UNE-EN ISO 16828:2026

This document specifies the general principles for the application of the time-of-flight diffraction (TOFD)

technique for both detection and sizing of discontinuities in low-alloyed carbon steel components.

This document can also be used for other types of materials, provided the application of the TOFD technique

is performed with necessary consideration of geometry, acoustical properties of the materials, and the test

sensitivity.

Although, this document is applicable, in general terms, for discontinuities in materials and applications

covered by ISO 16810, it contains references to the application on welds. This approach has been chosen for

reasons of clarity as to the probe positions and directions of scanning.

Unless otherwise specified in the referencing documents, the minimum requirements of this document are

applicable.

Unless explicitly stated otherwise, this document is applicable to the following product classes as defined in

ISO 16811:

class 1, without restrictions;

classes 2 and 3, specified restrictions apply.

NOTE 1 See Clause 10.

classes 4 and 5 require special procedures, which are also addressed.

NOTE 2 See Clause 10.

NOTE 3 Techniques for the use of TOFD for weld testing are described in ISO 10863 and the related acceptance

criteria are given in ISO 15626.