Overview
EN ISO 16823:2025 - "Non-destructive testing - Ultrasonic testing - Through-transmission technique" defines the principles and practical framework for ultrasonic through‑transmission testing (UT-TT). The standard covers the use of through‑transmission methods to detect discontinuities and determine sound attenuation, primarily for flat products such as plates and sheets and for situations where direct reflection techniques are unsuitable.
Key topics and technical requirements
EN ISO 16823:2025 addresses the essential elements needed to perform reliable through‑transmission ultrasonic testing:
- Scope and purpose: Use cases (discontinuity detection, attenuation measurement) and limitations (flat/thin items, high‑attenuation materials).
- NDT personnel: Applicability of personnel competence and responsibilities in line with ISO 16810.
- Test equipment: Requirements for instruments (ISO 22232‑1) and probes (ISO 22232‑2), including probe selection, frequency, transducer dimensions, dead‑zone and damping considerations.
- Coupling media: Guidance on selection and use of couplants for transmitter/receiver interfaces.
- Standard and reference blocks: Use of calibration/standard blocks and specific test blocks for sensitivity and verification.
- Principles of testing: Basic setups, capability to detect discontinuities, geometric/access requirements, and effects of coupling, angulation and probe alignment.
- Test technique: Sensitivity setting, scanning procedures, evaluation of discontinuities and methods to determine the attenuation coefficient (comparative methods using reference blocks and techniques based on the test object).
- Normative references and terminology: Aligns vocabulary with ISO 5577 and related calibration specifications.
Practical applications - who uses it
EN ISO 16823:2025 is intended for:
- NDT technicians and inspectors performing ultrasonic inspections on flat products (plates, sheets).
- Quality, inspection and NDT engineers specifying test procedures in manufacturing, fabrication and maintenance.
- Calibration laboratories and equipment manufacturers developing probes, instruments and reference blocks.
- Certification bodies and standards committees developing test programs or training curricula.
Typical applications:
- Inspection of metallic and non‑metallic flat products where reflectometric techniques fail due to geometry or orientation of flaws.
- Testing thin components and materials with high sound attenuation.
- Quantifying material attenuation for material characterization or process control.
Related standards
Keywords: EN ISO 16823:2025, ultrasonic testing, through-transmission, UT-TT, non-destructive testing, NDT, plates, sheets, attenuation, discontinuity detection, probes, calibration blocks.
