SANS 62226-1-2006 Exposure to electric or magnetic fields in the low and intermediate frequency range - Methods for calculating the current density and internal electric field indu.pdf

1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA

2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any

3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 0-626-18914-4 SANS 62226-1:2006Edition 1 IEC 62226-1:2004Edition 1SOUTH AFRICAN NATIONAL STANDARD Exposure to electric or magnetic fields in the low

4、 and intermediate frequency range Methods for calculating the current density and internal electric field induced in the human body Part 1: General This national standard is the identical implementation of IEC 62226-1:2004 and is adopted with the permission of the International Electrotechnical Comm

5、ission. Published by Standards South Africa 1 dr lategan road groenkloof private bag x191 pretoria 0001 tel: 012 428 7911 fax: 012 344 1568 international code + 27 12 www.stansa.co.za Standards South Africa SANS 62226-1:2006 Edition 1 IEC 62226-1:2004 Edition 1 Table of changes Change No. Date Scope

6、 National foreword This South African standard was approved by National Committee StanSA TC 73, Electromagnetic compatibility, in accordance with procedures of Standards South Africa, in compliance with annex 3 of the WTO/TBT agreement. This part of SANS 62226 was published in December 2006. NORME I

7、NTERNATIONALECEIIECINTERNATIONAL STANDARD 62226-1Premire ditionFirst edition2004-11Exposition aux champs lectriques ou magntiques basse et moyenne frquence Mthodes de calcul des densits de courant induit et des champs lectriques induits dans le corps humain Partie 1: Gnralits Exposure to electric or

8、 magnetic fields in the low and intermediate frequency range Methods for calculating the current density and internal electric field induced in the human body Part 1: General Pour prix, voir catalogue en vigueur For price, see current catalogue IEC 2004 Droits de reproduction rservs Copyright - all

9、rights reserved Aucune partie de cette publication ne peut tre reproduite ni utilise sous quelque forme que ce soit et par aucun procd, lectronique ou mcanique, y compris la photocopie et les microfilms, sans laccord crit de lditeur. No part of this publication may be reproduced or utilized in any f

10、orm or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Electrotechnical Commission, 3, rue de Varemb, PO Box 131, CH-1211 Geneva 20, SwitzerlandTelephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail:

11、inmailiec.ch Web: www.iec.ch CODE PRIX PRICE CODE N Commission Electrotechnique InternationaleInternational Electrotechnical Commission SANS 62226-1:2006This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .62226-1 IEC:2004 3 CONTENTS FOREWORD.5 IN

12、TRODUCTION.9 1 Scope.11 2 General data on electromagnetic fields and human exposure .11 2.1 General .11 2.2 Electric field 13 2.3 Magnetic field13 3 Terms and definitions, symbols and abbreviations 15 3.1 Terms and definitions 15 3.2 Physical quantities and units .21 3.3 Physical constants 23 4 Gene

13、ral procedure for assessing compliance with safety limits.23 Bibliography25 Figure 1 Overview of different methods for assessing compliance with exposure limits .23 SANS 62226-1:2006This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .62226-1 IEC:

14、2004 5 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ EXPOSURE TO ELECTRIC OR MAGNETIC FIELDS IN THE LOW AND INTERMEDIATE FREQUENCY RANGE METHODS FOR CALCULATING THE CURRENT DENSITY AND INTERNAL ELECTRIC FIELD INDUCED IN THE HUMAN BODY Part 1: General FOREWORD 1) The International Electrotechnical Comm

15、ission (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

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18、ce 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 intere

19、sted 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 responsib

20、le 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 be

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22、sers 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 o

23、ther 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

24、. 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 pat

25、ent rights. International Standard IEC 62226 has been prepared by IEC technical committee 106: Methods for the assessment of electric, magnetic and electromagnetic fields associated with human exposure. The text of this standard is based on the following documents: FDIS Report on voting 106/78/FDIS

26、106/82/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. SANS 62226-1:2006This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .62226-1 IEC:2004 7 This publicatio

27、n has been drafted in accordance with the ISO/IEC Directives, Part 2. This International Standard constitutes Part 1 of the IEC 62226 series, which will regroup several international standards and technical reports within the framework of the calculation of induced current densities and internal ele

28、ctric fields, and will be published under the general title Exposure to electric or magnetic fields in the low and intermediate frequency range - Methods for calculating the current density and internal electric field induced in the human body. This series is planned to be published according to the

29、 following structure: Part 1: General Part 2: Exposure to magnetic fields Part 2-1 : 2D models Part 2-2 : 3D models Part 2-3 : Guidelines for practical use of coupling factors Part 3: Exposure to electric fields Part 3-1: Analytical and 2D numerical models Part 3-2: 3D numerical models Part 4: Elect

30、rical parameters of human living tissues (Technical Report) The committee has decided that the contents of this publication will remain unchanged until the maintenance result date indicated on the IEC web site under “http:/webstore.iec.ch“ in the data related to the specific publication. At this dat

31、e, the publication will be reconfirmed; withdrawn; replaced by a revised edition, or amended. SANS 62226-1:2006This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .62226-1 IEC:2004 9 INTRODUCTION Public interest concerning human exposure to electr

32、ic and magnetic fields has led international and national organisations to propose limits based on recognised adverse effects. This standard applies to the frequency range for which the exposure limits are based on the induction of voltages or currents in human body, when exposed to electric and mag

33、netic fields. This frequency range covers the low and intermediate frequencies, up to 100 kHz. Some methods described in this standard can be used at higher frequencies under specific conditions. The exposure limits based on biological and medical experimentation about these fundamental induction ph

34、enomena are usually called “basic restrictions”. They include safety factors. The induced electrical quantities are not directly measurable, so simplified derived limits are also proposed. These limits, called “reference levels”, are given in terms of external electric and magnetic fields. They are

35、based on very simple models of coupling between external fields and the body. These derived limits are conservative. Sophisticated models for calculating induced currents in the body have been used and are the subject of a number of scientific publications. These use numerical 3D electromagnetic fie

36、ld computation codes and detailed models of the internal structure with specific electrical characteristics of each tissue within the body. However such models are still developing; the electrical conductivity data available at present has considerable shortcomings; and the spatial resolution of mod

37、els is still advancing. Such models are therefore still considered to be in the field of scientific research and at present it is not considered that the results obtained from such models should be fixed indefinitely within standards. However it is recognised that such models can and do make a usefu

38、l contribution to the standardisation process, especially for product standards in which particular cases of exposure are considered. When results from such models are used in standards, the results should be reviewed from time to time to ensure they continue to reflect the current status of the sci

39、ence. SANS 62226-1:2006This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .62226-1 IEC:2004 11 EXPOSURE TO ELECTRIC OR MAGNETIC FIELDS IN THE LOW AND INTERMEDIATE FREQUENCY RANGE METHODS FOR CALCULATING THE CURRENT DENSITY AND INTERNAL ELECTRIC F

40、IELD INDUCED IN THE HUMAN BODY Part 1: General 1 Scope This part of IEC 62226 provides means for demonstrating compliance with the basic restrictions on human exposure to low and intermediate frequency electric and magnetic fields specified in exposure standards or guidelines such as those produced

41、by IEEE and ICNIRP. The object of IEC 62226 is to propose a more realistic approach to the modelling of the human exposure to low frequency electric and magnetic fields, using a set of models of growing complexity for the field emission source, or the human body or both; to propose standardised valu

42、es for the electrical parameters of organs in human body: electrical conductivity and permittivity and their variation with the frequency. The present basic standard does not aim at replacing the definitions and procedures specified in exposure standards or guidelines, such as those produced by IEEE

43、 or ICNIRP, but aims at providing additional procedures with a view to allowing compliance assessment with these documents. The present basic standard provides means for demonstrating compliance with the basic restrictions without having to go to the sophisticated models. Nevertheless, when the expo

44、sure conditions are well characterized (such as in product standards, for example) and when results from such models are available, they can be used for demonstrating compliance with EMF standards or guidelines. NOTE 1 Examples of use of such sophisticated models can be found in the IEC Trend Techno

45、logy Assessment 21. NOTE 2 References to the scientific literature are given in the bibliography. 2 General data on electromagnetic fields and human exposure 2.1 General The total field emitted by any electrical device when operating is composed of the electric field and the magnetic field and is ca

46、lled the electromagnetic field. It is characterised by its frequency f or its wavelength , which is the ratio of the velocity of light in vacuum (c), divided by its frequency: = c/f. 1Figures in square brackets refer to the Bibliography SANS 62226-1:2006This s tandard may only be used and printed by

47、 approved subscription and freemailing clients of the SABS .62226-1 IEC:2004 13 Where the wavelength is large compared with the distance of the individual from the equipment, and the size of the individual, the exposure to the fields is defined as “near field exposure“. Under these conditions, elect

48、ric and magnetic fields are independent and can be studied separately. In practice this is valid for the range of frequencies covered by this standard. 2.2 Electric field Electric fields cause displacement of electric charges in conductive objects (including living bodies) and, because these fields

49、are alternating, the electric charges move to and from. The result is an “induced” alternating current, and related induced electric field, inside the conductive object. It is important to note that, for an object of uniform conductivity, to a very large degree, this current is independent of whether the object is a good or a poor conductor of electricity. By contrast, the associated induced electric field strongly depends on