CLC/TS 61949:2008

SLOVENSKI STANDARD
01-oktober-2008
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Ultrasonics - Field characterization - In situ exposure estimation in finite-amplitude
ultrasonic beams (IEC/TS 61949:2007)
Ultraschall - Charakterisierung von Feldern - Schätzung der In-situ-Expositionswerte in
Ultraschallbündeln mit finiten Amplituden (IEC/TS 61949:2007)
Ultrasons - Caractérisation des champs - Estimation de l'exposition in situ dans les
faisceaux ultrasonores d'amplitude finie (CEI/TS 61949:2007)
Ta slovenski standard je istoveten z: CLC/TS 61949:2008
ICS:
17.140.50 Elektroakustika Electroacoustics
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL SPECIFICATION
CLC/TS 61949
SPÉCIFICATION TECHNIQUE
July 2008
TECHNISCHE SPEZIFIKATION
ICS 17.140.50
English version
Ultrasonics -
Field characterization -
In situ exposure estimation in finite-amplitude ultrasonic beams
(IEC/TS 61949:2007)
Ultrasons -  Ultraschall -
Caractérisation des champs - Charakterisierung von Feldern -
Estimation de l'exposition in situ Schätzung der In-situ-Expositionswerte in
dans les faisceaux ultrasonores Ultraschallbündeln mit finiten Amplituden
d'amplitude finie (IEC/TS 61949:2007)
(CEI/TS 61949:2007)
This Technical Specification was approved by CENELEC on 2008-05-01.

CENELEC members are required to announce the existence of this TS in the same way as for an EN and to
make the TS available promptly at national level in an appropriate form. It is permissible to keep conflicting
national standards in force.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2008 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. CLC/TS 61949:2008 E
Foreword
The text of document 87/349/CDV, future edition 1 of IEC/TS 61949, prepared by IEC TC 87, Ultrasonics,
was submitted to the IEC-CENELEC Parallel Unique Acceptance Procedure and was approved by
CENELEC as CLC/TS 61949 on 2008-05-01.
The following date was fixed:
– latest date by which the existence of the CLC/TS
has to be announced at national level (doa) 2008-08-01
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the Technical Specification IEC/TS 61949:2007 was approved by CENELEC as a Technical
Specification without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
IEC 60601-2-37 NOTE  Harmonized as EN 60601-2-37:2008 (not modified).
IEC 61828 NOTE  Harmonized as EN 61828:2001 (not modified).
IEC 62359 NOTE  Harmonized as EN 62359:2005 (not modified).
__________
- 3 - CLC/TS 61949:2008
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.

NOTE  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.
Publication Year Title EN/HD Year
1) 2)
IEC 61161 - Ultrasonics - Power measurement - EN 61161 2007
Radiation force balances and performance
requirements
IEC 62127-1 2007 Ultrasonics - Hydrophones - EN 62127-1 2007
Part 1: Measurement and characterization of
medical ultrasonic fields up to 40 MHz

1)
Undated reference.
2)
Valid edition at date of issue.

IEC/TS 61949
Edition 1.0 2007-11
TECHNICAL
SPECIFICATION
Ultrasonics – Field characterization – In situ exposure estimation
in finite-amplitude ultrasonic beams

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
V
ICS 17.140.50 ISBN 2-8318-9463-8

– 2 – TS 61949 © IEC:2007(E)
CONTENTS
FOREWORD.3
INTRODUCTION.5

1 Scope.6
2 Normative references .6
3 Terms and definitions .6
4 List of symbols .10
5 Equipment required .11
6 Test methods .11
6.1 Establishing quasi-linear conditions.11
6.1.1 The local distortion parameter .11
6.1.2 Upper limit for quasi-linear conditions for σ .12
q
6.1.3 Range of applicability for quasi-linear conditions .12
6.2 Measurement procedure for estimated in situ exposure .13
6.2.1 Identification of quasi-linear conditions .13
6.2.2 Tables of limiting mean peak acoustic pressure.14
6.2.3 Measurement of acoustic quantities under quasi-linear conditions .14
6.2.4 Measurement of the scaling factor .14
6.2.5 Calculation of attenuated acoustic quantities .15
6.3 Uncertainties .16

Annex A (informative) Review of evidence .18
Annex B (informative) Review of alternative methods for managing finite-amplitude
effects during field measurement .21
Annex C (informative) Parameters to quantify nonlinearity .23
Annex D (informative) Tables of upper limits for mean peak acoustic pressure for
quasi-linear conditions .26

Bibliography.30

Figure 1 – Flow diagram for obtaining values of attenuated acoustic quantities.13

Table A.1 – Experimental evidence of nonlinear loss associated with the propagation
of ultrasound pulses under diagnostic conditions in water .19
Table A.2 – Theoretical evidence of nonlinear loss associated with the propagation of
ultrasound pulses under diagnostic conditions in water .19
Table B.1 – Methods for estimation of in-situ exposure in nonlinear beams.22
Table C.1 – Parameters for quantification of nonlinearity in an ultrasonic field .23
Table D.1 – The upper limit for mean peak acoustic pressure (MPa) associated with
quasi-linear conditions. σ ≤ 0,5. Acoustic working frequency, f = 2,0 MHz .26

q awf
Table D.2 – The upper limit for mean peak acoustic pressure (MPa) associated with
quasi-linear conditions. σ ≤ 0,5. Acoustic working frequency, f = 3,5 MHz .27

q awf
Table D.3 – The upper limit for mean peak acoustic pressure (MPa) associated with
quasi-linear conditions. σ ≤ 0,5. Acoustic working frequency, f = 5,0 MHz .28

q awf
Table D.4 – The upper limit for mean peak acoustic pressure (MPa) associated with
quasi-linear conditions. σ ≤ 0,5. Acoustic working frequency, f = 7,0 MHz.29
awf
q
TS 61949 © IEC:2007(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ULTRASONICS –
FIELD CHARACTERIZATION –
IN SITU EXPOSURE ESTIMATION
IN FINITE-AMPLITUDE ULTRASONIC BEAMS

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
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Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
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with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
The main task of IEC technical committees is to prepare International Standards. In
exceptional circumstances, a technical committee may propose the publication of a technical
specification when
• the required support cannot be obtained for the publication of an International Standard,
despite repeated efforts, or
• The subject is still under technical development or where, for any other reason, there is
the future but no immediate possibility of an agreement on an International Standard.
Technical specifications are subject to review within three years of publication to decide
whether they can be transformed into International Standards.
IEC 61949, which is a technical specification, has been prepared by IEC technical committee
87: Ultrasonics.
– 4 – TS 61949 © IEC:2007(E)
The text of this technical specification is based on the following documents:
Enquiry draft Report on voting
87/349/DTS 87/364A/RVC
Full information on the voting for the approval of this technical specification can be found in
the report on voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
This publication is being issued as a technical specification (according to 3.1.1.1 of the
IEC/ISO directives, Part 1) as a “prospective standard for provisional application” in the field
of finite-amplitude ultrasonic beams, because there is an urgent need for guidance on how
standards in this field should be used to meet an identified need.
This document is not to be regarded as an “International Standard”. It is proposed for
provis
...