ASTM C1182-91(2001)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:C1182–91(Reapproved2001)
Standard Test Method for
Determining the Particle Size Distribution of Alumina by
Centrifugal Photosedimentation
This standard is issued under the fixed designation C 1182; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope gal acceleration at a known or controlled temperature. At
predetermined times related to the sedimentation of specific
1.1 This test method covers the determination of the particle
Stokes’ diameters (Note 1), the optical absorbance is recorded
size distribution of alumina in the range from 0.1 to 20 µm
and ratioed to the initial value to determine the fraction of the
having a median particle diameter from 0.5 to 5.0 µm.
total sample that has sedimented a specific distance.Avolume
1.2 The procedure described in this test method may be
based size distribution is calculated from the absorbance-time
successfully applied to other ceramic powders in this general
data. Since alumina particles are not truly spherical, the results
size range. It is the responsibility of the user to determine the
are reported as equivalent diameters (spherical) (Note 2).
applicability of this test method to other material.
1.3 The values stated in SI units are to be regarded as the
NOTE 1—This diameter in micrometres is referred to as D in the
standard. The values given in parentheses are for information
equation:
only.
18 n ~H/t!
2 8
D 5 3 10 (1)
1.4 This standard does not purport to address all of the
~r 2r !u
s f
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
where:
n = viscosity of the fluid, P,
priate safety and health practices and determine the applica-
H = height of the settling particles, cm,
bility of regulatory limitations prior to use.
t = time for particle to settle, s,
2. Referenced Documents
r = particle density, g/cm ,
s
r = fluid density, g/cm , and
2.1 ASTM Standards: f
u = the rotational velocity, cm/s.
C 242 Terminology of Ceramic Whitewares and Related
Products
NOTE 2—Refer to Terminology C 242 for the ASTM definition of this
E 691 Practice for Conducting an Interlaboratory Study to
term. Most equipment manufacturers refer to this as the equivalent
spherical diameter.
Determine the Precision of a Test Method
E 177 Practice for Use of the Terms Precision and Bias in
4.2 The instruments that have been found suitable for this
ASTM Test Methods
test method incorporate microcomputers that control instru-
ment operation and perform all required data acquisition and
3. Terminology
computation functions.
3.1 Definitions:
3.1.1 Refer to Terminology C 242 for definitions of terms 5. Significance and Use
used in this test method.
5.1 Manufacturers and users of alumina powders will find
this test method useful to determine the particle size distribu-
4. Summary of Test Method
tion of these materials for product specification, quality con-
4.1 A homogeneous aqueous dispersion of the powder is
trol, and research and development testing.
prepared. While kept in a thoroughly mixed condition, a small
6. Apparatus
aliquot is transferred to the analyzer sample cell, which is
placed in the instrument and subjected to a controlled centrifu-
6.1 Centrifugal Particle Size Distribution Analyzer —The
analyzer shall incorporate a centrifuge capable of subjecting a
homogeneous dispersion of the sample to centrifugal accelera-
tion in specially designed sample cells. A collimated beam of
ThistestmethodisunderthejurisdictionofASTMCommitteeC21onCeramic
Whitewares and Related Products and is the direct responsibility of Subcommittee
C21.07 on Nonplastics.
Current edition approved April 15, 1991. Published August 1991.
2 4
Annual Book of ASTM Standards, Vol 15.02. Instruments from Horiba Instruments, Inc., 17671 Armstrong Ave., Irvine, CA
Annual Book of ASTM Standards, Vol 14.02. 92714, have been found satisfactory. Other instruments may also be found suitable.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C1182
visible light (either monochromatic or broad-band) shall even with the liquid level in the bath. Apply ultrasonic energy
traversethesamplecellatadefineddistancefromthetopofthe for 15 min with frequent stirring. Remove beaker from bath.
cell. The change in photo extinction resulting from sedimen- 8.1.1.2 Ultrasonic Probe—Insert the probe into the beaker
tation of the sample shall be measured by a photo detector and containing the sample and apply power for 30 s. Make sure the
appropriate electronic circuits, and used to calculate the sample is well suspended during this step. Remove probe from
volume-based sized distribution of the sample. the beaker.
6.2 Ultrasonic Probe, consisting of power unit, ultrasonic 8.1.2 Add a 25-mm (1-in.) stirring bar to the beaker and
transducer, and 13-mm ( ⁄2-in.) diameter probe, 200 to 250 W. place on a magnetic stirrer. Stir for approximately 3 min in a
6.3 Ultrasonic Water Bath,powerdensityapproximately0.3 cold water bath to bring the sample to ambient temperature.
2 2
W/cm (2 W/in. ). Continue stirring at constant temperature.
6.4 Balance, top-loading, accurate to 60.1 g.
NOTE 4—The concentration of the sample may require dilution with
6.5 Stirrer, magnetic, with 25-mm (1-in.) and 19-mm ( ⁄4-
0.1 % sodium hexametaphosphate solution to meet the optical absorbance
in.) stirring bars.
tolerance specified in the instrument operating manual. Thorough mixing
6.6 Thermometer,mercuryoralcohol,0to50°C,accurateto must accompany any dilution of the sample.
0.5°C.
8.2 Analyzer Preparation:
6.7 Sample Cells, as supplied by the instrument manufac-
8.2.1 To warm up the analyzer, apply power a minimum of
turer.
10 min prior to testing. Conduct the warm-up with the sample
compartment closed. Make certain that ventilation airflow is
7. Reagents
not restricted by adjacent equipment, papers, or other materi-
7.1 Purity of Reagents—Reagent grade chemicals shall be
als. Check the printer to ensure a sufficient supply of paper.
used in all tests. Unless otherwise indicated, it is intended that
Clean a pair of sample cells and caps, rinse with the 0.1 %
all reagents shall conform to the specifications of the Commit-
sodium hexametaphosphate solution and store inverted on
tee onAnalytical Reagents of theAmerican Chemical Society,
absorbent paper.
where such specifications are available. Other grades may be
8.2.2 If required
...