SIST EN ISO 25178-700:2023
(Main)Geometrical product specifications (GPS) - Surface texture: Areal - Part 700: Calibration, adjustment and verification of areal topography measuring instruments (ISO 25178-700:2022)
Geometrical product specifications (GPS) - Surface texture: Areal - Part 700: Calibration, adjustment and verification of areal topography measuring instruments (ISO 25178-700:2022)
This document specifies generic procedures for the calibration, adjustment and verification of metrological characteristics that areal topography measuring instruments have in common, as stated in ISO 25178-600.
Because surface profiles can be extracted from surface topography images, most of the methods described in this document can be adapted to profiling instruments.
Instrument-specific issues are not covered by this document. For example, for instruments based on mechanical probing where the probe follows an additional arcuate motion, additional measures are specified in ISO 25178-701.
This document does not include procedures for area-integrating methods, although those are also stated in ISO 25178-6. For example, light scattering belongs to a class of techniques known as area-integrating methods for measuring surface topography.
Geometrische Produktspezifikation (GPS) - Oberflächenbeschaffenheit: Fläche - Teil 700: Kalibrierung, Justierung und Verifizierung von flächenhaften Topographiemessgeräten (ISO 25178-700:2022)
Dieses Dokument legt allgemeine Verfahren für die Kalibrierung, Justierung und Verifizierung von messtechnischen Merkmalen fest, die flächenhafte Topographiemessgeräte gemeinsam haben, wie in ISO 25178 600 angegeben.
Da Oberflächenprofile aus Bildern von Oberflächentopographien extrahiert werden können, können die meisten der in diesem Dokument beschriebenen Verfahren an Profilmessgeräte angepasst werden.
Messgerätespezifische Fragen werden in diesem Dokument nicht behandelt. Für Geräte, die auf mechanischer Abtastung beruhen und bei denen die Sonde einer zusätzlichen bogenförmigen Bewegung folgt, sind beispielsweise in ISO 25178 701 zusätzliche Maßnahmen festgelegt.
Dieses Dokument schließt keine Verfahren für flächenhaft integrierende Methoden ein, obwohl diese ebenfalls in ISO 25178 6 angegeben sind. Lichtstreuung gehört beispielsweise zu einer Klasse von Techni¬ken, die als flächenhaft integrierende Methoden zur Messung der Oberflächentopographie bekannt sind.
Spécification géométrique des produits (GPS) - État de surface: Surfacique - Partie 700: Étalonnage, ajustage et vérification d'instruments de mesure de la topographie des surfaces (ISO 25178-700:2022)
Le présent document spécifie des modes opératoires génériques pour l’étalonnage, l’ajustage et la vérification des caractéristiques métrologiques que les instruments de mesure de la topographie des surfaces ont en commun, comme indiqué dans l’ISO 25178‑600.
Comme les profils peuvent être extraits des images par topographie de surface, la plupart des méthodes décrites dans le présent document peuvent être adaptées aux instruments de profilométrie.
Les problèmes spécifiques des instruments ne sont pas couverts dans le présent document. Par exemple, pour les instruments basés sur un palpage mécanique, lorsque le palpeur suit un mouvement arqué additionnel, des mesures additionnelles sont spécifiées dans l’ISO 25178‑701.
Le présent document n’inclut pas de modes opératoires pour les méthodes d’intégration des surfaces, bien que celles-ci soient aussi mentionnées dans l’ISO 25178‑6. Par exemple, la diffusion de la lumière appartient à une classe de techniques connue sous le nom de méthodes d’intégration des surfaces servant à mesurer la topographie des surfaces.
Specifikacija geometrijskih veličin izdelka (GPS) - Tekstura površine: ploskovna - 700. del: Umerjanje, nastavitev in preverjanje merilnih instrumentov za površinsko topografijo (ISO 25178-700:2022)
Ta del standarda ISO 25178 določa splošne postopke za umerjanje, nastavitev in preverjanje
merilnih instrumentov za površinsko topografijo z ravninskim in ne polnim 3D-merilnim obnašanjem ter za določanje komponent merilne negotovosti, povezanih z učinki na meroslovne lastnosti. Upošteva, kaj je skupnega vsem površinskim instrumentom, vključno z instrumenti za točkovno zaznavanje z napravami za bočno skeniranje. Za specifična načela posameznega instrumenta se lahko v skupini 700 standarda ISO 25178 razvijejo drugi deli. Umerjanje kontaktnih sistemov z dodatnim ločnim gibanjem na primer ni zajeto v tem standardu in se ga lahko opiše v prihodnji reviziji standarda ISO 25178-701.
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-marec-2023
Specifikacija geometrijskih veličin izdelka (GPS) - Tekstura površine: ploskovna -
700. del: Umerjanje, nastavitev in preverjanje merilnih instrumentov za površinsko
topografijo (ISO 25178-700:2022)
Geometrical product specifications (GPS) - Surface texture: Areal - Part 700: Calibration,
adjustment and verification of areal topography measuring instruments (ISO 25178-
700:2022)
Geometrische Produktspezifikation (GPS) - Oberflächenbeschaffenheit: Fläche - Teil
700: Kalibrierung, Justierung und Verifizierung von flächenhaften
Topographiemessgeräten (ISO 25178-700:2022)
Spécification géométrique des produits (GPS) - État de surface: Surfacique - Partie 700:
Étalonnage, ajustage et vérification d'instruments de mesure de la topographie des
surfaces (ISO 25178-700:2022)
Ta slovenski standard je istoveten z: EN ISO 25178-700:2023
ICS:
17.040.20 Lastnosti površin Properties of surfaces
17.040.40 Specifikacija geometrijskih Geometrical Product
veličin izdelka (GPS) Specification (GPS)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN ISO 25178-700
EUROPEAN STANDARD
NORME EUROPÉENNE
January 2023
EUROPÄISCHE NORM
ICS 17.040.20; 17.040.40
English Version
Geometrical product specifications (GPS) - Surface texture:
Areal - Part 700: Calibration, adjustment and verification
of areal topography measuring instruments (ISO 25178-
700:2022)
Spécification géométrique des produits (GPS) - État de Geometrische Produktspezifikation (GPS) -
surface: Surfacique - Partie 700: Étalonnage, ajustage Oberflächenbeschaffenheit: Fläche - Teil 700:
et vérification d'instruments de mesure de la Kalibrierung, Justierung und Verifizierung von
topographie des surfaces (ISO 25178-700:2022) flächenhaften Topographiemessgeräten (ISO 25178-
700:2022)
This European Standard was approved by CEN on 12 December 2022.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 25178-700:2023 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
European foreword
This document (EN ISO 25178-700:2023) has been prepared by Technical Committee ISO/TC 213
"Dimensional and geometrical product specifications and verification" in collaboration with Technical
Committee CEN/TC 290 “Dimensional and geometrical product specification and verification” the
secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by July 2023, and conflicting national standards shall be
withdrawn at the latest by July 2023.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 25178-700:2022 has been approved by CEN as EN ISO 25178-700:2023 without any
modification.
INTERNATIONAL ISO
STANDARD 25178-700
First edition
2022-12
Geometrical product specifications
(GPS) — Surface texture: Areal —
Part 700:
Calibration, adjustment and
verification of areal topography
measuring instruments
Spécification géométrique des produits (GPS) — État de surface:
Surfacique —
Partie 700: Étalonnage, ajustage et vérification d'instruments de
mesure de la topographie des surfaces
Reference number
ISO 25178-700:2022(E)
ISO 25178-700:2022(E)
© 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
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 25178-700:2022(E)
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms.2
5 Calibration, adjustment and verification of an instrument . 3
5.1 General . 3
5.2 Methods for calibration, adjustment and verification . 3
5.3 Instrument calibration procedure . 4
5.3.1 Calibration by measurement standards . 4
5.3.2 Handling of defects on material measures . 4
5.3.3 Measurement procedures for calibration with measurement standards . 4
5.3.4 Calibration conditions . 4
6 Determination of the metrological characteristics of the instrument .5
6.1 General . 5
6.2 Reporting of the measurement conditions . 5
6.3 Handling of non-measured points . 5
6.4 Handling of spurious data and outliers . 5
6.5 Metrological characteristic: measurement noise, N , and instrument noise, N . 5
M I
6.5.1 General . 5
6.5.2 Determination of measurement and instrument noise: application of filters
or operators . 6
6.5.3 Determination of measurement and instrument noise: material measures
for instrument and measurement noise estimation . 6
6.5.4 Determination of measurement and instrument noise: procedure for the
determination of measurement noise . 6
6.6 Determination of flatness deviation . 10
6.6.1 General . 10
6.6.2 Material measure for determination of flatness deviation . 10
6.6.3 Procedure for determination of flatness deviation . 10
6.6.4 Improvement of flatness deviation estimation . 10
6.6.5 Application of filters and operators . 11
6.6.6 Calibration of flatness deviation . 11
6.7 Determination of the amplification coefficient α for the z-axis . 11
z
6.7.1 General . 11
6.7.2 Determination of the amplification coefficient α for the z-axis: material
z
measures . 11
6.7.3 Procedure for determination of amplification coefficient α for the
z
instrument z-axis .12
6.7.4 Type PGR (profile-groove-rectangular): groove, straight (rectangular or
trapezoidal) measurement areas .12
6.7.5 Other material measures for the instrument z-axis calibration. 14
6.7.6 Procedure for determination of amplification coefficient α for the
z
instrument z-axis: range and distance of measurement positions for the
calibration of the z-scale of the instrument . 15
6.7.7 Range and distance of measurement position for the calibration of a
reduced z-scale of the instrument . 15
6.8 Determination of z-linearity deviation l . 15
z
6.8.1 General .15
6.8.2 Determination of the complete and local z-linearity deviation l : z-scan
z
range . 15
iii
ISO 25178-700:2022(E)
6.8.3 Determination of z-linearity deviation l . . 15
z
6.8.4 Determination of z-linearity deviation l : sizes of step heights to be
z
measured. 16
6.8.5 Determination of z-linearity deviation l : positions within the instrument
z
z-range . 17
6.8.6 Determination of z-linearity deviation l : Non-default methods. 17
z
6.9 Determination of the amplification coefficients α and α in x- and y-direction and
x y
mapping deviation Δ (x,y) and Δ (x,y) . 17
x y
6.9.1 General . 17
6.9.2 Determination of the amplification coefficient α and α in x- and
x y
y-direction and mapping deviation Δ (x,y) and Δ (x,y): material measures . 18
x y
6.9.3 Determination of the amplification coefficient α and α in x- and y-direction
x y
and mapping deviation Δ (x,y) and Δ (x,y): assessed measurement volume . 19
x y
6.9.4 Procedure for the determination of the amplification coefficient α and α
x y
and mapping deviation Δ (x,y) and Δ (x,y) of the x- and y-axes .20
x y
6.10 Perpendicularity of the instrument z-axis with respect to the x-y areal reference .20
6.11 Topographic spatial resolution W . 20
R
6.11.1 General .20
6.11.2 Material measures for topographic spatial resolution .20
6.11.3 Instrument transfer function (ITF) curve f . 21
ITF
6.11.4 Lateral period limit D . 21
LIM
6.11.5 Use of optical lateral resolution parameters . 21
6.12 Topography fidelity T . 21
FI
6.12.1 General . 21
6.12.2 Determination of the topography fidelity T using reference metrology . 21
FI
6.12.3 Determination of the small-scale fidelity limit T .22
FIL
6.12.4 Slope-dependent effects . 22
7 General information .22
Annex A (informative) Relation to the GPS matrix model .23
Bibliography .24
iv
ISO 25178-700:2022(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 213, Dimensional and geometrical product
specifications and verification, in collaboration with the European Committee for Standardization (CEN)
Technical Committee CEN/TC 290, Dimensional and geometrical product specification and verification, in
accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
A list of all parts in the ISO 25178 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.
v
ISO 25178-700:2022(E)
Introduction
This document is a geometrical product specification (GPS) standard and is to be regarded as a general
GPS standard (see ISO 14638). It influences chain links E, F and G of the chains of standards on profile
surface texture and areal surface texture.
The ISO/GPS matrix model given in ISO 14638 gives an overview of the ISO/GPS system, of which this
document is a part. The fundamental rules of ISO/GPS given in ISO 8015 apply to this document and
the default decision rules given in ISO 14253-1 apply to the specifications made in accordance with this
document, unless otherwise indicated.
For more detailed information of the relation of this document to other standards and the GPS matrix
model, see Annex A.
In the GPS concept, the design values of geometric parameters on workpieces and their tolerances are
compared with the measurement of those parameters on the corresponding manufactured workpieces
and their associated measurement uncertainties. For a reliable result it is therefore necessary to
calibrate the measurement instrument involved in this process.
This document specifies default procedures for the calibration, adjustment and verification of surface
topography measuring instruments, using material measures traceable to the meter through a national
metrology institute or qualified laboratory, see ISO/IEC Guide 99:2007, 2.41. Default methods are
recommended when no other calibration procedures have been clearly defined.
This document describes the calibration (see ISO/IEC Guide 99:2007, 2.39), adjustment (see
ISO/IEC Guide 99:2007, 3.11) and verification (see ISO/IEC Guide 99:2007, 2.44) in general for
topography measuring instruments.
The calibration of an instrument’s metrological characteristics enables the verification of the
instrument’s specifications when the specifications are based on these metrological characteristics.
This also enables the comparison of systems of different manufacturers that may be based on different
measurement principles.
The metrological characteristics capture all of the factors that can influence a measurement result
(influence quantities) and can be propagated appropriately through a specific measurement model to
estimate measurement uncertainty.
Calibration is a part of the determination of the overall uncertainty of measurement. The complete
evaluation of measurement uncertainty may include other factors such as operator variability, changing
environmental influences, the effects of thermal and mechanical stresses on the sample part and other
factors that are not accounted for in the instrument calibrations.
Alternative calibration techniques to the defaults given here are equally acceptable, depending on
the capabilities of the instrumentation and provided those alternatives have clear traceability paths.
Example techniques include those based on an independent realization of the meter using a natural
emission wavelength, the value for which has been established with a known uncertainty.
vi
INTERNATIONAL STANDARD ISO 25178-700:2022(E)
Geometrical product specifications (GPS) — Surface
texture: Areal —
Part 700:
Calibration, adjustment and verification of areal
topography measuring instruments
1 Scope
This document specifies generic procedures for the calibration, adjustment and verification of
metrological characteristics that areal topography measuring instruments have in common, as stated
in ISO 25178-600.
Because surface profiles can be extracted from surface topography images, most of the methods
described in this document can be adapted to profiling instruments.
Instrument-specific issues are not covered by this document. For example, for instruments based on
mechanical probing where the probe follows an additional arcuate motion, additional measures are
specified in ISO 25178-701.
This document does not include procedures for area-integrating methods, although those are also
stated in ISO 25178-6. For example, light scattering belongs to a class of techniques known as area-
integrating methods for measuring surface topography.
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 25178-600:2019, Geometrical product specifications (GPS) — Surface texture: Areal — Part 600:
Metrological characteristics for areal topography measuring methods
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/
3.1
non-measured points
surface locations for which no valid measured values exist
Note 1 to entry: The handling of non-measured points is specified in 6.3.
Note 2 to entry: Non-measured points may be caused by a feature of the measuring instrument or by a defect on
the surface of the measurement standard which is outside the range of the instrument.
ISO 25178-700:2022(E)
3.2
spurious data
data that have been qualified as measurable by the measurement principle but deviate significantly
from a reasonable value range, based on a priori knowledge
Note 1 to entry: Spurious data may relate to single points or a small group of points that have been classified as
measurable by the measurement instrument. They are identified as spurious data by determining their values
to be unlikely based on a priori knowledge about both the expected surface and the instrument, or simply by
defects and contamination on the surface. Spurious data may appear as outliers or spikes.
Note 2 to entry: Spurious data can be caused by environmental conditions, such as vibration or external light
sources, by interaction between the surface and instrument, or simply by defects and contamination on the
surface. Spurious data may appear as outliers or spikes.
Note 3 to entry: The handling of spurious data is specified in 6.4.
3.3
measurement noise
N
M
noise added to the output signal occurring during the normal use of the instrument
[SOURCE: ISO 25178-600:2019, 3.1.15, modified — Notes to entry removed.]
3.4
instrument noise
N
I
internal noise added to the output signal caused by the instrument if ideally placed in a noise-free
environment
[SOURCE: ISO 25178-600:2019, 3.1.14, modified — Notes to entry removed.]
3.5
z-linearity deviation
l
z
maximum local linearity difference between the line from which the amplification coefficient is derived
and the response function
[SOURCE: ISO 25178-600:2019, 3.1.11, modified — Term revised and note to entry removed.]
3.6
instrument transfer function curve
f
ITF
curve describing an instrument’s height response as a function of the spatial frequency of the surface
topography
[SOURCE: ISO 25178-600:2019, 3.1.19, modified — Term revised and notes to entry removed.]
3.7
topography fidelity
T
FI
closeness of agreement between a measured surface profile or measured topography and one whose
uncertainties are insignificant by comparison
[SOURCE: ISO 25178-600:2019, 3.1.26, modified — Note to entry removed.]
4 Symbols and abbreviated terms
The metrological characteristics for areal topography measuring methods and associated symbols
and abbreviated terms are defined in ISO 25178-600. Table 1 contains a list of these metrological
characteristics.
ISO 25178-700:2022(E)
a
Table 1 — List of metrological characteristics for surface texture measurement methods
Main potential error
Metrological characteristic Clause and figure in ISO 25178- along
Symbol
(and clause in this document) 600:2019 containing definition (ISO 25178-600:2019,
3.1.2)
Amplification coefficient (6.7) α , α , α 3.1.10 (Figure 2) x, y, z
x y z
Linearity deviation (6.8) l , l , l 3.1.11 (Figure 2) x, y, z
x y z
Flatness deviation (6.6) z 3.1.12 z
FLT
Measurement noise (6.5) N 3.1.15 z
M
Topographic spatial resolution (6.11) W 3.1.20 z
R
x-y mapping deviations (6.9) Δ (x,y), Δ (x,y) 3.1.13 x, y
x y
Topography fidelity (6.12) T 3.1.26 x, y, z
FI
NOTE 1 Depending on the measurement application, other axis motion errors (see ISO 230-1, ISO 10360-7 and ISO 10360-8) can also be significant but are
not listed here for surface texture measurement.
NOTE 2 The maximum measurable slope is an important limitation to be specified for a surface topography measurement instrument. However, users do not
need to measure this parameter unless it is part of a measurement model.
a
Adapted from ISO 25178-600:2019, Table 1.
5 Calibration, adjustment and verification of an instrument
5.1 General
This document defines default methods for calibration. It also specifies the general principle for
adjustment, verification and determining performance specifications, see Figure 1. Other methods
used for calibration shall meet the requirements as specified here and shall be specified.
If no adjustment is necessary, the initial calibration constitutes the verification. In this case the
calibration result contributes to the measurement uncertainty calculation.
If adjustment is done, verification may be done by a subsequent calibration after adjustment.
NOTE The white arrow indicates the possible subsequent comparison with specifications.
Figure 1 — Flow chart of calibration, adjustment and verification procedure
NOTE 1 Determination of the metrological characteristics is not intended to assess the errors due to the
calibration and computational algorithms. These algorithms can be verified using software measurement
standards, see ISO 25178-71 and ISO 25178-72.
NOTE 2 Performance specifications are typically provided by instrument manufacturers.
5.2 Methods for calibration, adjustment and verification
In this document, methods are defined for noise (6.5), flatness deviation (6.6.2), amplification
(6.7.2), linearity deviation (6.8.3) and x-y mapping deviations (6.9.2). For each of these metrological
characteristics a method for the determination of its value is defined. Depending on the characteristics
these methods can be used both to calibrate and to verify after adjustment.
No default methods are defined for perpendicularity of the instrument z-axis with respect to the x-y
areal reference (6.10), topographic spatial resolution (6.11) and topography fidelity (6.12).
ISO 25178-700:2022(E)
5.3 Instrument calibration procedure
5.3.1 Calibration by measurement standards
The default procedures all include the use of material measures. Calibrated measurement standards,
as defined in ISO 25178-70, shall be used during the determination of the metrological characteristics
of the instruments. The deviation from the values stated in the calibration certificate shall be recorded
and the uncertainty of the calibration values shall be taken into account. The measurement standards
(calibrated material measures) shall be selected by taking into account the characteristics of the surface
to be measured.
NOTE 1 The requirements for the material measures are described in ISO 25178-70 and for contact (stylus)
instruments in ISO 25178-701:2010, 5.2.1.2.
NOTE 2 Optical flats do not need to be calibrated for the determination of noise as specified in 6.5.
5.3.2 Handling of defects on material measures
Measurement standards without defects should be selected as a first preference. In all cases, however,
the possibility of surface defects (in the sense of ISO 25178-73:2019, 3.1.2) shall be addressed when a
physical measurement standard is used for calibration tasks. Defects shall be identified or described
in accordance with ISO 25178-73:2019, 3.2. Measurement records shall include a statement on the
selected response to any encountered surface defects (ISO 25178-73:2019, 3.3), paying attention to the
distinction between effective and ineffective defects. If it is not possible to plan valid measurements for
a task on a defective standard, that standard shall not be used for that task.
For brevity, such defect-response statements may refer to procedures stated on the calibration
certificate of the measurement standard or other suitable documentation from the supplier.
NOTE The supplier of the defective measurement standard will possibly be able to supply an alternative
calibration certificate and/or associated measurement procedure that are compatible with the observed defects,
allowing valid measurements to be planned without repair or replacement of the standard.
5.3.3 Measurement procedures for calibration with measurement standards
Measurement procedures specified on the calibration certificate of the measurement should be adhered
to as closely as possible while using it for the determination of metrological characteristics.
5.3.4 Calibration conditions
Determination of the metrological characteristics shall be performed for each individual instrument
and each instrument setup (configuration) used in practice. Environmental conditions shall be similar
to working conditions for subsequent measurement activity for that instrument. The selection and
configuration of evaluation software shall be the same as that used in practice.
Calibration for determining instrument specification shall be done under documented measurement
conditions and these conditions shall be reported (see ISO/IEC 17025:2017, 6.3).
NOTE The instrument setup (configuration) is generally application specific.
EXAMPLE Examples of different setups (configurations):
— use of objective lenses with different magnifications;
— use of different stylus tip radii;
— use of different scanning directions;
— use of different scanning speeds;
— different environmental conditions, such as a significantly different temperature.
ISO 25178-700:2022(E)
6 Determination of the metrological characteristics of the instrument
6.1 General
The metrological characteristics of the instrument that may influence the measurement result and the
evaluated measurement uncertainty shall be determined:
— within the measurement volume defined for the intended application;
— at different positions within the measurement volume, if applicable;
— according to an agreed or accepted measurement scheme;
— for different scanning speeds or directions, if applicable.
General measurement schemes are given in the following clauses and more detailed measurement
schemes may be specified for each measuring principle.
6.2 Reporting of the measurement conditions
Measurement conditions, relevant instrument settings and environmental conditions may influence
the metrological characteristics and shall be reported. Potential disturbances, such as acoustic noise,
vibration or lighting conditions, shall be reported but may be described qualitatively.
NOTE 1 Examples of instrument settings and environmental conditions include: temperature;
humidity; internal illumination configuration; scan increment; scan speed for scanning instruments (see
ISO 25178-604:2013, 2.5.12 and 2.5.13).
NOTE 2 Example phrases for qualitative reporting include “No vibrations or strong vibrations” and “no
disturbance by external illumination”; see also 6.5.2.
6.3 Handling of non-measured points
By default, no interpolation and filling of non-measured points within the relevant areas is applied for
the determination of the metrological characteristics. However, if interpolation and filling is applied,
it shall be reported. Measurements for which a significant number of the points are non-measured
should be discarded. Interpolation or other mathematical algorithms shall not change the status of non-
measured points to measured points.
6.4 Handling of spurious data and outliers
Depending on a priori knowledge and later applications, spurious data within the region of interest
should be removed from the measured points and should be treated in the same way as non-measured
points, as specified in 6.3.
6.5 Metrological characteristic: measurement noise, N , and instrument noise, N
M I
6.5.1 General
The instrument noise is the minimum achievable noise under the most ideal circumstances.
Evaluation of instrument noise shall be performed under the best conditions for the characterization of
instrument performance, see ISO 25178-600.
For some instruments, instrument noise cannot be completely separated from other types of
measurement noise because the instrument only acquires data while moving. If so, any measured noise
includes a dynamic component. See also static noise (ISO 25178-600: 2019, 3.2.6) and dynamic noise
(ISO 25178-600: 2019, 3.2.7).
ISO 25178-700:2022(E)
6.5.2 Determination of measurement and instrument noise: application of filters or operators
In applications where filters or operators are used, the measurement noise determination should
proceed under the same filter conditions as those used for measurements. The used filters with the
applied nesting indices and the used operators shall be reported.
A quantitative statement of measurement noise shall include any filters that may influence the spatial
frequencies over which the noise is determined.
An instrument noise specification shall include the relevant data acquisition time, the number of
independent data points and any spatial or temporal filters that may influence the spatial frequencies
over which the noise is determined (see Reference [19]).
NOTE The S-filter as a low-pass filter reduces the noise but can affect the topographic spatial resolution if
this resolution is limited by the lateral sampling. When estimating the noise for the highest lateral resolution, it
can be preferable to perform measurements without applying an S-filter.
EXAMPLE In a specification sheet a quantitative statement of instrument noise can be indicated as follows:
full measurement area, 1 s data acquisition (at 10 averages per second) and a 3 × 3 pixel median filter.
6.5.3 Determination of measurement and instrument noise: material measures for instrument
and measurement noise estimation
The default material measure for instrument noise determination should be one that:
— is compatible with the instrument measurement principle;
— has a smooth and flat surface;
— has surface properties that give an optimum signal-to-noise ratio.
By default, this material measure shall be optically aligned so that a minimum measurement range of
the instrument is used. Material measures with an antireflection coating for optical measurements
or those causing stick-slip during mechanical measurement may not provide an optimum signal-to-
noise ratio. Other types of surfaces can also be used if specified. For example, a minimum amount of
roughness may be required for measurement principles such as focus variation microscopy.
The evaluation of the measurement noise is best performed on the surface to be measured on a
workpiece under inspection or on a representative sample with similar surface features to the
workpiece surface.
EXAMPLE Type AFL material measures as defined in ISO 25178-70 can be used for the instrument noise
evaluation.
6.5.4 Determination of measurement and instrument noise: procedure for the determination
of measurement noise
6.5.4.1 General
The subtraction method, 6.5.4.3, is the default method for determination of measurement noise of areal
measuring instruments.
6.5.4.2 Assessed parameter
The assessed parameter is N according to Formula (1) or (3).
M
6.5.4.3 Estimation of measurement noise by the subtraction method
The default method for the determination of measurement noise is the measurement of a material
measure according to 6.5.3, which shall be measured twice at the same location with the shortest
possible time difference between the two sequential measurements. The two measured topographies
ISO 25178-700:2022(E)
are subtracted from each other. Ideally this makes the result independent of the exact topography of
the material measure, such that no filtration nor any further form removal of the material measure is
required. The vertical drift and any drift in the surface tilt can be eliminated by removing a least-
squares plane from the measurements or from the measurement difference. The measurement noise
N is the root mean square (RMS) of the remaining differences divided by 2 .
M
The measurement noise is determined in practice by calculating the RMS height S (or R for profile
q q
measurements), as defined in ISO 25178-2, of the difference of two maps. The noise is then obtained by
dividing this S value by 2 . S is assessed on the S-L or S-F surface, as appropriate. The nesting indices
q q
should be as close as possible to those nesting indices used afterwards for measurements.
For scanning point sensors, the instrument noise shall be determined accordingly by profile
measurements or scanning areal measurements, depending on the application.
NOTE 1 A mathematical description of the subtraction method for estimating the measurement noise is given
in Formula (1).
1 1 1
NS= (,zx()yz− ()xy,)= ()zx(),,yz− ()xy d xyd (1)
Mq 12 12
∫∫∫
A
2 2
A
where
N is the measurement noise;
M
S is the root mean square height;
q
A
is the measured area;
z is the topography result from the first measurement;
z
is the topography result from the second measurement.
NOTE 2 A mathematical description of the procedure for uniformly spaced discretely sampled data is given in
Formula (2).
N
N
y
x
1 1 2
N = zx ,,yz− xy (2)
()() ()
M 12jk jk
∑∑
NN
xy
j==11k
where
N is the measurement noise obtained by the subtraction method, taking two measurements;
M
N , N are the number of data points in the x- and y-directions,
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