IEC 62127-2:2007

Applies to - hydrophones employing piezoelectric sensor elements, designed to measure the pulsed and continuous-wave ultrasonic fields generated by ultrasonic equipment; - hydrophones used for measurements made in water and in the frequency range between 15 MHz and 40 MHz; - hydrophones with or without an integral amplifier; - hydrophones with a circular piezoelectrically active element. Specifies - relevant hydrophone characteristics; - methods of determining directional response and hydrophone sensitivity based on relative or comparative measurements; and describes - absolute hydrophone calibration methods. Recommendations and references to accepted literature are made for the various relative and absolute calibration methods in the frequency range covered by this International Standard.

Relates to hydrophones, employing piezoelectric sensor elements, designed to measure the pulsed and continuous-wave ultrasonic fields generated by ultrasonic medical equipment operating in the frequency range 0.5 MHz to 15 MHz. Covers the design and performance requirements of standard hydrophones and the data required to specify their characteristics, and defines a standard method for the measurement of the sensitivity of such hydrophones. Defines the performance characteristics that are required of hydrophones intended for use in a specified range of applications over the frequency band from 0.5 MHz to 15 MHz, particularly those associated with the measurement of pulsed and continuous-wave ultrasonic fields used in medical diagnosis. Establishes a scheme for the specification of the performance of these hydrophones. Describes a standardized procedure for their calibration.

Defines alternative procedures for the measurement of acoustic pressure and derived intensity parameters for the sound fields generated by single ultrasonic transducers which have cylindrical or spherical active elements and defines additional acoustical terms.

Specifies the methods of use of calibrated piezoelectric hydrophones for the measurement in liquids of acoustic fields generated by ultrasonic medical equipment operating in the frequency range 0,5 MHz to 15 MHz.

Specifies a method of absolute calibration of hydrophones based on the planar scanning technique in the frequency range 0,5 MHz to 15 MHz.

Provides guidance on the practical measurement of the acoustic output of various types of medical ultrasonic equipment. Contains also procedures for correcting limitations caused by the use of hydrophones with finite bandwidth and finite active element size.

IEC 62127-2:2025 specifies: - absolute hydrophone calibration methods; - relative (comparative) hydrophone calibration methods. Recommendations and references to accepted literature are made for the various relative and absolute calibration methods in the frequency range covered by this document. This document is applicable to - hydrophones used for measurements made in water and in the ultrasonic frequency range 50 kHz to 100 MHz; - hydrophones employing piezoelectric sensor elements, designed to measure the pulsed wave and continuous wave ultrasonic fields generated by ultrasonic equipment; - hydrophones with or without a hydrophone pre-amplifier. IEC 62127-2:2025 cancels and replaces the first edition published in 2007, Amendment 1:2013 and Amendment 2:2017. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) the upper frequency limit of 40 MHz has been removed; b) hydrophone sensitivity definitions have been changed to recognize sensitivities as complex-valued quantities; c) directional response measurement and effective size determination procedures have been updated in 12.5.1 to align with recent changes in IEC 62127-3; d) Annex F has been amended to comprise a calibration technique for high-frequency complex-valued calibration; e) the reciprocity method description in Annex K was extended to also comprise focusing transducers.