IEC TS 62903:2018

FOREWORD
INTRODUCTION
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols
5 General
6 Requirements of the measurement system
7 Measurement of the effective half-aperture of the
  spherically curved transducer
8 Measurements of the electroacoustical parameters
  and the acoustic output power
9 Measurement uncertainty
Annex A (informative) - Relation of the average
        amplitude reflection coefficient on a plane
        interface of water-stainless steel and the focus
        half-angle for a normally incident beam of a
        circular spherically curved transducer [1, 2]
Annex B (informative) - Diffraction correction
        coefficient G[sf] in the free-field selfreciprocity
        calibration method for circular spherically
        curved transducers in water neglecting
        attenuation [2, 3, 4]
Annex C (informative) - Calculation of the diffraction
        correction coefficient G[sf](R/[lambda],[beta]) in the
        free-field self-reciprocity calibration in a
        non-attenuating medium for a circular spherically
        curved transducer [2, 3, 4, 7]
Annex D (informative) - Speed of sound and attenuation
        in water
Annex E (informative) - Principle of reciprocity calibration
        for spherically curved transducers [2, 3, 4]
Annex F (informative) - Experimental arrangements
Annex G (informative) - Relationships between the
        electroacoustical parameters used in this
        application [13]
Annex H (informative) - Evaluation and expression of
        uncertainty in the measurements of the radiation
        conductance
Bibliography

IEC TS 62903:2018, which is a Technical Specification,
a) establishes the free-field convergent spherical wave self-reciprocity method for ultrasonic transducer calibration,
b) establishes the measurement conditions and experimental procedure required to determine the transducer's electroacoustic parameters and acoustic output power using the self-reciprocity method,
c) establishes the criteria for checking the reciprocity of these transducers and the linear range of the focused field, and
d) provides guiding information for the assessment of the overall measurement uncertainties for radiation conductance.
This document is applicable to:
i) circular spherically curved concave focusing transducers without a centric hole working in the linear amplitude range,
ii) measurements in the frequency range 0,5 MHz to 15 MHz, and
iii) acoustic pressure amplitudes in the focused field within the linear amplitude range.