Overview - IEC TS 62903:2018 (Ultrasonics, self‑reciprocity method)
IEC TS 62903:2018 is a Technical Specification from the IEC that defines the free‑field convergent spherical wave self‑reciprocity method for calibration and measurement of spherically curved ultrasonic transducers. It specifies the measurement conditions and experimental procedures to determine electroacoustical parameters and acoustic output power, sets criteria for reciprocity and linearity of the focused field, and gives guidance for assessing measurement uncertainty (radiation conductance). The document applies to circular, concave spherically curved focusing transducers (no centric hole), operating in the 0.5 MHz to 15 MHz frequency range and within the linear amplitude range of the focused field.
Key topics and technical requirements
- Measurement method: Free‑field self‑reciprocity calibration for spherically curved transducers.
- Applicable transducers: Circular spherically curved concave focusing transducers without a centric hole, linear amplitude operation.
- Frequency & amplitude: 0.5 MHz to 15 MHz; acoustic pressure amplitudes within the linear range.
- Required apparatus and setup: specifications for water tank, fixturing/positioning systems, reflectors, current monitor (probe), oscilloscope and measurement hydrophone.
- Geometric and beam parameters: measurement of effective half‑aperture, beamwidth, focus half‑angle and effective area.
- Calibration outputs: transmitting response (to current/voltage), voltage sensitivity, pulse‑echo sensitivity, radiation conductance, acoustic output power, mechanical Q, and electroacoustic efficiency.
- Diffraction & propagation: treatment of diffraction correction coefficients and guidance on speed of sound and attenuation in water.
- Reciprocity and linearity checks: criteria to verify transducer reciprocity and the focused field linear range.
- Uncertainty evaluation: informative annex with Type A/B uncertainty components and combined standard uncertainty for radiation conductance.
Applications and who uses this standard
IEC TS 62903:2018 is aimed at practitioners requiring traceable, repeatable ultrasonic transducer calibration and output power measurement:
- Calibration and metrology laboratories performing hydrophone and transducer calibration.
- Ultrasonic transducer manufacturers validating electroacoustical performance.
- Medical ultrasound device developers needing focused‑field power and sensitivity data.
- Nondestructive testing (NDT) labs and research institutions characterizing focused transducers for imaging or therapy.
- Engineers and quality teams implementing calibration procedures, uncertainty budgets, and compliance testing for focused ultrasonic sources.
Related standards (if applicable)
Refer to other international standards and IEC publications on ultrasonics, hydrophone calibration, acoustic power measurement and measurement uncertainty for complementary requirements and normative references. These provide broader context for traceability and conformity in ultrasonic metrology.