Overview
ISO 15549:2019 - "Non‑destructive testing - Eddy current testing - General principles" defines the general principles and practices for eddy current testing (ECT) to ensure defined, repeatable performance. This international standard covers the scope, examination techniques, equipment selection, probe and instrument requirements, verification, preparation of products, examination steps, acceptance criteria and documentation. It replaces ISO 15549:2008 (second edition, 2019) with a major update to Clause 5 on qualification of personnel.
Keywords: ISO 15549:2019, eddy current testing, non‑destructive testing, NDT, inspection.
Key Topics and Requirements
- Fundamental principles: ECT is based on induction of alternating currents in conductive materials; signal behavior is represented in the complex plane and is influenced by conductivity, permeability, geometry and probe positioning.
- Personnel qualification: Operators must be certified in accordance with ISO 9712 (or equivalent) - a key requirement for NDT personnel competence.
- Examination techniques: Supports static and dynamic scanning; common measurement modes include absolute, comparative, differential, double‑differential and pseudo‑differential techniques for crack detection, sorting and property assessment.
- Equipment and probes: The standard requires specification of the complete examination system (instrument, probes, cabling, mechanical fixtures and data units). Instrument and probe parameters must be characterized per ISO 15548‑1 and ISO 15548‑2.
- Reference test pieces: Use of material‑equivalent reference blocks, notches, induced defects or coating standards for setup, functional checks, capability verification and calibration.
- Verification and maintenance: Defines functional and preventive verification, and verification intervals to maintain repeatable performance.
- Preparation and documentation: Surface and product preparation, probe mounting/clearance control, scan-path control for mechanized inspection, acceptance criteria and full reporting requirements including application documents.
Keywords: instrument verification, probe characteristics, reference test pieces, calibration.
Applications and Users
Practical applications of ISO 15549:2019 include:
- On‑line quality control in rolling mills, finishing and drawing lines.
- In‑service inspection of heat‑exchanger tubing and hydraulic components.
- Verification of properties for mass‑produced parts, bars, tubes, wires and forged/cast components.
- Aircraft maintenance and inspection of multilayer aerospace components.
Primary users:
- NDT engineers and technicians
- Quality managers and inspection planners
- Aerospace, automotive, metal‑forming and power‑plant maintenance teams
- NDT equipment manufacturers and calibration laboratories
Keywords: NDT engineers, inspection planning, eddy current inspection.
Related Standards
- ISO 9712 - Qualification and certification of NDT personnel
- ISO 12718 - Eddy current testing - Vocabulary
- ISO 15548‑1 - ECT equipment: instrument characteristics and verification
- ISO 15548‑2 - ECT equipment: probe characteristics and verification
Using ISO 15549:2019 ensures consistent eddy current testing practice, traceable verification and reliable inspection results across industrial NDT applications.
