ISO 21363:2020

Nanotechnologies — Measurements of particle size and shape distributions by transmission electron microscopy

This document specifies how to capture, measure and analyse transmission electron microscopy images to obtain particle size and shape distributions in the nanoscale. This document broadly is applicable to nano-objects as well as to particles with sizes larger than 100 nm. The exact working range of the method depends on the required uncertainty and on the performance of the transmission electron microscope. These elements can be evaluated according to the requirements described in this document.

Nanotechnologies — Détermination de la distribution de taille et de forme des particules par microscopie électronique à transmission

Le présent document spécifie une méthode permettant d'acquérir, de mesurer et d'analyser des images de microscopie électronique à transmission afin d'obtenir des distributions de taille et de forme à l'échelle nanométrique. Le présent document s'applique de façon générale aux nano-objets ainsi qu'aux particules de dimensions supérieures à 100 nm. La plage de fonctionnement exacte de la méthode dépend de l'incertitude exigée et des performances du microscope électronique à transmission. Ces éléments peuvent être évalués conformément aux exigences décrites dans le présent document.

General Information

• Status: Published
• Publication Date: 24-Jun-2020
• ICS: 07.120 - Nanotechnologies
• Technical Committee: ISO/TC 229 - Nanotechnologies
• Drafting Committee: ISO/TC 229/JWG 2 - Measurement and characterization
• Parallel Committee: IEC/TC 113 - Nanotechnology for electrotechnical products and systems
• Current Stage: 6060 - International Standard published
• Start Date: 25-Jun-2020
• Due Date: 28-Oct-2019
• Completion Date: 25-Jun-2020

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 21363
First edition
2020-06
Nanotechnologies — Measurements of
particle size and shape distributions
by transmission electron microscopy
Nanotechnologies — Détermination de la distribution de taille et de
forme des particules par microscopie électronique à transmission
Reference number
ISO 21363:2020(E)
©
ISO 2020

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ISO 21363:2020(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

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ISO 21363:2020(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and symbols . 1
3.1 Core terms — Particles . 1
3.2 Core terms — Image capture and analysis . 4
3.3 Core terms — Statistical symbols and definitions . 5
3.4 Core terms — Measurands . 7
3.5 Core terms — Metrology .10
3.6 Core terms — Transmission electron microscopy .13
3.7 Statistical symbols, measurands and descriptors .14
3.7.1 Statistical symbols .14
3.7.2 Measurands and descriptors .14
4 Stakeholder needs for TEM measurement procedures .15
5 Sample preparation .16
5.1 General .16
5.2 Sample sources .17
5.3 Use a representative sample .17
5.3.1 General.17
5.3.2 Powder samples .17
5.3.3 Nanoparticle dispersions in liquids .17
5.4 Minimize particle agglomeration in the sample dispersion .18
5.5 Selection of the mounting support .18
6 Instrument factors .18
6.1 Instrument set-up.18
6.2 Calibration .19
6.2.1 General.19
6.2.2 Calibration standards .19
6.2.3 General calibration procedure .19
6.3 Setting TEM operating conditions for calibration .21
7 Image capture .22
7.1 General .22
7.2 Setting a suitable operating magnification .22
7.3 Minimum particle area .23
7.4 Number of particles to count for particle size and shape distributions .23
7.5 Uniform background .24
7.6 Measurement procedure .24
7.6.1 General.24
7.6.2 Developing a test sample .25
7.6.3 Effects of magnification .25
7.6.4 Frames (micrographs) .25
7.7 Revision of image capture protocols .25
8 Particle analysis .25
8.1 General .25
8.2 Individual particle analysis .25
8.3 Automated particle analysis .26
8.4 Example — Automated particle analysis procedure .26
9 Data analysis .27
9.1 General .27
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ISO 21363:2020(E)

9.2 Raw data triage — Detecting touching particles, unselected particles, artefacts and
contaminants .27
9.3 Data quality assessment — Repeatability, intermediate precision and reproducibility .28
9.4 Fitting distributions to data .30
9.5 Assessing measur ement uncertainty for samples under repeatability, intermediate
precision or reproducibility conditions.31
9.5.1 Grand statistics for fitted parameters — Three or more datasets .31
9.5.2 Measurement uncertainty of fitted parameters .31
9.5.3 Example — Measurement uncertainty for a size descriptor .32
9.6 Bivariate analysis .32
10 Reporting .33
Annex A (informative) Case studies overview .36
Annex B (informative) Discrete spheroidal nanoparticles .38
Annex C (informative) Size mixture .41
Annex D (informative) Shape mixture .53
Annex E (informative) Amorphous aggregates .58
Annex F (informative) Nanocrystalline aggregates .62
Annex G (informative) Nanofibres with irregular cross-sections .66
Annex H (informative) Nanoparticles with specific crystal habits .73
Bibliography .80
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ISO 21363:2020(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO’s adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 229, Nanotechnologies.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
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ISO 21363:2020(E)

Introduction
Characterization procedures for nanoparticles often include, but are not limited to, size, shape, surface
structure (or texture), and surface chemistry. These measurements, combined with phase information,
such as crystalline phase, constitute the morphology of the material. This document focuses on two
attributes of morphology, size and shape distributions, for discrete, agglomerated and aggregated nano-
objects (materials with at least one dimension in the nanoscale, 1 nm < a length dimension < 100 nm).
Transmission electron microscopy, a standard tool for measurements on the nanoscale, provides
two-dimensional images of particle projections. This generic workflow for measuring and evaluating
particle size and shape distributions on the nanoscale includes sample preparation, instrument factors,
image capture, particle analysis, data analysis, and reporting. Seven case studies have been included to
illustrate how the generic protocol can be applied to different particle morphologies and sample types.
Three discrete particle test samples are reported: spheroidal (gold nanospheres), a bimodal mixture of
particle sizes (colloidal silicas), and a mixture of particle shapes (gold nanorods and gold nanocubes).
Two aggregate test samples are reported: amorphous aciniform aggregates (carbon black) and
aggregates of primary crystallites (titania). Measurements methods are also presented for low aspect
ratio samples and nanoparticles with specific crystal habits. Several of the case studies are supported
by interlaboratory collaborations conducted under the guidelines of the Versailles Project on Advanced
[42]
Materials and Standards (VAMAS) for interlaboratory comparisons (ILCs) .
Three types of size and shape descriptors are considered. Size descriptors include those determined by
linear or areal measurements. Shape descriptors include elongational descriptors, such as ratios of two
length descriptors, and ruggedness descriptors, which represent surface irregularities.
The protocol emphasizes qualitative and quantitative analysis of data quality by the user. Qualitative
comparisons of datasets include determining the similarity or differences between single descriptor
means or multivariate means. Quantitative comparisons of datasets are based on difference or
similarities between the parameters of reference models fitted to descriptor distributions. At least two
parameters (mean and spread) and their uncertainties are needed to define a descriptor distribution.
In some cases, these two quantitative parameters and their uncertainties may not be sufficient for
characterization of particle size and shape distributions. Data visualization techniques, such as residual
deviation and quantile plots, and data correlations, such as pairs of size and shape descriptors or
fractal analysis, can provide additional ways to evaluate and differentiate test samples. Taken together,
qualitative and quantitative quality metrics plus visualization and correlation tools permit users to
tailor the protocol to their qualitative and quantitative quality targets.
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INTERNATIONAL STANDARD ISO 21363:2020(E)
Nanotechnologies — Measurements of particle size and
shape distributions by transmission electron microscopy
1 Scope
This document specifies how to capture, measure and analyse transmission electron microscopy
images to obtain particle size and shape distributions in the nanoscale.
This document broadly is applicable to nano-objects as well as to particles with sizes larger than
100 nm. The exact working range of the method depends on the required uncertainty and on the
performance of the transmission electron microscope. These elements can be evaluated according to
the requirements described in this document.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
ISO 9276-3, Representation of results of particle size analysis — Part 3: Adjustment of an experimental
curve to a reference model
ISO 9276-6:2008, Representation of results of particle size analysis — Part 6: Descriptive and quantitative
representation of particle shape and morphology
ISO 29301, Microbeam analysis — Analytical electron microscopy — Methods for calibrating image
magnification by using reference materials with periodic structures
3 Terms, definitions and symbols
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1 Core terms — Particles
3.1.1
nano-object
discrete piece of material with one, two or three external dimensions in the nanoscale (3.1.2)
[SOURCE: ISO/TS 80004-2:2015, 2.2]
3.1.2
nanoscale
length range approximately from 1 nm to 100 nm
[SOURCE: ISO/TS 80004-1:2015, 2.1, modified — Note 1 to entry has been deleted.]
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3.1.3
particle
minute piece of matter with defined physical boundaries
[SOURCE: ISO 26824:2013, 1.1, modified — Notes 1, 2 and 3 to entry have been deleted.]
3.1.4
constituent particle
identifiable, integral component of a larger particle (3.1.3)
[SOURCE: ISO/TS 80004-2:2015, 3.3, modified — Note 1 to entry has been deleted.]
3.1.5
agglomerate
collection of weakly or medium strongly bound particles (3.1.3) where the resulting external surface
area is similar to the sum of the surface areas of the individual components
Note 1 to entry: The forces holding an agglomerate together are weak forces, for example van der Waals forces or
simple physical entanglement.
Note 2 to entry: Agglomerates are also termed secondary particles and the original source particles are termed
primary particles.
[SOURCE: ISO/TS 80004-2:2015, 3.4]
3.1.6
aggregate
particle (3.1.3) comprising strongly bonded or fused particles where the resulting external surface area
may be significantly smaller than the sum of calculated surface areas of the individual components
Note 1 to entry: The forces holding an aggregate together are strong forces (for example, covalent bonds) or
those resulting from sintering or complex physical entanglement.
Note 2 to entry: Aggregates are also termed secondary particles and the original source particles are termed
primary particles.
Note 3 to entry: Entries 3.1.6 to 3.1.10 define elements of agglomerates and aggregates, some of which are
illustrated in Figure 1. Constituent particles in an aggregate are tightly fused into a discrete entity (the
aggregate), while the constituent particles in an agglomerate are weakly bound and generally easily dispersed
under shear or mechanical stress.
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ISO 21363:2020(E)

a)  Primary particles in an b)  Primary particles in an c)  Agglomerate of aggregates
agglomerate aggregate
d) Nano-object (if less than 100 nm) e)  Agglomerate of both primary
or particle particles and aggregates
Figure 1 — Schematic showing elements of agglomerates and aggregates
[SOURCE: ISO/TS 80004-2:2015, 3.5, modified — In the definition, “may be significantly smaller” has
replaced “is significantly smaller” and “calculated” has been added before “surface areas”. In Note 1
to entry, “ionic bonds” in the example and the final phrase “or otherwise combined former primary
particles” have been deleted. Note 3 to entry and Figure 1 have been added.]
3.1.7
nanoparticle
nano-object (3.1.1) with all three external dimensions in the nanoscale (3.1.2) where the lengths of the
longest and shortest axes of the nano-object do not differ significantly
[SOURCE: ISO/TS 80004-2:2015, 4.4, modified — “three” has been added and Note 1 to entry has been
deleted.]
3.1.8
nanorod
solid nanofibre (3.1.9)
[SOURCE: ISO/TS 80004-2:2015, 4.7]
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3.1.9
nanofibre
nano-object (3.1.1) with two similar external dimensions in the nanoscale (3.1.2) and the third
dimension significantly larger
[SOURCE: ISO/TS 80004-2:2015, 4.5, modified — “similar” has been added and Notes 1, 2 and 3 to entry
have been deleted.]
3.1.10
nanophase
physically or chemically distinct region or collective term for physically distinct regions of the same
kind in a material with the discrete regions having one, two or three dimensions in the nanoscale (3.1.2)
Note 1 to entry: Nano-objects (3.1.1) embedded in another phase constitute a nanophase.
3.1.11
nanodispersion
material in which nano-objects (3.1.1) or a nanophase (3.1.10) are dispersed in a continuous phase of a
different composition
[SOURCE: ISO/TS 80004-4:2011, 2.14]
3.1.12
particle size
x
dimension of a particle (3.1.3) determined by a specified measurement method and under specified
measurement conditions
Note 1 to entry: Different methods of analysis are based on the measurement of different physical properties.
Independent of the particle property actually measured, the particle size can be reported as a linear dimension,
an area or a volume.
Note 2 to entry: The symbol x is used denote linear particle size. However, it is recognized that the symbol d is
also widely used. Therefore, the symbol x may be replaced by d.
[SOURCE: ISO 9276-1:1998, 4.2, modified — Converted into a term and definition entry.]
3.1.13
particle size distribution
distribution of particles (3.1.3) as a function of particle size (3.1.12)
[SOURCE: ISO/TS 80004-6:2013, 3.1.2, modified — Note 1 to entry has been deleted.]
3.1.14
particle shape
external geometric form of a particle (3.1.3)
Note 1 to entry: Shape description requires two scalar descriptors, i.e. length and spread.
[SOURCE: ISO/TS 80004-6:2013, 3.1.3, modified — Note 1 to entry has been added.]
3.1.15
particle shape distribution
distribution of a specific particle shape (3.1.14) descriptor for a sample population
3.2 Core terms — Image capture and analysis
3.2.1
field of view
field that is viewed by the viewing device
[SOURCE: ISO 13322-1:2014, 3.1.6, modified — Note 1 to entry has been deleted.]
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ISO 21363:2020(E)

3.2.2
measurement frame
selected area from the field of view (3.2.1) in which particles (3.1.3) are sized and counted for image
analysis
[SOURCE: ISO 13322-1:2014, 3.1.10]
3.2.3
binary image
digitized image consisting of an array of pixels (3.2.4), each of which has a value of 0 or 1, whose
values are normally represented by dark and bright regions on the display screen or by the use of two
distinct colours
[SOURCE: ISO 13322-1:2014, 3.1.2]
3.2.4
pixel
smallest element of an image that can be uniquely processed, and is defined by its spatial coordinates
and encoded with colour values
[SOURCE: ISO 12640-2:2004, 3.6, modified — Note 1 to entry has been deleted.]
3.2.5
pixel-resolution
number of imaging pixels (3.2.4) per unit distance of the detector
[SOURCE: ISO 29301:2017, 3.24, modified — Note 1 to entry has been deleted.]
3.2.6
pixel count
total number of pixels (3.2.4) per file, length, or area depending on the unit used
[SOURCE: ISO 19262:2015, 3.191]
3.2.7
micrograph
record of an image formed by a microscope
[SOURCE: ISO 10934-1:2002, 2.94]
3.2.8
artefact
artifact
unwanted distortion or added feature in measured data arising from lack of idealness of equipment
[SOURCE: ISO 18115-2: 2013, 5.6]
3.3 Core terms — Statistical symbols and definitions
3.3.1
coefficient of variation
C
v
ratio of the standard deviation to the arithmetic mean
Note 1 to entry: It is commonly reported as a percentage.
Note 2 to entry: For example, the coefficient of variation for a sample mean may be represented by:
s⋅100
c =
v
x
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ISO 21363:2020(E)

where x is the descriptor’s mean and s is the descriptor’s standard deviation for several datasets. These “grand
statistics” are used to evaluate descriptor data for interlaboratory comparisons.
[SOURCE: ISO 27448:2009, 3.11, modified — Notes 1 and 2 to entry have been added.]
3.3.2
standard error of estimation
σ
est
measure of dispersion of the dependent variable (output) about the least-squares line obtained by curve
fitting or regression analysis
Note 1 to entry: The standard error of estimation may be determined by:
n
2
yy−
()
∑ i
i=1
σ =
est
nk−
where
n is the number of data points;
k is the number of coefficients in the equation.
Note 2 to entry: The standard error of the mean may be determined by:
s
σ =
est,x
n
Note 3 to entry: The standard error is the standard deviation of the sampling distribution of a statistic. The
example is for a sample mean. Standard error of the mean is an estimate of how close the sample mean is to the
population mean. This value decreases as the sample size increases.
[SOURCE: ISO 772:2011, 7.31, modified — The admitted term “residual standard deviation” has been
deleted. Notes 1, 2 and 3 to entry have replaced the original Notes 1 and 2 to entry.]
3.3.3
relative standard error
RSE
standard error divided by its statistic
Note 1 to entry: It is expressed as a percentage.
Note 2 to entry: For example,
...

NORME ISO
INTERNATIONALE 21363
Première édition
2020-06
Nanotechnologies — Détermination
de la distribution de taille et de
forme des particules par microscopie
électronique à transmission
Nanotechnologies — Measurements of particle size and shape
distributions by transmission electron microscopy
Numéro de référence
ISO 21363:2020(F)
©
ISO 2020

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ISO 21363:2020(F)

DOCUMENT PROTÉGÉ PAR COPYRIGHT
© ISO 2020
Tous droits réservés. Sauf prescription différente ou nécessité dans le contexte de sa mise en œuvre, aucune partie de cette
publication ne peut être reproduite ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique,
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Tél.: [phone]
E-mail: [e-mail]
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Publié en Suisse
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ISO 21363:2020(F)

Sommaire Page
Avant-propos .v
Introduction .vi
1 Domaine d’application . 1
2 Références normatives . 1
3 Termes, définitions et symboles . 1
3.1 Termes «cœur» — Particules. 1
3.2 Termes «cœur» — Acquisition et analyse d’image . 5
3.3 Termes «cœur» — Définitions et symboles statistiques . 6
3.4 Termes «cœur» — Mesurandes . 7
3.5 Termes «cœur» — Métrologie .11
3.6 Termes «cœur» — Microscopie électronique à transmission .13
3.7 Symboles statistiques, mesurandes et descripteurs .14
3.7.1 Symboles statistiques .14
3.7.2 Mesurandes et descripteurs .15
4 Besoins des parties prenantes en termes de modes opératoires de mesure par MET .16
5 Préparation des échantillons .17
5.1 Généralités .17
5.2 Sources d’échantillons .17
5.3 Emploi d’un échantillon représentatif .18
5.3.1 Généralités .18
5.3.2 Échantillons en poudre .18
5.3.3 Dispersions de nanoparticules dans des liquides .18
5.4 Minimisation de l’agglomération des particules dans la dispersion d’échantillon .19
5.5 Choix du support d’échantillon .19
6 Facteurs instrumentaux .20
6.1 Réglage de l’instrument .20
6.2 Étalonnage .20
6.2.1 Généralités .20
6.2.2 Étalons .20
6.2.3 Mode opératoire d’étalonnage général .20
6.3 Réglage des conditions de fonctionnement du MET pour l’étalonnage.22
7 Acquisition d’images .23
7.1 Généralités .23
7.2 Réglage d’un grandissement de fonctionnement adapté .24
7.3 Surface de particule minimale .24
7.4 Nombre de particules à compter pour les distributions de taille et de forme des
particules .24
7.5 Fond uniforme .25
7.6 Mode opératoire de mesure .26
7.6.1 Généralités .26
7.6.2 Élaboration d’un échantillon d’essai.26
7.6.3 Effets du grandissement .26
7.6.4 Images (micrographies) .26
7.7 Révision des protocoles d’acquisition d’images .26
8 Analyse des particules .27
8.1 Généralités .27
8.2 Analyse de particules individuelle .27
8.3 Analyse de particules automatisée .27
8.4 Exemple de mode opératoire d’analyse de particules automatisée .27
9 Traitement des données .28
9.1 Généralités .28
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9.2 Tri des données brutes — Détections des particules en contact, des particules non
sélectionnées, des artefacts et des contaminants .29
9.3 Évaluation de la qualité des données — Répétabilité, fidélité intermédiaire et
reproductibilité .30
9.4 Ajustement des distributions aux données .32
9.5 Évaluation de l’incertitude de mesure pour les échantillons dans des conditions de
répétabilité, de fidélité intermédiaire ou de reproductibilité .33
9.5.1 Statistiques générales des paramètres ajustés — Trois ensembles de
données ou plus .33
9.5.2 Incertitude de mesure des paramètres ajustés .34
9.5.3 Exemple — Incertitude de mesure pour un descripteur de taille .34
9.6 Analyse à deux variables .34
10 Rapport.35
Annexe A (informative) Présentation d’études de cas .38
Annexe B (informative) Nanoparticules sphéroïdales discrètes .40
Annexe C (informative) Mélange de tailles .43
Annexe D (informative) Mélange de formes .56
Annexe E (informative) Agrégats amorphes .61
Annexe F (informative) Agrégats nanocristallins.65
Annexe G (informative) Nanofibres à sections transverses irrégulières .69
Annexe H (informative) Nanoparticules à caractéristiques cristallines spécifiques .76
Bibliographie .83
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ISO 21363:2020(F)

Avant-propos
L’ISO (Organisation internationale de normalisation) est une fédération mondiale d’organismes
nationaux de normalisation (comités membres de l’ISO). L’élaboration des Normes internationales est
en général confiée aux comités techniques de l’ISO. Chaque comité membre intéressé par une étude
a le droit de faire partie du comité technique créé à cet effet. Les organisations internationales,
gouvernementales et non gouvernementales, en liaison avec l’ISO participent également aux travaux.
L’ISO collabore étroitement avec la Commission électrotechnique internationale (IEC) en ce qui
concerne la normalisation électrotechnique.
Les procédures utilisées pour élaborer le présent document et celles destinées à sa mise à jour sont
décrites dans les Directives ISO/IEC, Partie 1. Il convient, en particulier, de prendre note des différents
critères d’approbation requis pour les différents types de documents ISO. Le présent document a été
rédigé conformément aux règles de rédaction données dans les Directives ISO/IEC, Partie 2 (voir www
.iso .org/ directives).
L’attention est attirée sur le fait que certains des éléments du présent document peuvent faire l’objet de
droits de propriété intellectuelle ou de droits analogues. L’ISO ne saurait être tenue pour responsable
de ne pas avoir identifié de tels droits de propriété et averti de leur existence. Les détails concernant
les références aux droits de propriété intellectuelle ou autres droits analogues identifiés lors de
l’élaboration du document sont indiqués dans l’Introduction et/ou dans la liste des déclarations de
brevets reçues par l’ISO (voir www .iso .org/ brevets).
Les appellations commerciales éventuellement mentionnées dans le présent document sont données
pour information, par souci de commodité, à l’intention des utilisateurs et ne sauraient constituer un
engagement.
Pour une explication de la nature volontaire des normes, la signification des termes et expressions
spécifiques de l’ISO liés à l’évaluation de la conformité, ou pour toute information au sujet de l’adhésion
de l’ISO aux principes de l’Organisation mondiale du commerce (OMC) concernant les obstacles
techniques au commerce (OTC), voir www .iso .org/ avant -propos.
Le présent document a été élaboré par le comité technique ISO/TC 229, Nanotechnologies.
Il convient que l’utilisateur adresse tout retour d’information ou toute question concernant le présent
document à l’organisme national de normalisation de son pays. Une liste exhaustive desdits organismes
se trouve à l’adresse www .iso .org/ fr/ members .html.
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ISO 21363:2020(F)

Introduction
Les modes opératoires de caractérisation des nanoparticules couvrent souvent, mais sans s’y limiter, la
taille, la forme, la structure de surface (ou la texture) et la chimie de surface. Ces mesurages, associés à
des informations sur les phases, telles que la phase cristalline, constituent la morphologie du matériau.
Le présent document porte sur deux attributs de morphologie, les distributions de taille et de forme,
des nano-objets discrets, agglomérés et agrégés (matériaux comportant au moins une dimension à
l’échelle nanométrique, 1 nm < une dimension < 100 nm). La microscopie électronique à transmission,
un outil classique de mesure à l’échelle nanométrique, fournit des images bidimensionnelles de
projections de particules. Ce flux d’opérations générique permettant de mesurer et d’évaluer des
distributions de taille et de forme à l’échelle nanométrique comprend la préparation des échantillons,
les facteurs instrumentaux, l’acquisition d’images, l’analyse des particules, le traitement des données
et la communication des résultats au travers d’un rapport. Sept études de cas ont été incluses pour
illustrer la façon dont le protocole générique peut être appliqué à différentes morphologies particulaires
et à différents types d’échantillons. Trois échantillons de particules discrètes sont présentés: un type
sphéroïdal (nanosphères d’or), un mélange de particules avec une granulométrie bimodale (silices
colloïdales) et un mélange de formes de particules (nanotiges d’or et nanocubes d’or). Deux échantillons
agrégés sont mentionnés: des agrégats amorphes en grappes (noir de carbone) et des agrégats de
cristallites primaires (dioxyde de titane). Des méthodes de mesure sont également présentées pour les
échantillons à faible rapport d’aspect et les nanoparticules à caractéristiques cristallines spécifiques.
Plusieurs des études de cas s’appuient sur des collaborations interlaboratoires menées conformément
aux lignes directrices du VAMAS (Versailles Project on Advanced Materials and Standards) concernant
[42]
les comparaisons interlaboratoires (CIL) .
Trois types de descripteurs de taille et de forme sont pris en compte. Les descripteurs de taille incluent
ceux déterminés par des mesurages linéaires ou surfaciques. Les descripteurs de forme comprennent
des descripteurs d’allongement, tels que les rapports entre deux descripteurs de longueur, et des
descripteurs de rugosité, représentant les irrégularités de surface.
Le protocole met l’accent sur l’analyse qualitative et quantitative de la qualité des données par
l’utilisateur. Les comparaisons qualitatives d’ensembles de données incluent la détermination de la
similitude ou des différences entre des moyennes de descripteur unique ou des moyennes à plusieurs
variables. Les comparaisons quantitatives d’ensembles de données s’appuient sur la différence ou les
similitudes entre les paramètres des modèles de référence ajustés aux distributions des descripteurs.
Au moins deux paramètres (moyenne et dispersion) ainsi que leurs incertitudes sont nécessaires pour
définir une distribution de descripteur. Dans certains cas, ces deux paramètres quantitatifs et leurs
incertitudes peuvent ne pas suffire à caractériser les distributions de taille et de forme. Les techniques
de visualisation des données, telles que les diagrammes quantiles et d’écart résiduel, et les corrélations
de données, telles que les paires de descripteurs de taille et de forme ou l’analyse fractale, peuvent
fournir d’autres méthodes pour évaluer et différencier des échantillons d’essai. L’association de mesures
de qualité quantitatives et d’outils de visualisation et de corrélation permet aux utilisateurs d’adapter
le protocole à leurs objectifs de qualité qualitatifs et quantitatifs.
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NORME INTERNATIONALE ISO 21363:2020(F)
Nanotechnologies — Détermination de la distribution
de taille et de forme des particules par microscopie
électronique à transmission
1 Domaine d’application
Le présent document spécifie une méthode permettant d’acquérir, de mesurer et d’analyser des images
de microscopie électronique à transmission afin d’obtenir des distributions de taille et de forme à
l’échelle nanométrique.
Le présent document s’applique de façon générale aux nano-objets ainsi qu’aux particules de dimensions
supérieures à 100 nm. La plage de fonctionnement exacte de la méthode dépend de l’incertitude exigée
et des performances du microscope électronique à transmission. Ces éléments peuvent être évalués
conformément aux exigences décrites dans le présent document.
2 Références normatives
Les documents suivants sont cités dans le texte de sorte qu’ils constituent, pour tout ou partie de leur
contenu, des exigences du présent document. Pour les références datées, seule l’édition citée s’applique.
Pour les références non datées, la dernière édition du document de référence s’applique (y compris les
éventuels amendements).
ISO 9276-3, Représentation de données obtenues par analyse granulométrique — Partie 3: Ajustement
d’une courbe expérimentale à un modèle de référence
ISO 9276-6:2008, Représentation de données obtenues par analyse granulométrique — Partie 6:
Description et représentation quantitative de la forme et de la morphologie des particules
ISO 29301, Analyse par microfaisceaux — Microscopie électronique analytique — Méthodes d’étalonnage
du grandissement d’image au moyen de matériaux de référence de structures périodiques
3 Termes, définitions et symboles
Pour les besoins du présent document, les termes et définitions suivants s’appliquent.
L’ISO et l’IEC tiennent à jour des bases de données terminologiques destinées à être utilisées en
normalisation, consultables aux adresses suivantes:
— ISO Online browsing platform: disponible à l’adresse https:// www .iso .org/ obp
— IEC Electropedia: disponible à l’adresse http:// www .electropedia .org/
3.1 Termes «cœur» — Particules
3.1.1
nano-objet
portion discrète de matériau dont une, deux ou les trois dimensions externes sont à l’échelle
nanométrique (3.1.2)
[SOURCE: ISO/TS 80004-2:2015, 2.2]
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ISO 21363:2020(F)

3.1.2
échelle nanométrique
échelle de longueur s’étendant approximativement de 1 nm à 100 nm
[SOURCE: ISO/TS 80004-1:2015, 2.1, modifiée — La Note 1 à l’article a été supprimée.]
3.1.3
particule
élément de matière isolé possédant des limites physiques définies
[SOURCE: ISO 26824:2013, 1.1, modifiée — Les Notes 1, 2 et 3 à l’article ont été supprimées.]
3.1.4
particule constituante
composante identifiable faisant partie intégrante d’une particule (3.1.3) plus grande
[SOURCE: ISO/TS 80004-2:2015, 3.3, modifiée — La Note 1 à l’article a été supprimée.]
3.1.5
agglomérat
ensemble de particules (3.1.3) faiblement ou moyennement liées, dont l’aire de la surface externe
résultante est similaire à la somme des aires de surface de chacun des composants
Note 1 à l'article: Les forces assurant la cohésion d’un agglomérat sont faibles, par exemple des forces de Van der
Waals ou des forces résultant d’un simple enchevêtrement physique.
Note 2 à l'article: Les agglomérats sont également appelés particules secondaires et les particules sources
initiales sont appelées particules primaires.
[SOURCE: ISO/TS 80004-2:2015, 3.4]
3.1.6
agrégat
particule (3.1.3) composée de particules fortement liées ou fusionnées, dont l’aire de la surface externe
résultante peut être significativement plus petite que la somme des aires de surface calculées de chacun
des composants
Note 1 à l'article: Les forces assurant la cohésion d’un agrégat sont puissantes, par exemple des liaisons covalentes,
ou des forces résultant d’un frittage ou d’un enchevêtrement physique complexe.
Note 2 à l'article: Les agrégats sont également appelés particules secondaires et les particules sources initiales
sont appelées particules primaires.
Note 3 à l'article: Les entrées 3.1.6 à 3.1.10 définissent des éléments des agglomérats et des agrégats, dont
certains sont illustrés à la Figure 1. Les particules constituantes d’un agrégat sont étroitement fusionnées en
une entité discrète (l’agrégat), tandis que les particules constituantes d’un agglomérat sont faiblement liées et se
dispersent généralement facilement sous l’effet d’un cisaillement ou d’une contrainte mécanique.
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ISO 21363:2020(F)

a)  Particules primaires dans b)  Particules primaires dans c)  Agglomérat d’agrégats
un agglomérat un agrégat
d)  Nano-objet (si inférieur à 100 nm) ou e)  Agglomérat de particules primaires et
particule d’agrégats
Figure 1 — Représentation schématique des éléments des agglomérats et des agrégats
[SOURCE: ISO/TS 80004-2:2015, 3.5, modifiée — Dans la définition, «peut être significativement
plus petite» a remplacé «est significativement plus petite» et «calculées» a été ajouté après «aires de
surface». Dans la Note 1 à l’article, «ou ioniques» dans l’exemple et la fin de phrase «ou sinon d’anciennes
particules primaires combinées» ont été supprimés. La Note 3 à l’article et la Figure 1 ont été ajoutées.]
3.1.7
nanoparticule
nano-objet (3.1.1) dont les trois dimensions externes sont à l’échelle nanométrique (3.1.2) et dont les
longueurs du plus grand et du plus petit axes ne diffèrent pas de façon significative
[SOURCE: ISO/TS 80004-2:2015, 4.4, modifiée — «trois» a été ajouté et la Note 1 à l’article a été
supprimée.]
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ISO 21363:2020(F)

3.1.8
nanobâtonnet
nanotige
nanofibre (3.1.9) solide
[SOURCE: ISO/TS 80004-2:2015, 4.7]
3.1.9
nanofibre
nano-objet (3.1.1) ayant deux dimensions externes similaires à l’échelle nanométrique (3.1.2) et la
troisième dimension externe significativement plus grande
[SOURCE: ISO/TS 80004-2:2015, 4.5, modifiée — «similaires» a été ajouté et les Notes 1, 2 et 3 à l’article
a été supprimées.]
3.1.10
nanophase
région physiquement ou chimiquement distincte, ou terme collectif désignant un ensemble de régions
de même nature et physiquement distinctes dans un matériau, cette ou ces régions discrètes ayant une,
deux ou trois dimensions à l’échelle nanométrique (3.1.2)
Note 1 à l'article: Les nano-objets (3.1.1) incorporés dans une autre phase constituent une nanophase.
3.1.11
nanodispersion
matériau dans lequel des nano-objets (3.1.1) ou une nanophase (3.1.10) sont dispersés dans une phase
continue de composition différente
[SOURCE: ISO/TS 80004-4:2011, 2.14]
3.1.12
taille d’une particule
x
dimension d’une particule (3.1.3) déterminée par une méthode de mesure spécifiée dans des conditions
de mesure spécifiées
Note 1 à l'article: Différentes méthodes d’analyse sont fondées sur le mesurage de différentes propriétés
physiques. Indépendamment de la propriété de particule réellement mesurée, la taille de la particule peut être
consignée comme une dimension linéaire, une surface ou un volume.
Note 2 à l'article: Le symbole x est utilisé pour indiquer la taille linéaire d’une particule. Cependant, il est reconnu
que le symbole d est également couramment utilisé. Le symbole x peut donc être remplacé par d.
[SOURCE: ISO 9276-1:1998, 4.2, modifiée — Un terme et sa définition ont été créés à partir de ce
paragraphe.]
3.1.13
distribution de taille de particules
distribution de particules (3.1.3) en fonction de leur taille (3.1.12)
[SOURCE: ISO/TS 80004-6:2013, 3.1.2, modifiée — La Note 1 à l’article a été supprimée.]
3.1.14
forme d’une particule
forme géométrique externe d’une particule (3.1.3)
Note 1 à l'article: La description de la forme exige deux descripteurs scalaires, la longueur et la largeur.
[SOURCE: ISO/TS 80004-6:2013, 3.1.3, modifiée — La Note 1 à l’article a été ajoutée.]
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ISO 21363:2020(F)

3.1.15
distribution de forme de particules
distribution d’un descripteur de forme de particule (3.1.14) spécifique pour une population d’échantillons
3.2 Termes «cœur» — Acquisition et analyse d’image
3.2.1
champ de vision
champ qui est perçu par un dispositif d’observation
[SOURCE: ISO 13322-1:2014, 3.1.6, modifiée — La Note 1 à l’article a été supprimée.]
3.2.2
cadre de mesure
surface sélectionnée d’un champ de vision (3.2.1) dans laquelle des particules (3.1.3) sont dimensionnées
et comptabilisées pour l’analyse d’images
[SOURCE: ISO 13322-1:2014, 3.1.10]
3.2.3
image binaire
image numérisée constituée d’une matrice de pixels (3.2.4), possédant chacun une valeur 0 ou 1, dont
les valeurs sont normalement représentées par des régions sombres et claires sur l’écran d’affichage ou
par l’utilisation de deux couleurs distinctes
[SOURCE: ISO 13322-1:2014, 3.1.2]
3.2.4
pixel
plus petit élément d’une image pouvant être traité de façon unique, qui est défini par ses coordonnées
spatiales et codé avec des valeurs de couleurs
[SOURCE: ISO 12640-2:2004, 3.6, modifiée — La Note 1 à l’article a été supprimée.]
3.2.5
résolution de pixels
nombre de pixels (3.2.4) par unité de distance d’un détecteur
[SOURCE: ISO 29301:2017, 3.24, modifiée — La Note 1 à l’article a été supprimée.]
3.2.6
comptage de pixels
nombre total de pixel
...

INTERNATIONAL ISO
STANDARD 21363
First edition
Nanotechnologies — Measurements of
particle size and shape distributions
by transmission electron microscopy
Nanotechnologies — Détermination de la distribution de taille et de
forme des particules par microscopie électronique à transmission
PROOF/ÉPREUVE
Reference number
ISO 21363:2020(E)
©
ISO 2020

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ISO/FDIS 21363:2020(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH­1214 Vernier, Geneva
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

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ISO/FDIS 21363:2020(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and symbols . 1
3.1 Core terms — Particles . 1
3.2 Core terms — Image capture and analysis . 4
3.3 Core terms — Statistical symbols and definitions . 5
3.4 Core terms — Measurands . 7
3.5 Core terms — Metrology .10
3.6 Core terms — Transmission electron microscopy .13
3.7 Statistical symbols, measurands and descriptors .14
3.7.1 Statistical symbols .14
3.7.2 Measurands and descriptors .14
4 Stakeholder needs for TEM measurement procedures .15
5 Sample preparation .16
5.1 General .16
5.2 Sample sources .17
5.3 Use a representative sample .17
5.3.1 General.17
5.3.2 Powder samples .17
5.3.3 Nanoparticle dispersions in liquids .17
5.4 Minimize particle agglomeration in the sample dispersion .18
5.5 Selection of the mounting support .18
6 Instrument factors .18
6.1 Instrument set­up.18
6.2 Calibration .19
6.2.1 General.19
6.2.2 Calibration standards .19
6.2.3 General calibration procedure .19
6.3 Setting TEM operating conditions for calibration .21
7 Image capture .22
7.1 General .22
7.2 Setting a suitable operating magnification .22
7.3 Minimum particle area .23
7.4 Number of particles to count for particle size and shape distributions .23
7.5 Uniform background .24
7.6 Measurement procedure .24
7.6.1 General.24
7.6.2 Developing a test sample .25
7.6.3 Effects of magnification .25
7.6.4 Frames (micrographs) .25
7.7 Revision of image capture protocols .25
8 Particle analysis .25
8.1 General .25
8.2 Individual particle analysis .25
8.3 Automated particle analysis .26
8.4 Example — Automated particle analysis procedure .26
9 Data analysis .27
9.1 General .27
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ISO/FDIS 21363:2020(E)

9.2 Raw data triage — Detecting touching particles, unselected particles, artefacts and
contaminants .27
9.3 Data quality assessment — Repeatability, intermediate precision and reproducibility .28
9.4 Fitting distributions to data .30
9.5 Assessing measur ement uncertainty for samples under repeatability, intermediate
precision or reproducibility conditions.31
9.5.1 Grand statistics for fitted parameters — Three or more datasets .31
9.5.2 Measurement uncertainty of fitted parameters .31
9.5.3 Example — Measurement uncertainty for a size descriptor .32
9.6 Bivariate analysis .32
10 Reporting .33
Annex A (informative) Case studies overview .36
Annex B (informative) Discrete spheroidal nanoparticles .38
Annex C (informative) Size mixture .41
Annex D (informative) Shape mixture .53
Annex E (informative) Amorphous aggregates .58
Annex F (informative) Nanocrystalline aggregates .62
Annex G (informative) Nanofibres with irregular cross-sections .66
Annex H (informative) Nanoparticles with specific crystal habits .73
Bibliography .80
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ISO/FDIS 21363:2020(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non­governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO’s adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 229, Nanotechnologies.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
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ISO/FDIS 21363:2020(E)

Introduction
Characterization procedures for nanoparticles often include, but are not limited to, size, shape, surface
structure (or texture), and surface chemistry. These measurements, combined with phase information,
such as crystalline phase, constitute the morphology of the material. This document focuses on two
attributes of morphology, size and shape distributions, for discrete, agglomerated and aggregated nano-
objects (materials with at least one dimension in the nanoscale, 1 nm < a length dimension < 100 nm).
Transmission electron microscopy, a standard tool for measurements on the nanoscale, provides
two-dimensional images of particle projections. This generic workflow for measuring and evaluating
particle size and shape distributions on the nanoscale includes sample preparation, instrument factors,
image capture, particle analysis, data analysis, and reporting. Seven case studies have been included to
illustrate how the generic protocol can be applied to different particle morphologies and sample types.
Three discrete particle test samples are reported: spheroidal (gold nanospheres), a bimodal mixture of
particle sizes (colloidal silicas), and a mixture of particle shapes (gold nanorods and gold nanocubes).
Two aggregate test samples are reported: amorphous aciniform aggregates (carbon black) and
aggregates of primary crystallites (titania). Measurements methods are also presented for low aspect
ratio samples and nanoparticles with specific crystal habits. Several of the case studies are supported
by interlaboratory collaborations conducted under the guidelines of the Versailles Project on Advanced
[42]
Materials and Standards (VAMAS) for interlaboratory comparisons (ILCs) .
Three types of size and shape descriptors are considered. Size descriptors include those determined by
linear or areal measurements. Shape descriptors include elongational descriptors, such as ratios of two
length descriptors, and ruggedness descriptors, which represent surface irregularities.
The protocol emphasizes qualitative and quantitative analysis of data quality by the user. Qualitative
comparisons of datasets include determining the similarity or differences between single descriptor
means or multivariate means. Quantitative comparisons of datasets are based on difference or
similarities between the parameters of reference models fitted to descriptor distributions. At least two
parameters (mean and spread) and their uncertainties are needed to define a descriptor distribution.
In some cases, these two quantitative parameters and their uncertainties may not be sufficient for
characterization of particle size and shape distributions. Data visualization techniques, such as residual
deviation and quantile plots, and data correlations, such as pairs of size and shape descriptors or
fractal analysis, can provide additional ways to evaluate and differentiate test samples. Taken together,
qualitative and quantitative quality metrics plus visualization and correlation tools permit users to
tailor the protocol to their qualitative and quantitative quality targets.
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FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 21363:2020(E)
Nanotechnologies — Measurements of particle size and
shape distributions by transmission electron microscopy
1 Scope
This document specifies how to capture, measure and analyse transmission electron microscopy
images to obtain particle size and shape distributions in the nanoscale.
This document broadly is applicable to nano-objects as well as to particles with sizes larger than
100 nm. The exact working range of the method depends on the required uncertainty and on the
performance of the transmission electron microscope. These elements can be evaluated according to
the requirements described in this document.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
ISO 9276­3, Representation of results of particle size analysis — Part 3: Adjustment of an experimental
curve to a reference model
ISO 9276­6:2017, Representation of results of particle size analysis — Part 6: Descriptive and quantitative
representation of particle shape and morphology
ISO 29301, Microbeam analysis — Analytical electron microscopy — Methods for calibrating image
magnification by using reference materials with periodic structures
3 Terms, definitions and symbols
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1 Core terms — Particles
3.1.1
nano-object
discrete piece of material with one, two or three external dimensions in the nanoscale (3.1.2)
[SOURCE: ISO/TS 80004­2:2015, 2.2]
3.1.2
nanoscale
length range approximately from 1 nm to 100 nm
[SOURCE: ISO/TS 80004-1:2015, 2.1, modified — Note 1 to entry has been deleted.]
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ISO/FDIS 21363:2020(E)

3.1.3
particle
minute piece of matter with defined physical boundaries
[SOURCE: ISO 26824:2013, 1.1, modified — Notes 1, 2 and 3 to entry have been deleted.]
3.1.4
constituent particle
identifiable, integral component of a larger particle (3.1.3)
[SOURCE: ISO/TS 80004-2:2015, 3.3, modified — Note 1 to entry has been deleted.]
3.1.5
agglomerate
collection of weakly or medium strongly bound particles (3.1.3) where the resulting external surface
area is similar to the sum of the surface areas of the individual components
Note 1 to entry: The forces holding an agglomerate together are weak forces, for example van der Waals forces or
simple physical entanglement.
Note 2 to entry: Agglomerates are also termed secondary particles and the original source particles are termed
primary particles.
[SOURCE: ISO/TS 80004­2:2015, 3.4]
3.1.6
aggregate
particle (3.1.3) comprising strongly bonded or fused particles where the resulting external surface area
may be significantly smaller than the sum of calculated surface areas of the individual components
Note 1 to entry: The forces holding an aggregate together are strong forces (for example, covalent bonds) or
those resulting from sintering or complex physical entanglement.
Note 2 to entry: Aggregates are also termed secondary particles and the original source particles are termed
primary particles.
Note 3 to entry: Entries 3.1.6 to 3.1.10 define elements of agglomerates and aggregates, some of which are
illustrated in Figure 1. Constituent particles in an aggregate are tightly fused into a discrete entity (the
aggregate), while the constituent particles in an agglomerate are weakly bound and generally easily dispersed
under shear or mechanical stress.
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a)  Primary particles in an b)  Primary particles in an c)  Agglomerate of aggregates
agglomerate aggregate
d) Nano-object (if less than 100 nm) e)  Agglomerate of both primary
or particle particles and aggregates
Figure 1 — Schematic showing elements of agglomerates and aggregates
[SOURCE: ISO/TS 80004-2:2015, 3.5, modified — In the definition, “may be significantly smaller” has
replaced “is significantly smaller” and “calculated” has been added before “surface areas”. In Note 1
to entry, “ionic bonds” in the example and the final phrase “or otherwise combined former primary
particles” have been deleted. Note 3 to entry and Figure 1 have been added.]
3.1.7
nanoparticle
nano-object (3.1.1) with all three external dimensions in the nanoscale (3.1.2) where the lengths of the
longest and shortest axes of the nano-object do not differ significantly
[SOURCE: ISO/TS 80004-2:2015, 4.4, modified — “three” has been added and Note 1 to entry has been
deleted.]
3.1.8
nanorod
solid nanofibre (3.1.9)
[SOURCE: ISO/TS 80004­2:2015, 4.7]
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3.1.9
nanofibre
nano-object (3.1.1) with two similar external dimensions in the nanoscale (3.1.2) and the third
dimension significantly larger
[SOURCE: ISO/TS 80004-2:2015, 4.5, modified — Note 1 to entry has been deleted.]
3.1.10
nanophase
physically or chemically distinct region or collective term for physically distinct regions of the same
kind in a material with the discrete regions having one, two or three dimensions in the nanoscale (3.1.2)
Note 1 to entry: Nano-objects (3.1.1) embedded in another phase constitute a nanophase.
3.1.11
nanodispersion
material in which nano-objects (3.1.1) or a nanophase (3.1.10) are dispersed in a continuous phase of a
different composition
[SOURCE: ISO/TS 80004­4:2011, 2.14]
3.1.12
particle size
x
dimension of a particle (3.1.3) determined by a specified measurement method and under specified
measurement conditions
Note 1 to entry: Different methods of analysis are based on the measurement of different physical properties.
Independent of the particle property actually measured, the particle size can be reported as a linear dimension,
an area or a volume.
Note 2 to entry: The symbol x is used denote linear particle size. However, it is recognized that the symbol d is
also widely used. Therefore, the symbol x may be replaced by d.
[SOURCE: ISO 9276-1:1998, 4.2, modified — Converted into a term and definition entry.]
3.1.13
particle size distribution
distribution of particles (3.1.3) as a function of particle size (3.1.12)
[SOURCE: ISO/TS 80004-6:2013, 3.1.2, modified — Note 1 to entry has been deleted.]
3.1.14
particle shape
external geometric form of a particle (3.1.3)
Note 1 to entry: Shape description requires two scalar descriptors, i.e. length and spread.
[SOURCE: ISO/TS 80004-6:2013, 3.1.3, modified — Note 1 to entry has been added.]
3.1.15
particle shape distribution
distribution of a specific particle shape (3.1.14) descriptor for a sample population
3.2 Core terms — Image capture and analysis
3.2.1
field of view
field that is viewed by the viewing device
[SOURCE: ISO 13322-1:2014, 3.1.6, modified — Note 1 to entry has been deleted.]
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3.2.2
measurement frame
selected area from the field of view (3.2.1) in which particles (3.1.3) are sized and counted for image
analysis
[SOURCE: ISO 13322­1:2014, 3.1.10]
3.2.3
binary image
digitized image consisting of an array of pixels (3.2.4), each of which has a value of 0 or 1, whose
values are normally represented by dark and bright regions on the display screen or by the use of two
distinct colours
[SOURCE: ISO 13322­1:2014, 3.1.2]
3.2.4
pixel
smallest element of an image that can be uniquely processed, and is defined by its spatial coordinates
and encoded with colour values
[SOURCE: ISO 12640-2:2004, 3.6, modified — Note 1 to entry has been deleted.]
3.2.5
pixel-resolution
number of imaging pixels (3.2.4) per unit distance of the detector
[SOURCE: ISO 29301:2017, 3.24, modified — Note 1 to entry has been deleted.]
3.2.6
pixel count
total number of pixels (3.2.4) per file, length, or area depending on the unit used
[SOURCE: ISO 19262:2015, 3.191]
3.2.7
micrograph
record of an image formed by a microscope
[SOURCE: ISO 10934­1:2002, 2.94]
3.2.8
artefact
artifact
unwanted distortion or added feature in measured data arising from lack of idealness of equipment
[SOURCE: ISO 18115­2: 2013, 5.6]
3.3 Core terms — Statistical symbols and definitions
3.3.1
coefficient of variation
C
v
ratio of the standard deviation to the arithmetic mean
Note 1 to entry: It is commonly reported as a percentage.
Note 2 to entry: For example, the coefficient of variation for a sample mean may be represented by:
s⋅100
c =
v
x
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where x is the descriptor’s mean and s is the descriptor’s standard deviation for several datasets. These “grand
statistics” are used to evaluate descriptor data for interlaboratory comparisons.
[SOURCE: ISO 27448:2009, 3.11, modified — Notes 1 and 2 to entry have been added.]
3.3.2
standard error of estimation
σ
est
measure of dispersion of the dependent variable (output) about the least-squares line obtained by curve
fitting or regression analysis
Note 1 to entry: The standard error of estimation may be determined by:
n
2
yy−
()
∑ i
i=1
σ =
est
nk−
where
n is the number of data points;
k is the number of coefficients in the equation.
Note 2 to entry: The standard error of the mean may be determined by:
s
σ =
est,x
n
Note 3 to entry: The standard error is the standard deviation of the sampling distribution of a statistic. The
example is for a sample mean. Standard error of the mean is an estimate of how close the sample mean is to the
population mean. This value decreases as the sample size increases.
[SOURCE: ISO 772:2011, 7.31, modified — The admitted term “residual standard deviation” has been
deleted. Notes 1, 2 and 3 to entry have replaced the original Notes 1 and 2 to entry.]
3.3.3
relative standard error
RSE
standard error divided by its statistic
Note 1 to entry: It is ex
...