IEC 62489-2:2011

IEC 62489-2 ®
Edition 1.0 2011-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Electroacoustics – Audio-frequency induction loop systems for assisted
hearing –
Part 2: Methods of calculating and measuring the low-frequency magnetic field
emissions from the loop for assessing conformity with guidelines on limits for
human exposure
Electroacoustique – Systèmes de boucles d’induction audiofréquences pour
améliorer l'audition –
Partie 2: Méthodes de calcul et de mesure des émissions de champ magnétique
basse fréquence à partir de la boucle pour l’évaluation de la conformité aux
instructions sur les limites d’exposition humaine

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IEC 62489-2 ®
Edition 1.0 2011-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Electroacoustics – Audio-frequency induction loop systems for assisted
hearing –
Part 2: Methods of calculating and measuring the low-frequency magnetic field
emissions from the loop for assessing conformity with guidelines on limits for
human exposure
Electroacoustique – Systèmes de boucles d’induction audiofréquences pour
améliorer l'audition –
Partie 2: Méthodes de calcul et de mesure des émissions de champ magnétique
basse fréquence à partir de la boucle pour l’évaluation de la conformité aux
instructions sur les limites d’exposition humaine

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX Q
ICS 17.140.50 ISBN 978-2-88912-318-6
– 2 – 62489-2  IEC:2011
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Rated values . 5
4 Situation regarding current standards . 6
5 Configurations of loops . 6
5.1 Main types of configuration . 6
5.2 General considerations . 6
5.3 Large-area loops . 6
5.4 Medium-area loops . 7
5.5 Small-area loops . 7
5.6 Solenoid antennas . 7
6 Calculations . 8
6.1 General . 8
6.2 Solenoid antennas . 8
7 Measurements . 8
7.1 General . 8
7.2 Input signal . 8
7.3 Measuring instrument . 9
8 Comparison of calculated or measured results with guidelines or limits . 9
9 Meeting limits or guidelines . 10
10 Measurement uncertainty . 10
Annex A (informative) Rationale for this product-family magnetic field emission
standard for audio-frequency induction-loop systems (AFILS) in the context of human
exposure to non-ionizing radiation . 11
Annex B (informative) Example calculation using the coupling factor K . 15
Bibliography . 16

Figure 1 – An earhook induction transducer, with a BTE (Behind The Ear) hearing aid
body for scale . 7
Figure 2 – K factor as a function of least distance between wire and disc . 10
Figure A.1 – ICNIRP magnetic field reference levels . 11

Table A.1 – Extract from IEC 62311, Table A.1 – Characteristics and parameters of the
equipment to be considered, with the application to AFILS added . 13

62489-2  IEC:2011 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTROACOUSTICS –
AUDIO-FREQUENCY INDUCTION LOOP SYSTEMS
FOR ASSISTED HEARING –
Part 2: Methods of calculating and measuring the low-frequency
magnetic field emissions from the loop for assessing conformity
with guidelines on limits for human exposure

FOREWORD
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International Standard IEC 62489-2 has been prepared by IEC technical committee 29:
Electroacoustics.
The text of this standard is based on the following documents:
FDIS Report on voting
29/728/FDIS 29/736/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.

– 4 – 62489-2  IEC:2011
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts of the IEC 62489 series, published under the general title Electroacoustics –
Audio-frequency induction loop systems for assisted hearing, can be found on the IEC
website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site 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.
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