BS ISO 24489:2024
Non-destructive testing. Acoustic emission testing. Detection of corrosion at atmospheric and low-pressure metallic storage tank floors
- Standard No.
- BS ISO 24489:2024
- Release Date
- 2024
- Published By
- British Standards Institution (BSI) GB / BSI
- Latest
- BS ISO 24489:2024
- Introduction
Analysis of the core content of the standard
BS ISO 24489:2024 is a technical specification for acoustic emission testing jointly issued by the International Organization for Standardization (ISO) and the British Standards Institution (BSI). It is specifically used to evaluate the corrosion state of the bottom plate of atmospheric and low-pressure (≤50kPa) metal storage tanks. The standard establishes a corrosion activity classification system for the first time, filling the technical gap in the existing acoustic emission standards.
Technical Framework Comparison
Technical Elements ISO 24489 Requirements Traditional Detection Methods Detection Principle Analysis of Elastic Wave Signals Generated by Corrosion Process Visual Inspection/Ultrasonic Thickness Measurement Equipment Requirements 20-80kHz Sensor, 65dB Dynamic Range Reliance on Manually Operated Equipment Data Dimensions Real-time Acquisition of 7 Parameters (Amplitude, Count, etc.) Single-Point Thickness Data Evaluation system Four levels of corrosion classification (Ⅰ-Ⅳ) Subjective experience judgment
Technical specifications for key equipment
The standard puts forward strict requirements for acoustic emission sensors:
- Frequency response: 20-80kHz main frequency range
- Sensitivity: ≥60dB (reference 1V·s/m)
- Temperature stability: ±3dB fluctuation
- Electromagnetic shielding: RF/EMI protection is required
Acoustic emission instruments must meet the following requirements:
- Sampling rate ≥10 times the center frequency of the sensor
- Time resolution ≤1μs
- Dynamic range ≥ 65dB
- Real-time display delay <10 seconds
Corrosion classification and maintenance recommendations
The standard innovatively establishes a four-level corrosion assessment system:
Corrosion grade Characteristic description Maintenance recommendations Re-inspection cycle Grade I No significant activity No maintenance required 60 months Grade II Weak activity Consider maintenance 36 months Level III Active corrosion Priority maintenance 12 months Level IV Intense activity Immediate maintenance - Note: The assessment needs to combine the time difference positioning analysis and the overall bottom plate condition analysis.
Implementation points and cases
50,000m³ storage tank inspection case
In the inspection of a crude oil storage tank with a diameter of 60.16m:
- 14 30kHz sensors are arranged with a spacing of ≤15m
- Background noise controlled at 40dBAE
- 9 Level II areas and 2 Level III areas were found in 2 hours of data collection
- Finally assessed as Level III corrosion status, re-inspection is recommended within 12 months
88,000m³ storage tank inspection case
- Dual-row sensor array (1m/4m height)
- 61,200 effective impact signals
- Identified 1 Level 3 and 2 Level 2 local damages
- Comprehensively assessed as Level III corrosion risk
Background of standard evolution
With the development of acoustic emission technology in three aspects, standard formulation is promoted:
- Sensor technology: Wide-band differential sensor improves signal-to-noise ratio
- Data Analysis: Waveform processing algorithm enhances corrosion signal identification
- Engineering verification: Supported by measured data of 36 storage tanks ≥50,000m³
For the first time, the standard promoted regional standards such as ASTM E1930 to international unified specifications, making up for the shortcomings of EN 15856 in the classification system.
BS ISO 24489:2024 Referenced Document
- EN 13477-2 Non-destructive testing - Acoustic emission testing - Equipment characterisation - Part 2: Verification of operating characteristics
- ISO 12716 Non-destructive testing — Acoustic emission testing — Vocabulary*， 2026-05-13 Update
BS ISO 24489:2024 history
- 2024 BS ISO 24489:2024 Non-destructive testing. Acoustic emission testing. Detection of corrosion at atmospheric and low-pressure metallic storage tank floors
