Overview
CEN ISO/TR 13115:2011 - "Non-destructive testing - Methods for absolute calibration of acoustic emission transducers by the reciprocity technique" - is a technical report that describes established laboratory procedures to determine absolute sensitivity of acoustic emission (AE) transducers. The document defines the reciprocity technique using three reversible AE transducers on a solid transfer medium, plus a two-transducer procedure and an impulse-response method based on frequency-domain measurements. It provides measurement methods, definitions (index point, reception voltage sensitivity, transmission current response), and ways to represent calibration results.
Key topics and technical requirements
- Reciprocity technique (three-transducer calibration)
- Uses three reversible AE transducers of the same kind arranged on a solid transfer medium to form three transmitter–receiver pairs.
- Determines absolute sensitivity (frequency response of amplitude and phase) from electrical measurements of transmission current and reception voltage using derived reciprocity parameters.
- Two-transducer calibration
- Uses a transducer previously calibrated by three-transducer reciprocity as a reference transmitter to determine reception sensitivity of an optional (not necessarily reversible) transducer.
- Impulse-response calibration
- Measures complex frequency responses (amplitude and phase) via tone-burst or other calibrated signals and computes impulse responses by inverse Fourier transform.
- Uses time-windowing (e.g., Hanning) and frequency-domain processing to represent impulse behavior.
- Measurement setup and signal types
- Defines transfer medium requirements, mounting of transducers, calibration signals (tone-burst, squared-cosine), and how to compute reciprocity parameters.
- Representation of results
- Prescribes how to report frequency response (amplitude and phase), impulse response, calibration uncertainty and measurement conditions.
Applications and practical value
- Ensures traceable, laboratory-grade calibration of AE sensors used in non-destructive testing (NDT) for materials, pressure vessels, civil structures and machinery monitoring.
- Enables consistent comparison of AE data between laboratories and over time by providing absolute sensitivity references for Rayleigh surface waves and longitudinal waves.
- Useful for AE sensor manufacturers, calibration laboratories, NDT service providers, research institutions and quality/competence assessment bodies that require standardized AE sensor characterization.
Who should use this standard
- AE calibration laboratories and metrology facilities
- NDT engineers and acoustic emission specialists
- AE transducer manufacturers and R&D teams
- Certification bodies and laboratories performing sensor acceptance or inter-laboratory comparisons
Related standards
Keywords: acoustic emission calibration, reciprocity technique, three-transducer calibration, two-transducer calibration, impulse response calibration, absolute sensitivity, non-destructive testing, AE transducer.