BS EN 62226-1-2005 Exposure to electric or magnetic fields in the low and intermediate frequency range - Methods for calculating the current density and internal electric field ind.pdf

1、BRITISH STANDARD BS EN 62226-1:2005 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 The European Standard EN 62226-1:2005 has the status of a British

2、Standard ICS 17.220.20 BS EN 62226-1:2005 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 5 April 2005 BSI 5 April 2005 ISBN 0 580 45698 6 National foreword This British Standard is the official English language version of EN 62226-1:2005. It

3、 is identical with IEC 62226-1:2005. The UK participation in its preparation was entrusted to Technical Committee GEL/106, Human exposure to Lf and Hf electromagnetic radiation, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its s

4、ecretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Ca

5、talogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understan

6、d the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a

7、front cover, an inside front cover, the EN title page, pages 2 to 13 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEAN STANDARD EN 62226-1 NORME EUROPENNE EUROPISCHE NO

8、RM March 2005 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2005 CENELEC - All rights of exploitation in any form and by any m

9、eans reserved worldwide for CENELEC members. Ref. No. EN 62226-1:2005 E ICS 17.220.20 English version 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

10、(IEC 62226-1:2004) Exposition 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 (CEI 62226-1:2004) Sicherheit in elektrischen oder magnetischen Feldern im niedrigen un

11、d mittleren Frequenzbereich - Verfahren zur Berechnung der induzierten Krperstromdichte und des im menschlichen Krper induzierten elektrischen Feldes Teil 1: Allgemeines (IEC 62226-1:2004) This European Standard was approved by CENELEC on 2005-02-01. CENELEC members are bound to comply with the CEN/

12、CENELEC Internal Regulations which stipulate the conditions for giving this European Standard 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 Central Secretariat or to a

13、ny CENELEC member. This European Standard 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 Central Secretariat has the same status as the official ve

14、rsions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spa

15、in, Sweden, Switzerland and United Kingdom. EN 62226-:10025 - - 2 Foreword The text of document 106/78/FDIS, future edition 1 of IEC 62226-1, prepared by IEC TC 106, Methods for the assessment of electric, magnetic and electromagnetic fields associated with human exposure, was submitted to the IEC-C

16、ENELEC parallel vote and was approved by CENELEC as EN 62226-1 on 2005-02-01. The following dates were fixed: latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2005-11-01 latest date by which the national stan

17、dards conflicting with the EN have to be withdrawn (dow) 2008-02-01 _ Endorsement notice The text of the International Standard IEC 62226-1:2004 was approved by CENELEC as a European Standard without any modification. In the official version, for Bibliography, the following notes have to be added fo

18、r the standards indicated: CISPR 11 NOTE Harmonized in EN 55011 series (modified). CISPR 14 NOTE Harmonized in EN 55014 series (not modified). CISPR 16 NOTE Harmonized in EN 55016 series (not modified). _ Page2 EN622261:2005262-621 IEC:2004 3 TNOCENTS OFREWODR.5 TNIRODTCUOIN.9 1 Scope.4 2 General da

19、ta on electromagnetic fields and human exposure .4 2.1 General.4 2.2 Electric field 5 2.3 Magnetic field5 3 Terms and definitions, symbols and abbreviations6 3.1 Terms and definitions6 3.2 Physical quantities and units .9 3.3 Physical constants 10 4 General procedure for assessing compliance with sa

20、fety limits.10 Bibliography11 Figure 1 Overview of different methods for assessing compliance with exposure limits .10 Page3 EN622261:2005 262-621 IEC:2004 3 CONTENTS OFREWODR.5 TNIRODTCUOIN.9 1 cSpoe.11 2 Gerenal data on elcertmoganetic filesd and muhan xeposure .11 .21 Gerenal.11 .22 Elcertci fiel

21、d31 .23 aMgnetci field31 3 Terms dna definiitons, symslob and barbevaitions51 .31 Terms dna definiitons 51 .32 Physcial quanttiies nad unist .12 .33 Physcial cosntastn32 4 Gerenal rpcoedure for sasessnig compliacne iwht safety limist.32 Bibliorgaphy52 iFugre 1 O vreview fo different methods for sase

22、ssign complicnae tiwh exsoprue limist .32 262-621 EI:C0024 11 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 1 Scope This part of IEC 62226 provides

23、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 by IEEE and ICNIRP. The object of IEC 62226 is to propose a more realistic approach to

24、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 values for the electrical parameters of organs in human body: electrical conductivity and p

25、ermittivity 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 or ICNIRP, but aims at providing additional procedures with a view to allowing complia

26、nce 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 exposure conditions are well characterized (such as in product standards, for example) and

27、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 Technology Assessment 2 1 . NOTE 2 References to the scientific literature are given in the b

28、ibliography. 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 called the electromagnetic field. It is characterised by its frequency f or its wavelen

29、gth , 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 Page4 EN622261:2005262-621 EI:C0024 31 Where the wavelength is large compared with the distance of the individual from the equipment, and the size o

30、f the individual, the exposure to the fields is defined as “near field exposure“. Under these conditions, electric 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 ca

31、use displacement of electric charges in conductive objects (including living bodies) and, because these fields 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

32、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 the electrical conductivity of the body. The current induce

33、d by an electric field depends on the shape and size of the conducting object; the characteristics (magnitude, polarisation, degree of non uniformity, etc.) of the unperturbed field (see definition 3.1.19); the frequency of the field. The induced alternating current would also depend on whether the

34、body is in electrical contact with the ground and on the presence of other conducting bodies nearby. 2.3 Magnetic field Alternating magnetic fields create alternating electric fields and associated currents in conductive media. These currents are called eddy currents. Because living tissues are elec

35、trically conducting, induction also occurs in the human body. The current induced by a magnetic field depends on the shape, size and conductivity of the conducting object; the characteristics (magnitude, polarisation, degree of non uniformity, etc.) of the field. In contrast to electric field, magne

36、tic field is not normally perturbed by nearby objects; the frequency of the field. The magnetic field level decreases with distance from its source. The variation of field with distance is described for three different types of source. A single conductor (e.g. railway overhead power supply): the mag

37、netic field decreases as 1/d, where d is the distance from the energised conductor (Amperes law). A system of parallel conductors, energised by a system of balanced currents (e.g. electrical networks): the magnetic fields decrease as 1/d, where d is the mean distance from the energised conductors. T

38、his empirical law is valid only when d is large compared with the distance between the different conductors. Page5 EN622261:2005262-621 EI:C0024 51 Localised sources (e.g. electrical domestic appliances) can be considered as magnetic dipoles: the magnetic fields decrease as 1/d 3 , where d is the di

39、stance from the source. In the same way as previously, this approximate law only applies when d is large compared with the size of the source itself. 3 Terms and definitions, symbols and abbreviations 3.1 Terms and definitions For the purposes of this document, the terms and definitions given below

40、apply. 3.1.1 basic restrictions according to the terminology in use in health recommendations relating to the exposure to electromagnetic fields, the exposure limits based on biological effects established by biological and medical experimentation about these fundamental induction phenomena Basic re

41、strictions usually include safety factors to allow for uncertainty in the scientific information defining the threshold for the effect. NOTE 1 The precise definition of this term may vary from one EMF health guideline to another. NOTE 2 For the frequency range covered by this standard the basic rest

42、rictions to make reference to are generally expressed in terms of induced current density or internal electric field. Because the basic restriction is a quantity inside the body that cannot be measured, a corresponding reference level is generally derived and used in EMF health guidelines. 3.1.2 cou

43、pling factor K factor used to enable exposure assessment for complex exposure situations, such as non- uniform magnetic field or perturbed electric field NOTE 1 The coupling factor K has different physical interpretations depending on whether it relates to electric or magnetic field exposure. NOTE 2

44、 The value of the coupling factor K depends on the model used for the field source and the model used for the human body. When exposure conditions are defined, such as in a product standard, precise values of the coupling factors can be specified directly and can be used such as defined in product s

45、tandards. 3.1.3 current density vector quantity whose magnitude is equal to the charge that crosses per unit time a unit surface area perpendicular to the flow of charge NOTE Current density is expressed in amperes per square metre (A/m 2 ). 3.1.4 environmental field electric or magnetic field exter

46、nal to the body, and measured in the absence of the body 3.1.5 electric field strength E magnitude of the vector field E rwhich determines the force F ron a static electrical charge q: E q F r r = NOTE The electric field strength is expressed in units of volts per metre (V/m). Page6 EN622261:2005262

47、-621 EI:C0024 71 3.1.6 electric displacement D magnitude of a field vector D rthat is related to the electric field E rby the formula: E D r r r 0 = where ris the relative permittivity of the medium and 0is the permittivity of vacuum NOTE The electric displacement is expressed in units of coulombs p

48、er square metre (C/m 2 ). 3.1.7 exposure situation that occurs wherever a person is subjected to electric, magnetic or electromagnetic fields NOTE The word “exposure” is also commonly used to mean “exposure level” (see 3.1.8). 3.1.8 exposure level value of the considered quantity when a person is ex

49、posed to electric, magnetic or electromagnetic fields 3.1.9 exposure, partial-body exposure that results from localized absorption of the energy 3.1.10 exposure, non-uniform exposure levels that result when fields are non-uniform over volumes comparable to the whole human body NOTE See also definitions 3.1.8 and 3.1.9. 3.1.11 hot spot localised area of higher fi