This part of IEC 62127 specifies methods of use of calibrated hydrophones for the measurement in liquids of acoustic fields generated by ultrasonic medical equipment including bandwidth criteria and calibration frequency range requirements in dependence on the spectral content of the fields to be characterized.

This document:
- defines a group of acoustic parameters that can be measured on a physically sound basis;
- defines a second group of parameters that can be derived under certain assumptions from these measurements, and called derived intensity parameters;
- defines a measurement procedure that can be used for the determination of acoustic pressure parameters;
- defines the conditions under which the measurements of acoustic parameters can be made using calibrated hydrophones;
- defines procedures for correcting for limitations caused by the use of hydrophones with finite bandwidth and finite active element size, and for estimating the corresponding uncertainties.

NOTE 1 Throughout this document, SI units are used. In the specification of certain parameters, such as beam areas and intensities, it can be convenient to use decimal multiples or submultiples. For example, beam area is likely to be specified in cm2 and intensities in W/cm2 or mW/cm2.

NOTE 2 The hydrophone as defined can be of a piezoelectric or an optic type.