SIST EN 62127-2:2008/A2:2017

Ultrasonics - Hydrophones - Part 2: Calibration for ultrasonic fields up to 40 MHz (IEC 62127-2:2007/A2:2017)

Ultraschall - Hydrophone - Teil 2: Kalibrierung für Ultraschallfelder bis zu 40 MHz (IEC 62127-2:2007/A2:2017)

Ultrasons - Hydrophones - Partie 2: Etalonnage des champs ultrasoniques jusqu'à 40 Mhz (IEC 62127-2:2007/A2:2017)

Ultrazvok - Hidrofoni - 2. del: Kalibracija za ultrazvočna polja do 40 MHz - Dopolnilo A2 (IEC 62127-2:2007/A2:2017)

General Information

• Status: Published
• Publication Date: 08-Aug-2017
• ICS: 11.040.01 - Medical equipment in general
• ICS: 17.140.50 - Electroacoustics
• Technical Committee: I11 - Imaginarni 11
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 21-Jun-2017
• Due Date: 26-Aug-2017
• Completion Date: 09-Aug-2017
• Ref Project: EN 62127-2:2007/A2:2017 - Ultrasonics - Hydrophones - Part 2: Calibration for ultrasonic fields up to 40 MHz

Relations

• Replaced By: SIST EN IEC 62127-2:2025 - Ultrasonics - Hydrophones - Part 2: Calibration for ultrasonic fields (IEC 62127-2:2025)
• Effective Date: 01-Apr-2025
• Amends: SIST EN 62127-2:2008 - Ultrasonics - Hydrophones -- Part 2: Calibration for ultrasonic fields up to 40 MHz
• Effective Date: 03-May-2016

Overview

EN 62127-2:2007/A2:2017 (equivalent to IEC 62127-2:2007/A2:2017) is the European amendment covering hydrophone calibration for ultrasonic fields up to 40 MHz. It specifies primary reference measurement procedures - notably the free-field reciprocity calibration - and provides detailed guidance on apparatus, measurement geometry, corrections and uncertainty considerations needed to obtain traceable hydrophone sensitivities for accurate acoustic pressure measurement.

Key topics and technical requirements

• Scope and approach
  • Primary reference calibration under free‑field conditions using the principle of reciprocity.
  • Amendment A2 refines terms, symbols and measurement clauses, and adds normative references (e.g., IEC 61689).
• Two‑transducer reciprocity method
  • Detailed in revised Annex K: fundamentals, equations linking electrical and acoustic quantities (reciprocity coefficient J, diffraction correction G, reflection coefficient R, attenuation).
  • Self‑calibration of an auxiliary transducer is the first step to define acoustic pressure at a measurement spot.
• Auxiliary transducers and frequencies
  • Circular plane‑piston auxiliary transducers are recommended for generating fields; practical use in the method is limited to the effective range 1 MHz to 15 MHz. Effective radiation area (AER) must be measured per IEC 61689.
• Reflector and measurement field
  • Reflector specifications: flat surface, minimum linear dimension ≥ 4× effective transducer radius, strict flatness and surface finish limits to avoid spurious reflections.
  • Measurement distances relative to the transducer near‑field parameter N (recommended measurement range: ~0.9×N to 2.2×N); tank walls and surfaces must be far enough or acoustically absorbed to prevent interference.
• Electrical and acoustic measurands
  • Precise measurement of transmitting current, open‑circuit voltage, and application of electrical corrections.
  • Definitions and corrections for diffraction, characteristic acoustic impedance (ρc), and reciprocity coefficients are given to compute hydrophone sensitivity and end‑of‑cable responses.
• Uncertainty and practical notes
  • Guidance on experimental determination of AER, locating the last pressure minimum, and including interference sources in the uncertainty budget.
  • Notes allow use of time‑gated tone bursts, chirps or time‑delay spectrometry to realize free‑field conditions in confined tanks.

Applications and users

• Calibration laboratories and metrology institutes establishing traceable hydrophone sensitivities.
• Manufacturers of hydrophones and ultrasonic transducers performing production and reference calibrations.
• Medical ultrasound and physiotherapy test facilities (ICS classifications include medical equipment and electroacoustics) requiring reliable acoustic pressure measurements up to 40 MHz.
• Research groups measuring ultrasonic fields where accurate hydrophone calibration is required.

Related standards

• IEC 62127-2:2007 (base publication)
• IEC 61689 (referenced for transducer effective radiation area and field measurement methods)
• JCGM 200:2012 (reference for primary measurement procedures and metrological concepts)

Keywords: EN 62127-2, IEC 62127-2:2007/A2:2017, hydrophone calibration, reciprocity calibration, ultrasonic fields up to 40 MHz, two-transducer method, hydrophone sensitivity, ultrasound measurement, calibration laboratory.

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2017
8OWUD]YRN+LGURIRQLGHO.DOLEUDFLMD]DXOWUD]YRþQDSROMDGR0+]
'RSROQLOR$,(&$
Ultrasonics - Hydrophones - Part 2: Calibration for ultrasonic fields up to 40 MHz (IEC
62127-2:2007/A2:2017)
Ultraschall - Hydrophone - Teil 2: Kalibrierung für Ultraschallfelder bis zu 40 MHz (IEC
62127-2:2007/A2:2017)
Ultrasons - Hydrophones - Partie 2: Etalonnage des champs ultrasoniques jusqu'à 40
Mhz (IEC 62127-2:2007/A2:2017)
Ta slovenski standard je istoveten z: EN 62127-2:2007/A2:2017
ICS:
11.040.01 Medicinska oprema na Medical equipment in general
splošno
17.140.50 Elektroakustika Electroacoustics
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 62127-2:2007/A2

NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2017
ICS 17.140.50
English Version
Ultrasonics - Hydrophones - Part 2: Calibration for ultrasonic
fields up to 40 MHz
(IEC 62127-2:2007/A2:2017)
Ultrasons - Hydrophones - Partie 2: Etalonnage des Ultraschall - Hydrophone - Teil 2: Kalibrierung für
champs ultrasoniques jusqu'à 40 Mhz Ultraschallfelder bis zu 40 MHz
(IEC 62127-2:2007/A2:2017) (IEC 62127-2:2007/A2:2017)
This amendment A2 modifies the European Standard EN 62127-2:2007; it was approved by CENELEC on 2017-04-26. CENELEC
members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this amendment the
status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This amendment exists in three official versions (English, French, German). A version in any other language made by translation under the
responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the same status as
the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden,
Switzerland, Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 62127-2:2007/A2:2017 E

European foreword
The text of document 87/612/CDV, future IEC 62127-2:2007/A2, prepared by IEC/TC 87 "Ultrasonics"
was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 62127-
2:2007/A2:2017.
The following dates are fixed:
• latest date by which the document has to be (dop) 2018-01-26
implemented at national level by
publication of an identical national
standard or by endorsement
(dow) 2020-04-26
• latest date by which the national
standards conflicting with the
document have to be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Endorsement notice
The text of the International Standard IEC 62127-2:2007/A2:2017 was approved by CENELEC as a
European Standard without any modification.
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod), the relevant

EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here:
www.cenelec.eu.
Addition:
Publication Year Title EN/HD Year
IEC 61689 -  Ultrasonics - Physiotherapy systems - Field EN 61689 -
specifications and methods of
measurement in the frequency range 0,5
MHz to 5 MHz
IEC 62127-2 ®
Edition 1.0 2017-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
A MENDMENT 2
AM ENDEMENT 2
Ultrasonics – Hydrophones –
Part 2: Calibration for ultrasonic fields up to 40 MHz

Ultrasons – Hydrophones –
Partie 2: Etalonnage des champs ultrasoniques jusqu’à 40 MHz

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.140.50 ISBN 978-2-8322-3904-9

– 2 – IEC 62127-2:2007/AMD2:2017
© IEC 2017
FOREWORD
This amendment has been prepared by IEC technical committee 87: Ultrasonics.
The text of this amendment is based on the following documents:
CDV Report on voting
87/612/CDV 87/639/RVC
Full information on the voting for the approval of this amendment can be found in the report
on voting indicated in the above table.
The committee has decided that the contents of this amendment and the base publication will
remain unchanged until the stability date indicated on the IEC website under
"http://webstore.iec.ch" in the data related to the specific publication. At this date, the
publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
_____________
2 Normative references
Add the following new reference:
IEC 61689, Ultrasonics – Physiotherapy systems – Field specifications and methods of
measurement in the frequency range 0,5 MHz to 5 MHz
3 Terms, definitions and symbols
3.26
derived instantaneous intensity
(added by Amendment 1)
Delete the following text below the term:
"approximation of the instantaneous intensity"
Replace the existing four lines before Equation (1) by the following:
quotient of squared instantaneous acoustic pressure and characteristic acoustic impedance of
the medium at a particular instant in time at a particular point in an acoustic field

IEC 62127-2:2007/AMD2:2017 – 3 –
© IEC 2017
4 List of symbols
Replace:
ρc specific acoustic impedance
by
ρc characteristic acoustic impedance of the measurement liquid (water)
Add the following new symbols:
d distance between the auxiliary transducer and the reflector measured along the axis of
symmetry
d distance between the auxiliary transducer and the active element of the hydrophone
h
measured along the axis of symmetry
d distance between the auxiliary transducer and the last minimum of the acoustic
m
pressure amplitude along the axis of symmetry of the auxiliary transducer
R amplitude reflection coefficient for the reflector/water interface
RT
Z characteristic acoustic impedance of the reflector
RT
J reciprocity coefficient for plane waves
p
*
S apparent transmitting current response of an auxiliary transducer
t
*
M apparent receiving voltage response of an auxiliary transducer
t
p acoustic pressure generated by a transducer at its surface
a
p acoustic pressure incident on a transducer surface
i
p acoustic pressure incident on the hydrophone surface
h
I transmitting current driven to a transducer
t
U voltage generated by a transducer in the receiving mode
t
G correction that accounts for the diffraction in the propagation field and is related to the
th
waveform generation by the transducer and the reception by the hydrophone
G correction that accounts for the diffraction in the propagation field and is related to the
tt
generation and the reception by the transducer
U voltage measured with the transducer coupled to the system
load
I current measured over a short circuit jumper replacing the transducer
sc
9 Free field reciprocity calibration
9.1 General
Replace the existing text by the following:
This clause specifies the primary reference measurement procedure (see JCGM 200:2012,
2.8 [79]) calibration of hydrophones under free field conditions using the principle of
reciprocity.
Add the following new note:
NOTE The free field condition can be achieved in a confined water space by following any of a variety of
measurement procedures, such as with the use of tone-burst (time-gated sine wave – see 10.5.3), time-delay
spectrometry [63, 68], frequency modulated chirp [80, 81] or other techniques [82].

– 4 – IEC 62127-2:2007/AMD2:2017
© IEC 2017
9.4 Two-transducer reciprocity calibration method
9.4.1 Apparatus
Replace the existing subclause title and text by the following:
9.4.1 Auxiliary transducers
Circularly plane piston auxiliary transducers should be used to generate the ultrasonic field in
the frequency range of interest, limited to the maximum range between 1 MHz and 15 MHz.
The effective radiation area (A ) shall be determined, according to IEC 61689, for each
ER
transducer and at all frequencies the transducer is intended to be used. If a frequency
modulated chirp is to be used as excitation signal, the A shall be determined at least in the
ER
minimum, maximum and one intermediate frequency in the range of interest.
The position of the last minimum of acoustic pressure amplitude along the axis of symmetry,
d , shall be determined with an uncertainty not larger than 1 mm. It shall be done as an on-
m
axis line scan, according to IEC 61689, at the same frequencies the A was determined. The
ER
near field distance produced by the auxiliary transducer is defined as N = a /λ, where λ is
1 t
the ultrasonic wavelength in water at the frequency of operation and a = 2λd +λ is the
t m
effective radius of the ultrasonic transducer.
NOTE Focusing auxiliary transducers can be used, but several corrections need to be applied, and this document
is only intended for plane-piston transducers. A detailed implementation of a reciprocity-based calibration method
using focusing transducers can be found in [84].
The effective radiation area (A ) is used in the equations of Annex K to properly assess the
ER
diffraction correction and the reciprocity coefficient for plane waves, whilst the last minimum
) is used to indirectly define the near
of pressure amplitude along the axis of symmetry (d
m
field distance (N ), being N = (2λd + λ )/λ. Although both quantities A and d are directly
1 1 m ER m
linked for ideal transducers, both shall be determined experimentally according to IEC 61689.
9.4.2 Procedure
Replace the existing subclause title and text by the following:
9.4.2 Reflector
The reflector should comprise a flat surface whose smallest linear dimension shall be at least
four times the effective radius of the ultrasonic transducer a . The reflector shall also be flat to
t
±10 μm, with a surface finish good to ±5 μm (surface roughness: R < 5 μm; R < 5 μm;
v p
R < 1 μm). The thickness of the reflector shall be such that the first reflection from the rear
a
surface will not interfere with that directly from the front surface for any of the excitation
signals to be used. Special attention shall be given for long burst or low-rate frequency
modulated chirps, mainly at the lowest frequencies of interest.
The amplitude reflection coefficient for the reflector/water interface R shall be
RT
experimentally determined, for instance by the relation R = (Z – ρc)/(Z + ρc), were ρc
RT RT RT
is the characteristic acoustic impedance of the water and Z is the characteristic acoustic
RT
impedance of the reflector.
NOTE R is the maximum valley depth, R is the maximum peak height and R is the arithmetic average
v p a
describing the reflector profile roughness amplitude parameters.
Add the following new subclauses:
9.4.3 Measurement field
As both the auxiliary transducer and the hydrophone have finite apertures, a diffraction
pattern is present in the ultrasonic field. To minimize uncertainties due to the analytical or

IEC 62127-2:2007/AMD2:2017 – 5 –
© IEC 2017
numerical corrections to be applied to the measurement quantities, the nearest measurement
shall be performed at least at 0,9 × N , and the furthest distance shall not be larger than
2,2 × N . Water-air surface and tank walls shall be far enough from the ultrasonic path such
that any reflected waveform will not interfere with the direct waveform at the measurement
spot.
If any structure is too close to the direct ultrasonic waveform path, it shall be covered with
absorbing lining to minimize the interference with the measurement signal, an
...