ISO 16827-2025 PDF

Full title and description

Non-destructive testing — Ultrasonic testing — Characterization and sizing of discontinuities (ISO 16827:2025). This international standard specifies general principles and techniques for characterizing and sizing discontinuities previously detected by ultrasonic testing to enable their evaluation against applicable acceptance criteria.

Abstract

This document specifies the general principles and techniques for the characterization and sizing of previously detected discontinuities so they can be evaluated against applicable acceptance criteria. It is applicable, in general terms, to discontinuities in the materials and applications covered by ISO 16810. Techniques using phased-array (multi-element) probes may be applied but can require additional steps or verifications.

General information

• Status: Published.
• Publication date: 11 June 2025 (Edition 2, 2025-06).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 19.100 (Non-destructive testing).
• Edition / version: Edition 2 (2025).
• Number of pages: 50 pages.

Core bibliographic details and lifecycle (replacement of ISO 16827:2012) are recorded in the official ISO catalogue.

Scope

ISO 16827:2025 provides requirements and guidance for the characterization (qualitative description) and sizing (measurement of relevant dimensions) of discontinuities detected by ultrasonic testing. The standard is written to be used alongside general ultrasonic principles (ISO 16810) and application-specific documents; it does not by itself define acceptance criteria or detailed scan plans but enables consistent assessment of defect geometry and attributes needed for acceptance decisions. Phased-array techniques are acknowledged and covered with notes that additional verifications or method-specific steps may be necessary.

Key topics and requirements

• Definitions and classification of discontinuities relevant to ultrasonic characterization.
• Recommended measurement techniques for sizing discontinuity length, height/depth and orientation using conventional and array probes.
• Principles for calibration, verification and use of reference blocks or calibration artefacts.
• Guidance on probe movement techniques, beam path consideration and angle/positioning for accurate sizing.
• Requirements for reporting measured dimensions, uncertainty estimation and applicable metadata (equipment, settings, calibration status).
• Considerations for the interpretation of ultrasonic signals (echo amplitude, multiple echoes, signal-to-noise) when characterizing discontinuities.
• Notes on the application of phased-array/multi-element techniques and when extra validation steps are required.
• References to general ultrasonic testing principles (ISO 16810) and related weld-testing methods for assessment context.

Typical use and users

This standard is intended for nondestructive testing practitioners, inspection engineers, procedure writers, calibration laboratories, asset owners and regulatory bodies who need standardized methods to characterize and size ultrasonic-detected discontinuities. Common application sectors include manufacturing quality control, oil & gas, power generation, aerospace, transport (rail/ship), and welded-structure inspection where reliable defect assessment is required prior to acceptance or fitness-for-service decisions.

Related standards

Key related documents referenced or commonly used with ISO 16827:2025 include: ISO 16810 (Ultrasonic testing — General principles) which establishes overarching UT principles, and ultrasonic weld-testing standards such as ISO 17640 for manual ultrasonic testing of welded joints. The 2025 edition of ISO 16827 replaces the earlier ISO 16827:2012.

Keywords

ultrasonic testing, nondestructive testing, NDT, discontinuity characterization, defect sizing, phased-array, calibration, inspection reporting, ISO 16827, ISO 16810.

FAQ

Q: What is this standard?

A: ISO 16827:2025 is an international standard that provides principles and techniques for characterizing and sizing discontinuities detected by ultrasonic testing.

Q: What does it cover?

A: It covers methods for describing and measuring the geometry and relevant attributes of ultrasonic-detected discontinuities so they can be evaluated against acceptance criteria defined elsewhere. It is applicable across materials and applications referenced by ISO 16810 and notes how phased-array techniques may be used with additional verifications.

Q: Who typically uses it?

A: NDT technicians and inspectors, inspection engineers, quality managers, procedure developers, calibration labs and asset owners in industries such as oil & gas, power, aerospace, manufacturing and transportation—anywhere reliable ultrasonic defect characterization and sizing are required.

Q: Is it current or superseded?

A: ISO 16827:2025 is the current published edition (Edition 2, published June 2025) and it replaces ISO 16827:2012.

Q: Is it part of a series?

A: Yes. ISO 16827 is part of a family of ultrasonic testing documents (for example ISO 16810 for general ultrasonic principles) and is typically used alongside application-specific UT standards such as ISO 17640 for weld testing.

Q: What are the key keywords?

A: Ultrasonic testing, nondestructive testing (NDT), discontinuity sizing, characterization, phased-array, calibration, inspection reporting, ISO 16827, ISO 16810.