SIST EN ISO 16826:2025

SLOVENSKI STANDARD
01-junij-2025
Neporušitvene preiskave - Ultrazvočne preiskave - Preiskave za odkrivanje
nehomogenosti, ki potekajo pravokotno na površino (ISO 16826:2025)
Non-destructive testing - Ultrasonic testing - Testing for discontinuities perpendicular to
the surface (ISO 16826:2025)
Zerstörungsfreie Prüfung - Ultraschallprüfung - Prüfung auf Inhomogenitäten senkrecht
zur Oberfläche (ISO 16826:2025)
Essais non destructifs - Contrôle par ultrasons - Contrôle des discontinuités
perpendiculaires à la surface (ISO 16826:2025)
Ta slovenski standard je istoveten z: EN ISO 16826:2025
ICS:
19.100 Neporušitveno preskušanje Non-destructive testing
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 16826
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2025
EUROPÄISCHE NORM
ICS 19.100 Supersedes EN ISO 16826:2014
English Version
Non-destructive testing - Ultrasonic testing - Testing for
discontinuities perpendicular to the surface (ISO
16826:2025)
Essais non destructifs - Contrôle par ultrasons - Zerstörungsfreie Prüfung - Ultraschallprüfung -
Contrôle des discontinuités perpendiculaires à la Prüfung auf Inhomogenitäten senkrecht zur Oberfläche
surface (ISO 16826:2025) (ISO 16826:2025)
This European Standard was approved by CEN on 1 March 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 16826:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 16826:2025) 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 September 2025, and conflicting national standards
shall be withdrawn at the latest by September 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 16826:2014.
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 16826:2025 has been approved by CEN as EN ISO 16826:2025 without any modification.

International
Standard
ISO 16826
Second edition
Non-destructive testing — Ultrasonic
2025-03
testing — Testing for discontinuities
perpendicular to the surface
Essais non destructifs — Contrôle par ultrasons — Contrôle des
discontinuités perpendiculaires à la surface
Reference number
ISO 16826:2025(en) © ISO 2025
ISO 16826:2025(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
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 16826:2025(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Test equipment and test personnel . 1
5 Tandem technique . 2
5.1 General .2
5.2 Probe movement .3
5.3 Time base setting .3
5.4 Sensitivity setting .3
5.5 Determination of test zones .4
5.6 Depth-gain diagram for tandem technique .5
5.7 Corrections of sensitivity .6
5.8 Test objects with concentric surfaces .6
5.8.1 General .6
5.8.2 Scanning on a concave surface .7
5.8.3 Scanning on a convex surface .7
6 Longitudinal-longitudinal-transverse wave technique . 8
6.1 General .8
6.2 Time base setting and determination of depth of a discontinuity .9
6.3 Sensitivity setting .10
6.4 Determination of the depth of the intersection of the beam axes .10
6.5 Sensitivity diagram for LLT technique .11
6.6 Correction of sensitivity .11
Annex A (informative) Nomograms for tandem distances for convex and concave surfaces .12
Bibliography .15

iii
ISO 16826:2025(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 maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
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 135, Non-destructive testing, Subcommittee
SC 3, Ultrasonic testing, in collaboration with the European Committee for Standardization (CEN) Technical
Committee CEN/TC 138, Non-destructive testing, in accordance with the Agreement on technical cooperation
between ISO and CEN (Vienna Agreement).
This second edition cancels and replaces the first edition (ISO 16826:2012), which has been technically
revised.
The main changes are as follows:
— revised figures and formulae;
— editorial revisions.
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.

iv
ISO 16826:2025(en)
Introduction
The following documents on ultrasonic tes
...