1、 I n t e r n a t i o n a l T e l e c o m m u n i c a t i o n U n i o n ITU-T K.52 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (12/2016) SERIES K: PROTECTION AGAINST INTERFERENCE Guidance on complying with limits for human exposure to electromagnetic fields Recommendation ITU-T K.52 Rec. ITU-T K.
2、52 (12/2016) i Recommendation ITU-T K.52 Guidance on complying with limits for human exposure to electromagnetic fields Summary Recommendation ITU-T K.52 aims to help with compliance of telecommunication installations and mobile handsets or other radiating devices used against the head with safety l
3、imits for human exposure to electromagnetic fields (EMFs). It presents general guidance, a calculation method and an installation assessment procedure. The assessment procedure for telecommunication installations, based on safety limits provided by the International Commission on Non-Ionizing Radiat
4、ion Protection (ICNIRP), helps users determine the likelihood of installation compliance based on accessibility criteria, antenna properties and emitter power. The IEC Standard for the compliance measurement of mobile handsets is recommended. History Edition Recommendation Approval Study Group Uniqu
5、e ID* 1.0 ITU-T K.52 2000-02-25 5 11.1002/1000/4915 2.0 ITU-T K.52 2004-12-14 5 11.1002/1000/7427 2.1 ITU-T K.52 (2004) Cor.1 2009-05-29 5 11.1002/1000/10020 2.2 ITU-T K.52 (2004) Amd. 1 2013-02-07 5 11.1002/1000/11905 3.0 ITU-T K.52 2014-08-29 5 11.1002/1000/12238 4.0 ITU-T K.52 2016-12-14 5 11.100
6、2/1000/13131 Keywords Exposure level, basic restrictions, reference levels, exposure assessment, compliance, inherently compliant sources, normally compliant installations. _ * To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of your web browser, followed by the
7、Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T K.52 (12/2016) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). Th
8、e ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standa
9、rdization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information
10、technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Com
11、pliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other
12、obligatory language such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTSITU draws attention to the possibility that the practice or implement
13、ation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As
14、 of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged
15、 to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2017 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T K.52 (12/2016) iii Table of Contents Page 1 Scope . 1 2 References . 1 3
16、Terms and definitions . 2 4 Abbreviations and acronyms 5 5 General principles . 5 5.1 Multiple sources and frequencies . 6 5.2 Exposure duration . 6 6 EMF safety limits . 6 7 Compliance of mobile handsets 6 8 Achieving compliance to EMF safety limits for telecommunication installations . 7 8.1 Deter
17、mining the need for assessment for telecommunication equipment 7 8.2 Procedures for EMF exposure assessment . 7 8.3 Exposure level assessment procedure 8 9 EMF evaluation techniques 10 9.1 Calculation methods . 10 9.2 Measurement procedures 12 10 Mitigation techniques . 12 10.1 Occupational zone 13
18、10.2 Exceedance zone 13 Annex A The application flow chart . 14 Annex B Basic criteria for determining the installation class . 15 B.1 Inherently compliant sources 15 B.2 Normally compliant installations . 15 Appendix I ICNIRP limits 21 I.1 Basic restrictions 21 I.2 Reference levels 22 I.3 Simultane
19、ous exposure to multiple sources . 23 Appendix II Example of simple evaluation of EMF exposure . 25 II.1 Exposure at the ground level 25 II.2 Exposure at an adjacent building 26 Appendix III Example of EIRPth calculation 28 III.1 The EIRPth values . 28 Appendix IV Rationale for the EIRPth values of
20、Tables in Appendix III . 35 IV.1 Inherently compliant sources 35 IV.2 Normally compliant 35 Bibliography. 37 iv Rec. ITU-T K.52 (12/2016) Introduction This Recommendation aims to help with compliance of telecommunication installations and mobile handsets or other radiating devices used against the h
21、ead with safety limits for human exposure to electromagnetic fields (EMFs). This Recommendation does not set safety limits; it seeks to provide techniques and procedures for assessing the compliance of telecommunication installations and handsets with national or international EMF safety limits. Rec
22、. ITU-T K.52 (12/2016) 1 Recommendation ITU-T K.52 Guidance on complying with limits for human exposure to electromagnetic fields 1 Scope This Recommendation aims to help with compliance of telecommunication installations with safety limits for human exposure to electromagnetic fields (EMFs) produce
23、d by telecommunication equipment in the frequency range 8.3 kHz to 300 GHz1. This Recommendation provides techniques and procedures for assessing the severity of field exposure and for limiting the exposure to workers and the general public to these fields if the limits are exceeded. This Recommenda
24、tion also applies to exposure due to mobile handsets or other radiating devices, operating in the frequency range 300 MHz to 3 GHz and used against the head. Where national laws, standards or guidelines on exposure limits to EMF exist and provide procedures that are at variance with this Recommendat
25、ion, the pertinent national laws, standards or guidelines shall take precedence over the procedures provided in this Recommendation. This Recommendation covers the exposure of people present on telecommunication sites, and the exposure of people outside telecommunication sites, to EMF produced by te
26、lecommunication equipment and equipment on telecommunication sites. Contact current exposure, due to contact with conductive objects irradiated by electromagnetic fields, is not covered in this Recommendation. Exposure due to the use of mobile handsets or other radiating devices, used in close proxi
27、mity to the human body other than the head, is not covered. b-ITU-T Dir. VI covers safety issues related to people coming in contact with telecommunication circuits exposed to the induction of a.c. electric power or a.c. electrified railway lines. 2 References The following ITU-T Recommendations and
28、 other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encour
29、aged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone docu
30、ment, the status of a Recommendation. ITU-T K.61 Recommendation ITU-T K.61 (2003), Guidance to measurement and numerical prediction of electromagnetic fields for compliance with human exposure limits for telecommunication installations. IEC 62209-1 IEC 62209-1:2005, Human exposure to radio frequency
31、 fields from hand-held and body-mounted wireless communication devices Human models, instrumentation, and procedures Part 1: Procedure to determine the Specific Absorption Rate (SAR) for hand-held devices used in close proximity of the ear (frequency range of 300 MHz to 3 GHz). _ 1 Appendix I also g
32、ives the ICNIRP limits for lower frequencies. 2 Rec. ITU-T K.52 (12/2016) 3 Terms and definitions This Recommendation defines the following terms: 3.1 antenna gain: The antenna gain G (, ) is the ratio of power radiated per unit solid angle multiplied by 4 to the total input power. Gain is frequentl
33、y expressed in decibels with respect to an isotropic antenna (dBi). The equation defining gain is: where: , are the angles in a polar coordinate system Pr is the radiated power along the (, ) direction Pin is the total input power elementary solid angle along the direction of observation 3.2 average
34、 (temporal) power (Pavg): The time-averaged rate of energy transfer defined by: where t1 and t2 are the start and stop time of the exposure. The period t1 t2 is the exposure duration time. 3.3 averaging time (Tavg): The averaging time is the appropriate time period over which exposure is averaged fo
35、r purposes of determining compliance with the limits. 3.4 continuous exposure: Continuous exposure is defined as exposure for duration exceeding the corresponding averaging time. Exposure for less than the averaging time is called short-term exposure. 3.5 contact current: Contact current is the curr
36、ent flowing into the body by touching a conductive object in an electromagnetic field. 3.6 controlled/occupational exposure: Controlled/occupational exposure applies to situations where persons are exposed as a consequence of their employment and in which those persons who are exposed have been made
37、 fully aware of the potential for exposure and can exercise control over their exposure. Occupational/controlled exposure also applies where the exposure is of transient nature as a result of incidental passage through a location where the exposure limits may be above the general population/uncontro
38、lled limits, as long as the exposed person has been made fully aware of the potential for exposure and can exercise control over his or her exposure by leaving the area or by some other appropriate means. 3.7 directivity: Directivity is the ratio of the power radiated per unit solid angle over the a
39、verage power radiated per unit solid angle. 3.8 equivalent isotropically radiated power (EIRP): The EIRP is the product of the power supplied to the antenna and the maximum antenna gain relative to an isotropic antenna. 3.9 exposure: Exposure occurs wherever a person is subjected to electric, magnet
40、ic or electromagnetic fields, or to contact currents other than those originating from physiological processes in the body or other natural phenomena. 3.10 exposure level: Exposure level is the value of the quantity used when a person is exposed to electromagnetic fields or contact currents. ddPPG r
41、in4),( 21 )(1 12 tta v g dttPttPRec. ITU-T K.52 (12/2016) 3 3.11 exposure, non-uniform/partial body: Non-uniform or partial-body exposure levels result when fields are non-uniform over volumes comparable to the whole human body. This may occur due to highly directional sources, standing waves, scatt
42、ered radiation or in the near field. 3.12 far-field region: That region of the field of an antenna where the angular field distribution is essentially independent of the distance from the antenna. In the far-field region, the field has a predominantly plane-wave character, i.e., locally uniform dist
43、ribution of electric field strength and magnetic field strength in planes transverse to the direction of propagation. 3.13 general public: All non-workers (see definition of workers in clause 3.27) are defined as the general public. 3.14 induced current: Induced current is the current induced inside
44、 the body as a result of direct exposure to electric, magnetic or electromagnetic fields. 3.15 intentional emitter: Intentional emitter is a device that intentionally generates and emits electromagnetic energy by radiation or induction. 3.16 near-field region: The near-field region exists in proximi
45、ty to an antenna or other radiating structure in which the electric and magnetic fields do not have a substantially plane-wave character but vary considerably from point-to-point. The near-field region is further subdivided into the reactive near-field region, which is closest to the radiating struc
46、ture and that contains most or nearly all of the stored energy, and the radiating near-field region where the radiation field predominates over the reactive field, but lacks substantial plane-wave character and is complicated in structure. NOTE For many antennas, the outer boundary of the reactive n
47、ear-field is taken to exist at a distance of one-half wavelength from the antenna surface. 3.17 power density (S): Power flux-density is the power per unit area normal to the direction of electromagnetic wave propagation, usually expressed in units of Watts per square metre (W/m2). NOTE For plane wa
48、ves, power flux-density, electric field strength (E), and magnetic field strength (H) are related by the intrinsic impedance of free space, 0 = 377 . In particular, where E and H are expressed in units of V/m and A/m, respectively, and S in units of W/m2. Although many survey instruments indicate po
49、wer density units, the actual quantities measured are E or H. 3.18 power density, average (temporal): The average power density is equal to the instantaneous power density integrated over a source repetition period. NOTE This averaging is not to be confused with the measurement averaging time. 3.19 power density, peak: The peak power density is the maximum instantaneous power density occurring when power is transmitted. 3.20 power density, plane-wave equivalent (Seq): The equivale
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