1、Designation: C1070 01 (Reapproved 2014)Standard Test Method forDetermining Particle Size Distribution of Alumina or Quartzby Laser Light Scattering1This standard is issued under the fixed designation C1070; the number immediately following the designation indicates the year oforiginal adoption or, i
2、n the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of particlesize distribution of alumina
3、or quartz using laser light scatter-ing instrumentation in the range from 0.1 to 500 m.1.2 The procedure described in this test method may beapplied to other nonplastic ceramic powders. It is at thediscretion of the user to determine the methods applicability.1.3 This test method applies to analysis
4、 using aqueousdispersions.1.4 This standard may involve hazardous materials, opera-tions and equipment. This standard does not purport to addressall of the safety concerns, if any, associated with its use. It isthe responsibility of the user of this standard to establishappropriate safety and health
5、 practices and determine theapplicability of regulatory limitations prior to use.1.5 Quartz has been classified by IARC as a Group Icarcinogen. For specific hazard information in handling thismaterial, see the suppliers Material Safety Data Sheet.2. Terminology2.1 Definitions of Terms Specific to Th
6、is Standard:2.1.1 background,extraneous scattering of light by ele-ments other than the particles to be measured. This includesscattering by contamination in the measurement zone.2.1.2 Fraunhofer Diffraction,the optical theory that de-scribes the low-angle scattering of light by particles that arela
7、rge compared to the wavelength of the incident light.2.1.3 Mie Scattering,the complex electromagnetic theorythat describes the scattering of light by spherical particles. It isusually applied to particles with diameters that are close to thewavelength of the incident light. The real and the imaginar
8、yindices of light diffraction are needed.22.1.4 multiple scattering,the rescattering of light by aparticle in the path of light scattered by another particle. Thismay occur in heavy concentrations of a particle dispersion.3. Summary of Test Method3.1 A sample dispersed in an aqueous medium is circul
9、atedthrough the path of a light beam. As the particles pass throughthe light beam, the particles scatter light at angles inverselyproportional to their size and with an intensity directly propor-tional to their size. Detectors collect the scattered light whichis converted to electrical signals and a
10、nalyzed in a micropro-cessor. The signal is converted to size distribution usingFraunhofer Diffraction or Mie Scattering, or a combination ofboth. The scattering information is then processed, assumingthe particles to be spherical, using algorithms or modelsproprietary to the particular instrument m
11、anufacturer. Calcu-lated particle size distributions are presented as equivalentspherical diameters.4. Significance and Use4.1 It is important to recognize that the results obtained bythis method or any other method for particle size distributionutilizing different physical principles may disagree.
12、The resultsare strongly influenced by the physical principles employed byeach method of particle size analysis. The results of anyparticle sizing method should be used only in a relative sense,and should not be regarded as absolute when comparing resultsobtained by other methods.4.2 Light scattering
13、 theory that is used for determination ofparticle size has been available for many years. Severalmanufacturers of testing equipment have units based on theseprinciples.Although each type of testing equipment utilizes thesame basic principles for light scattering as a function ofparticle size, differ
14、ent assumptions pertinent to applications of1This test method is under the jurisdiction of ASTM Committee C28 onAdvanced Ceramics and is the direct responsibility of Subcommittee C28.03 onPhysical Properties and Non-Destructive Evaluation.Current edition approved Jan. 1, 2014. Published January 2014
15、. Originallyapproved in 1986. Last previous edition approved in 2007 as C1070-01 (2007).DOI: 10.1520/C1070-01R14.2Muly, E. C., Frock, H. W., “Industrial Particle Size Measurement Using LightScattering,” Optical Engineering, 196, pp. 86169 (1990).Copyright ASTM International, 100 Barr Harbor Drive, P
16、O Box C700, West Conshohocken, PA 19428-2959. United States1the theory and different models for converting light measure-ments to particle size may lead to different results for eachinstrument. Therefore, the use of this test method cannotguarantee directly comparable results from the various manu-f
17、acturers instruments.4.3 Manufacturers and purchasers of alumina and quartzwill find the method useful to determine particle size distribu-tions for materials specifications, manufacturing control, andresearch and development.5. Interferences5.1 Air bubbles entrained in the circulating fluid will sc
18、atterlight and then be reported as particles. Circulating fluids do notrequire degassing, but should be bubble-free upon visualinspection.5.2 Reagglomeration or settling of particles during analysesmay cause erroneous results. Stable dispersions shall bemaintained throughout the analyses. To determi
19、ne if stability ispresent, make multiple runs on the same sample and observe ifthe distribution stays the same throughout the analysis. If thedistribution gets coarser, then agglomeration is occurring. Ifthe distribution gets finer, there exists the possibility ofmaterial settling. Dispersion proper
20、ties may be altered bychanging dispersants, use of ultrasonic energy prior to orduring analyses, and change of pumping speed during analyses.5.3 Insufficient sample loading may cause electrical noiseinterference and poor data repeatability. Excessive sampleloading may cause excessive light attenuati
21、on and multiplescattering, thereby resulting in erroneous particle size distribu-tions. The size distribution will have a tendency to be finer thanactually exists.6. Apparatus6.1 Particle Size Analyzer, based on Fraunhofer Diffractionor Mie Scattering or a combination of both light scatteringanalysi
22、s techniques. Care must be taken to ensure that theanalyzer system or subsystem is optimum for the size rangebeing tested.6.2 Liquid Handling System.7. Reagents7.1 Purity of ReagentsReagent grade of chemicals shallbe used in all tests. Unless otherwise indicated, it is intendedthat all reagents shal
23、l conform to the specifications of theCommittee on Analytical Reagents of the American ChemicalSociety, where such specifications are available. Other gradesmay be used, provided it is first ascertained that the reagent isof sufficiently high purity to permit its use without lesseningthe precision o
24、f the determination.7.2 Dispersion MediaDissolve 1.5 g of sodium metaphos-phate in 1 liter of distilled water and use this solution at anappropriate level so that the particles remain suspended in theaqueous system without creating bubbles. Other dispersantsmay be used for this purpose as well, such
25、 as SodiumPyrophosphate, Tween 80, Triton X100, Photoflow, or others.The optimum dispersant for the analysis is dependent on thematerial being analyzed and the amount of mixing and ultra-sound available for each particular particle size analyzersystem.8. Calibration and Standardization8.1 Performanc
26、e of the instrument is defined by the spacingand position of the optical components. Refer to the manufac-turers instruction manual.8.2 Diagnostic materials should be available from the in-strument manufacturer to ensure consistent instrument func-tioning.8.3 Since no absolute standards are availabl
27、e for particlesize analysis, it is recommended that one should develop asecondary reference material to assist in evaluating and opti-mizing instrument performance.9. Procedure9.1 Allow the instrument to warm up for the time recom-mended by the instrument manufacturer.9.2 If necessary, select applic
28、able instrument range as indi-cated by the instrument manufacturers instructions and estab-lish correct optical alignment according to the instructions.9.3 If required and available, use the index of refractioncapability of the instrument. Many of the common compoundshave their index of refraction l
29、isted in the Handbook ofPhysical Chemistry. Many compounds can also be found listedin the instrument manufacturers instruction manual. The indexof refraction used should be relative to the aqueous media,which has a refractive index of 1.33. When entering the indexof refraction for the material being
30、 analyzed therefore, it isnecessary to divide the index of refraction of the compoundbeing analyzed by the index of refraction of water.9.4 Measure the background in the mode in which theanalysis will be performed. The dispersion media should beadded to the sampling chamber before the background mea
31、-surement is performed. Be sure that the carrier fluid is flowingthrough the light path and the sample cell while measuring thebackground, and make sure that no bubbles are present.Background values shall not exceed the manufacturers speci-fications. If the background values exceed the manufacturers
32、recommendations, perform the necessary procedures as speci-fied by the manufacturer to bring the background values withinacceptable limits.9.5 Before adding the sample, be sure to use the appropriateamount of the dispersion media to the sampling chamber. Thenadd the test sample. Obtain a test sample
33、 using appropriatesampling techniques. Sample-splitting equipment such as chuteriflers and rotary rifflers are available commercially to assist inthese tasks. Refer to the instrument manufacturers recommen-dation to insure that the amount of the test sample is acceptableto obtain optimum light scatt
34、ering conditions. A range ofsample size is acceptable depending upon the median particlesize and particle density.9.6 Select the appropriate run time for the sample. Thisprocedure is very specific to the application and is generallygauged by the run-to-run repeatability.C1070 01 (2014)29.7 Select th
35、e desired data output parameters according tothe requirements set forth by the instrument manufacturer.9.8 Determine proper dispersion conditions for the testsample. An example is described in Test Method C690 sec-tion6.4.NOTE 1Some instruments have built-in ultrasonic baths to aid indispersion. Oth
36、ers do not, and as a result, dispersions will have to be madeexternally using ultrasonic baths or probes. Also, food processors such asblenders may be used.9.9 Perform the analysis according to the manufacturersinstruction.9.10 Upon completing the analysis, drain and rinse systemin preparation for t
37、he next analysis. Drain and rinse as manytimes as necessary to obtain the background values as specifiedby the manufacturer.10. Precision and Bias10.1 PrecisionRepeatability study varied from 0.18 %above 7 m to 0.01 % at 1 m. Reproducibility study variedfrom 0.5 % above 7 m to 0.1 % below 1 m.10.2 B
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