Non-destructive testing - Equipment for eddy current examination - Part 2: Probe characteristics and verification (ISO 15548-2:2013)

EN ISO 15548-2 identifies the functional characteristics of a probe and its interconnecting elements and provides methods for their measurement and verification. The evaluation of these characteristics permits a well-defined description and comparability of eddy current equipment. By careful choice of the characteristics, a consistent and effective eddy current examination system can be designed for a specific application. Where accessories are used, these should be characterised using the principles of this part of ISO 15548. This part of ISO 15548 does not give the extent of verification nor acceptance criteria for the characteristics. These are given in the application documents.

Zerstörungsfreie Prüfung - Technische Ausrüstung für die Wirbelstromprüfung - Teil 2: Kenngrößen von Sensoren und deren Verifizierung (ISO 15548-2:2013)

Dieser Teil von ISO 15548 legt die Funktionskenngrößen von Sensoren und der zugehörigen Verbindungselemente fest und enthält Verfahren für deren Messung und Verifizierung.
Die Beurteilung dieser Kenngrößen ermöglicht eine genaue Beschreibung und Vergleichbarkeit von Wirbelstromprüfgeräten.
Durch sorgfältige Auswahl der Kenngrößen kann ein reproduzierbares und effektives Wirbelstromprüfsystem für spezifische Anwendungen entworfen werden.
Bei der Verwendung von Zubehörteilen sollten diese nach den Grundlagen dieses Teils von ISO 15548 charakterisiert werden.
Dieser Teil von ISO 15548 enthält weder Vorschriften für den Umfang der Verifizierung noch für die Annahmekriterien der Kenngrößen. Diese sind in den Anwendungsdokumenten enthalten.

Essais non destructifs - Appareillage pour examen par courants de Foucault - Partie 2: Caractéristiques des capteurs et vérifications (ISO 15548-2:2013)

L'ISO 15548-2:2013 identifie les caractéristiques fonctionnelles d'un capteur à courants de Foucault et de ses éléments d'interconnexion et fournit des méthodes pour les mesurer et les vérifier.
L'évaluation de ces caractéristiques permet de donner une description bien définie de l'appareillage à courants de Foucault et d'assurer la comparabilité entre appareillages.
Un système d'examen par courants de Foucault, cohérent et efficace, peut être conçu en choisissant méticuleusement les caractéristiques pour une application spécifique.
Lorsque des accessoires sont mis en oeuvre, il convient de les caractériser en appliquant les principes de l'ISO 15548-2:2013.
L'ISO 15548-2:2013 ne fournit pas l'étendue des vérifications ni des critères d'acceptation pour les caractéristiques. Ceux-ci sont définis dans les documents d'application.

Neporušitvene preiskave - Oprema za preiskave z vrtinčnimi tokovi - 2. del: Značilnosti sond in preverjanje (ISO 15548-2:2013)

Standard EN ISO 15548-2 določa funkcijske značilnosti sonde in njenih povezovalnih elementov in navaja metode za merjenje in preverjanje s temi instrumenti. Ocena teh značilnosti omogoča dobro opredeljen opis in primerjavo opreme za preiskave z vrtinčnimi tokovi. S skrbno izbiro značilnosti se lahko oblikuje dosleden in učinkovit preiskovalni sistem za opremo za preiskave z vrtinčnimi tokovi za določeno uporabo. Če je uporabljen pribor, bi moral biti opisan po načelih tega dela standarda ISO 15548. Ta del standarda ISO 15548 ne določa obsega preverjanja, niti kriterijev sprejemljivosti za značilnosti. Te so podane v dokumentu, ki obravnava uporabo.

General Information

Status
Published
Public Enquiry End Date
29-Nov-2013
Publication Date
30-Jun-2014
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
29-May-2014
Due Date
03-Aug-2014
Completion Date
01-Jul-2014

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Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 15548-2:2014
01-julij-2014
1DGRPHãþD
SIST EN ISO 15548-2:2009
1HSRUXãLWYHQHSUHLVNDYH2SUHPD]DSUHLVNDYH]YUWLQþQLPLWRNRYLGHO
=QDþLOQRVWLVRQGLQSUHYHUMDQMH ,62
Non-destructive testing - Equipment for eddy current examination - Part 2: Probe
characteristics and verification (ISO 15548-2:2013)
Zerstörungsfreie Prüfung - Technische Ausrüstung für die Wirbelstromprüfung - Teil 2:
Kenngrößen von Sensoren und deren Verifizierung (ISO 15548-2:2013)
Essais non destructifs - Appareillage pour examen par courants de Foucault - Partie 2:
Caractéristiques des capteurs et vérifications (ISO 15548-2:2013)
Ta slovenski standard je istoveten z: EN ISO 15548-2:2013
ICS:
19.100 Neporušitveno preskušanje Non-destructive testing
SIST EN ISO 15548-2:2014 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 15548-2:2014

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SIST EN ISO 15548-2:2014

EUROPEAN STANDARD
EN ISO 15548-2

NORME EUROPÉENNE

EUROPÄISCHE NORM
December 2013
ICS 19.100 Supersedes EN ISO 15548-2:2008
English Version
Non-destructive testing - Equipment for eddy current
examination - Part 2: Probe characteristics and verification (ISO
15548-2:2013)
Essais non destructifs - Appareillage pour examen par Zerstörungsfreie Prüfung - Technische Ausrüstung für die
courants de Foucault - Partie 2: Caractéristiques des Wirbelstromprüfung - Teil 2: Kenngrößen von Sensoren und
capteurs et vérifications (ISO 15548-2:2013) deren Verifizierung (ISO 15548-2:2013)
This European Standard was approved by CEN on 12 November 2013.

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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2013 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 15548-2:2013 E
worldwide for CEN national Members.

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SIST EN ISO 15548-2:2014
EN ISO 15548-2:2013 (E)
Contents Page
Foreword .3
2

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SIST EN ISO 15548-2:2014
EN ISO 15548-2:2013 (E)
Foreword
This document (EN ISO 15548-2:2013) has been prepared by Technical Committee ISO/TC 135 “Non-
destructive testing” in collaboration with Technical Committee CEN/TC 138 “Non-destructive testing” 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 June 2014, and conflicting national standards shall be withdrawn at
the latest by June 2014.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 15548-2:2008.
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, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
Endorsement notice
The text of ISO 15548-2:2013 has been approved by CEN as EN ISO 15548-2:2013 without any modification.


3

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SIST EN ISO 15548-2:2014

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SIST EN ISO 15548-2:2014
INTERNATIONAL ISO
STANDARD 15548-2
Second edition
2013-12-01
Non-destructive testing — Equipment
for eddy current examination —
Part 2:
Probe characteristics and verification
Essais non destructifs — Appareillage pour examen par courants
de Foucault —
Partie 2: Caractéristiques des capteurs et vérifications
Reference number
ISO 15548-2:2013(E)
©
ISO 2013

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SIST EN ISO 15548-2:2014
ISO 15548-2:2013(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2013
All rights reserved. Unless otherwise specified, 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
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2013 – All rights reserved

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SIST EN ISO 15548-2:2014
ISO 15548-2:2013(E)

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Characteristics of probe and interconnecting elements . 1
4.1 General characteristics . 1
4.2 Electrical characteristics . 3
4.3 Functional characteristics . 3
5 Verification . 4
5.1 General . 4
5.2 Levels of verification . 4
5.3 Verification procedure . 5
5.4 Corrective actions . 5
6 Measurement of electrical and functional characteristics of a probe .5
6.1 Electrical characteristics . 5
6.2 Functional characteristics . 6
6.3 Normalised impedance plane diagram .24
7 Influence of interconnecting elements .24
Annex A (informative) Reference block A6 .25
Bibliography .27
© ISO 2013 – All rights reserved iii

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SIST EN ISO 15548-2:2014
ISO 15548-2:2013(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. 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. 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.
The committee responsible for this document is ISO/TC 135, Non-destructive Testing, Subcommittee
SC 4, Eddy current methods.
This second edition cancels and replaces the first edition (ISO 15548-2:2008), of which it constitutes a
minor revision.
ISO 15548 consists of the following parts, under the general title Non-destructive testing — Equipment
for eddy current examination:
— Part 1: Instrument characteristics and verification
— Part 2: Probe characteristics and verification
— Part 3: System characteristics and verification
iv © ISO 2013 – All rights reserved

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SIST EN ISO 15548-2:2014
INTERNATIONAL STANDARD ISO 15548-2:2013(E)
Non-destructive testing — Equipment for eddy current
examination —
Part 2:
Probe characteristics and verification
1 Scope
This part of ISO 15548 identifies the functional characteristics of a probe and its interconnecting
elements and provides methods for their measurement and verification.
The evaluation of these characteristics permits a well-defined description and comparability of eddy
current equipment.
By careful choice of the characteristics, a consistent and effective eddy current examination system can
be designed for a specific application.
Where accessories are used, these should be characterised using the principles of this part of ISO 15548.
This part of ISO 15548 does not give the extent of verification nor acceptance criteria for the
characteristics. These are given in the application documents.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 12718, Non-destructive testing — Eddy current testing — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 12718 apply.
4 Characteristics of probe and interconnecting elements
4.1 General characteristics
4.1.1 Application
Probes and interconnecting elements are selected to satisfy the requirements of the intended application.
The design is influenced by the instrument with which they are used.
4.1.2 Probe types
The probe is described by the following:
— type of material to be examined, i.e. ferromagnetic or non-ferromagnetic, with high or low
conductivity;
© ISO 2013 – All rights reserved 1

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SIST EN ISO 15548-2:2014
ISO 15548-2:2013(E)

— function, e.g. separate or combined transmit/receive probe;
— family, e.g. coaxial probe, surface probe;
— measurement mode, e.g. absolute, differential;
— purpose of the examination, e.g. detection of discontinuities, sorting or thickness measurement, etc.;
— specific features, e.g. focused, shielded, etc.
4.1.3 Interconnecting elements
They may include the following:
— cables and/or extensions;
— connectors;
— slip rings;
— rotating heads;
— transformers;
— active devices, e.g. multiplexer, amplifier, etc.
4.1.4 Physical characteristics
The following shall be stated among others:
— external size and shape;
— weight;
— information about mechanical mounting;
— model number and serial number;
— material of manufacture of probe housing;
— composition and thickness of facing material;
— presence and purpose of core or shield;
— type of interconnecting elements (see 4.1.3);
— orientation mark (direction for maximum sensitivity, see 6.2.3.3);
— position mark (electrical centre, see 6.2.3.4).
4.1.5 Safety
The probe and its interconnecting elements shall meet the applicable safety regulations regarding
electrical hazard, surface temperature, or explosion.
Normal use of the probe should not create a hazard.
4.1.6 Environmental conditions
The temperature and humidity for normal use, storage and transport should be specified for the probe
and its interconnecting elements.
2 © ISO 2013 – All rights reserved

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SIST EN ISO 15548-2:2014
ISO 15548-2:2013(E)

The tolerance of the probe and its interconnecting elements to the effects of interference noise and
electromagnetic radiation shall conform to electromagnetic compatibility (EMC) regulations.
Materials used in the manufacture of the probe should be resistant to contaminants.
4.2 Electrical characteristics
The external electrical connections to the probe shall be clearly identified or declared in writing.
The electrical characteristics of a probe connected to a specified length and type of cable are as follows:
— recommended range of excitation current and voltage for safe operation;
— recommended range of excitation frequencies;
— impedance of the excitation element in air;
— resonant frequency of the excitation element in air;
— impedance of the receiving element(s) in air.
The electrical characteristics of an extension cable shall also be clearly identified.
4.3 Functional characteristics
The functional characteristics of a probe shall be determined for a defined system.
The measurement of the functional characteristics of a probe requires the use of calibration blocks. The
material used for the reference block is determined by the application.
The functional characteristics of a probe are as follows:
— directionality;
— response to elementary discontinuities (hole, slot);
— length and width of coverage;
— area of coverage;
— minimum dimensions of discontinuities for constant response;
— penetration characteristics;
— geometric effects;
— normalised impedance locus (when the frequency is varied) of the exciting element with minimum
probe clearance from a homogeneous block of a specified material.
These characteristics cannot be used alone to establish the performance (e.g. resolution, smallest
detectable discontinuity, etc.) of the probe in a given test system, for a given application.
When relevant, the influence of interconnecting elements on the functional characteristics of the probe
shall be measured.
© ISO 2013 – All rights reserved 3

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SIST EN ISO 15548-2:2014
ISO 15548-2:2013(E)

5 Verification
5.1 General
For a consistent and effective eddy current examination, it is necessary to verify that the performance of
the component parts of the eddy current test system is maintained within acceptable limits.
The physical condition of the reference blocks shall be verified to be within acceptable limits, before
being used to verify the system or probes.
The measuring equipment used for verification shall be in a known state of calibration.
For a better understanding, the verification procedure is described identically in all three parts of ISO 15548.
5.2 Levels of verification
There are three levels of verification. Each level defines the time intervals between verification and the
complexity of the verification.
It is understood that initial type testing has already been carried out by the manufacturer or under his
control.
a) Level 1: Global functional check
A verification is performed at regular intervals of time on the eddy current test system, using
reference blocks to verify that the performance is within specified limits.
The verification is usually performed at the examination location.
The time interval and the reference blocks are defined in the verification procedure.
b) Level 2: Detailed functional check and calibration
A verification on an extended time scale is performed to ensure the stability of selected characteristics
of the eddy current instrument, probe, accessories and reference blocks.
c) Level 3: Characterisation
A verification is performed on the eddy current instrument, probe accessories and reference blocks
to ensure conformity with the characteristics supplied by the manufacturer.
The organization requiring the verification shall specify the characteristics to be verified.
The main features of verification are shown in Table 1.
Table 1 — Verification levels
Level Object Typical time period Instruments Responsible entity
1
Stability of system Frequently,
Global functional Reference blocks User
performance e.g. hourly, daily
check
Stability of selected
2 Less frequently but Calibrated measur-
characteristics of the
Detailed functional at least annually and ing instruments, User
instrument, probes
check and calibration after repair reference blocks
and accessories
All characteristics Calibrated labora-
Once
3 of the instrument, tory measuring
(on release) Manufacturer, user
Characterisation probes and acces- instruments and
and when required.
sories reference blocks
4 © ISO 2013 – All rights reserved

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SIST EN ISO 15548-2:2014
ISO 15548-2:2013(E)

5.3 Verification procedure
The characteristics to be verified are dependent on the application. The essential characteristics and the
level of verification shall be specified in a verification procedure.
The examination procedure for the application shall refer to the verification procedure. This can restrict
the number of characteristics of a general-purpose instrument to be verified for a defined application.
Sufficient data on the characteristics featured in an instrument, probe and reference block shall be
provided, in order that verification may be performed within the scope of this part of ISO 15548.
5.4 Corrective actions
Level 1: When the performance is not within the specified limits, a decision shall be made concerning
the product examined since the previous successful verification. Corrective actions shall be made to
bring the performance within acceptable limits.
Level 2: When the deviation of the characteristic is greater than the acceptable limits specified by the
manufacturer or in the application document, a decision shall be made concerning the instrument, the
probe or the accessory being verified.
Level 3: When the characteristic is out of the acceptable range specified by the manufacturer or by the
application document, a decision shall be made concerning the instrument, the probe or the accessory
being verified.
6 Measurement of electrical and functional characteristics of a probe
6.1 Electrical characteristics
6.1.1 General
The electrical characteristics alone do not define the characteristics of the probe in its application.
The methods and measuring instruments given in 6.1.2 to 6.1.5 are for guidance; other equivalent
methods and instrumentation can be used.
6.1.2 Measurement conditions
The measurements are made at the probe connector without the use of interconnecting elements of the
inspection system. The probe is placed in air and away from any conductive or magnetic material.
The measurements are made for each element of the probe accessible at the probe connector. The other
elements are left in open circuit.
When the probe is designed for use under particular conditions, for example, temperature or pressure,
any additional measurements that are required shall be specified in the application document.
6.1.3 Resonant frequency of the excitation element
6.1.3.1 Excitation element with a single coil
Using an impedance meter, measure the resonant frequency f of the excitation element.
res
6.1.3.2 Excitation elements with multiple coils
An excitation element containing multiple coils will give multiple resonance frequencies. The lowest
frequency shall be reported/measured.
© ISO 2013 – All rights reserved 5

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SIST EN ISO 15548-2:2014
ISO 15548-2:2013(E)

6.1.4 Impedance of the excitation element
Measure the resistance R using a multimeter, and the inductance L using an impedance meter. The
0 0
inductance is measured at the lowest frequency of the recommended operating range for the probe.
If the capacitance C is too small to be measured directly, calculation should provide a more accurate result:
0
1
C = (1)
0
2 2
4π fL
res 0
The model of the excitation-element impedance is given in Figure 1.
Figure 1 — Excitation-element impedance
6.1.5 Impedance of the receiving element(s)
Measure the resistance using a multimeter, and the inductance and the capacitance using an impedance
meter. The measured values of impedance can be given as a curve against frequency.
6.2 Functional characteristics
6.2.1 General
This part of ISO 15548 characterises commonly used probe types. Probes which are designed for special
(unusual) applications shall be characterised in accordance with an application document which follows
the methodology of this part of ISO 15548. The characteristics described in this part of ISO 15548 can
give useful information about such probes.
The functional characteristics are defined for two classes of probes: surface probes and co-axial probes.
6.2.2 Measurement conditions
6.2.2.1 General
A general-purpose eddy current instrument, characterised in accordance with ISO 15548-1, can be used,
provided that it has the required accuracy.
Alternatively, sufficient instrumentation comprising a voltage/current generator, synchronous detection
amplifier and a voltmeter or oscilloscope can be used.
When the probe does not feature a connecting cable, the characteristics of the cable used for the
measurements shall be documented.
The probe characteristics are measured within the frequency range specified by the probe manufacturer
using reference blocks containing known features, such as slots and holes.
The reference blocks shall be made using the specifications in the application document for the material,
metallurgical properties and surface finish. Its geometry shall comply with the requirements included
in the following subclauses. Blocks made from ferromagnetic material shall be demagnetized before use.
The reference block can be replaced by any other device, the equivalence of which shall be demonstrated
for the measured characteristic (alternative blocks, electric circuit, coil, ball, etc.).
6 © ISO 2013 – All rights reserved

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SIST EN ISO 15548-2:2014
ISO 15548-2:2013(E)

The functional characteristics can be affected by the presence of any perturbing electromagnetic field
or ferromagnetic material in the zone of influence of the probe. Care shall be taken to avoid these effects
when making the measurements described in 6.2.2.2 and 6.2.2.3.
The measurement conditions for each characteristic shall be recorded, for example, excitation frequency
and voltage/current, details of the reference block, etc.
The measured values are the amplitude of the signal and, when applicable, the phase of the signal.
6.2.2.2 Measurement of the amplitude of the signal
a) Absolute measurements
The amplitude of the signal is the length of the vector joining the balance point to the point
corresponding to the maximum excursion of the signal from the balance point, unless otherwise
specified in an application document, see Figure 2 a).
b) Differential measurements
The amplitude of the signal is the length of the line joining the two extreme points of the signature,
i.e. peak to peak value, unless otherwise specified in an application document; see Figure 2 b).
c) Other measurements
The method shall be specified in an application document.
a) Amplitude measurement for an absolute signal
b) Amplitude measurement for a differential signal
Figure 2 — Amplitude measurements for signals
6.2.2.3 Measurement of the phase angle of the signal
The reference for the measurement of phase angle shall be the positive x-axis.
© ISO 2013 – All rights reserved 7

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SIST EN ISO 15548-2:2014
ISO 15548-2:2013(E)

The span shall be 360°, either as 0° to 360° or 0° to ±180°.
The polarity of measurement shall be specified as follows:
— P360: 0° to 360°, positive is anticlockwise (mathematical convention);
— N360: 0° to 360°, positive is clockwise;
— P180: 0 to ±180°, positive is anticlockwise;
— N180: 0 to ±180°, positive is clockwise.
The phase angle is the angle between the reference line and the line representing the signal amplitude
determined in 6.2.2.2.
6.2.3 Surface probes
Unless otherwise specified, the measurements shall be conducted with constant probe clearance, which
will be specified in the application document.
6.2.3.1 Reference blocks
Reference blocks (A1 to A5) are described in general terms in Figure 3.
The detailed requirements of each block shall be given in a procedure.
For each of these reference blocks, the length and width shall be at least 10 times the length of coverage
of the probe as defined in the probe specifications. When this feature is not known, it shall be replaced
by the largest (active) dimension of the probe in the scanning plane. Verification can be made after
having measured the length of coverage as described in 6.2.3.8.
The thickness of the reference block shall be at least twice the standard depth of penetration for the
lowest frequency nominated in the probe specification.
Block A1
It contains a slot in its centre.
As a minimum:
— the slot shall be longer than the “minimum slot length for constant probe response”, determined
according to the methodology described in 6.2.3.10;
— the slot shall be deeper than the “minimum depth of surface-breaking slot for constant probe
response”, determined according to the methodology described in 6.2.3.11;
— the slot width shall be defined in the application document.
Block A2
It contains a hole in its centre.
The diameter of the hole is defined in the application document. It is recommended that the depth of the
hole be the same as that of the slot in block A1.
Block A3
It is the same as block A1, without a slot, and with varying thicknesses up to 3 times the standard depth
of penetration, or twice the active dimension of the probe.
8 © ISO 2013 – All rights reserved

---------------------- Page: 18 ---------
...

SLOVENSKI STANDARD
kSIST FprEN ISO 15548-2:2013
01-november-2013
1HSRUXãLWYHQRSUHVNXãDQMH2SUHPD]DSUHVNXãDQMH]YUWLQþQLPLWRNRYLGHO
=QDþLOQRVWLVRQGLQSUHYHUMDQMH ,62)',6
Non-destructive testing - Equipment for eddy current examination - Part 2: Probe
characteristics and verification (ISO/FDIS 15548-2:2013)
Zerstörungsfreie Prüfung - Technische Ausrüstung für die Wirbelstromprüfung - Teil 2:
Kenngrößen von Sensoren und deren Verifizierung (ISO/FDIS 15548-2:2013)
Essais non destructifs - Appareillage pour examen par courants de Foucault - Partie 2:
Caractéristiques des capteurs et vérifications (ISO/FDIS 15548-2:2013)
Ta slovenski standard je istoveten z: FprEN ISO 15548-2
ICS:
19.100 Neporušitveno preskušanje Non-destructive testing
kSIST FprEN ISO 15548-2:2013 en,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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kSIST FprEN ISO 15548-2:2013

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kSIST FprEN ISO 15548-2:2013
FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 15548-2
ISO/TC 135/SC 4
Non-destructive testing — Equipment
Secretariat: AFNOR
for eddy current examination —
Voting begins on:
2013-07-11
Part 2:
Voting terminates on:
Probe characteristics and verification
2013-09-11
Essais non destructifs — Appareillage pour examen par courants
de Foucault —
Partie 2: Caractéristiques des capteurs et vérifications
Please see the administrative notes on page iii
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 SUPPORTING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 15548-2:2013(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 2013

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kSIST FprEN ISO 15548-2:2013
ISO/FDIS 15548-2:2013(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2013
All rights reserved. Unless otherwise specified, 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
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2013 – All rights reserved

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kSIST FprEN ISO 15548-2:2013
ISO/FDIS 15548-2:2013(E)

ISO/CEN PARALLEL PROCESSING
This final draft has been developed within the International Organization for Standardization (ISO), and pro-
cessed under the ISO-lead mode of collaboration as defined in the Vienna Agreement. The final draft was
established on the basis of comments received during a parallel enquiry on the draft.
This final draft is hereby submitted to the ISO member bodies and to the CEN member bodies for a parallel
two-month approval vote in ISO and formal vote in CEN.
Positive votes shall not be accompanied by comments.
Negative votes shall be accompanied by the relevant technical reasons.
© ISO 2013 – All rights reserved iii

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kSIST FprEN ISO 15548-2:2013
ISO/FDIS 15548-2:2013(E)

Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Characteristics of probe and interconnecting elements . 1
4.1 General characteristics . 1
4.2 Electrical characteristics . 3
4.3 Functional characteristics . 3
5 Verification . 4
5.1 General . 4
5.2 Levels of verification . 4
5.3 Verification procedure . 5
5.4 Corrective actions . 5
6 Measurement of electrical and functional characteristics of a probe .5
6.1 Electrical characteristics . 5
6.2 Functional characteristics . 6
6.3 Normalised impedance plane diagram .24
7 Influence of interconnecting elements .24
Annex A (informative) Reference block A6 .25
Bibliography .27
iv © ISO 2013 – All rights reserved

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kSIST FprEN ISO 15548-2:2013
ISO/FDIS 15548-2:2013(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. 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. 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.
The committee responsible for this document is ISO/TC 135, Non-destructive Testing, Subcommittee
SC 4, Eddy current methods.
This second edition cancels and replaces the first edition (ISO 15548-2:2008), of which it constitutes a
minor revision.
ISO 15548 consists of the following parts, under the general title Non-destructive testing — Equipment
for eddy current examination:
— Part 1: Instrument characteristics and verification
— Part 2: Probe characteristics and verification
— Part 3: System characteristics and verification
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kSIST FprEN ISO 15548-2:2013

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kSIST FprEN ISO 15548-2:2013
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 15548-2:2013(E)
Non-destructive testing — Equipment for eddy current
examination —
Part 2:
Probe characteristics and verification
1 Scope
This part of ISO 15548 identifies the functional characteristics of a probe and its interconnecting
elements and provides methods for their measurement and verification.
The evaluation of these characteristics permits a well-defined description and comparability of eddy
current equipment.
By careful choice of the characteristics, a consistent and effective eddy current examination system can
be designed for a specific application.
Where accessories are used, these should be characterised using the principles of this part of ISO 15548.
This part of ISO 15548 does not give the extent of verification nor acceptance criteria for the
characteristics. These are given in the application documents.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 12718, Non-destructive testing — Eddy current testing — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 12718 apply.
4 Characteristics of probe and interconnecting elements
4.1 General characteristics
4.1.1 Application
Probes and interconnecting elements are selected to satisfy the requirements of the intended application.
The design is influenced by the instrument with which they are used.
4.1.2 Probe types
The probe is described by the following:
— type of material to be examined, i.e. ferromagnetic or non-ferromagnetic, with high or low
conductivity;
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kSIST FprEN ISO 15548-2:2013
ISO/FDIS 15548-2:2013(E)

— function, e.g. separate or combined transmit/receive probe;
— family, e.g. coaxial probe, surface probe;
— measurement mode, e.g. absolute, differential;
— purpose of the examination, e.g. detection of discontinuities, sorting or thickness measurement, etc.;
— specific features, e.g. focused, shielded, etc.
4.1.3 Interconnecting elements
They may include the following:
— cables and/or extensions;
— connectors;
— slip rings;
— rotating heads;
— transformers;
— active devices, e.g. multiplexer, amplifier, etc.
4.1.4 Physical characteristics
The following shall be stated among others:
— external size and shape;
— weight;
— information about mechanical mounting;
— model number and serial number;
— material of manufacture of probe housing;
— composition and thickness of facing material;
— presence and purpose of core or shield;
— type of interconnecting elements (see 4.1.3);
— orientation mark (direction for maximum sensitivity, see 6.2.3.3);
— position mark (electrical centre, see 6.2.3.4).
4.1.5 Safety
The probe and its interconnecting elements shall meet the applicable safety regulations regarding
electrical hazard, surface temperature, or explosion.
Normal use of the probe should not create a hazard.
4.1.6 Environmental conditions
The temperature and humidity for normal use, storage and transport should be specified for the probe
and its interconnecting elements.
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kSIST FprEN ISO 15548-2:2013
ISO/FDIS 15548-2:2013(E)

The tolerance of the probe and its interconnecting elements to the effects of interference noise and
electromagnetic radiation shall conform to electromagnetic compatibility (EMC) regulations.
Materials used in the manufacture of the probe should be resistant to contaminants.
4.2 Electrical characteristics
The external electrical connections to the probe shall be clearly identified or declared in writing.
The electrical characteristics of a probe connected to a specified length and type of cable are as follows:
— recommended range of excitation current and voltage for safe operation;
— recommended range of excitation frequencies;
— impedance of the excitation element in air;
— resonant frequency of the excitation element in air;
— impedance of the receiving element(s) in air.
The electrical characteristics of an extension cable shall also be clearly identified.
4.3 Functional characteristics
The functional characteristics of a probe shall be determined for a defined system.
The measurement of the functional characteristics of a probe requires the use of calibration blocks. The
material used for the reference block is determined by the application.
The functional characteristics of a probe are as follows:
— directionality;
— response to elementary discontinuities (hole, slot);
— length and width of coverage;
— area of coverage;
— minimum dimensions of discontinuities for constant response;
— penetration characteristics;
— geometric effects;
— normalised impedance locus (when the frequency is varied) of the exciting element with minimum
probe clearance from a homogeneous block of a specified material.
These characteristics cannot be used alone to establish the performance (e.g. resolution, smallest
detectable discontinuity, etc.) of the probe in a given test system, for a given application.
When relevant, the influence of interconnecting elements on the functional characteristics of the probe
shall be measured.
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kSIST FprEN ISO 15548-2:2013
ISO/FDIS 15548-2:2013(E)

5 Verification
5.1 General
For a consistent and effective eddy current examination, it is necessary to verify that the performance of
the component parts of the eddy current test system is maintained within acceptable limits.
The physical condition of the reference blocks shall be verified to be within acceptable limits, before
being used to verify the system or probes.
The measuring equipment used for verification shall be in a known state of calibration.
For a better understanding, the verification procedure is described identically in all three parts of ISO 15548.
5.2 Levels of verification
There are three levels of verification. Each level defines the time intervals between verification and the
complexity of the verification.
It is understood that initial type testing has already been carried out by the manufacturer or under his
control.
a) Level 1: Global functional check
A verification is performed at regular intervals of time on the eddy current test system, using
reference blocks to verify that the performance is within specified limits.
The verification is usually performed at the examination location.
The time interval and the reference blocks are defined in the verification procedure.
b) Level 2: Detailed functional check and calibration
A verification on an extended time scale is performed to ensure the stability of selected characteristics
of the eddy current instrument, probe, accessories and reference blocks.
c) Level 3: Characterisation
A verification is performed on the eddy current instrument, probe accessories and reference blocks
to ensure conformity with the characteristics supplied by the manufacturer.
The organization requiring the verification shall specify the characteristics to be verified.
The main features of verification are shown in Table 1.
Table 1 — Verification levels
Level Object Typical time period Instruments Responsible entity
1
Stability of system Frequently,
Global functional Reference blocks User
performance e.g. hourly, daily
check
Stability of selected
2 Less frequently but Calibrated measur-
characteristics of the
Detailed functional at least annually and ing instruments, User
instrument, probes
check and calibration after repair reference blocks
and accessories
All characteristics Calibrated labora-
Once
3 of the instrument, tory measuring
(on release) Manufacturer, user
Characterisation probes and acces- instruments and
and when required.
sories reference blocks
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kSIST FprEN ISO 15548-2:2013
ISO/FDIS 15548-2:2013(E)

5.3 Verification procedure
The characteristics to be verified are dependent on the application. The essential characteristics and the
level of verification shall be specified in a verification procedure.
The examination procedure for the application shall refer to the verification procedure. This can restrict
the number of characteristics of a general-purpose instrument to be verified for a defined application.
Sufficient data on the characteristics featured in an instrument, probe and reference block shall be
provided, in order that verification may be performed within the scope of this part of ISO 15548.
5.4 Corrective actions
Level 1: When the performance is not within the specified limits, a decision shall be made concerning
the product examined since the previous successful verification. Corrective actions shall be made to
bring the performance within acceptable limits.
Level 2: When the deviation of the characteristic is greater than the acceptable limits specified by the
manufacturer or in the application document, a decision shall be made concerning the instrument, the
probe or the accessory being verified.
Level 3: When the characteristic is out of the acceptable range specified by the manufacturer or by the
application document, a decision shall be made concerning the instrument, the probe or the accessory
being verified.
6 Measurement of electrical and functional characteristics of a probe
6.1 Electrical characteristics
6.1.1 General
The electrical characteristics alone do not define the characteristics of the probe in its application.
The methods and measuring instruments given in 6.1.2 to 6.1.5 are for guidance; other equivalent
methods and instrumentation can be used.
6.1.2 Measurement conditions
The measurements are made at the probe connector without the use of interconnecting elements of the
inspection system. The probe is placed in air and away from any conductive or magnetic material.
The measurements are made for each element of the probe accessible at the probe connector. The other
elements are left in open circuit.
When the probe is designed for use under particular conditions, for example, temperature or pressure,
any additional measurements that are required shall be specified in the application document.
6.1.3 Resonant frequency of the excitation element
6.1.3.1 Excitation element with a single coil
Using an impedance meter, measure the resonant frequency f of the excitation element.
res
6.1.3.2 Excitation elements with multiple coils
An excitation element containing multiple coils will give multiple resonance frequencies. The lowest
frequency shall be reported/measured.
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kSIST FprEN ISO 15548-2:2013
ISO/FDIS 15548-2:2013(E)

6.1.4 Impedance of the excitation element
Measure the resistance R using a multimeter, and the inductance L using an impedance meter. The
0 0
inductance is measured at the lowest frequency of the recommended operating range for the probe.
If the capacitance C is too small to be measured directly, calculation should provide a more accurate result:
0
1
C = (1)
0
2 2
4π fL
res 0
The model of the excitation-element impedance is given in Figure 1.
Figure 1 — Excitation-element impedance
6.1.5 Impedance of the receiving element(s)
Measure the resistance using a multimeter, and the inductance and the capacitance using an impedance
meter. The measured values of impedance can be given as a curve against frequency.
6.2 Functional characteristics
6.2.1 General
This part of ISO 15548 characterises commonly used probe types. Probes which are designed for special
(unusual) applications shall be characterised in accordance with an application document which follows
the methodology of this part of ISO 15548. The characteristics described in this part of ISO 15548 can
give useful information about such probes.
The functional characteristics are defined for two classes of probes: surface probes and co-axial probes.
6.2.2 Measurement conditions
6.2.2.1 General
A general-purpose eddy current instrument, characterised in accordance with ISO 15548-1, can be used,
provided that it has the required accuracy.
Alternatively, sufficient instrumentation comprising a voltage/current generator, synchronous detection
amplifier and a voltmeter or oscilloscope can be used.
When the probe does not feature a connecting cable, the characteristics of the cable used for the
measurements shall be documented.
The probe characteristics are measured within the frequency range specified by the probe manufacturer
using reference blocks containing known features, such as slots and holes.
The reference blocks shall be made using the specifications in the application document for the material,
metallurgical properties and surface finish. Its geometry shall comply with the requirements included
in the following subclauses. Blocks made from ferromagnetic material shall be demagnetized before use.
The reference block can be replaced by any other device, the equivalence of which shall be demonstrated
for the measured characteristic (alternative blocks, electric circuit, coil, ball, etc.).
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kSIST FprEN ISO 15548-2:2013
ISO/FDIS 15548-2:2013(E)

The functional characteristics can be affected by the presence of any perturbing electromagnetic field
or ferromagnetic material in the zone of influence of the probe. Care shall be taken to avoid these effects
when making the measurements described in 6.2.2.2 and 6.2.2.3.
The measurement conditions for each characteristic shall be recorded, for example, excitation frequency
and voltage/current, details of the reference block, etc.
The measured values are the amplitude of the signal and, when applicable, the phase of the signal.
6.2.2.2 Measurement of the amplitude of the signal
a) Absolute measurements
The amplitude of the signal is the length of the vector joining the balance point to the point
corresponding to the maximum excursion of the signal from the balance point, unless otherwise
specified in an application document, see Figure 2 a).
b) Differential measurements
The amplitude of the signal is the length of the line joining the two extreme points of the signature,
i.e. peak to peak value, unless otherwise specified in an application document; see Figure 2 b).
c) Other measurements
The method shall be specified in an application document.
a) Amplitude measurement for an absolute signal
b) Amplitude measurement for a differential signal
Figure 2 — Amplitude measurements for signals
6.2.2.3 Measurement of the phase angle of the signal
The reference for the measurement of phase angle shall be the positive x-axis.
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kSIST FprEN ISO 15548-2:2013
ISO/FDIS 15548-2:2013(E)

The span shall be 360°, either as 0° to 360° or 0° to ±180°.
The polarity of measurement shall be specified as follows:
— P360: 0° to 360°, positive is anticlockwise (mathematical convention);
— N360: 0° to 360°, positive is clockwise;
— P180: 0 to ±180°, positive is anticlockwise;
— N180: 0 to ±180°, positive is clockwise.
The phase angle is the angle between the reference line and the line representing the signal amplitude
determined in 6.2.2.2.
6.2.3 Surface probes
Unless otherwise specified, the measurements shall be conducted with constant probe clearance, which
will be specified in the application document.
6.2.3.1 Reference blocks
Reference blocks (A1 to A5) are described in general terms in Figure 3.
The detailed requirements of each block shall be given in a procedure.
For each of these reference blocks, the length and width shall be at least 10 times the length of coverage
of the probe as defined in the probe specifications. When this feature is not known, it shall be replaced
by the largest (active) dimension of the probe in the scanning plane. Verification can be made after
having measured the length of coverage as described in 6.2.3.8.
The thickness of the reference block shall be at least twice the standard depth of penetration for the
lowest frequency nominated in the probe specification.
Block A1
It contains a slot in its centre.
As a minimum:
— the slot shall be longer than the “minimum slot length for constant probe response”, determined
according to the methodology described in 6.2.3.10;
— the slot shall be deeper than the “minimum depth of surface-breaking slot for constant probe
response”, determined according to the methodology described in 6.2.3.11;
— the slot width shall be defined in the application document.
Block A2
It contains a hole in its centre.
The diameter of the hole is defined in the application document. It is recommended that the depth of the
hole be the same as that of the slot in block A1.
Block A3
It is the same as block A1, without a slot, and with varying thicknesses up to 3 times the standard depth
of penetration, or twice the active dimension of the probe.
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kSIST FprEN ISO 15548-2:2013
ISO/FDIS 15548-2:2013(E)

Block A4
It is the same as block A1, with n parallel slots.
— all the slots have the same length and width as the slot of block A1;
— the slot depth increases from slot 1 to n by a constant step specified in the application document;
— the spacing between two consecutive slots shall be at least 5 times the length of coverage (6.2.3.8);
— the distance from the first and the last slot to the adjacent edge shall be at least 2,5 times the edge-
effect length.
The number of slots and their depths are defined in the application document.
Block A5
It is the same as block A1, with n parallel slots.
— all the slots have the same depth and width as the slot of block A1;
— the slot length increases from slot 1 to n by a constant step specified in the application document;
the ends of the longest slot shall be further than 2,5 times the edge-effect length away from the edge;
— the spacing between two consecutive slots shall be at least 5 times the length of coverage (6.2.3.8);
— the distance from the first and the last slot to the adjacent edge shall be at least 2,5 times the edge-
effect length;
— all the slots are centred with respect to the block;
— the number of slots and their lengths are defined in the application document.
Figure 3 — Reference blocks for surface probes
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kSIST FprEN ISO 15548-2:2013
ISO/FDIS 15548-2:2013(E)

Block A6
This block is defined to obtain a transfer signal. See 6.2.3.16
6.2.3.2 Reference signal
Reference block: block A1 shall be used for this measurement.
Probe motion
Balance the probe on the block with the probe mid-way between the slot and the adjacent edge of the block.
Verify that no significant change occurs when moving the probe in the vicinity of this position, in the
direction of the slot and that of the edge.
A linear scan is performed over the middle of the slot, with the preferred orientation of the probe
perpendicular to the slot (see Figure 4). For this measurement, the preferred orientation shall be the
one defined by the manufacturer. In the case where the probe is explicitly designed for scanning slots
non-perpendicular to the probe motion (e.g. parallel), an alternative procedure shall be described in the
application document.
Results
The instrument is adjusted so that the maximum signal corresponds to a given value of
...

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