1、BRITISH STANDARDBS EN50420:2006Basic standard for the evaluation of human exposure to electromagnetic fields from a stand alone broadcast transmitter (30 MHz 40 GHz)The European Standard EN 50420:2006 has the status of a British StandardICS 13.280g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g
2、3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 50420:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2006 BSI 2006ISBN 0 580
3、 48952 3National forewordThis British Standard is the official English language version of EN 50420:2006. 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 organizati
4、ons represented on this committee can be obtained on request to its secretary.Cross-referencesThe 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
5、 Index”, or by using the “Search” facility of the BSI Electronic Catalogue 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
6、confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulga
7、te them in the UK.Summary of pagesThis document comprises a front cover, an inside front cover, the EN title page, pages 2 to 22, an inside back cover and a back cover.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationA
8、md. No. Date CommentsEUROPEAN STANDARD EN 50420 NORME EUROPENNE EUROPISCHE NORM June 2006 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050
9、 Brussels 2006 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 50420:2006 E ICS 13.280 English version Basic standard for the evaluation of human exposure to electromagnetic fields from a stand alone broadcast transmitter (30 MHz
10、- 40 GHz) Norme pour le calcul et la mesure de lexposition des personnes aux champs lectromagntiques provenant des metteurs de radiodiffusion isols (30 MHz - 40 GHz) Grundnorm fr die Ermittlung der Exposition gegenber elektromagnetischen Feldern von einzelnen Rundfunksendern (30 MHz bis 40 GHz) This
11、 European Standard was approved by CENELEC on 2005-12-06. CENELEC members are bound to comply with the CEN/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 refe
12、rences concerning such national standards may be obtained on application to the Central Secretariat or to any 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
13、member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Irela
14、nd, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. EN 50420:2006 - 2 - Foreword This European Standard was prepared by Technical Committee CENELEC TC 106X, Electromagnetic fields
15、in the human environment. The text of the draft was submitted to the formal vote and was approved by CENELEC as EN 50420 on 2005-12-06. 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 endorseme
16、nt (dop) 2007-01-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2009-01-01 _ - 3 - EN 50420:2006 Contents 1 Scope.4 2 Normative references 4 3 Physical quantities, units and constants5 3.1 Quantities.5 3.2 Constants.5 4 Terms and definitions 5 5 App
17、licability of compliance assessment methods .9 5.1 Introduction9 5.2 Assessment procedure9 5.3 Representative antennas for each service11 6 SAR measurement and calculation .11 6.1 Whole-body SAR implicit compliance11 6.2 SAR compliance 11 7 Electromagnetic field measurement 11 7.1 Measurement.11 7.2
18、 Uncertainty 12 8 Electromagnetic field calculation .15 8.1 Field regions 15 8.2 Calculation models 16 9 Contact currents measurement and calculation 17 10 Induced current measurement and calculation17 Annex A (normative) Field volume measurement 18 Annex B (informative) Compliance boundary examples
19、 21 Figure 1 Alternative routes to calculate E-field, H-field values at point of investigation 15 Figure A.1 Block diagram of the EUT measurement system 18 Figure A.2 Cylindrical, cartesian and spherical co-ordinates defined relative to the EUT 19 Table 1 Applicable methods for each antenna region.
20、10 Table 2 Representative antennas for each service. 11 Table 3 Recommended parameters . 12 Table 4 Representative antennas for each service. 14 Table B.1 Compliance boundary examples. 22 EN 50420:2006 - 4 - 1 Scope This standard applies to a broadcast transmitter operating in the frequency range 30
21、 MHz to 40 GHz when put on the market. The objective of the standard is to specify, for such equipment operating in typical conditions, the method for assessment of compliance distances according to the basic restrictions (directly or indirectly via compliance with reference levels) related to human
22、 exposure to radio frequency electromagnetic fields. 2 Normative references 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 (includin
23、g any amendments) applies. Council Recommendation 1999/519/EC of 12 July 1999 on the limitation of exposure of the general public to electromagnetic fields (0 Hz to 300 GHz) (Official Journal L 199 of 30 July 1999) EN 504131), Basic standard on measurement and calculation procedures for human exposu
24、re to electric, magnetic and electromagnetic fields (0 Hz - 300 GHz) EN 50421, Product standard to demonstrate the compliance of stand alone broadcast transmitters with the reference levels or the basic restrictions related to public human exposure to radio frequency electromagnetic fields (30 MHz -
25、 40 GHz) EN 55016-4-2, Specification for radio disturbance and immunity measuring apparatus and methods Part 4-2: Uncertainties, statistics and limit modelling Uncertainty in EMC measurements (CISPR 16-4-2) EN ISO/IEC 17025:2000, General requirements for the competence of testing and calibration lab
26、oratories (ISO/IEC 17025:1999) European Commission Enterprise Directorate General Standardisation Mandate addressed to CEN, CENELEC, and ETSI in the field of electro-technology, information technology and telecommunications M/305 Brussels IEEE Std C95.1:1999, IEEE Standard for Safety Levels with Res
27、pect to Human Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz International Commission on Non-Ionizing Radiation Protection, Guidelines for Limiting Exposure to Time-Varying Electric, Magnetic, and Electromagnetic Fields (up to 300 GHz), Health Physics Vol. 74, No 4, pp 494-522,
28、 1998 ISO Guide to the expression of uncertainty in measurement, 1995 1)At draft stage. - 5 - EN 50420:2006 3 Physical quantities, units and constants 3.1 Quantities The internationally accepted SI-units are used throughout the standard. Quantity Symbol Unit Dimensions Current density J ampere per s
29、quare metre A/m Electric field strength E volt per metre V/mElectric flux density D coulomb per square metre C/m Electric conductivity siemens per metre S/m Frequency f hertz Hz Magnetic field strength H ampere per metre A/m Magnetic flux density B tesla (Vs/m) T Mass density kilo per cubic metre kg
30、/m Permeability henry per metre H/m Permittivity farad per metre F/m Specific absorption rate SAR watt per kilogram W/kg Wavelength metre mTemperature T kelvin K 3.2 Constants Physical constant Magnitude Speed of light in a vacuum c 2,997 x 108m/s Permittivity of free space 08,854 x 10-12F/m Permeab
31、ility of free space 04 x 10-7H/m Impedance of free space 0 120 (approx. 377) 4 Terms and definitions For the purposes of this document, the following terms and definitions apply. 4.1 antenna device that serves as a transducer between a guided wave (e.g. coaxial cable) and a free space wave, or vice
32、versa 4.2 basic restriction restrictions on exposure to time-varying electric, magnetic, and electromagnetic fields that are based directly on established health effects. In the frequency range from 30 MHz to 10 GHz, the physical quantity used is the specific absorption rate. Between 10 GHz and 40 G
33、Hz, the physical quantity is the power density EN 50420:2006 - 6 - 4.3 broadcasting service radiocommunication service in which the transmissions are intended for direct reception by the general public. This service may include sound transmissions, television transmissions or other types of transmis
34、sion 4.4 compliance distance minimum distance from the antenna where a point of investigation is deemed to be compliant. The set of compliance distances therefore defines the boundary outside which the exposure levels do not exceed the basic restrictions irrespective of the time of exposure. The dis
35、tances are measured related to the nearest point of the antenna in each investigation direction 4.5 conductivity ( ) ratio of the conduction-current density in a medium to the electric field strength. Conductivity is expressed in units of siemens per metre (S/m) 4.6 contact current current produced
36、in the body involved by human contact with metallic objects in the field. Shocks and burns can be the adverse indirect effects . Contact current relates to an instantaneous effect and so cant be time-averaged 4.7 electric field strength (E) magnitude of a field vector at a point that represents the
37、force (F) on a positive small charge (q) divided by the charge E =Fq(1) Electric field strength is expressed in units of volt per metre (V/m) 4.8 electric flux density (D) magnitude of a field vector that is equal to the electric field strength (E) multiplied by the permittivity ( ) D = E(2) Electri
38、c flux density is expressed in units of coulomb per square metre (C/m) 4.9 equipment under test (EUT) device (such as transmitter, base station or antenna as appropriate) that is the subject of the specific test investigation being described 4.10 induced current currents circulating inside a human b
39、ody resulting directly from an exposure to an electromagnetic field 4.11 intrinsic impedance (of free space 0 ) ratio of the electric field strength to the magnetic field strength of a propagating electromagnetic wave. The intrinsic impedance of a plane wave in free space is 120 (approximately 377)
40、- 7 - EN 50420:2006 4.12 isotropy e.g., of a hypothetical receiving or transmitting antenna is, having equal intensities in all directions. Deviations of isotropy have to be considered at all measured values of EMF with regard to various angles of incidence and polarization of the measured field In
41、this document it is defined for incidences covering a hemisphere centred at the tip of the probe, with an equatorial plane normal to the probe and expanding outside the probe. The axial isotropy is defined by the maximum deviation of the measured quantity when rotating the probe along its main axis
42、with the probe exposed to a reference wave with normal incidence with regard to the axis of the probe. The hemispherical isotropy is defined by the maximum deviation of the measured quantity when rotating the probe along its main axis with the probe exposed to a reference wave with varying angles of
43、 incidences and polarisation with regard to the axis of the probe in the half space in front of the probe 4.13 linearity e.g. of an antenna or any other technical device is showed, when all relationships between a reference quantity and the deviations of this quantity lie along a straight line. The
44、maximum deviation over the measurement range of the measured quantity value from the closest linear reference curve defined over a given interval has to be taken into account in measurement procedures 4.14 magnetic field strength (H) magnitude of a field vector in a point that results in a force ( F
45、 ) on a charge q moving with the velocity v F = q (v H)(3) The magnetic field strength is expressed in units of ampere per metre (A/m) 4.15 magnetic flux density (B) magnitude of a field vector that is equal to the magnetic field strength H multiplied by the permeability () of the medium B = H (4) M
46、agnetic flux density is expressed in units of tesla (T) 4.16 modulation process, or the result of the process, where some characteristic of the wave (amplitude, frequency or phase) is varied in accordance with another wave or signal. It must also be taken into consideration when carrying out measure
47、ments and calculations to determine whether or not the limits are being exceeded 4.17 permeability ( ) magnetic permeability of a material defined by the magnetic flux density B divided by the magnetic field strength H: =BH, (5) where is the permeability of the medium expressed in henry per metre (H
48、/m) EN 50420:2006 - 8 - 4.18 permittivity ( ) property of a dielectric material (e.g., biological tissue) defined by the electrical flux density D divided by the electrical field strength E =DE(6) The permittivity is expressed in units of farad per metre (F/m) 4.19 point of investigation (PI) locati
49、on in space at which the value of E-field, H-field, Power flux density or SAR is evaluated. This location is defined in cartesian, cylindrical or spherical co-ordinates relative to the reference point on the EUT 4.20 power density (S) radiant power incident perpendicular to a surface, divided by the area of the surface. The power density is expressed in units of watt per square metre (W/m) 4.21 reference levels reference levels of exposure are provided for comparison with measured values of phys
