Overview
ISO 23865:2021 - Non-destructive testing - Ultrasonic testing - General use of full matrix capture/total focusing technique (FMC/TFM) and related technologies - provides general provisions and good-practice guidance for applying array-based ultrasonic inspection using FMC/TFM. The standard promotes consistent, repeatable ultrasonic testing (UT) workflows for manufacturing, in-service inspection and repairs. It focuses on imaging, characterization and sizing of discontinuities in homogeneous, isotropic materials (e.g., low-alloy carbon steels and common aerospace aluminium and titanium alloys) and gives recommendations for other materials (for example, austenitic steels). ISO 23865:2021 does not define acceptance levels for discontinuities; weld-specific guidance is covered in ISO 23864.
Key Technical Topics and Requirements
ISO 23865:2021 addresses the full lifecycle of FMC/TFM inspection and related technologies, including:
- Principle and comparison: explanation of FMC/TFM vs conventional phased array (PAUT), and when to use total focusing technique for superior image resolution.
- Surface condition and couplant: requirements to ensure reliable acoustic coupling and repeatable results.
- Information before testing: data needed to plan procedures (material, geometry, expected defects).
- Personnel: competency and qualification expectations aligned with ISO 9712 for NDT personnel.
- Equipment and probes: instrument, probe and scanning mechanism requirements; sampling frequency and probe characteristics.
- Data acquisition & processing: FMC capture, TFM imaging, post-processing, sensitivity correction and grid verification.
- Preparation & verification: system checks, sensitivity setting, ROI/grid verification, and recommended test parameters.
- Evaluation & reporting: interpretation of TFM images, assessment of image quality, identification/characterization of indications, data storage and test report content.
Practical Applications and Users
ISO 23865:2021 is intended for professionals implementing advanced ultrasonic imaging and inspection programs:
- NDT engineers and inspection technicians applying FMC/TFM for high-resolution imaging.
- Manufacturers and quality teams using ultrasonic array inspection during production.
- Asset owners and service providers performing in-service inspection, damage assessment, characterization and sizing.
- NDT training and certification bodies referencing best practices for array-based UT.
Benefits include improved defect detectability and sizing accuracy through full matrix capture and total focusing processing, making FMC/TFM well suited for complex geometries and critical aerospace, petroleum, power and transport components.
Related Standards
Key normative and related references mentioned in ISO 23865:2021:
Keywords: ISO 23865:2021, FMC/TFM, full matrix capture, total focusing technique, ultrasonic testing, NDT, phased array, inspection, characterization, sizing.