1、 International Telecommunication Union ITU-T K.83TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (03/2011) SERIES K: PROTECTION AGAINST INTERFERENCE Monitoring field strengths of electromagnetic fields Recommendation ITU-T K.83 Rec. ITU-T K.83 (03/2011) i Recommendation ITU-T K.83 Monitoring field s
2、trengths of electromagnetic fields Summary Recommendation ITU-T K.83 gives guidance on how to make long-term measurements for the monitoring of electromagnetic fields (EMF) in the selected areas that are under public concern, in order to show that EMFs are under control and under the limits. The pur
3、pose of this Recommendation is to provide for the general public clear and easily available data concerning electromagnetic field levels in the form of results of continuous measurement. History Edition Recommendation Approval Study Group 1.0 ITU-T K.83 2011-03-09 5 ii Rec. ITU-T K.83 (03/2011) FORE
4、WORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying
5、 technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups w
6、hich, 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 technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO a
7、nd IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (
8、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 obligatory language such as “must“ and the negative equivalents are used to express requirements. The use of such wor
9、ds does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position con
10、cerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by
11、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 to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2011 All rights reserved. No part of this p
12、ublication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T K.83 (03/2011) iii Table of Contents Page 1 Scope 1 2 References. 1 3 Definitions 1 4 Abbreviations and acronyms 4 5 Physical quantities, units and constants 4 6 General process . 5 6.1 Des
13、cription of the general method . 5 6.2 Exposure limits . 6 7 Frequency selective measurement procedure . 7 7.1 Frequency sub-ranges . 7 7.2 Automatic level range determination . 7 7.3 Measurement of frequency bands . 7 7.4 Measurement of special services 8 7.5 Result evaluation 8 7.6 Measurement equ
14、ipment, general requirements . 8 7.7 Measurement probe 9 7.8 Measurement instrument 9 7.9 Measurement control 9 7.10 Mechanical and protective housing 9 8 Broadband measurement procedure . 9 8.1 Measuring equipment . 9 8.2 Measurement probe 10 8.3 Measurement instrument 10 8.4 Protection 10 8.5 Meas
15、urement method . 10 8.6 Measurement of exposure to multiple sources or frequencies . 11 9 Uncertainty . 11 10 Report on the measurement results . 12 Appendix I Links to the official websites with results of the EMF monitoring . 14 iv Rec. ITU-T K.83 (03/2011) Introduction Electromagnetic fields are
16、imperceptible and unknown for the general public. This unawareness and imperceptibility generates distrust and rejection among the population, which can result in social conflicts and lead to delays in the deployment of new wireless technologies. The solution to these problems is the control of the
17、electromagnetic emissions by taking measurements and having a proper communication. Measurements turn emissions into something objective and, when presented to the public in an understandable format, help diminish the unawareness and helplessness of the public. These measurements of electromagnetic
18、fields must meet three requirements: must be objective, reliable, and continuous. The objectivity of the measurements is achieved whenever a public and/or independent body carries out the taking of the measurements and manages their publication. Reliability derives from compliance with international
19、 norms and standards regarding the measurement of electromagnetic fields and by an accredited calibration of the measuring equipment. The continuous taking of objective and reliable measurements (24/365) provides permanent monitoring of emissions and a maximum transparency. For years, in various par
20、ts of the world, broadband systems have been used for the continuous measurement of electromagnetic fields with satisfactory results, increasing citizens confidence in governments, and reducing their fear and ignorance regarding electromagnetic emissions. An alternative are the frequency selective m
21、easurement systems which should be applied to meet particular requirements. This Recommendation presents the basis for the implementation of continuous measurement systems for electromagnetic emissions, in order to constitute a common practice at the international level for this type of measurements
22、. Rec. ITU-T K.83 (03/2011) 1 Recommendation ITU-T K.83 Monitoring field strengths of electromagnetic fields 1 Scope This Recommendation specifies the methods and characteristics of the monitoring system to be used for the continuous monitoring of electromagnetic fields emitted by radio transmitters
23、, both in the broadband and in the frequency selective measurement systems, in order to assess the long-term exposure of people to electromagnetic fields in the band of 9 kHz-300 GHz. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in
24、 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 encouraged to investigate the possibility of applying the most recent
25、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 document, the status of a Recommendation. EN 50383 EN 50383 (2010),
26、Basic standard for the calculation and measurement of electromagnetic field strength and SAR related to human exposure from radio base stations and fixed terminal stations for wireless telecommunication systems (110 MHz-40 GHz). EN 50400 EN 50400 (2005), Basic standard to demonstrate the compliance
27、of fixed equipment for radio transmission (110 MHz-40 GHz) intended for use in wireless telecommunication networks with the basic restrictions or the reference levels related to general public exposure to radio frequency electromagnetic fields, when put into service. EN 50413 EN 50413 (2008), Basic
28、standard on measurement and calculation procedures for human exposure to electric, magnetic and electromagnetic fields (0 Hz-300 GHz). EN 50492 EN 50492 (2008), Basic standard for in-situ measurement of electromagnetic field strength related to human exposure in the vicinity of base stations. ICNIRP
29、 ICNIRP (1998), Guidelines for Limiting Exposure to Time-Varying Electric, Magnetic and Electromagnetic Fields (up to 300 GHz). IEC 62311 IEC 62311 (2007), Assessment of electronic and electrical equipment related to human exposure restrictions for electromagnetic fields (0 Hz-300 GHz). IEEE C95.3 I
30、EEE Std C95.3-2002, IEEE Recommended Practice for Measurements and Computations of Radio Frequency Electromagnetic Fields With Respect to Human Exposure to Such Fields, 100 kHz-300 GHz. ISO/IEC Guide ISO/IEC Guide to the Expression of Uncertainty in Measurement, 1995. 3 Definitions This Recommendati
31、on defines the following terms: 3.1 averaging time (tavg): Appropriate time over which exposure is averaged for purposes of determining compliance with the limits. 2 Rec. ITU-T K.83 (03/2011) 3.2 electric field strength (E): Magnitude of a field vector at a point that represents the force (F) on a s
32、mall test charge (q) divided by the charge: qFE = The electric field strength is expressed in units of volt per metre (V/m). 3.3 exposure: Exposure occurs whenever a person is exposed to electric, magnetic or electromagnetic fields. 3.4 exposure ratio: The assessed exposure parameter at a specified
33、location for each operating frequency of a radio source, expressed as the fraction of the related limit. For assessments against reference levels: Between 9 kHz and 10 MHz: =HLHELEMAXER , Between 100 kHz and 300 GHz: =22,HLHELEMAXER or between 10 MHz and 300 GHz: =SLSER where: ER is the exposure rat
34、io at each operating frequency for the source EL is the investigation E-field limit at frequency f HL is the investigation H-field limit at frequency f SL is the equivalent plane-wave power density limit at frequency f E is the assessed E-field at frequency f for the source H is the assessed H-field
35、 at frequency f for the source S is the assessed equivalent plane-wave power density at frequency f for the source f is each operating frequency of the source ER is applicable to limits based on national regulations, or if they are not defined then in ICNIRP principles. 3.5 far-field region: Region
36、of the field of an antenna where the radial field distribution is essentially dependent inversely on the distance from the antenna. In this region, the field has a predominantly plane-wave character, i.e., locally uniform distribution of electric field and magnetic field in planes transverse to the
37、direction of propagation. NOTE In the far-field region, the vectors of the electric field E and the magnetic field H are perpendicular to each other, and the quotient between the value of the electric field strength E and the magnetic field strength H is constant and equals the impedance of free spa
38、ce Z0. Rec. ITU-T K.83 (03/2011) 3 3.6 impedance of free space: The impedance of free space Z0is defined as the square root of the free space permeability 0divided by the permittivity of free space 0: = 377120000Z 3.7 linearity: Maximum deviation over the measurement range of the measured quantity f
39、rom the closest linear reference curve defined over the range. 3.8 magnetic field strength (H): The magnitude of a field vector in a point that results in a force (F) on a charge q moving with the velocity v: )( HvqF = The magnetic field strength is expressed in units of amperes per meter (A/m). 3.9
40、 modulation: The process of modifying the amplitude, phase and/or frequency of a periodic waveform in order to convey information. 3.10 near-field region: Region generally in proximity to an antenna or other radiating structure, in which the electric and magnetic fields do not have a substantially p
41、lane-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 structure and that contains most or nearly all of the stored energy, and the radiating near-field region where the radiat
42、ion field predominates over the reactive field, but lacks substantial plane-wave character and is complex in structure. 3.11 permeability (): Magnetic permeability of a material is defined by the magnetic flux density B divided by the magnetic field strength H: HB= where is the permeability of the m
43、edium expressed in henry per metre (H/m). 3.12 permittivity (): Property of a dielectric material (e.g., biological tissue). In case of an isotropic material, it is defined by the electrical flux density D divided by the electrical field strength E: ED= The permittivity is expressed in units of fara
44、ds per metre (F/m). 3.13 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). 3.14 relevant source: A radio source which, at a given measurement point, has an exposure ratio l
45、arger than 0.05. 3.15 root mean square (rms): Effective value or rms value obtained by taking the square root of the average of the square of the value of the periodic function taken throughout one period. 3.16 total exposure ratio (TER) EN 50383: The total exposure ratio is the maximum value of the
46、 sum of exposure ratios of the equipment under test and all relevant sources over the frequency range 9 kHz to 300 GHz. RSEUTERERTER += 4 Rec. ITU-T K.83 (03/2011) where: EREUTis the assessed exposure ratio from the equipment under test ERRSis the assessed exposure ratio of all the relevant sources
47、3.17 unperturbed field: Field that exists in a space in the absence of a person or an object that could influence the field. NOTE The field measured or calculated with a person or object present may differ considerably. 4 Abbreviations and acronyms This Recommendation uses the following abbreviation
48、s and acronyms: CDMA Code Division Multiple Access DVB-T Digital Video Broadcasting Terrestrial EMF ElectroMagnetic Field ER Exposure Ratio ICNIRP International Commission on Non-Ionizing Radiation Protection IEC International Electrotechnical Commission IEEE Institute of Electrical and Electronics
49、Engineers RBW Resolution Bandwidth RMS Root Mean Square TER Total Exposure Ratio WCDMA Wideband CDMA 5 Physical quantities, units and constants The internationally accepted SI-units are used throughout this Recommendation. Quantity Symbol Unit DimensionCurrent density J ampere per square metre A/m2Electric field strength E volt per metre V/m Electric flux density D coulomb per square metre C/m2Frequency f hertz Hz Magnetic field strength H ampere per metre A/m Magnetic flux densi
