ASTM C1182-91(1995)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: C 1182 – 91 (Reapproved 1995)
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
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 Stokes’ diameters (Note 1), the optical absorbance is recorded
and ratioed to the initial value to determine the fraction of the
1.1 This test method covers the determination of the particle
total sample that has sedimented a specific distance. A volume
size distribution of alumina in the range from 0.1 to 20 μm
based size distribution is calculated from the absorbance-time
having a median particle diameter from 0.5 to 5.0 μm.
data. Since alumina particles are not truly spherical, the results
1.2 The procedure described in this test method may be
are reported as equivalent diameters (spherical) (Note 2).
successfully applied to other ceramic powders in this general
size range. It is the responsibility of the user to determine the
NOTE 1—This diameter in micrometres is referred to as D in the
applicability of this test method to other material. equation:
1.3 The values stated in SI units are to be regarded as the
18 n ~H/t!
2 8
D 5 3 10 (1)
standard. The values given in parentheses are for information
~r 2r !u
s f
only.
1.4 This standard does not purport to address all of the
where:
safety concerns, if any, associated with its use. It is the n 5 viscosity of the fluid, P,
H 5 height of the settling particles, cm,
responsibility of the user of this standard to establish appro-
t 5 time for particle to settle, s,
priate safety and health practices and determine the applica-
r 5 particle density, g/cm ,
bility of regulatory limitations prior to use. s
r 5 fluid density, g/cm , and
f
u 5 the rotational velocity, cm/s.
2. Referenced Documents
2.1 ASTM Standards:
NOTE 2—Refer to Terminology C 242 for the ASTM definition of this
C 242 Terminology of Ceramic Whitewares and Related term. Most equipment manufacturers refer to this as the equivalent
spherical diameter.
Products
E 691 Practice for Conducting an Interlaboratory Study to
4.2 The instruments that have been found suitable for this
Determine the Precision of a Test Method
test method incorporate microcomputers that control instru-
E 177 Practice for Use of the Terms Precision and Bias in
ment operation and perform all required data acquisition and
ASTM Test Methods
computation functions.
3. Terminology
5. Significance and Use
3.1 Definitions:
5.1 Manufacturers and users of alumina powders will find
3.1.1 Refer to Terminology C 242 for definitions of terms
this test method useful to determine the particle size distribu-
used in this test method.
tion of these materials for product specification, quality con-
trol, and research and development testing.
4. Summary of Test Method
6. Apparatus
4.1 A homogeneous aqueous dispersion of the powder is
prepared. While kept in a thoroughly mixed condition, a small
6.1 Centrifugal Particle Size Distribution Analyzer —The
aliquot is transferred to the analyzer sample cell, which is
analyzer shall incorporate a centrifuge capable of subjecting a
placed in the instrument and subjected to a controlled centrifu-
homogeneous dispersion of the sample to centrifugal accelera-
gal acceleration at a known or controlled temperature. At
tion in specially designed sample cells. A collimated beam of
predetermined times related to the sedimentation of specific
visible light (either monochromatic or broad-band) shall
traverse the sample cell at a defined distance from the top of the
cell. The change in photo extinction resulting from sedimen-
This test method is under the jurisdiction of ASTM Committee C-21 on
tation of the sample shall be measured by a photo detector and
Ceramic 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.
C 1182
appropriate electronic circuits, and used to calculate the 8.1.2 Add a 25-mm (1-in.) stirring bar to the beaker and
volume-based sized distribution of the sample. place on a magnetic stirrer. Stir for approximately 3 min in a
6.2 Ultrasonic Probe, consisting of power unit, ultrasonic cold water bath to bring the sample to ambient temperature.
transducer, and 13-mm ( ⁄2-in.) diameter probe, 200 to 250 W. Continue stirring at constant temperature.
6.3 Ultrasonic Water Bath, power density approximately 0.3
NOTE 4—The concentration of the sample may require dilution with
2 2
W/cm (2 W/in. ).
0.1 % sodium hexametaphosphate solution to meet the optical absorbance
6.4 Balance, top-loading, accurate to 60.1 g.
tolerance specified in the instrument operating manual. Thorough mixing
6.5 Stirrer, magnetic, with 25-mm (1-in.) and 19-mm ( ⁄4- must accompany any dilution of the sample.
in.) stirring bars.
8.2 Analyzer Preparation:
6.6 Thermometer, mercury or alcohol, 0 to 50°C, accurate to
8.2.1 To warm up the analyzer, apply power a minimum of
0.5°C.
10 min prior to testing. Conduct the warm-up with the sample
6.7 Sample Cells, as supplied by the instrument manufac-
compartment closed. Make certain that ventilation airflow is
turer.
not restricted by adjacent equipment, papers, or other materi-
7. Reagents als. Check the printer to ensure a sufficient supply of paper.
Clean a pair of sample cells and caps, rinse with the 0.1 %
7.1 Purity of Reagents—Reagent grade chemicals shall be
sodium hexametaphosphate solution and store inverted on
used in all tests. Unless otherwise indicated, it is intended that
absorbent paper.
all reagents shall conform to the specifications of the Commit-
8.2.2 If required by the manufacturer’s operating manual,
tee on Analytical Reagents of the American Chemical Society,
5 check and adjust the zero and full-scale settings.
where such specifications are available. Other grades may be
8.2.3 Input the test parameters (sample and fluid density,
...