ASTM_C_690_-_09_2014.pdf

Designation:C69009(Reapproved 2014)Standard Test Method forParticle Size Distribution of Alumina or Quartz Powders byElectrical Sensing Zone Technique1This standard is issued under the fixed designation C690;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.Scope*1.1 This test method,one of several found valuable for themeasurement of particle size,covers the determination of theparticle size distribution of alumina or quartz powders(0.6 to56.0 m)using electrical sensing zone particle size analyzers.These instruments use an electric current path of small dimen-sions which is modulated by individual particle passagethrough an aperture,and produces individual pulses of ampli-tude proportional to the particle volume.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety problems,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Summary of Test Method2.1 A carefully dispersed,dilute suspension of the powderin a beaker filled with an electrolyte is placed on the instrumentsample stand.The suspension is forced through a restrictingaperture.Each particle passing generates an electric pulse thatis recorded on an electronic counter.2.2 The instrument response is essentially related to particlevolume(liquid displacement).Equivalent spherical diameter iscommonly used to express the particle size.(Comparisons withother techniques have been found to be good for sphericalparticles;for non-spherical particles results may differ.)3.Significance and Use3.1 This test method is useful to both sellers and purchasersof alumina and quartz powders for determining particle sizedistributions for materials specifications,manufacturingcontrol,and development and research.4.Apparatus4.1 Electrical Sensing Zone Particle Counter.4.2 Aperture Tubes,diameter ranging from approximately30 to 140 m.The diameter required is dependent upon theparticle size distribution of the sample.Generally any giventube will cover a particle size range from 2 to 60%of itsaperture diameter.NOTE1In certain cases,apertures up to 300 m are usable.4.3 Sample Beaker,capable of maintaining all particlesuniformly in suspension(for example,round-bottom).4.4 Blender,capacity 1-Lglass container.Ameans to controlspeed is required.4.5 Beakers,100,500,and 1000-mL.4.6 Pipet.4.7 Wash Bottles.4.8 Membrane Filtering Device,rated at 0.45-m filters orfiner.5.Reagents5.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.2Other grades may beused,provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.5.2 Dispersing MediaTen percent solution of purified orreagent grade sodium hexametaphosphate in distilled watertwice filtered through the membrane filtering device.NOTE2Deionized water may be substituted for distilled water.NOTE3This liquid should not be retained longer than 1 month andshould not be pH modified or heated.1This test method is under the jurisdiction ofASTM Committee C21 on CeramicWhitewares and Related Productsand is the direct responsibility of SubcommitteeC21.04 on Raw Materials.Current edition approved Dec.1,2014.Published December 2014.Originallyapproved in 1971.Last previous edition approved in 2009 as C690 09.DOI:10.1520/C0690-09R14.2Reagent Chemicals,American Chemical Society Specifications,AmericanChemical Society,Washington,DC.For suggestions on the testing of reagents notlisted by the American Chemical Society,see Analar Standards for LaboratoryChemicals,VWR International Ltd.,U.K.,and the United States Pharmacopoeia,USPC,Rockville,MD.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.3 ElectrolyteDissolve 10.0 g of reagent grade sodiumchloride(NaCl)in 1000 mL of distilled water and filter twicethrough the membrane filtering device.5.4 Wash WaterDistilled water twice filtered through themembrane filtering device.5.5 Calibration ParticlesNIST or NIST traceable mono-sized particle standards.6.Procedure6.1 SummaryDisperse the test powder in the electrolytewith a blender.Transfer a representative portion to the samplebeaker that contains filtered electrolyte.Place sample beaker inthe apparatus an