ASTM_D_4464_-_15_2020.pdf

Designation:D446415(Reapproved 2020)Standard Test Method forParticle Size Distribution of Catalytic Materials by LaserLight Scattering1This standard is issued under the fixed designation D4464;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 the particlesize distribution of catalyst,catalyst carrier,and catalytic rawmaterial particles and is one of several found valuable for themeasurement of particle size.The range of average particlesizes investigated was from 1 to 300 m equivalent sphericaldiameter.The technique is capable of measuring particlesabove and below this range.The angle and intensity of laserlight scattered by the particles are selectively measured topermit calculation of a volume distribution using light-scattering techniques.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 concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D3766 Terminology Relating to Catalysts and CatalysisE105 Practice for Probability Sampling of MaterialsE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE456 Terminology Relating to Quality and StatisticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE1617 Practice for Reporting Particle Size CharacterizationData3.Terminology3.1 Definitions and recommended nomenclature pertainingto catalysts and to materials used in their manufacture can befound in Terminology D3766.3.2 Definitions of Terms Specific to This Standard:3.2.1 backgroundextraneous scattering of light by mate-rial present in the dispersion fluid other than the particles to bemeasured.It includes scattering by contamination in themeasurement path.3.2.2 Fraunhofer Diffractionthe optical theory that de-scribes the low-angle scattering of light by particles that arelarge compared to the wavelength of the incident light.3.2.3 Mie Scatteringthe complex electromagnetic theorythat describes the scattering of light by spherical particles.It isapplied when the sample includes particles with diameters thatare close to the wavelength of the incident light.The real andimaginary indices of light refraction of the particles are needed.3.2.4 multiple scatteringthe re-scattering of light by aparticle in the path of light scattered by another particle.Thisusually occurs in heavy concentrations of a particle dispersion.4.Summary of Test Method4.1 Aprepared sample of particulate material is dispersed inwater or a compatible organic liquid and is circulated throughthe path of a laser light beam or some other suitable source oflight.The particles pass through the light beam and scatter it.Photodetector arrays collect the scattered light which is con-verted to electrical signals to be analyzed using FraunhoferDiffraction,or Mie Scattering,or both.Scattering information,typically,is analyzed assuming a spherical geometry for theparticles.Calculated particle sizes are,therefore,presented asequivalent spherical diameters.1This test method is under the jurisdiction of ASTM Committee D32 onCatalysts and is the direct responsibility of Subcommittee D32.02 on Physical-Mechanical Properties.Current edition approved May 15,2020.Published June 2020.Originallyapproved in 1985.Last previous edition approved in 2015 as D4464 15.DOI:10.1520/D4464-15R20.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.5.Significance and Use5.1 It is important to recognize that the results obtained bythis test method or any other method f