Overview
EN ISO 16811:2025 - Non‑destructive testing - Ultrasonic testing - Sensitivity and range setting (ISO 16811:2025) specifies the general rules for setting the time‑base range and sensitivity (gain) of manually operated ultrasonic instruments with A‑scan display. Its purpose is to ensure reproducible determination of reflector location and echo height when using contact ultrasonic techniques with a single probe (single or dual transducers). This edition (2025) is prepared by ISO/TC 135 and endorsed by CEN, superseding EN ISO 16811:2014. It does not apply to immersion testing or multi‑probe techniques.
Key topics and technical requirements
The standard addresses practical and technical elements needed for reliable ultrasonic testing and calibration:
- Scope and definitions for quantities, symbols and personnel qualification requirements.
- Test equipment requirements: instrument characteristics, probe types, coupling media and damping considerations.
- Probe selection and characteristics: frequency, transducer dimensions, dead zone, focusing, and probes curved longitudinally or transversely.
- Reference and standard blocks: use of calibration blocks, reference reflectors and specific test blocks for setting time base and sensitivity.
- Probe index point and beam angle: mechanical and reference‑block techniques for determining probe position and beam direction.
- Time‑base (range) setting methods for straight‑beam and angle‑beam probes, including alternative range settings for flat and curved surfaces.
- Sensitivity and echo‑height evaluation: procedures for setting gain and interpreting echo heights, including Distance‑Amplitude Curve (DAC) and Distance‑Gain‑Size (DGS) techniques and use of DAC/DGS reference blocks.
Practical applications and users
This standard is intended for organizations and professionals involved in manual contact ultrasonic inspection, including:
- NDT technicians and inspectors conducting thickness, flaw detection and weld inspection using A‑scan instruments.
- Calibration and test laboratories that prepare and validate reference blocks and probe settings.
- Quality, safety and inspection engineers developing inspection procedures and acceptance criteria.
- Training bodies and certification schemes for ultrasonic testing personnel.
Benefits include improved reproducibility of echo height measurements, consistent time‑base settings across inspections, and clearer traceability of calibration and sensitivity decisions.
Related standards and context
- EN ISO 16811:2025 is the CEN‑endorsed version of ISO 16811:2025 and replaces the 2014 edition.
- Users should apply this standard alongside other ultrasonic NDT guidance and organizational inspection procedures to ensure complete coverage of test methods, acceptance criteria and personnel qualifications.
Keywords: EN ISO 16811:2025, ultrasonic testing, non‑destructive testing, A‑scan, sensitivity and range setting, DAC, DGS, probe calibration, time‑base, single probe.
