subcommittee C21.04
on Raw Materials.
Current edition approved Dec. 1, 2014Oct. 1, 2019. Published December 2014October 2019. Originally approved in 1971. Last previous edition approved in 20092014
as C690 – 09.C690 – 09 (2014). DOI: 10.1520/C0690-09R14.10.1520/C0690-09R19.
*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
C690 − 09 (2019)
4.8 Membrane Filtering Device, rated at 0.45-μm filters or finer.
5. Reagents
5.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where
such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high
purity to permit its use without lessening the accuracy of the determination.
5.2 Dispersing Media—Ten percent solution of purified or reagent grade sodium hexametaphosphate in distilled water twice
filtered through the membrane filtering device.
NOTE 2—Deionized water may be substituted for distilled water.
NOTE 3—This liquid should not be retained longer than 1 month and should not be pH modified or heated.
5.3 Electrolyte—Dissolve 10.0 g of reagent grade sodium chloride (NaCl) in 1000 mL of distilled water and filter twice through
the membrane filtering device.
5.4 Wash Water—Distilled water twice filtered through the membrane filtering device.
5.5 Calibration Particles—NIST or NIST traceable monosized particle standards.
6. Procedure
6.1 Summary—Disperse the test powder in the electrolyte with a blender. Transfer a representative portion to the sample beaker
that contains filtered electrolyte. Place sample beaker in the apparatus and obtain particle size distribution in a chosen size range.
Obtain relative weight fraction by assuming constant particle density.
6.2 Precalibrate the aperture and electrolyte combination following the manufacturer’s instruction manual.
NOTE 4—Calibration should be performed in accordance with the instruction manual. Monosized NIST or NIST traceable calibration standards should
be selected from Fig. A1.1. Mutual agreement on the source and size of calibration standards is necessary for interlaboratory comparisons.
6.3 Check background counts by filling the sample beaker with filtered electrolyte and taking counts without any sample added.
Follow 6.6, 6.7, and 6.8.
6.4 Disperse approximately 0.7 g of sample in 200 mL of electrolyte containing 5 drops of dispersing media, by mixing at high
speed on the blender or its equivalent for 5 min.
NOTE 5—The proper dispersion conditions for a given mixer or blender should be predetermined by obtaining a time-speed versus median diameter
curve (
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