SIST EN 725-5:2007

SLOVENSKI STANDARD
SIST EN 725-5:2007
01-maj-2007
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SIST EN 725-5:2000
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Advanced technical ceramics - Methods of test for ceramic powders - Part 5:
Determination of particle size distribution
Hochleistungskeramik - Prüfverfahren für keramische Pulver - Teil 5: Bestimmung der
Teilchengrößenverteilung
Céramiques techniques avancées - Méthodes d'essais pour poudre céramiques - Partie
5: Détermination de la distribution granulométrique
Ta slovenski standard je istoveten z: EN 725-5:2007
ICS:
81.060.30 Sodobna keramika Advanced ceramics
SIST EN 725-5:2007 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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EUROPEAN STANDARD
EN 725-5
NORME EUROPÉENNE
EUROPÄISCHE NORM
January 2007
ICS 81.060.30 Supersedes EN 725-5:1996
English Version
Advanced technical ceramics - Methods of test for ceramic
powders - Part 5: Determination of particle size distribution
Céramiques techniques avancées - Méthodes d'essais Hochleistungskeramik - Prüfverfahren für keramische
pour poudre céramiques - Partie 5: Détermination de la Pulver - Teil 5: Bestimmung der Teilchengrößenverteilung
distribution granulométrique
This European Standard was approved by CEN on 2 December 2006.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2007 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 725-5:2007: E
worldwide for CEN national Members.

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EN 725-5:2007 (E)
Contents Page
Foreword.3
1 Scope .4
2 Normative references .4
3 Apparatus .4
4 Preparation of the suspension.4
5 Calibration .5
6 Procedure .5
7 Expression of results .6
8 Test report .6
Annex A (informative) Suspending liquids and dispersing agents.7
Annex B (informative) Certified reference materials.11
Annex C (informative) Suspension and dispersion data.12
Annex D (informative) Example of particle size distribution.13
Annex E (informative) Presentation of particle size distribution data .14
Bibliography .15

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EN 725-5:2007 (E)
Foreword
This document (EN 725-5:2007) has been prepared by Technical Committee CEN/TC 184 “Advanced
technical ceramics”, the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by July 2007, and conflicting national standards shall be withdrawn at the
latest by July 2007.
This document supersedes EN 725-5:1996.
EN 725 Advanced technical ceramics — Methods of test for ceramic powders was prepared in Parts as
follows:
Part 1: Determination of impurities in alumina
Part 2: Determination of impurities in barium titanate
Part 3: Determination of the oxygen content of non-oxides by thermal extraction with a carrier gas
Part 4: Determination of oxygen content in aluminium nitride by XRF analysis
Part 5: Determination of particle size distribution
Part 6: Determination of the specific surface area [withdrawn]
Part 7: Determination of the absolute density [withdrawn]
Part 8: Determination of tapped bulk density
Part 9: Determination of un-tapped bulk density
Part 10: Determination of compaction properties
Part 11: Determination of densification on natural sintering
Part 12: Chemical analysis of zirconia
Parts 6 and 7 of the series were superseded in 2005 by EN ISO 18757 and EN ISO 18753 respectively.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and United Kingdom.
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EN 725-5:2007 (E)
1 Scope
This Part of EN 725 describes the preparation of suspensions and calibration of apparatus, prior to the
measurement of particle size distribution of powders used for advanced technical ceramics.
The preparation described is appropriate for measurements either by the sedimentation method or the laser
light scattering method.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
EN ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories (ISO/IEC
17025:2005)
3 Apparatus
3.1 Glass microscope slides and cover slips.
3.2 Optical microscope.
3.3 Beaker, 50 ml to 100 ml.
3.4 Ultrasonicator.
3.5 Magnetic stirrer.
3.6 Particle size analyser.
4 Preparation of the suspension
4.1 Selection of liquid
The dispersing liquid for the suspension shall not react with or dissolve the powder.
For the sedimentation method of analysis, the density of the liquid shall be less than that of the powder by at
least 0,5 g/cm³.
For the laser light scattering method of analysis, the liquid shall be optically transparent for the wavelength
used.
NOTE 1 This is generally 633 nm.
The liquid shall have a refractive index which is substantially different from that of the sample.
NOTE 2 Any specific manufacturer’s instructions regarding the refractive index of the dispersing liquid should be taken
into account.
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EN 725-5:2007 (E)
The liquid for the suspension shall be selected, together with any dispersing agent, from those given in Annex
A.
NOTE 3 Additional information is given in the bibliographical references listed.
The dispersion of powder in the liquid shall be checked by one of the methods given in 4.2.
4.2 Dispersion checking
4.2.1 Optical microscopic examination
Place a drop of the prepared suspension on the glass slide (3.1) of a microscope (3.2) and carefully cover with
a cover slip (3.1). Observe the preparation under a suitable magnification, to determine if particles are
completely separated and well dispersed, or if they are gathered together in chains or clusters.
NOTE This method is not suitable for powders with particle diameters of less than 5 µm.
4.2.2 Qualitative test by sedimentation
Allow the suspension to stand. A correctly dispersed suspension settles less rapidly than a suspension which
flocculates, and shows no clear border line between the liquid which becomes clear and the layer which is still
turbid as sedimentation proceeds. The sediment obtained is compact and of a minimal volume.
4.2.3 Scanning electron microscope (S.E.M.) examination
Check the correlation of the particle size distribution obtained with the mean size of the ultimate particles
observed by S.E.M. If the suspension is not sufficiently dispersed, particles are partially aggregated and
particle size distribution measurements thus give values much higher than the mean size of the ultimate
particles observed.
4.2.4 Quantitative test by sedimentation
Perform the quantitative tests, while allowing a variation of the various parameters liable to influence the
dispersion quality. Choose the dispersion procedure which gives the smallest mean particle diameter. An
examination of the shape of the distribution can give an indication of the presence of agglomerates.
5 Calibration
Check the working order of the apparatus, by analysing standard powders regularly.
NOTE Information on available standard reference powders is provided in Annex B.
6 Procedure
6.1 Determine the quantity of powder, the type and quantity of suspending liquid and the dispersing agent
to be used.
NOTE In principle, and within the limits imposed by the instrument, the sample mass to be dispersed has no
influence on the results. However, it is preferable to use dilute suspensions.
6.2 For the sedimentation method, ensure that the volume co
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