Overview
ISO 24489:2024 - Non-destructive testing (NDT) - Acoustic emission testing (AE) - provides a standardized methodology to detect and classify corrosion on atmospheric and low‑pressure (≤ 50 kPa) metallic storage tank floors. The standard applies to floors made of construction steel and is based on detecting acoustic emission generated by an active corrosion process. It specifies test equipment, personnel qualification, test procedures, data interpretation and a classification system with maintenance recommendations.
Key topics and technical requirements
- Scope: Atmospheric and low‑pressure metallic tank floors where corrosion is the primary damage mechanism; good results expected if corrosion conditions are stable.
- Personnel: Test personnel should be competent - ISO 9712 or equivalent recommended.
- AE system components: AE instrument and software, sensors, preamplifiers, cables, couplant and mounting devices. All essential parts must be documented in a written test instruction.
- Sensor requirements:
- Main response frequency 20 kHz–80 kHz
- Minimum sensitivity ≥ 60 dB (referred to 1 V·s/m) in appropriate wave settings
- Shielding against radio‑frequency/electromagnetic noise; metallic housing electrically isolated from tank
- Stability within ±3 dB across expected frequency and temperature range
- Verification: a Hsu‑Nielsen source at 100 mm must produce a peak amplitude ≥ 80 dB AE
- Preamplifiers and cables:
- Preamplifier circuit noise RMS < 7 µV
- Cables shielded; sensor‑to‑preamplifier cable length ≤ 1 m unless losses are accounted for
- Test procedures:
- Site inspection, sensor mounting, instrument setup, simulation of AE sources, determination of sound velocity, background noise checks, sensitivity/threshold adjustment
- Consideration of tank liquid level and interfering AE sources
- Data handling & classification:
- Data acquisition, processing and a classification system (including time‑difference location analysis - Annex A, and overall floor condition analysis - Annex B)
- Documentation: Written test instructions, records and comprehensive test reports.
Applications and users
ISO 24489:2024 is intended for:
- NDT service providers and AE technicians
- Storage tank operators, asset managers and maintenance planners in petrochemical, oil & gas, terminals and utilities
- Inspection engineers and regulatory bodies evaluating floor corrosion risk
Practical benefits include early detection of active corrosion, prioritization of maintenance, reduced unplanned outages and support for risk‑based inspection programs.
Related standards
- ISO 12716 - Acoustic emission vocabulary
- EN 13477‑2 - AE equipment characterization (verification)
- ISO 9712 - Personnel qualification (recommended)
Keywords: ISO 24489:2024, acoustic emission testing, AE, non‑destructive testing, corrosion detection, metal storage tank floors, atmospheric tank, low‑pressure.