EN ISO 16827:2025

SLOVENSKI STANDARD
01-oktober-2025
Neporušitvene preiskave - Ultrazvočne preiskave - Karakterizacija in velikosti
nezveznosti (ISO 16827:2025)
Non-destructive testing - Ultrasonic testing - Characterization and sizing of discontinuities
(ISO 16827:2025)
Zerstörungsfreie Prüfung - Ultraschallprüfung - Beschreibung und Größenbestimmung
von Inhomogenitäten (ISO 16827:2025)
Essais non destructifs - Contrôle par ultrasons - Caractérisation et dimensionnement des
discontinuités (ISO 16827:2025)
Ta slovenski standard je istoveten z: EN ISO 16827:2025
ICS:
19.100 Neporušitveno preskušanje Non-destructive testing
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 16827
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2025
EUROPÄISCHE NORM
ICS 19.100 Supersedes EN ISO 16827:2014
English Version
Non-destructive testing - Ultrasonic testing -
Characterization and sizing of discontinuities (ISO
16827:2025)
Essais non destructifs - Contrôle par ultrasons - Zerstörungsfreie Prüfung - Ultraschallprüfung -
Caractérisation et dimensionnement des discontinuités Beschreibung und Größenbestimmung von
(ISO 16827:2025) Inhomogenitäten (ISO 16827:2025)
This European Standard was approved by CEN on 7 June 2025.

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
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 16827:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 16827:2025) 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 December 2025, and conflicting national standards
shall be withdrawn at the latest by December 2025.
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.
This document supersedes EN ISO 16827:2014.
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 16827:2025 has been approved by CEN as EN ISO 16827:2025 without any modification.

International
Standard
ISO 16827
Second edition
Non-destructive testing —
2025-06
Ultrasonic testing —
Characterization and sizing of
discontinuities
Essais non destructifs — Contrôle par ultrasons —
Caractérisation et dimensionnement des discontinuités
Reference number
ISO 16827:2025(en) © ISO 2025
ISO 16827:2025(en)
© ISO 2025
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
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CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 16827:2025(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principles of characterization of discontinuities . 1
4.1 General .1
4.2 Requirements for surface condition .2
5 Pulse-echo techniques . 2
5.1 General .2
5.2 Location of discontinuity .2
5.3 Orientation of discontinuity .3
5.4 Assessment of multiple indications .3
5.5 Shape of discontinuity .4
5.5.1 Simple classification .4
5.5.2 Detailed classification .4
5.6 Maximum echo height of indication .5
5.7 Size of discontinuity.5
5.7.1 General .5
5.7.2 Maximum echo height techniques .5
5.7.3 Probe movement sizing techniques .6
5.7.4 Selection of sizing techniques .7
5.7.5 Sizing techniques with focusing probes .8
5.7.6 Use of mathematical algorithms for sizing .8
5.7.7 Special sizing techniques .8
6 Through-transmission technique . 9
6.1 General .9
6.2 Location of discontinuity .9
6.3 Evaluation of multiple discontinuities .9
6.4 Reduction of signal amplitude .10
6.5 Size of discontinuity.10
Annex A (normative) Analysis of multiple indications .12
Annex B (normative) Techniques for the classification of discontinuity shape . 14
Annex C (normative) Sizing technique using the maximum echo height .23
Annex D (normative) Sizing techniques using probe movement .25
Annex E (informative) Iterative sizing technique .37
Annex F (informative) Mathematical algorithms for the estimation of the actual size of a
discontinuity . 41
Annex G (informative) Examples of special sizing techniques . 47
Bibliography .50

iii
ISO 16827:2025(en)
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 mai
...