ASTM C690-09(2024)

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.
Designation: C690 − 09 (Reapproved 2024)
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 μm distributions for materials specifications, manufacturing
to 56.0 μm) using electrical sensing zone particle size analyz- control, and development and research.
ers. These instruments use an electric current path of small
4. Apparatus
dimensions which is modulated by individual particle passage
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 μm 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
aperture diameter.
1.3 This standard does not purport to address all of the
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.
4.4 Blender, capacity 1-L glass container. A means to control
1.4 This international standard was developed in accor-
speed is required.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
4.5 Beakers, 100 mL, 500 mL, 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
5. Reagents
in a beaker filled with an electrolyte is placed on the instrument
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-
tee on Analytical Reagents of the American Chemical Society,
2.2 The instrument response is essentially related to particle
volume (liquid displacement). Equivalent spherical diameter is where such specifications are available. Other grades may be
used, provided it is first ascertained that the reagent is of
commonly used to express the particle size. (Comparisons with
other techniques have been found to be good for spherical sufficiently high purity to permit its use without lessening the
accuracy of the determination.
particles; for non-spherical particles results may differ.)
1 2
This test method is under the jurisdiction of ASTM Committee C21 on Ceramic ACS Reagent Chemicals, Specifications and Procedures for Reagents and
Whitewares and Related Productsand is the direct responsibility of Subcommittee Standard-Grade Reference Materials, American Chemical Society, Washington,
C21.04 on Raw Materials. DC. For suggestions on the testing of reagents not listed by the American Chemical
Current edition approved Feb. 1, 2024. Published February 2024. Originally Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset,
approved in 1971. Last previous edition approved in 2019 as C690 – 09 (2019). U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharma-
DOI: 10.1520/C0690-09R24. copeial Convention, Inc. (USPC), Rockville, MD.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C690 − 09 (2024)
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 t
...