ASTM_C_1070_-_01_2014.pdf

Designation:C107001(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,in 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 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 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 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 This 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 arelarge 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 imaginaryindices 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 circulatedthrough 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 analyzed 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 manufacturer.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.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 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,different 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.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,PO Box C700,West Conshohocken,PA 19428-2959.United States1 the 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-facturers 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 entraine