ISO 14644-9:2022
(Main)Cleanrooms and associated controlled environments — Part 9: Assessment of surface cleanliness for particle concentration
Cleanrooms and associated controlled environments — Part 9: Assessment of surface cleanliness for particle concentration
This document establishes a procedure for the assessment of particle cleanliness levels on solid surfaces in cleanrooms and associated controlled environment applications. Recommendations on testing and measuring methods, as well as information about surface characteristics, are given in Annexes A to D. This document applies to all solid surfaces in cleanrooms and associated controlled environments, such as walls, ceilings, floors, working environments, tools, equipment and products. The procedure for the assessment of surface cleanliness by particle concentration (SCP) is limited to particles of between 0,05 µm and 500 µm. The following issues are not considered in this document: — requirements for the cleanliness and suitability of surfaces for specific processes; — procedures for the cleaning of surfaces; — material characteristics; — references to interactive bonding forces or generation processes that are usually time-dependent and process-dependent; — selection and use of statistical methods for assessment and testing; — other characteristics of particles, such as electrostatic charge, ionic charges and microbiological state.
Salles propres et environnements maîtrisés apparentés — Partie 9: Évaluation de la propreté des surfaces en fonction de la concentration de particules
Le présent document établit un mode opératoire pour l’évaluation des niveaux de propreté particulaire des surfaces solides, applicables aux salles propres et aux environnements maîtrisés apparentés. Les Annexes A à D fournissent des recommandations relatives aux essais et aux méthodes de mesurage, ainsi que des informations sur les caractéristiques des surfaces. Le présent document s’applique à toutes les surfaces solides dans les salles propres et environnements maîtrisés apparentés telles que les murs, les plafonds, les sols, les environnements de travail, les outils, les équipements et les produits. Le mode opératoire d’évaluation de la propreté des surfaces par la concentration de particules (SCP) se limite à des tailles de particules comprises entre 0,05 µm et 500 µm. Le présent document n’aborde pas les points suivants: — les exigences pour la propreté et l’adéquation des surfaces à des processus spécifiques; — les modes opératoires de nettoyage des surfaces; — les caractéristiques des matériaux; — les références aux forces de liaison ou aux processus de génération qui sont généralement fonction du temps et qui dépendent du procédé; — le choix et l’utilisation de méthodes statistiques pour l’évaluation et les essais; — d’autres caractéristiques des particules, telles que la charge électrostatique, les charges ioniques et l’état microbiologique.
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INTERNATIONAL ISO
STANDARD 14644-9
Second edition
2022-05
Cleanrooms and associated controlled
environments —
Part 9:
Assessment of surface cleanliness for
particle concentration
Salles propres et environnements maîtrisés apparentés —
Partie 9: Évaluation de la propreté des surfaces en fonction de la
concentration de particules
Reference number
ISO 14644-9:2022(E)
© ISO 2022
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ISO 14644-9:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022
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
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Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
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ISO 14644-9:2022(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 2
5 The surface cleanliness level assessment system . 3
5.1 ISO-SCP grading level format . 3
5.2 Designation . 6
5.3 General information on surface cleanliness levels of particle concentration . 6
6 Demonstration of conformity .6
6.1 Principle . 6
6.2 Testing . 6
6.3 Test report . 7
Annex A (informative) Surface characteristics . 9
Annex B (informative) Descriptor for specific particle size ranges .12
Annex C (informative) Parameters influencing the SCP grading level assessments.15
Annex D (informative) Measurement methods for determining surface cleanliness by
particle concentration .17
Bibliography .26
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ISO 14644-9:2022(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 209, Cleanrooms and associated controlled
environments, in collaboration with the European Committee for Standardization (CEN) Technical
Committee CEN/TC 243, Cleanroom technology, in accordance with the Agreement on technical
cooperation between ISO and CEN (Vienna Agreement).
This second edition cancels and replaces the first edition (ISO 14644-9:2012), of which it constitutes a
minor revision. The changes are as follows:
— "Class" (classification, classified) has been changed to grade or assessment where appropriate;
— ISO 14644-6 has been removed from the opening text of Clause 3 and, as a result, Clause 2;
— entry 3.8 removed from Clause 3;
— ISO 4287 and ISO 4288 replaced by ISO 21920-2 and ISO 21920-3, respectively;
— ISO 16232-2, ISO 16232-3, ISO 16232-4 and ISO 16232-5 replaced by ISO 16232;
— minor editorial changes.
A list of all parts in the ISO 14644 series can be found on the ISO website.
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 14644-9:2022(E)
Introduction
Cleanrooms and associated controlled environments provide for the control of contamination to levels
appropriate for accomplishing contamination-sensitive activities. Products and processes that benefit
from the control of contamination include those in such industries as aerospace, microelectronics,
optics, nuclear and life sciences (pharmaceuticals, medical devices, food, healthcare).
ISO 14644-1 to ISO 14644-8, ISO 14698-1 and ISO 14698-2 deal exclusively with airborne particle
and chemical contamination. Many factors, besides the assessment of surface cleanliness, should
be considered in the design, specification, operation and control of cleanrooms and other controlled
environments. These factors are covered in some detail in other parts of ISO 14644 and ISO 14698.
This document provides an analytical process for the determination and designation of surface
cleanliness levels based on particle concentration. This document also lists some methods of testing, as
well as procedure(s) for determining the concentration of particles on surfaces.
Where regulatory agencies impose supplementary guidelines or restrictions, appropriate adaptations
of the testing procedures might be required.
NOTE When assessment of surface cleanliness by particle concentration (SCP) at critical control point(s) is
used as an additional cleanliness attribute to classification of air cleanliness by airborne particle concentration
in accordance with ISO 14644-1, then the space can be described as a cleanroom or clean-zone. If SCP is used
alone, then the space is described as a controlled zone.
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INTERNATIONAL STANDARD ISO 14644-9:2022(E)
Cleanrooms and associated controlled environments —
Part 9:
Assessment of surface cleanliness for particle
concentration
1 Scope
This document establishes a procedure for the assessment of particle cleanliness levels on solid surfaces
in cleanrooms and associated controlled environment applications. Recommendations on testing and
measuring methods, as well as information about surface characteristics, are given in Annexes A to D.
This document applies to all solid surfaces in cleanrooms and associated controlled environments, such
as walls, ceilings, floors, working environments, tools, equipment and products. The procedure for the
assessment of surface cleanliness by particle concentration (SCP) is limited to particles of between
0,05 µm and 500 µm.
The following issues are not considered in this document:
— requirements for the cleanliness and suitability of surfaces for specific processes;
— procedures for the cleaning of surfaces;
— material characteristics;
— references to interactive bonding forces or generation processes that are usually time-dependent
and process-dependent;
— selection and use of statistical methods for assessment and testing;
— other characteristics of particles, such as electrostatic charge, ionic charges and microbiological
state.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
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ISO 14644-9:2022(E)
3.1
descriptor for specific particle size ranges
differential descriptor that expresses surface cleanliness by particle concentration (SCP) level within
specific particle size ranges
Note 1 to entry: The descriptor may be applied to particle size ranges of special interest or those particle size
ranges that are outside the range of the grading system and specified independently or as a supplement to the
SCP levels.
3.2
direct measurement method
assessment of the contamination without any intermediate steps
3.3
indirect measurement method
assessment of the contamination with intermediate steps
3.4
solid surface
boundary between the solid and a second phase
3.5
surface particle
solid and/or liquid matter adhered and discretely distributed on a surface of interest, excluding film-
like matter that covers the whole surface
Note 1 to entry: Surface particles are adhered via chemical and/or physical interactions.
3.6
surface cleanliness by particle concentration
SCP
condition of a surface with respect to its particle concentration
Note 1 to entry: The surface cleanliness depends upon material and design characteristics, stress loads
(complexity of loads acting on a surface) and prevailing environmental conditions, along with other factors.
3.7
surface cleanliness by particle concentration level
SCP rating
grading number stating the maximum allowable surface concentration, in particles per square metre,
for a considered size of particles [surface cleanliness by particle concentration (SCP) grades 1 to 8],
where level 1 represents the cleanest level
3.8
surface particle concentration
number of individual particles per unit of surface area under consideration
4 Abbreviated terms
For the purposes of this document, the following abbreviated terms apply.
AFM atomic force microscopy
CNC condensation nucleus counter
EDX energy dispersive X-ray spectroscopy
ESCA electron spectroscopy for chemical analysis
ESD electrostatic discharge
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ISO 14644-9:2022(E)
IR infrared (absorption spectroscopy)
OPC optical particle counter
PET polyethylene terephthalate
SCP surface cleanliness by particle concentration
SEM scanning electron microscopy
UV ultraviolet (spectroscopy)
WDX wavelength-dispersive X-ray spectroscopy
5 The surface cleanliness level assessment system
5.1 ISO-SCP grading level format
The degree of SCP in a cleanroom or associated controlled environment shall be designated by a
cleanliness level grading number, N, specifying the maximum total particle concentration on surfaces
permitted for a considered particle size. N shall be determined from Formula (1) with the maximum
permitted total particle concentration on the surface, C , in particles per square metre of surface,
SCP;D
for each considered particle size, D:
N
10
Ck= (1)
SCP;D
D
where
C is the maximum permitted total surface concentration, in particles per square metre of
SCP;D
surface, of particles that are equal to or larger than the considered particle size; C is
SCP;D
rounded to the nearest whole number, using no more than three significant figures;
N is the SCP cleanliness level grading number, which is limited to SCP grade level 1 to SCP
grade level 8; the SCP grade level number N is qualified by the measured particle diameter
D, in micrometres;
NOTE N refers to the exponent base 10 for the concentration of particles at the reference
particle size of 1 µm.
D is the considered particle size, in micrometres;
k is a constant 1, in micrometres.
NOTE 1 The SCP grade level based on the particle concentration can be a time- and process-dependent value
due to the dynamic characteristics of particle generation and transportation.
NOTE 2 Due to the complexity of statistical evaluations and readily available additional references, the
selection and use of statistical methods for testing are not described in this document.
The concentration C , as derived from Formula (1), shall serve as the definitive value. Table 1
SCP;D
presents selected SCP grading levels and corresponding maximum cumulative permitted total surface
concentrations for considered particle sizes.
Figure 1 provides a representation of the selected surface particle grade levels in graphical form.
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ISO 14644-9:2022(E)
Table 1 — Selected SCP grading levels for cleanrooms and associated controlled environments
Units in particles per square metre
Particle size
SCP level
≥ 0,05 µm ≥ 0,1 µm ≥ 0,5 µm ≥ 1 µm ≥ 5 µm ≥ 10 µm ≥ 50 µm ≥ 100 µm ≥ 500 µm
SCP level 1 (200) 100 20 (10)
SCP level 2 (2 000) 1 000 200 100 (20) (10)
SCP level 3 (20 000) 10 000 2 000 1 000 (200) (100)
SCP level 4 (200 000) 100 000 20 000 10 000 2 000 1 000 (200) (100)
SCP level 5 1 000 000 200 000 100 000 20 000 10 000 2 000 1 000 (200)
SCP level 6 (10 000 000) 2 000 000 1 000 000 200 000 100 000 20 000 10 000 2 000
SCP level 7 10 000 000 2 000 000 1 000 000 200 000 100 000 20 000
SCP level 8 10 000 000 2 000 000 1 000 000 200 000
The values in Table 1 are concentrations of particles of the related particle size and SCP level per surface area of one square metre
2
(1 m ) equal to or larger than the considered particle size (C ).
SCP;D
For figures in parentheses, the corresponding particle sizes should not be used for level determination purposes; select another
particle size for more accurate determination.
The minimum area for testing should be statistically representative of the surface under consideration.
NOTE Assessment of the lower SCP levels requires numerous measurements to establish a significant value.
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ISO 14644-9:2022(E)
Key
X considered particle size, D (µm)
2
Y particle concentration on a surface ≥ D, C (particles/m )
SCP;D
1 SCP grade level 1
2 SCP grade level 2
3 SCP grade level 3
4 SCP grade level 4
5 SCP grade level 5
6 SCP grade level 6
7 SCP grade level 7
8 SCP grade level 8
The solid lines shown on the graph shall be used for level assessment purposes. The dashed lines should not be used
for level assessment purposes.
NOTE Particle distribution on surfaces typically is not a normal distribution, but is affected by different
factors, such as roughness, porosity, electrostatic charge and deposition mechanisms (see Annex A).
2 5
EXAMPLE SCP grade level 5 (1 µm) signifies that 1 m of surface may carry a maximum of 10 particles with
2
a considered particle size ≥ 1 µm (D = 1). SCP grade level 5 (10 µm) signifies that 1 m of surface may carry a
4
maximum of 10 particles per square metre with a considered particle size ≥ 10 µm (D = 10). Any other measured
particle size (D = x) which leads to a concentration that lies below the relevant SCP line is within the specification
of SCP grade level 5 (x µm).
Figure 1 — SCP grade levels
For particle sizes outside the limits of the level numbering system and in cases where only a narrow
particle range or individual particle sizes are of interest, a descriptor can be used (see Annex B).
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ISO 14644-9:2022(E)
5.2 Designation
The SCP grade level number shall be formatted as follows: SCP grade level N (D µm).
The designation of the SCP grade for cleanrooms and associated controlled environments shall also
include the following:
a) the surface type measured;
b) the surface area measured;
c) the measurement method applied.
Details of measurement methods applied, including sampling techniques and measurement devices,
should be retrieved from test reports.
The considered particle size should be determined by agreement between the customer and supplier.
The SCP grade level shall be stated in relation to the measured particle size diameter.
2
EXAMPLE 1 SCP grade level 2 (0,1 µm); wafer or glass substrate, surface area: 310 cm ; surface particle
counter.
2
EXAMPLE 2 SCP grade level 5 (0,5 μm); inner wall of a bottle, surface area: 200 cm ; liquid dispersion — liquid
particle counter.
5.3 General information on surface cleanliness levels of particle concentration
Airborne particle concentration and surface particle concentration are generally related. The
relationship is dependent on many factors, such as airflow turbulence, rate of deposition, time of
deposition, deposition velocity, concentration within the air and surface characteristics such as
electrostatic charge (see A.2.4).
To determine SCP, various parameters (see Annex C) and surface characteristics (see Annex A) that
influence testing should be taken into account.
6 Demonstration of conformity
6.1 Principle
Conformity with SCP grade cleanliness level requirements, as specified by the customer, is verified by
performing tests and by providing documentation of the results and conditions of the testing.
Details for demonstrating conformity (see 6.3) shall be agreed upon between the customer and supplier
in advance of testing.
6.2 Testing
Tests performed to demonstrate conformity shall be conducted in a controlled environment using
suitable test methods and calibrated instruments, whenever possible.
Direct and indirect test methods can be used for demonstrating conformity and are given in Annex D.
The list of typical methods described is not exhaustive. Alternative methods of comparable accuracy
may be specified by agreement.
NOTE Measurement by different methods, even when correctly applied, can produce different results of
equal validity.
Repeated measurements are recommended.
The test method and environment shall be agreed upon between the customer and supplier.
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ISO 14644-9:2022(E)
Precautions should be taken to reduce electrostatic charge around the test zone, since electrostatic
charge enhances particle deposition onto surfaces. If the surface is neither conductive, nor grounded
or charge-neutralized, electrostatic charges can occur (see Annex A). Therefore, test results can vary.
6.3 Test report
The results from testing each surface shall be recorded and submitted as a comprehensive report, along
with a statement of conformity or non-conformity with the specified SCP grade levels.
The test report shall include as a minimum the following:
a) basic data:
— date and time of testing;
— name and address of the testing organization;
— name of testing personnel;
b) references consulted:
— standards;
— guidelines;
— regulations;
— number and year of publication of this document, i.e. ISO 14644-9:2022;
c) environmental data:
— environmental conditions for sampling (i.e. temperature, humidity, cleanliness);
— environmental conditions for measurement (i.e. temperature, humidity, cleanliness) (not
essential for use with direct methods);
— location (e.g. room) used for the measurements;
d) specimen:
— clear identification of the test object;
— description of the test object;
— graph and/or sketch of the test specimen;
e) test setup:
— photo and/or sketch of the test setup;
— description of operating parameters;
— description of measurement points;
— description of hardware used in the test setup;
f) measurement devices:
— identification of the instrument(s) and measuring devices used and current calibration
certificate(s);
— measurement range of measuring devices used;
— reference of calibration certificates;
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ISO 14644-9:2022(E)
g) performing the test:
— relevant details of the test procedure used, with any available data describing deviations from
the test procedure (if agreed);
— surface condition before sampling (e.g. after cleaning, after packaging, under atmospheric or
vacuum conditions);
— specified test and measurement procedure or method;
— occupancy state(s) during sampling and measurement;
— specified test method(s);
— all agreed documentation (e.g. raw data, background particle concentrations, pictures, graphs,
cleaning and packaging);
— duration, location and position of sampling (not essential for use with direct methods);
— duration, location and position of measurement (not essential for use with direct methods);
— noticeable observations made during sampling or measurement, where applicable;
— number of measurements performed;
— clear identification of the position and the area of the surface measured and specific designations
for coordinates of the surface, if applicable;
h) results and analysis:
— visual inspection of the test surface before and after measurement, where applicable;
— measurement values and/or their analysis;
— statement of data quality;
— particle size ranges considered;
— test results, including particle concentration data for given particle sizes, for all tests performed;
— SCP grading level with designation expressed as SCP cleanliness grade level N;
— acceptance criteria for the clean surface, if agreed between the customer and the supplier.
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ISO 14644-9:2022(E)
Annex A
(informative)
Surface characteristics
A.1 Surface description
A surface is commonly characterized by its texture (such as roughness, porosity), its mechanical
properties (such as hardness) and its physicochemical properties (such as electrostatic surface charge
and surface tension). Each of these properties should be considered before selecting a test method for
the surface cleanliness assessment, or as an aid for the interpretation of the test results.
A.2 Surface characteristics
A.2.1 Roughness
A.2.1.1 Description
As the roughness of a surface affects many of its physical properties, surface roughness is not easily
described by one single parameter, nor is it an intrinsic property of the surface. Roughness exists in
two principal planes: at right angles to the surface, where it may be characterized by height, and in the
plane of the surface, identified as “texture” and characterized by waviness. The roughness of a surface
can be determined by mechanical or optical methods.
A.2.1.2 Testing
A frequently used mechanical method for the determination of roughness is the stylus instrument (see,
for example, ISO 21920-2 or ISO 21920-3).
Frequently used optical methods for the determination of roughness and porous texture are
microscopes (optical, confocal, interferometry, with or without tunnel effect, taper sectioning).
A.2.2 Porosity
A.2.2.1 Definition and description
Porosity is a measure of the void spaces in a material and is expressed as a decimal between 0 and 1, or
as a percentage between 0 % and 100 %.
— Effective porosity (also called open porosity) refers to the fraction of the total volume in which
fluid flow is effectively taking place (this excludes dead-end pores or non-connected cavities).
— Macroporosity refers to pores equal to or greater than 50 nm in diameter. Fluid flow through
macropores is described by bulk diffusion.
— Mesoporosity refers to pores equal to or greater than 2 nm but less than 50 nm in diameter.
— Microporosity refers to pores smaller than 2 nm in diameter. Movement in micropores is by
activated diffusion.
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ISO 14644-9:2022(E)
A.2.2.2 Testing
There are several ways to estimate the porosity of a given material or mixture of materials, which is
called material matrix.
The volume/density method is fast and highly accurate (normally within ± 2 % of the actual porosity).
The volume and the weight of the material are measured. The weight of the material divided by the
density of the material gives the volume that the material takes up, minus the pore volume. Therefore,
the pore volume is simply equal to the total volume minus the material volume, i.e. (pore volume) = (total
volume) − (material volume).
The water saturation method is slightly more difficult but is more accurate and more direct. Take a
known volume of the material and a known volume of water. Slowly dump the material into the water
and allow it to saturate while pouring. Allow it to sit for a few hours to ensure that the material is fully
saturated. Then remove the unsaturated water from the top of the beaker and measure its volume.
The total volume of the water originally in the beaker minus the volume of water not saturated is the
volume of the pore space, i.e. (pore volume) = (total volume of water) − (unsaturated water).
Mercury intrusion porosimetry requires the sample to be placed in a special filling device that allows
the sample to be evacuated, followed by the introduction of liquid mercury. The size of the mercury
envelope is then measured as a function of increased applied pressure. The greater the applied pressure,
the smaller the pore entered by mercury. Typically, this method is used over the range of pores from
300 µm to 0,0 035 µm. Because of increased safety concerns over the use of mercury, several non-
mercury intrusion techniques have been developed and should be considered as alternatives.
Nitrogen gas adsorption is used to determine fine porosity in materials. In very small pores, nitrogen
gas condenses on pore walls that are less than 0,090 µm in diameter. This condensation is measured
either by volume or weight.
A.2.3 Hardness
There are many National and International Standards on hardness tests for each material type.
Hardness is frequently measured by the penetrating force of a diamond ball or tip, by the indentation of
a hard body or by the rebound properties of an impactor.
The Rockwell, Brinell, Shore and Vickers method for metals is covered by ASTM E18-07. Geometry
and pressure are chosen at the beginning of the test as a function of the thickness of the sample, the
composition of the metal and the supposed hardness.
A.2.4 Static electricity
A.2.4.1 Definition and description
Static electricity is defi
...
NORME ISO
INTERNATIONALE 14644-9
Deuxième édition
2022-05
Salles propres et environnements
maîtrisés apparentés —
Partie 9:
Évaluation de la propreté des surfaces
en fonction de la concentration de
particules
Cleanrooms and associated controlled environments —
Part 9: Assessment of surface cleanliness for particle concentration
Numéro de référence
ISO 14644-9:2022(F)
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ISO 14644-9:2022(F)
DOCUMENT PROTÉGÉ PAR COPYRIGHT
© ISO 2022
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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Publié en Suisse
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ISO 14644-9:2022(F)
Sommaire Page
Avant-propos .iv
Introduction .v
1 Domaine d’application . 1
2 Références normatives .1
3 Termes et définitions . 1
4 Termes abrégés . 2
5 Système d’évaluation du niveau de propreté des surfaces . 3
5.1 Format du niveau de gradation SCP de l’ISO . 3
5.2 Désignation . 6
5.3 Informations générales sur les niveaux de propreté de surface en fonction de la
concentration de particules . 6
6 Démonstration de la conformité . 6
6.1 Principe . 6
6.2 Essais . 6
6.3 Rapport d’essai . 7
Annexe A (informative) Caractéristiques des surfaces . 9
Annexe B (informative) Descripteur pour des domaines granulométriques spécifiques.12
Annexe C (informative) Paramètres influençant l’évaluation des niveaux de gradation SCP.15
Annexe D (informative) Méthodes de mesurage pour la détermination de la propreté des
surfaces par la concentration particulaire.17
Bibliographie .26
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ISO 14644-9:2022(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 209, Salles propres et environnements
maîtrisés apparentés, en collaboration avec le comité technique CEN/TC 243, Technologie des salles
propres, du Comité européen de normalisation (CEN) conformément à l’Accord de coopération technique
entre l’ISO et le CEN (Accord de Vienne).
Cette deuxième édition annule et remplace la première édition (ISO 14644-9:2012), dont elle constitue
une révision mineure. Les modifications sont les suivantes:
— «classe» (classification, classifié) a été remplacé par grade ou évaluation, le cas échéant;
— l’ISO 14644-6 a été supprimée du texte d’introduction de l’Article 3 et, par conséquent, de l’Article 2;
— l’entrée 3.8 a été supprimée de l’Article 3;
— ISO 4287 et ISO 4288 remplacées respectivement par ISO 21920-2 et ISO 21920-3;
— ISO 16232-2, ISO 16232-3, ISO 16232-4 et ISO 16232-5 remplacées par l'ISO 16232;
— modifications rédactionnelles mineures.
Une liste de toutes les parties de la série ISO 14644 se trouve sur le site web de l’ISO.
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 14644-9:2022(F)
Introduction
Les salles propres et environnements maîtrisés apparentés permettent la maîtrise de la contamination
à des niveaux appropriés pour mener des activités sensibles à la contamination. Parmi les produits
et procédés qui bénéficient de cette maîtrise de la contamination figurent entre autres ceux de
l’industrie aérospatiale, de la micro-électronique, de l’optique, du nucléaire et des sciences biologiques
(produits pharmaceutiques, appareils médicaux, agroalimentaire et santé).
L’ISO 14644-1 à l’ISO 14644-8, l’ISO 14698-1 et l’ISO 14698-2 traitent exclusivement des particules en
suspension dans l’air et de la contamination chimique. Outre l’évaluation de la propreté des surfaces,
il convient de prendre en considération bien d’autres facteurs en vue de la conception, de la spécification,
de l’exploitation et de la maîtrise des salles propres et environnements maîtrisés apparentés.
Ces facteurs sont traités plus en détail dans d’autres parties de l’ISO 14644 et de l’ISO 14698.
Le présent document fournit un processus d’analyse pour la détermination et la désignation des niveaux
de propreté des surfaces fondée sur la concentration particulaire. Le présent document énumère
également un certain nombre de méthodes d’essai ainsi qu’un ou des modes opératoires permettant de
déterminer la concentration particulaire sur les surfaces.
Lorsque des organismes de réglementation imposent des principes directeurs ou des restrictions
supplémentaires, des adaptations des modes opératoires d’essai peuvent s’avérer nécessaires.
NOTE Lorsque l’évaluation de la propreté des surfaces par la concentration de particules (SCP) au(x) point(s)
de contrôle critique(s) est utilisée comme attribut de propreté supplémentaire à la classification de la propreté
de l’air par la concentration de particules en suspension dans l’air conformément à l’ISO 14644-1, l’espace peut
être décrit comme une salle propre ou une zone propre. Si la SCP est utilisée seule, alors l’espace est décrit comme
une zone maîtrisée.
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NORME INTERNATIONALE ISO 14644-9:2022(F)
Salles propres et environnements maîtrisés apparentés —
Partie 9:
Évaluation de la propreté des surfaces en fonction de la
concentration de particules
1 Domaine d’application
Le présent document établit un mode opératoire pour l’évaluation des niveaux de propreté particulaire
des surfaces solides, applicables aux salles propres et aux environnements maîtrisés apparentés.
Les Annexes A à D fournissent des recommandations relatives aux essais et aux méthodes de mesurage,
ainsi que des informations sur les caractéristiques des surfaces.
Le présent document s’applique à toutes les surfaces solides dans les salles propres et environnements
maîtrisés apparentés telles que les murs, les plafonds, les sols, les environnements de travail, les
outils, les équipements et les produits. Le mode opératoire d’évaluation de la propreté des surfaces par
la concentration de particules (SCP) se limite à des tailles de particules comprises entre 0,05 µm et
500 µm.
Le présent document n’aborde pas les points suivants:
— les exigences pour la propreté et l’adéquation des surfaces à des processus spécifiques;
— les modes opératoires de nettoyage des surfaces;
— les caractéristiques des matériaux;
— les références aux forces de liaison ou aux processus de génération qui sont généralement fonction
du temps et qui dépendent du procédé;
— le choix et l’utilisation de méthodes statistiques pour l’évaluation et les essais;
— d’autres caractéristiques des particules, telles que la charge électrostatique, les charges ioniques et
l’état microbiologique.
2 Références normatives
Le présent document ne contient aucune référence normative.
3 Termes et définitions
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 https:// www .electropedia .org/
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ISO 14644-9:2022(F)
3.1
descripteur pour des domaines granulométriques spécifiques
descripteur différentiel exprimant le niveau de propreté des surfaces par la concentration de particules
(SCP) pour des domaines granulométriques spécifiques
Note 1 à l'article: Le descripteur peut être appliqué à des domaines granulométriques revêtant un intérêt
particulier ou à des granulométries qui ne s’inscrivent pas dans le domaine pris en compte par le système de
gradation, et qui sont spécifiées de manière séparée ou en complément aux niveaux de SCP.
3.2
méthode de mesurage directe
évaluation de la contamination sans étapes intermédiaires
3.3
méthode de mesurage indirecte
évaluation de la contamination avec des étapes intermédiaires
3.4
surface solide
limite entre le solide et une seconde phase
3.5
particule de surface
matière solide et/ou liquide qui adhère et qui est discrètement répartie sur la surface d’intérêt, à
l’exclusion du film qui couvre l’ensemble de la surface
Note 1 à l'article: Les particules de surface adhèrent par des interactions chimiques et/ou physiques.
3.6
propreté de surface par la concentration de particules
propreté de surface par la concentration particulaire
SCP
état d’une surface eu égard à sa concentration en particules
Note 1 à l'article: La propreté de la surface dépend des caractéristiques de matériau et de conception, des
charges de contraintes appliquées (complexité des forces agissant sur une surface donnée) et des paramètres
environnementaux, en complément d’autres facteurs.
3.7
niveau de propreté d’une surface par la concentration de particules
niveau de SCP
indice de gradation indiquant la concentration maximale admissible sur une surface, en particules
par mètre carré, pour une taille de particule donnée [grades 1 à 8 de propreté de surface par la
concentration de particules (SCP)], le niveau 1 représentant le niveau le plus propre
3.8
concentration particulaire de surface
nombre de particules individuelles par unité de surface de la surface considérée
4 Termes abrégés
Pour les besoins du présent document, les termes abrégés suivants s’appliquent.
AFM microscopie à force atomique (atomic force microscopy)
CNC compteur de noyaux de condensation
EDX spectroscopie X à dispersion d’énergie (energy dispersive X-ray spectroscopy)
ESCA spectroscopie électronique pour l’analyse chimique (electron spectroscopy for chemical analysis)
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ISO 14644-9:2022(F)
ESD décharge électrostatique (electrostatic discharge)
IR infrarouge (spectroscopie d’absorption)
MEB microscopie électronique à balayage
OPC compteur optique de particules (optical particle counter)
PET polyéthylène téréphtalate
SCP propreté de surface par la concentration de particules (surface cleanliness by particle concen-
tration)
UV ultraviolet (spectroscopie)
WDX spectroscopie X à dispersion de longueur d’onde (wavelength-dispersive X-ray spectroscopy)
5 Système d’évaluation du niveau de propreté des surfaces
5.1 Format du niveau de gradation SCP de l’ISO
Le degré de SCP dans une salle propre ou un environnement maîtrisé apparenté doit être désigné par un
numéro de gradation du niveau de propreté, N, spécifiant la concentration particulaire totale maximale
sur la surface admise pour chaque taille de particule considérée. N doit être déterminé à partir de
la Formule (1) qui exprime la valeur maximale de la concentration particulaire totale admise sur la
surface, C , en particules par mètre carré de surface, pour chaque taille de particule considérée, D:
SCP;D
N
10
Ck= (1)
SCP;D
D
où
C est la concentration de surface totale maximale admissible (en particules par mètre carré
SCP;D
de surface) des particules de taille supérieure ou égale à la taille de particule considérée;
C est arrondie à l’entier le plus proche, en se limitant à trois chiffres significatifs;
SCP;D
N est le numéro de gradation du niveau de propreté SCP, allant du niveau 1 de grade SCP au
niveau 8 de grade SCP. Le numéro N du niveau de grade SCP est qualifié par le diamètre de
particule, D, mesuré en micromètres;
NOTE N fait référence à l’exposant en base décimale pour la concentration de particules à
la taille de particule de référence de 1 µm.
D est la taille de particule considérée, en micromètres;
k est une constante égale à 1, en micromètres.
NOTE 1 Du fait des caractéristiques dynamiques de la génération et du transport des particules, le niveau de
grade SCP fondé sur la concentration particulaire peut être une valeur qui dépend du temps et du processus.
NOTE 2 Du fait de la complexité des évaluations statistiques et de références bibliographiques supplémentaires
facilement disponibles, le choix et l’utilisation de méthodes statistiques pour les essais ne sont pas décrits dans le
présent document.
La concentration C , calculée par la Formule (1), doit servir de valeur définitive. Le Tableau 1
SCP;D
présente les niveaux de gradation SCP sélectionnés et la valeur cumulée maximale des concentrations
particulaires surfaciques correspondantes pour les tailles de particules considérées.
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ISO 14644-9:2022(F)
La Figure 1 donne une représentation graphique des niveaux de grade retenus pour les particules de
surface.
Tableau 1 — Niveaux de gradation SCP retenus pour les salles propres et environnements
maîtrisés apparentés
Unités en particules par mètre carré
Taille de particule
Niveau de
SCP
≥ 0,05 µm ≥ 0,1 µm ≥ 0,5 µm ≥ 1 µm ≥ 5 µm ≥ 10 µm ≥ 50 µm ≥ 100 µm ≥ 500 µm
Niveau SCP 1 (200) 100 20 (10)
Niveau SCP 2 (2 000) 1 000 200 100 (20) (10)
Niveau SCP 3 (20 000) 10 000 2 000 1 000 (200) (100)
Niveau SCP 4 (200 000) 100 000 20 000 10 000 2 000 1 000 (200) (100)
Niveau SCP 5 1 000 000 200 000 100 000 20 000 10 000 2 000 1 000 (200)
Niveau SCP 6 (10 000 000) 2 000 000 1 000 000 200 000 100 000 20 000 10 000 2 000
Niveau SCP 7 10 000 000 2 000 000 1 000 000 200 000 100 000 20 000
Niveau SCP 8 10 000 000 2 000 000 1 000 000 200 000
2
Les valeurs du Tableau 1 sont les concentrations, pour la taille de particules et le niveau de SCP considéré pour une surface d’un mètre carré (1 m ), en
particules de taille supérieure ou égale à la taille de particules considérée (C ).
SCP;D
Pour ce qui concerne les chiffres entre parenthèses, il convient de ne pas utiliser pour la détermination du niveau les tailles de particules correspondantes;
choisir une autre taille de particule pour une détermination plus précise.
Il convient que la surface d’essai minimale soit, d’un point de vue statistique, représentative de la surface considérée.
NOTE L’évaluation des niveaux de SCP inférieurs nécessite de multiples mesures pour pouvoir obtenir une valeur significative.
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ISO 14644-9:2022(F)
Légende
X taille de particule considérée, D (µm)
2
Y concentration surfacique en particules ≥ D, C (particules/m )
SCP;D
1 niveau 1 de grade SCP
2 niveau 2 de grade SCP
3 niveau 3 de grade SCP
4 niveau 4 de grade SCP
5 niveau 5 de grade SCP
6 niveau 6 de grade SCP
7 niveau 7 de grade SCP
8 niveau 8 de grade SCP
Les lignes pleines présentées sur le graphique doivent être utilisées aux fins de l’évaluation des niveaux. Il convient
de ne pas utiliser les lignes en pointillés à des fins d’évaluation des niveaux.
NOTE De manière générale, la distribution des particules sur les surfaces n’est pas une distribution normale,
mais elle est affectée par différents facteurs tels que la rugosité, la porosité, la charge électrostatique et les
mécanismes de dépôt (voir Annexe A).
2
EXEMPLE Le niveau 5 de grade SCP (1 µm) signifie que 1 m de surface peut porter au maximum
5 2
10 particules d’une taille considérée ≥ 1 µm (D = 1). Le niveau 5 de grade SCP (10 µm) signifie que 1 m de
4
surface peut porter au maximum 10 particules par mètre carré d’une taille de particule considérée ≥ 10 µm
(D = 10). Toute autre taille de particule mesurée (D = x) donnant lieu à une concentration s’inscrivant au-dessous
de la ligne SCP appropriée, répond à la spécification du niveau 5 de grade SCP (x µm).
Figure 1 — Niveaux de grade SCP
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ISO 14644-9:2022(F)
Pour les tailles de particules en dehors des limites du système de numérotation des niveaux et dans les
cas où seulement une gamme étroite de particules ou des tailles de particules individuelles sont d’un
intérêt particulier, un descripteur peut être utilisé (voir l’Annexe B).
5.2 Désignation
Le numéro du niveau de grade SCP doit être noté selon le format suivant: niveau N de grade SCP (D µm).
La désignation du grade SCP pour des salles propres et environnements maîtrisés apparentés doit
également inclure les informations suivantes:
a) le type de surface mesuré;
b) la surface mesurée;
c) la méthode de mesurage appliquée.
Il convient que les détails relatifs aux méthodes de mesurage appliquées, y compris les techniques
d’échantillonnage et les appareils de mesure, soient extraits des rapports d’essais.
Il convient que la taille de particule prise en considération soit convenue par accord entre le client et le
fournisseur.
Le niveau de grade SCP doit être indiqué par rapport au diamètre particulaire mesuré.
2
EXEMPLE 1 Niveau 2 de grade SCP (0,1 µm); plaque ou substrat en verre, surface: 310 cm ; compteur de
particules de surface.
2
EXEMPLE 2 Niveau 5 de grade SCP (0,5 µm); paroi intérieure d’un flacon, surface: 200 cm ; compteur de
particules liquides — dispersion de liquide.
5.3 Informations générales sur les niveaux de propreté de surface en fonction de la
concentration de particules
La concentration de particules en suspension dans l’air et la concentration particulaire de surface sont
en général liées. La relation est dépendante de nombreux facteurs, tels que la turbulence du flux d’air, le
taux du dépôt, la durée du dépôt, la vitesse du dépôt, la concentration dans l’air, et les caractéristiques
de surface telles que la charge électrostatique (voir A.2.4).
Pour déterminer la SCP, il convient que divers paramètres (voir Annexe C) et caractéristiques de surface
(voir Annexe A) qui influencent les essais soient pris en compte.
6 Démonstration de la conformité
6.1 Principe
La conformité aux exigences relatives au niveau de propreté du grade SCP, telles que spécifiées par le
client, est vérifiée en effectuant des essais et en fournissant la documentation relative aux résultats et
aux conditions d’essais.
Les détails concernant la démonstration de la conformité (voir 6.3) doivent être soumis à accord avant
les essais entre le client et le fournisseur.
6.2 Essais
Les essais réalisés pour démontrer la conformité doivent être menés en environnement maîtrisé, en
utilisant, dans la mesure du possible, des méthodes d’essais appropriées et des instruments étalonnés.
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ISO 14644-9:2022(F)
Des méthodes d’essais directes et indirectes peuvent être utilisées pour démontrer la conformité et sont
indiquées en Annexe D. La liste des méthodes types décrites n’est pas exhaustive. D’autres méthodes
ayant une exactitude comparable peuvent être spécifiées sous réserve d’un accord.
NOTE Des mesurages effectués selon des méthodes différentes, même correctement appliquées, peuvent
donner des résultats différents, mais tout aussi valables.
Il est recommandé d’effectuer des mesurages répétés.
La méthode et l’environnement d’essai doivent être convenus entre le client et le fournisseur.
Il convient de prendre les mesures nécessaires pour réduire la charge électrostatique autour de la zone
d’essai, car la charge électrostatique favorise les dépôts de particules sur les surfaces. Des charges
électrostatiques peuvent apparaître si la surface n’est pas conductrice, ni mise à la terre ni encore à
charge neutralisée (voir Annexe A). Des résultats d’essais différents peuvent donc être obtenus.
6.3 Rapport d’essai
Les résultats des essais effectués sur chaque surface doivent être enregistrés et remis sous forme de
rapport détaillé avec une déclaration de conformité ou de non-conformité aux niveaux de grade SCP
spécifiés.
Le rapport d’essai doit au minimum comporter les informations suivantes:
a) données générales:
— la date et l’heure de l’essai;
— le nom et l’adresse de l’organisme chargé des essais;
— le nom du personnel chargé des essais;
b) références consultées:
— les normes;
— les guides d’application;
— la réglementation;
— le numéro et l’année de publication du présent document, c’est-à-dire ISO 14644-9:2022;
c) données environnementales:
— les conditions ambiantes d’échantillonnage (c’est-à-dire température, humidité, propreté);
— les conditions ambiantes de mesurage (c’est-à-dire température, humidité, propreté)
(non essentielles lorsqu’il s’agit de méthodes directes);
— l’endroit (salle, par exemple) utilisé pour les mesurages;
d) échantillon:
— l’identification claire de la surface soumise à essai;
— la description de la surface soumise à essai;
— le graphique et/ou le croquis de l’échantillon d’essai;
e) environnement d’essai:
— la photo et/ou le graphique de l’environnement d’essai;
— la description des paramètres de fonctionnement;
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ISO 14644-9:2022(F)
— la description des points de mesurage;
— la description du matériel utilisé dans l’environnement d’essai;
f) dispositifs de mesurage:
— l’identification de l’instrument ou des instruments et des dispositifs de mesurage utilisés ainsi
que le ou les certificats d’étalonnage correspondants en cours de validité;
— l’étendue de mesurage des appareils de mesure utilisés;
— la référence des certificats d’étalonnage;
g) réalisation de l’essai:
— les détails pertinents quant au mode opératoire d’essai utilisé, en fournissant les éventuelles
données disponibles décrivant des écarts par rapport au mode opératoire d’essai
(si préalablement convenus);
— l’état de la surface avant le prélèvement (par exemple, après nettoyage, après conditionnement,
sous conditions atmosphériques ou sous vide);
— l’essai spécifié et le mode opératoire ou la méthode de mesurage;
— l’état ou les états d’occupation lors de l’échantillonnage et des mesurages;
— la ou les méthodes d’essais spécifiées;
— l’ensemble des documents convenus (par exemple des données brutes, l’historique des
concentrations particulaires, des photographies, des graphiques, le nettoyage et le
conditionnement);
— la durée, le lieu et l’emplacement de l’échantillonnage (non essentiels lorsqu’il s’agit de méthodes
directes);
— la durée, le lieu et l’emplacement du mesurage (non essentiels lorsqu’il s’agit de méthodes
directes);
— observations apparentes faites pendant l’échantillonnage ou le mesurage, s’il y a lieu;
— le nombre de mesurages effectués;
— l’identification claire de l’emplacement et de la surface mesurée et, le cas échéant, les désignations
spécifiques des coordonnées de la surface;
h) résultats et analyse:
— l’inspection visuelle de la surface d’essai avant et après le mesurage, s’il y a lieu;
— les valeurs de mesurage et/ou leur analyse;
— le rapport de qualité des données;
— les gammes de dimension particulaire considérées;
— les résultats d’essai, y compris les données relatives à la concentration particulaire, pour les
tailles des particules concernées, pour tous les essais effectués;
— le niveau de gradation SCP avec une désignation exprimée sous la forme niveau N de grade de
propreté SCP;
— les critères d’acceptation de la surface propre, s’ils ont été convenus entre le client et
le fournisseur.
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ISO 14644-9:2022(F)
Annexe A
(informative)
Caractéristiques des surfaces
A.1 Description des surfaces
Une surface est en général caractérisée par sa texture (par exemple, la rugosité, la porosité), ses
propriétés mécaniques (par exemple, la dureté) et ses propriétés physico-chimiques (par exemple,
la charge électrostatique et la tension superficielle). Il convient de tenir compte de chacune de ces
propriétés avant de choisir une méthode d’essai pour l’évaluation de la propreté de surface, ou pour
l’interprétation des résultats d’essai.
A.2 Caractéristiques des surfaces
A.2.1 Rugosité
A.2.1.1 Description
Étant donné que la rugosité d’une surface affecte de nombreuses propriétés physiques, il est peu aisé
de décrire cette rugosité au moyen d’un seul paramètre, par ailleurs il ne s’agit pas d’une propriété
intrinsè
...
FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 14644-9
ISO/TC 209
Cleanrooms and associated controlled
Secretariat: ANSI
environments —
Voting begins on:
2021-12-14
Part 9:
Voting terminates on:
Assessment of surface cleanliness for
2022-03-08
particle concentration
ISO/CEN PARALLEL PROCESSING
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 14644-9:2021(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS. © ISO 2021
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ISO/FDIS 14644-9:2021(E)
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© ISO 2021
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ISO/FDIS 14644-9:2021(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 2
5 The surface cleanliness level assessment system . 3
5.1 ISO-SCP grading level format . 3
5.2 Designation . 6
5.3 General information on surface cleanliness levels of particle concentration . 6
6 Demonstration of conformity .6
6.1 Principle . 6
6.2 Testing . 6
6.3 Test report . 7
Annex A (informative) Surface characteristics . 9
Annex B (informative) Descriptor for specific particle size ranges .12
Annex C (informative) Parameters influencing the SCP grading level assessments.15
Annex D (informative) Measurement methods for determining surface cleanliness by
particle concentration .17
Bibliography .26
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ISO/FDIS 14644-9:2021(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 209, Cleanrooms and associated controlled
environments, in collaboration with the European Committee for Standardization (CEN) Technical
Committee CEN/TC 243, Cleanroom technology, in accordance with the Agreement on technical
cooperation between ISO and CEN (Vienna Agreement).
This second edition cancels and replaces the first edition (ISO 14644-9:2012), of which it constitutes a
minor revision. The changes are as follows:
— "Class" (classification, classified) has been changed to grade or assessment where appropriate;
— ISO 14644-6 has been removed from the opening text of Clause 3 and, as a result, Clause 2;
— entry 3.8 removed from Clause 3;
— minor editorial changes.
A list of all parts in the ISO 14644 series can be found on the ISO website.
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 14644-9:2021(E)
Introduction
Cleanrooms and associated controlled environments provide for the control of contamination to levels
appropriate for accomplishing contamination-sensitive activities. Products and processes that benefit
from the control of contamination include those in such industries as aerospace, microelectronics,
optics, nuclear and life sciences (pharmaceuticals, medical devices, food, healthcare).
ISO 14644-1 to ISO 14644-8, ISO 14698-1 and ISO 14698-2 deal exclusively with airborne particle
and chemical contamination. Many factors, besides the assessment of surface cleanliness, should
be considered in the design, specification, operation and control of cleanrooms and other controlled
environments. These factors are covered in some detail in other parts of ISO 14644 and ISO 14698.
This document provides an analytical process for the determination and designation of surface
cleanliness levels based on particle concentration. This document also lists some methods of testing, as
well as procedure(s) for determining the concentration of particles on surfaces.
Where regulatory agencies impose supplementary guidelines or restrictions, appropriate adaptations
of the testing procedures might be required.
NOTE When assessment of surface cleanliness by particle concentration (SCP) at critical control point(s) is
used as an additional cleanliness attribute to classification of air cleanliness by airborne particle concentration
in accordance with ISO 14644-1, then the space can be described as a cleanroom or clean-zone. If SCP is used
alone, then the space is described as a controlled zone.
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FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 14644-9:2021(E)
Cleanrooms and associated controlled environments —
Part 9:
Assessment of surface cleanliness for particle
concentration
1 Scope
This document establishes a procedure for the assessment of particle cleanliness levels on solid surfaces
in cleanrooms and associated controlled environment applications. Recommendations on testing and
measuring methods, as well as information about surface characteristics, are given in Annexes A to D.
This document applies to all solid surfaces in cleanrooms and associated controlled environments, such
as walls, ceilings, floors, working environments, tools, equipment and products. The procedure for the
assessment of surface cleanliness by particle concentration (SCP) is limited to particles of between
0,05 µm and 500 µm.
The following issues are not considered in this document:
— requirements for the cleanliness and suitability of surfaces for specific processes;
— procedures for the cleaning of surfaces;
— material characteristics;
— references to interactive bonding forces or generation processes that are usually time-dependent
and process-dependent;
— selection and use of statistical methods for assessment and testing;
— other characteristics of particles, such as electrostatic charge, ionic charges and microbiological
state.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
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ISO/FDIS 14644-9:2021(E)
3.1
descriptor for specific particle size ranges
differential descriptor that expresses surface cleanliness by particle concentration (SCP) level within
specific particle size ranges
Note 1 to entry: The descriptor may be applied to particle size ranges of special interest or those particle size
ranges that are outside the range of the grading system and specified independently or as a supplement to the
SCP levels.
3.2
direct measurement method
assessment of the contamination without any intermediate steps
3.3
indirect measurement method
assessment of the contamination with intermediate steps
3.4
solid surface
boundary between the solid and a second phase
3.5
surface particle
solid and/or liquid matter adhered and discretely distributed on a surface of interest, excluding film-
like matter that covers the whole surface
Note 1 to entry: Surface particles are adhered via chemical and/or physical interactions.
3.6
surface cleanliness by particle concentration
SCP
condition of a surface with respect to its particle concentration
Note 1 to entry: The surface cleanliness depends upon material and design characteristics, stress loads
(complexity of loads acting on a surface) and prevailing environmental conditions, along with other factors.
3.7
surface cleanliness by particle concentration level
SCP rating
grading number stating the maximum allowable surface concentration, in particles per square metre,
for a considered size of particles [surface cleanliness by particle concentration (SCP) grades 1 to 8],
where level 1 represents the cleanest level
3.8
surface particle concentration
number of individual particles per unit of surface area under consideration
4 Abbreviated terms
For the purposes of this document, the following abbreviated terms apply.
AFM atomic force microscopy
CNC condensation nucleus counter
EDX energy dispersive X-ray spectroscopy
ESCA electron spectroscopy for chemical analysis
ESD electrostatic discharge
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ISO/FDIS 14644-9:2021(E)
IR infrared (absorption spectroscopy)
OPC optical particle counter
PET polyethylene terephthalate
SCP surface cleanliness by particle concentration
SEM scanning electron microscopy
UV ultraviolet (spectroscopy)
WDX wavelength-dispersive X-ray spectroscopy
5 The surface cleanliness level assessment system
5.1 ISO-SCP grading level format
The degree of SCP in a cleanroom or associated controlled environment shall be designated by a
cleanliness level grading number, N, specifying the maximum total particle concentration on surfaces
permitted for a considered particle size. N shall be determined from Formula (1) with the maximum
permitted total particle concentration on the surface, C , in particles per square metre of surface,
SCP;D
for each considered particle size, D:
N
10
Ck= (1)
SCP;D
D
where
C is the maximum permitted total surface concentration, in particles per square metre of
SCP;D
surface, of particles that are equal to or larger than the considered particle size; C is
SCP;D
rounded to the nearest whole number, using no more than three significant figures;
N is the SCP cleanliness level grading number, which is limited to SCP grade level 1 to SCP
grade level 8; the SCP grade level number N is qualified by the measured particle diameter
D, in micrometres;
NOTE N refers to the exponent base 10 for the concentration of particles at the reference
particle size of 1 µm.
D is the considered particle size, in micrometres;
k is a constant 1, in micrometres.
NOTE 1 The SCP grade level based on the particle concentration can be a time- and process-dependent value
due to the dynamic characteristics of particle generation and transportation.
NOTE 2 Due to the complexity of statistical evaluations and readily available additional references, the
selection and use of statistical methods for testing are not described in this document.
The concentration C , as derived from Formula (1), shall serve as the definitive value. Table 1
SCP;D
presents selected SCP grading levels and corresponding maximum cumulative permitted total surface
concentrations for considered particle sizes.
Figure 1 provides a representation of the selected surface particle grade levels in graphical form.
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ISO/FDIS 14644-9:2021(E)
Table 1 — Selected SCP grading levels for cleanrooms and associated controlled environments
Units in particles per square metre
Particle size
SCP level
≥ 0,05 µm ≥ 0,1 µm ≥ 0,5 µm ≥ 1 µm ≥ 5 µm ≥ 10 µm ≥ 50 µm ≥ 100 µm ≥ 500 µm
SCP level 1 (200) 100 20 (10)
SCP level 2 (2 000) 1 000 200 100 (20) (10)
SCP level 3 (20 000) 10 000 2 000 1 000 (200) (100)
SCP level 4 (200 000) 100 000 20 000 10 000 2 000 1 000 (200) (100)
SCP level 5 1 000 000 200 000 100 000 20 000 10 000 2 000 1 000 (200)
SCP level6 (10 000 000) 2 000 000 1 000 000 200 000 100 000 20 000 10 000 2 000
SCP level 7 10 000 000 2 000 000 1 000 000 200 000 100 000 20 000
SCP level 8 10 000 000 2 000 000 1 000 000 200 000
The values in Table 1 are concentrations of particles of the related particle size and SCP level per surface area of one square metre
2
(1 m ) equal to or larger than the considered particle size (C ).
SCP;D
For figures in parentheses, the corresponding particle sizes should not be used for level determination purposes; select another
particle size for more accurate determination.
The minimum area for testing should be statistically representative of the surface under consideration.
NOTE Assessment of the lower SCP levels requires numerous measurements to establish a significant value.
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ISO/FDIS 14644-9:2021(E)
Key
X considered particle size, D (µm)
2
Y particle concentration on a surface ≥ D, C (particles/m )
SCP;D
1 SCP grade level 1
2 SCP grade level 2
3 SCP grade level 3
4 SCP grade level 4
5 SCP grade level 5
6 SCP grade level 6
7 SCP grade level 7
8 SCP grade level 8
The solid lines shown on the graph shall be used for level assessment purposes. The dashed lines should not be used
for level assessment purposes.
NOTE Particle distribution on surfaces typically is not a normal distribution, but is affected by different
factors, such as roughness, porosity, electrostatic charge and deposition mechanisms (see Annex A).
2 5
EXAMPLE SCP grade level 5 (1 µm) signifies that 1 m of surface may carry a maximum of 10 particles with
2
a considered particle size ≥ 1 µm (D = 1). SCP grade level 5 (10 µm) signifies that 1 m of surface may carry a
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maximum of 10 particles per square metre with a considered particle size ≥ 10 µm (D = 10). Any other measured
particle size (D = x) which leads to a concentration that lies below the relevant SCP line is within the specification
of SCP grade level 5 (x µm).
Figure 1 — SCP grade levels
For particle sizes outside the limits of the level numbering system and in cases where only a narrow
particle range or individual particle sizes are of interest, a descriptor can be used (see Annex B).
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ISO/FDIS 14644-9:2021(E)
5.2 Designation
The SCP grade level number shall be formatted as follows: SCP grade level N (D µm).
The designation of the SCP grade for cleanrooms and associated controlled environments shall also
include the following:
a) the surface type measured;
b) the surface area measured;
c) the measurement method applied.
Details of measurement methods applied, including sampling techniques and measurement devices,
should be retrieved from test reports.
The considered particle size should be determined by agreement between the customer and supplier.
The SCP grade level shall be stated in relation to the measured particle size diameter.
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EXAMPLE 1 SCP grade level 2 (0,1 µm); wafer or glass substrate, surface area: 310 cm ; surface particle
counter.
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EXAMPLE 2 SCP grade level 5 (0,5 μm); inner wall of a bottle, surface area: 200 cm ; liquid dispersion — liquid
particle counter.
5.3 General information on surface cleanliness levels of particle concentration
Airborne particle concentration and surface particle concentration are generally related. The
relationship is dependent on many factors, such as airflow turbulence, rate of deposition, time of
deposition, deposition velocity, concentration within the air and surface characteristics such as
electrostatic charge (see A.2.4).
To determine SCP, various parameters (see Annex C) and surface characteristics (see Annex A) that
influence testing should be taken into account.
6 Demonstration of conformity
6.1 Principle
Conformity with SCP grade cleanliness level requirements, as specified by the customer, is verified by
performing tests and by providing documentation of the results and conditions of the testing.
Details for demonstrating conformity (see 6.3) shall be agreed upon between the customer and supplier
in advance of testing.
6.2 Testing
Tests performed to demonstrate conformity shall be conducted in a controlled environment using
suitable test methods and calibrated instruments, whenever possible.
Direct and indirect test methods can be used for demonstrating conformity and are given in Annex D.
The list of typical methods described is not exhaustive. Alternative methods of comparable accuracy
may be specified by agreement.
NOTE Measurement by different methods, even when correctly applied, can produce different results of
equal validity.
Repeated measurements are recommended.
The test method and environment shall be agreed upon between the customer and supplier.
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ISO/FDIS 14644-9:2021(E)
Precautions should be taken to reduce electrostatic charge around the test zone, since electrostatic
charge enhances particle deposition onto surfaces. If the surface is neither conductive, nor grounded
or charge-neutralized, electrostatic charges can occur (see Annex A). Therefore, test results can vary.
6.3 Test report
The results from testing each surface shall be recorded and submitted as a comprehensive report, along
with a statement of conformity or non-conformity with the specified SCP grade levels.
The test report shall include as a minimum the following:
a) basic data:
— date and time of testing;
— name and address of the testing organization;
— name of testing personnel;
b) references consulted:
— standards;
— guidelines;
— regulations;
— number and year of publication of this document, i.e. ISO 14644-9:—;
c) environmental data:
— environmental conditions for sampling (i.e. temperature, humidity, cleanliness);
— environmental conditions for measurement (i.e. temperature, humidity, cleanliness) (not
essential for use with direct methods);
— location (e.g. room) used for the measurements;
d) specimen:
— clear identification of the test object;
— description of the test object;
— graph and/or sketch of the test specimen;
e) test setup:
— photo and/or sketch of the test setup;
— description of operating parameters;
— description of measurement points;
— description of hardware used in the test setup;
f) measurement devices:
— identification of the instrument(s) and measuring devices used and current calibration
certificate(s);
— measurement range of measuring devices used;
— reference of calibration certificates;
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ISO/FDIS 14644-9:2021(E)
g) performing the test:
— relevant details of the test procedure used, with any available data describing deviations from
the test procedure (if agreed);
— surface condition before sampling (e.g. after cleaning, after packaging, under atmospheric or
vacuum conditions);
— specified test and measurement procedure or method;
— occupancy state(s) during sampling and measurement;
— specified test method(s);
— all agreed documentation (e.g. raw data, background particle concentrations, pictures, graphs,
cleaning and packaging);
— duration, location and position of sampling (not essential for use with direct methods);
— duration, location and position of measurement (not essential for use with direct methods);
— noticeable observations made during sampling or measurement, where applicable;
— number of measurements performed;
— clear identification of the position and the area of the surface measured and specific designations
for coordinates of the surface, if applicable;
h) results and analysis:
— visual inspection of the test surface before and after measurement, where applicable;
— measurement values and/or their analysis;
— statement of data quality;
— particle size ranges considered;
— test results, including particle concentration data for given particle sizes, for all tests performed;
— SCP grading level with designation expressed as SCP cleanliness grade level N;
— acceptance criteria for the clean surface, if agreed between the customer and the supplier.
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ISO/FDIS 14644-9:2021(E)
Annex A
(informative)
Surface characteristics
A.1 Surface description
A surface is commonly characterized by its texture (such as roughness, porosity), its mechanical
properties (such as hardness) and its physicochemical properties (such as electrostatic surface charge
and surface tension). Each of these properties should be considered before selecting a test method for
the surface cleanliness assessment, or as an aid for the interpretation of the test results.
A.2 Surface characteristics
A.2.1 Roughness
A.2.1.1 Description
As the roughness of a surface affects many of its physical properties, surface roughness is not easily
described by one single parameter, nor is it an intrinsic property of the surface. Roughness exists in
two principal planes: at right angles to the surface, where it may be characterized by height, and in the
plane of the surface, identified as “texture” and characterized by waviness. The roughness of a surface
can be determined by mechanical or optical methods.
A.2.1.2 Testing
A frequently used mechanical method for the determination of roughness is the stylus instrument (see,
for example, ISO 4287 or ISO 4288).
Frequently used optical methods for the determination of roughness and porous texture are
microscopes (optical, confocal, interferometry, with or without tunnel effect, taper sectioning).
A.2.2 Porosity
A.2.2.1 Definition and description
Porosity is a measure of the void spaces in a material and is expressed as a decimal between 0 and 1, or
as a percentage between 0 % and 100 %.
— Effective porosity (also called open porosity) refers to the fraction of the total volume in which
fluid flow is effectively taking place (this excludes dead-end pores or non-connected cavities).
— Macroporosity refers to pores equal to or greater than 50 nm in diameter. Fluid flow through
macropores is described by bulk diffusion.
— Mesoporosity refers to pores equal to or greater than 2 nm but less than 50 nm in diameter.
— Microporosity refers to pores smaller than 2 nm in diameter. Movement in micropores is by
activated diffusion.
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A.2.2.2 Testing
There are several ways to estimate the porosity of a given material or mixture of materials, which is
called material matrix.
The volume/density method is fast and highly accurate (normally within ± 2 % of the actual porosity).
The volume and the weight of the material are measured. The weight of the material divided by the
density of the material gives the volume that the material takes up, minus the pore volume. Therefore,
the pore volume is simply equal to the total volume minus the material volume, i.e. (pore volume) = (total
volume) − (material volume).
The water saturation method is slightly more difficult but is more accurate and more direct. Take a
known volume of the material and a known volume of water. Slowly dump the material into the water
and allow it to saturate while pouring. Allow it to sit for a few hours to ensure that the material is fully
saturated. Then remove the unsaturated water from the top of the beaker and measure its volume.
The total volume of the water originally in the beaker minus the volume of water not saturated is the
volume of the pore space, i.e. (pore volume) = (total volume of water) − (unsaturated water).
Mercury intrusion porosimetry requires the sample to be placed in a special filling device that allows
the sample to be evacuated, followed by the introduction of liquid mercury. The size of the mercury
envelope is then measured as a function of increased applied pressure. The greater the applied pressure,
the smaller the pore entered by mercury. Typically, this method is used over the range of pores from
300 µm to 0,0 035 µm. Because of increased safety concerns over the use of mercury, several non-
mercury intrusion techniques have been developed and should be considered as alternatives.
Nitrogen gas adsorption is used to determine fine porosity in materials. In very small pores, nitrogen
gas condenses on pore walls that are less than 0,090 µm in diameter. This condensation is measured
either by volume or weight.
A.2.3 Hardness
There are many National and International Standards on hardness tests for each material type.
Hardness is frequently measured by the penetrating force of a diamond ball or tip, by the indentation of
a hard body or by the rebound pro
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