Overview
EN ISO 16809:2025 / ISO 16809:2025 - "Non‑destructive testing - Ultrasonic thickness determination" - defines principles for measuring the thickness of metallic and non‑metallic materials using ultrasonic contact or immersion techniques based solely on the time‑of‑flight of ultrasonic pulses. Adopted by CEN as EN ISO 16809:2025 (superseding EN ISO 16809:2019), this international standard provides guidance on equipment, technique selection, instrument setting and factors affecting measurement accuracy for ultrasonic thickness determination.
Key topics and requirements
The standard covers practical and technical requirements in these areas:
- Modes of determination: contact technique and immersion technique using time‑of‑flight.
- General requirements: ultrasonic instruments, probes, couplants, reference blocks and test object considerations.
- Qualification: competence and qualification of test personnel for reliable ultrasonic thickness measurement.
- Application guidance: surface condition and preparation, procedures for manufacture and in‑service residual wall thickness determination.
- Selection criteria: how to choose probes and instruments for specific materials and geometries.
- Special conditions: guidance for measurements at low or elevated temperatures and in hazardous atmospheres.
- Instrument setting: methods for setting devices (numerical displays and A‑scan presentation) and checks of settings.
- Accuracy influences: effects of surface condition, temperature, coatings (metallic/non‑metallic), geometry, material inhomogeneity, anisotropy and sound attenuation.
- Reporting: required test report information and presentation of results.
- Informative annexes: corrosion in vessels/piping, typical instrument settings, parameters influencing accuracy and technique selection.
Keywords naturally addressed: ultrasonic thickness determination, ultrasonic thickness measurement, non‑destructive testing, time‑of‑flight, contact technique, immersion technique, ISO 16809:2025.
Applications
EN ISO 16809:2025 is applicable wherever reliable thickness data are required without destructive sectioning:
- Corrosion and erosion monitoring of pipelines, pressure vessels and storage tanks
- Quality control during manufacture of metal and composite components
- Routine in‑service inspection and remaining wall thickness assessments
- Material verification where non‑invasive thickness checks are needed
Who uses this standard
Typical users include:
- NDT technicians and inspection engineers
- Asset integrity and corrosion engineers
- Manufacturing quality managers
- Third‑party inspection bodies and certification authorities
- Standards committees and technical trainers
Related standards
- ISO 16809:2025 (third edition) as the source document; adopted by CEN as EN ISO 16809:2025.
- Other NDT and ultrasonic testing standards (refer to national bodies and ISO/TC 135 for specific complementary documents).
This standard is essential for practitioners specifying, performing or interpreting ultrasonic thickness measurements to ensure consistent, reproducible and defensible results.
