Overview
EN ISO 18081:2024 - Non‑destructive testing (NDT) - Acoustic emission testing (AT) - Leak detection by means of acoustic emission (ISO 18081:2024) specifies the general principles for detecting leaks using acoustic emission (AE). The standard covers AE generation phenomena, the effects of fluid type and gap geometry, wave propagation and environmental influences. It also addresses instrumentation, application techniques, data presentation, test documentation and provides example procedures (Annex A). This edition supersedes the 2016 version and is intended for use on structures and components where pressure-driven leak flow produces detectable AE.
Key Topics
- Principle of AE leak detection: description of acoustic emission phenomena and how pressure differences generate leak-related AE.
- Influence factors: effects of fluid phase, leak-path geometry, and wave propagation on AE signals.
- Equipment and sensors:
- Requirements for sensors (frequency ranges, mounting, temperature and immersion considerations).
- Instrument types (portable vs. fixed, single-channel and multi-channel systems).
- Intrinsic safety and integral electronics (amplifiers, RMS/ASL converters, band‑pass).
- Signal features and acquisition: RMS, ASL, hit/continuous/burst AE, system verification using artificial leak sources.
- Location methods: single‑sensor attenuation techniques and multi‑sensor Δt methods (threshold/peak timing, cross‑correlation).
- Data presentation & interpretation: level meters, parametric functions, frequency spectra, leak validation, correlation with pressure, and leakage‑rate estimation.
- Quality management: requirements for test procedures, test instructions, personnel qualification, documentation and reporting.
Applications and Users
EN ISO 18081:2024 is relevant for professionals and organizations involved in acoustic emission leak testing and NDT, including:
- NDT engineers and technicians performing leak detection on pressure vessels, piping, storage tanks and process equipment.
- Inspection and maintenance teams in oil & gas, petrochemical, power generation, water utilities and manufacturing.
- Asset owners, quality managers and certification bodies specifying AE leak testing requirements.
- Test equipment manufacturers and service providers designing AE instrumentation and test protocols.
Practical applications include on‑site leak localization, screening of fabricated components, periodic integrity inspections and condition-based maintenance programs where non-invasive AE leak detection provides fast, sensitive detection without depressurization where feasible.
Related Standards (if applicable)
The standard references general NDT standards and ISO/TC 135 outputs for AE testing; users should consider companion standards for personnel qualification, instrument calibration, and sector‑specific leak testing requirements when developing test plans and reports.