What is BS EN IEC 60565-1 - Hydrophones about?
BS EN IEC 60565-1 is the first part of the BS EN IEC 60565 series of documents that specifies methods and procedures for free-field calibration of hydrophones, as well as individual electroacoustic transducers that can be used as hydrophones (receivers) and/or projectors (source transducers). Two general types of calibration is covered within BS EN IEC 60565-1: absolute calibration using the method of the transducer spherical-wave reciprocity, and relative calibration by comparison with a reference to the device which has already been the subject of an absolute calibration.
The maximum frequency range of the methods specified in BS EN IEC 60565-1 is from 200 Hz to 1 MHz. The lowest acoustic frequency of application will depend on a number of factors and will typically be in the range of 200 Hz to 5 kHz depending mainly on the dimensions of the chosen test facility, The highest frequency of application for the methods described here is 1 MHz.
BS EN IEC 60565-1 presents a description of the requirements for free-field calibration in terms of the test facility, equipment and instrumentation, signal processing, and frequency limitations. A description of achievable uncertainty and rules for the presentation of the calibration data are provided. Also included are informative annexes that provide additional guidance on:
- Measurement of the directional response of a hydrophone or projector
- Measurement of electrical impedance of hydrophones and projectors
- Electrical loading corrections
- Acoustic far-field criteria in underwater acoustic calibration
- Pulsed techniques in free-field calibrations
- Assessment of uncertainty in the free-field calibration of hydrophones and projectors
- Derivation of the formulae for three-transducer spherical-wave reciprocity calibrations
- Calibration using traveling-wave tubes
- Calibration of hydrophones using optical interferometry
- Calibrations in reverberant water tanks using continuous signals
Who is BS EN IEC 60565-1 - Hydrophones for?
BS EN IEC 60565-1 on the calibration of hydrophones is beneficial for:
- Marine environmental laboratories
- Maritime industries
- Manufacturers of ultrasonic devices
- Research laboratories
Why should you use BS EN IEC 60565-1 - Hydrophones?
Underwater acoustic measurements are made to provide validation and qualification in a wide range of ocean applications, including oceanography, defence, fisheries, geophysics, and in developments in the offshore energy industries.
Hydrophones are the most used sensor to measure sound in the ocean. BS EN IEC 60565-1 is beneficial as it assists the user with hydrophones. Hydrophones are the most used sensor to measure sound in the ocean. It is important that the hydrophones used to measure sound pressure are calibrated using agreed standard methodologies, with valid uncertainties. The purpose of BS EN IEC 60565-1 is to establish procedures for calibration under free-field conditions of hydrophones used in underwater acoustics for ocean applications. BS EN IEC 60565-1 also covers calibration procedures for individual underwater electroacoustic transducers which can be used as a hydrophone and/or source transducer. BS EN IEC 60565-1 also provides principles, procedures, and sources of uncertainty.
Overall, BS EN IEC 60565-1 is helpful in giving a description of acoustic far-field, which is a sound field at a sufficient distance from a sound source in a uniform medium where the sound pressure and sound particle velocity are in-phase and the direct-path sound pressure amplitude, compensated for absorption loss, varies inversely with distance.
What’s changed since the last update?
BS EN IEC 60565-1:2020 supersedes BS EN 60565:2007, which is withdrawn.This first edition of IEC 60565-1, together with IEC 60565-2, cancels and replaces the secondedition of IEC 60565 published in 2006. This edition constitutes a technical revision.
BS EN IEC 60565-1:2020 includes the following significant technical changes with respect to the previous edition:
- Removal of all descriptions of methods for pressure calibrations of hydrophones – these are now included in Part 2
- Removal of the derivations of formulae for free-field reciprocity calibration (both amplitude sensitivity and phase sensitivity) and placement of these into an informative annex
- Inclusion within the scope of the calibration of the transmitting response of individual source transducers and hydrophones (but not sonar arrays)
- Re-ordering of the sections within the document such that the more general procedures for calibration such as guidance on obtaining conditions of acoustic free-field, far-field and steady-state, appear before the descriptions of procedures for absolute or relative calibrations
- Revision of informative Annex A to include guidance on measurement of directional response of a hydrophone or projector.
