I E C 61 0 -4-2 ® Edition 2.0 201 6-1 I N TE RN ATI ON AL S TAN D ARD colour i n sid e BASIC EMC PUBLICATION E l ectrom ag n eti c com pati bi l i ty (E M C ) – P art 4-2 : Tes ti n g an d m e as u re m e n t tech n i q u es – Te s t m eth od s for prote cti ve IEC 61 000-4-23:201 6-1 0(en) d evi ces for H E M P an d oth er rad i ate d d i s tu rban ce s Copyright International Electrotechnical Commission T H I S P U B L I C AT I O N I S C O P YRI G H T P RO T E C T E D C o p yri g h t © I E C , G e n e v a , S wi tz e rl a n d All rights reserved Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either IEC or IEC's member National Committee in the country of the requester If you have any questions about I EC copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or your local I EC member National Committee for further information IEC Central Office 3, rue de Varembé CH-1 21 Geneva 20 Switzerland Tel.: +41 22 91 02 1 Fax: +41 22 91 03 00 info@iec.ch www.iec.ch Ab ou t th e I E C The I nternational Electrotechnical Commission (I EC) is the leading global organization that prepares and publishes I nternational Standards for all electrical, electronic and related technologies Ab o u t I E C p u b l i ca ti o n s The technical content of IEC publications is kept under constant review by the IEC Please make sure that you have the latest edition, a corrigenda or an amendment might have been published I E C Catal og u e - webstore i ec ch /catal og u e The stand-alone application for consulting the entire bibliographical information on IEC International Standards, Technical Specifications, Technical Reports and other documents Available for PC, Mac OS, Android Tablets and iPad I E C pu bl i cati on s s earch - www i ec ch /search pu b The advanced search enables to find IEC publications by a variety of criteria (reference number, text, technical committee,…) It also gives information on projects, replaced and withdrawn publications E l ectroped i a - www el ectroped i a org The world's leading online dictionary of electronic and electrical terms containing 20 000 terms and definitions in English and French, with equivalent terms in additional languages Also known as the International Electrotechnical Vocabulary (IEV) online I E C G l os sary - s td i ec ch /g l oss ary 65 000 electrotechnical terminology entries in English and French extracted from the Terms and Definitions clause of IEC publications issued since 2002 Some entries have been collected from earlier publications of IEC TC 37, 77, 86 and CISPR I E C J u st Pu bl i s h ed - webstore i ec ch /j u stpu bl i sh ed Stay up to date on all new IEC publications Just Published details all new publications released Available online and also once a month by email Copyright International Electrotechnical Commission I E C C u stom er S ervi ce C en tre - webstore i ec ch /csc If you wish to give us your feedback on this publication or need further assistance, please contact the Customer Service Centre: csc@iec.ch I E C 61 0 -4-2 ® Edition 2.0 201 6-1 I N TE RN ATI ON AL S TAN D ARD colour i n sid e BASIC EMC PUBLICATION E l ectrom ag n e ti c com pati bi l i ty (E M C ) – P art 4-2 : Tes ti n g an d m eas u re m e n t tech n i q u es – Tes t m eth od s for prote cti ve d e vi ces for H E M P an d oth er rad i ate d d i s tu rban ce s INTERNATIONAL ELECTROTECHNICAL COMMISSION ICS 33.1 00.99 ISBN 978-2-8322-3687-1 Warn i n g ! M ake s u re th a t you ob tai n ed th i s p u b l i cati on from an au th ori zed d i stri b u tor ® Registered trademark of the International Electrotechnical Commission Copyright International Electrotechnical Commission –2– I EC 61 000-4-23:201 © I EC 201 CONTENTS FOREWORD I NTRODUCTI ON Scope Norm ative references Terms and definitions HEMP test concepts General Testing of shielding enclosures General 2 Buildings Shelters and shielded rooms 20 4 Cabinets, racks and boxes 21 Testing of shielded cables and connectors 23 General 23 Testing of cable shields 23 3 Testing of cable connectors 26 4 Testing of shielding materials 27 4 General 27 4 Conducting gaskets 27 4 Conducting sheets and screens 29 4 Cut-off waveguides and honeycombs 32 Summ ary of test concepts 33 Test methods for measuring the shielding effectiveness of H EMP protection facilities 34 General 34 Electromagnetic field testing 34 General 34 2 Pulse field testing 34 CW field testing 40 Current injection test procedures 55 General 55 I nj ection testing of enclosures 55 3 Transfer im pedance and adm ittance of cable shields and connectors 57 Testing of gasket material 57 Annex A (informative) H EM P test concepts for electrical system s 60 A Overview 60 A Types of H EMP tests 60 A 2.1 General 60 A 2.2 System -level transient tests 60 A 2.3 CW field illum ination tests 61 A 2.4 Current inj ection testing 61 A 2.5 Partial illumination testing 62 A 2.6 Subsystem and com ponent testing 62 A Definition of the testing interface 63 A Use of test data 65 A 4.1 General 65 Copyright International Electrotechnical Commission I EC 61 000-4-23: 201 © I EC 201 –3– A 4.2 Acceptance of new system s 65 A 4.3 System assessm ents 65 A 4.4 Hardness surveillance monitoring 65 A 4.5 System design 65 A Testing uncertainties 66 Annex B (informative) Characterization of shielded cables 67 B Fundam entals of cable shielding 67 B Definitions of transfer im pedance and transfer admittance 68 B Relative significance of Z′t and Y′t 71 Annex C (inform ative) Equipment for H EMP pulse m easurem ents 72 C General 72 C Sensors for H EM P m easurem ents 72 C B - and H- field sensors 72 C 2 D - and E-field sensors 74 C Current sensors 76 C Signal transm ission 77 C General 77 C Fibre optic links 77 C 3 Fibre optic transducers 78 C Signal detection and processing 78 Annex D (inform ative) Equipment for CW testing 80 D General 80 D Antenna system 80 D Power am plifier 82 D Receiver (network anal yser) 83 D Reference and response sensors 83 D Fibre optic system 85 D Lim itations of m easurements 88 Annex E (informative) Characterization of a planar shield for H EMP protection 89 E General 89 E Problem geom etry 90 E Equivalent circuit representation 91 E 3.1 General 91 E 3.2 Chain parameter representation of the shield 92 E 3.3 Circuit responses 93 Annex F (inform ative) I nside-to-out m easurem ent method 97 F.1 Purpose 97 F.2 Comparison of existing SE test m ethods 97 F.3 I nside-to-out SE test of shielded rooms 98 F Measurements of the inside-to-out SE 98 F Summ ary 01 Bibliograph y 02 Figure – Exam ple of measured magnitude and phase of the transfer function T(ω ) = Hin /Hout for a shielded enclosure Figure – Electric field and m agnetic field shielding effectiveness of a 0, mm thick alum inum enclosure [29] Figure – Measured m agnetic field shielding effectiveness SE H for a building Copyright International Electrotechnical Commission –4– I EC 61 000-4-23:201 © I EC 201 Figure – Conceptual illustration of the H EMP test of a building Figure – I llustration of a shielded room or enclosure excited by H EMP fields 21 Figure – I llustration of equipm ent racks, cabinets and box excited by internal H EM P disturbance 21 Figure – A general shield excited by current injection 22 Figure – Basic configuration for transfer impedance measurem ent 24 Figure – Measured transfer im pedance magnitude and phase of transfer impedance per unit length for four braided shield cables with good shielding properties 25 Figure – Basic configuration for transfer admittance m easurement 26 Figure 1 – Test configuration for transfer impedance m easurem ent of a cable connector 26 Figure – Examples of conducting gaskets used as H EMP protection devices 28 Figure – Circuit model representing the behaviour of a conducting gasket for H EMP protection 28 Figure – Measurem ent configuration for the resistivity of a sam ple 29 Figure – Test concept for m easuring the resistivity with surface probes 30 Figure – Concepts for shielding effectiveness measurem ent of conducting sheets and screens 32 Figure – Example of the calculated plane-wave shielding effectiveness of a 0, 01 m m thick plate of different m aterial as a function of frequency 32 Figure – Cut-off waveguides and honeycom b used as protective elem ents 33 Figure – Examples of full-scale, pulse-radiating H EMP simulators 37 Figure 20 – Test procedure for the pulse test 39 Figure 21 – Typical configuration of a CW test facility 40 Figure 22 – Example CW measurem ent set-up 41 Figure 23 – Test and anal ysis procedures for conducting a CW test 42 Figure 24 – Analysis flow diagram for extrapolating a measured CW spectrum to the HEMP response 43 Figure 25 – Example scan from kH z to GH z for the ambient electromagnetic field from communication signals 44 Figure 26 – Test procedure for the am bient EM excitation test 45 Figure 27 – Double-ended TEM cell for field illumination testing of small enclosures 46 Figure 28 – Example test set-up for field illum ination in the TEM cell 47 Figure 29 – I llustration of the single-ended TEM cell and associated equipment 48 Figure 30 – Test set-up for the plane-wave shielding effectiveness m easurements 50 Figure 31 – Test set-up for the H-field shielding effectiveness measurem ents 51 Figure 32 – Example of antenna locations for the localized antenna tests for a h ypothetical shielded enclosure or facility 52 Figure 33 – Test concept and equipm ent configuration for current inj ection testing of a shielded enclosure or box 56 Figure 34 – Surface probe for volum e resistivity m easurem ent 59 Figure A – Sam ple H EMP interaction diagram illustrating penetration mechanism s, system responses and generic test interface locations 64 Figure B – Geom etry of a shielded coaxial line with an internal circuit 67 Figure B – Coaxial cable located over a conducting ground plane 68 Figure B – Two per-unit-length circuits form ed by the sheath and its ground return, and the sheath and the internal conductor 69 Copyright International Electrotechnical Commission I EC 61 000-4-23: 201 © I EC 201 –5– Figure C – Magnetic field sensors [23] 73 Figure C.2 – Single-slot, cylindrical coil sensor [23] 73 Figure C.3 – Two- and four-slot cylindrical coil sensors [23] 74 Figure C.4 – Electrical configuration of an E-field sensor [23] 74 Figure C.5 – Biconical E-field sensor 75 Figure C.6 – E-field sensor m ounted on a conducting ground plane [23] 75 Figure C.7 – Equipotential shapes for an optim ally designed E-field sensor [23] 75 Figure C.8 – Rogowski coil used for current measurements [23] 76 Figure C.9 – Toroidal current sensor m ade of m agnetic m aterial [23] 76 Figure C.1 – Voltage pick-up points on the edges of the toroidal sensor [23] 76 Figure C.1 – Example of a single-channel fibre optic transmission system [23] 77 Figure C.1 – Attenuation of coaxial lines and fibre optic cables as a function of frequency 78 Figure D.1 – Various antennas for CW testing 81 Figure D.2 – Relationship between the CW antenna and the incident H EM P field 82 Figure D.3 – I ncident and ground-reflected field contributions to the reference sensor excitations 84 Figure D.4 – Measured reference H-field spectrum and its inverse Fourier transform 85 Figure D.5 – Measured sensor responses and calibration function 87 Figure D.6 – Measured transfer function, corrected by calibration file 87 Figure E – Example of a general shielding problem 89 Figure E – Behaviour of the impedance ratio EH as a function of distance from a source [29] 90 Figure E – Conducting slab of thickness, d, and infinite extent serving as an electromagnetic barrier 91 Figure E – Equivalent circuit representation of the shielding problem 92 Figure E – Two-port representation of a circuit 93 Figure F – Test set-up for the outside-to-in and inside-to-out SE measurement 00 Table Table Table Table Table Table Table Table Table – Recommended test procedure for different test obj ects 34 – Dimensions and composition of distances d1 to d3 , with reference to Figure 30 50 – Dimensions and composition of distances d1 to d3 , with reference to Figure 31 51 – Measurement frequencies and antennas in plane-wave 52 – Measurement frequencies and antennas in m agnetic field 54 E – Surface resistance and electrical parameters for selected m aterials 95 F – Comparison with other standards 98 F – Test shielded room s 99 F – Comparison of the SE m easurement results 01 Copyright International Electrotechnical Commission –6– I EC 61 000-4-23:201 © I EC 201 INTERNATI ONAL ELECTROTECHNI CAL COMMISSI ON E L E C T RO M AG N E T I C C O M P AT I B I L I T Y ( E M C ) – P a rt -2 : T e s ti n g a n d m e a s u re m e n t te c h n i q u e s – T e s t m e th o d s fo r p ro te c ti ve d e vi c e s fo r H E M P a n d o th e r d i a te d d i s t u rb a n c e s FOREWORD ) The I nternati on al Electrotechni cal Comm ission (I EC) is a worl d wid e organization for stan dardization com prisin g all n ation al el ectrotechnical comm ittees (I EC National Comm ittees) The object of I EC is to prom ote internati onal co-operation on all q uestions concerni ng stand ardi zati on in the el ectrical an d electronic fi elds To this en d and in additi on to other acti vities, I EC pu blish es I nternational Stan dards, Techn ical Specificati ons, Technical Reports, Publicl y Avail abl e Specificati ons (PAS) an d Gu ides (h ereafter referred to as “I EC Publication(s)”) Th ei r preparation is entrusted to tech nical comm ittees; any I EC N ational Comm ittee interested in the subj ect dealt with m ay partici pate in this preparatory work I nternational, governm ental an d n on governm ental organ izations l iaising with th e I EC also participate i n this preparation I EC collaborates closel y with the I ntern ational Organi zation for Stand ardization (I SO) in accordance with ditions determ ined by agreem ent between th e two organi zati ons 2) The form al decisions or ag reem ents of I EC on tech nical m atters express, as n early as possible, an i nternati onal consensus of opi nion on the rel evant subjects since each technical com m ittee has representati on from all interested I EC N ational Com m ittees 3) I EC Publications have the form of recom m endations for intern ational use an d are accepted by I EC National Com m ittees in that sense While all reasonable efforts are m ade to ensure that the tech nical content of I EC Publications is accu rate, I EC cann ot be h eld responsi ble for th e way in which th ey are used or for an y m isinterpretation by an y en d u ser 4) I n order to prom ote intern ational u niform ity, I EC National Com m ittees und ertake to apply I EC Publications transparentl y to the m axim um extent possible i n their national an d regi on al publicati ons Any d ivergence between an y I EC Publication and the correspondi ng national or regi on al publicati on sh all be clearl y in dicated in the latter 5) I EC itself d oes n ot provi de an y attestation of conform ity I n depend ent certificati on bodies provi de conform ity assessm ent services and, in som e areas, access to I EC m arks of conform ity I EC is not responsi ble for any services carri ed out by ind ependent certification bodi es 6) All users shou ld ensure that th ey have the l atest editi on of thi s publicati on 7) No liability shall attach to I EC or its directors, em ployees, servants or ag ents inclu din g in divi dual experts an d m em bers of its technical com m ittees and I EC Nati on al Com m ittees for any person al i njury, property d am age or other dam age of any nature whatsoever, wheth er di rect or indirect, or for costs (includ i ng leg al fees) and expenses arisi ng out of the publ ication, use of, or relian ce upon, this I EC Publicati on or any other I EC Publications 8) Attention is drawn to th e N orm ative references cited in th is publ ication Use of the referenced publ ications is indispensable for the correct applicati on of this publication 9) Attention is drawn to the possibility that som e of the elem ents of this I EC Publication m ay be the su bject of patent rig hts I EC shall not be held responsibl e for identifyi ng any or all such patent ri ghts I nternational Standard I EC 61 000-4-23 has been prepared by subcommittee 77C: H igh power transient phenomena, of I EC technical comm ittee 77: Electrom agnetic com patibility I t forms Part 4-23 of I EC 61 000 I t has the status of a basic EMC publication in accordance with I EC Guide 07 This second edition cancels and replaces the first edition published in 2000 This edition constitutes a technical revision This edition includes the following significant technical changes with respect to the previous edition: a) updates to the shielding effectiveness (SE) test method in Clause 5; b) a new Annex F describing methods for testing ‘inside-to-out’ has been added Copyright International Electrotechnical Commission I EC 61 000-4-23: 201 © I EC 201 –7– The text of this standard is based on the following documents: CDV Report on votin g 77C/253/CDV 77C/257/RVC Full information on the voting for the approval of this standard can be found in the report on voting indicated in the above table This publication has been drafted in accordance with the I SO/I EC Directives, Part A list of all parts in the I EC 61 000 series, published under the general title can be found on the I EC website compatibility (EMC) , Electromagnetic The comm ittee has decided that the contents of this publication will remain unchanged until the stability date indicated on the I EC website under "http: //webstore iec.ch" in the data related to the specific publication At this date, the publication will be • • • • reconfirmed, withdrawn, replaced by a revised edition, or am ended A bilingual version of this publication m ay be issued at a later date I M P O R T AN T – T h e ' c o l o u r i n s i d e ' th at it tai n s u n d e rs t a n d i n g c o l o u r p ri n t e r Copyright International Electrotechnical Commission of c o l o u rs i ts wh i c h c o n te n ts l ogo a re U s e rs on th e co ve r p ag e o f th i s c o n s i d e re d s h ou l d to t h e re fo re be p u b l i c ati o n u s e fu l p ri n t th i s fo r i n d i c a te s th e d o cu m en t c o rre c t u sin g a –8– I EC 61 000-4-23:201 © I EC 201 INTRODUCTION I EC 61 000 is published in separate parts, according to the following structure: P a rt : G e n e l General considerations (introduction, fundam ental principles) Definitions, term inology P a rt : E n v i ro n m e n t Description of the environm ent Classification of the environment Com patibility levels P a rt : L i m i ts Em ission limits I mm unity limits (in so far as they not fall under the responsibility of the product committees) P a rt : T e s ti n g a n d m e a s u re m e n t t e c h n i q u e s Measurem ent techniques Testing techniques P a rt : I n s ta l l at i o n an d m i ti g a ti o n g u i d el i n es I nstallation guidelines Mitigation m ethods and devices P a rt : G e n e ri c S t a n d a rd s P a rt : M i s ce l l an eo u s Each part is further subdivided into several parts, published either as international standards, as technical specifications or technical reports, some of which have alread y been published as sections Others will be published with the part num ber followed by a dash and a second number identifying the subdivision (exam ple: I EC 61 000-6-1 ) The I EC has initiated the preparation of standardized methods to protect civilian society from the effects of high power electromagnetic (H PEM) environm ents Such effects could disrupt system s for comm unications, electric power, information technology, etc This part of I EC 61 000 is an international standard that establishes the test concepts, set-ups, required equipment, and test procedures for protective devices against H EM P radiated disturbances Annex F provides exam ples of the SE test m ethod placing the TX antenna inside the barrier Copyright International Electrotechnical Commission – 92 – I EC 61 000-4-23:201 © I EC 201 source voltage of Ei nc A similar transformation can be used to obtain the electrically dual source: a current source of Hi nc in shunt with the impedance Zc On the shielded side of the slab, the model contains a load impedance Zc , which is equal to the characteristic im pedance of free space With either of the equivalent sources shown in exciting the slab, suitable expressions for determ ining the tangential E2tan and H 2tan fields on the shielded side can be developed Ei n c Hi n c H1tan Zc Etan H2tan Con ductin g slab Etan Zc IEC a) Circuit represen tation of the conducting slab Zc Ei n c H1tan Etan H2tan Con ductin g slab Etan Zc IEC b) Alternate circui t representation of th e condu cting slab Figu re E.4 – Equivalent circuit representation of the shielding problem E.3.2 Chain parameter representation of the shield A general two-port circuit as shown in Figure E.5 can be represented by a number of different m atrix relationships: – – – – – open-circuit impedance param eters ( Z); short-circuit adm ittance param eters ( Y); chain (or ABCD ) param eters; scattering parameters ( S); h ybrid parameters ( h ) I n the present case, the chain parameters are the m ost useful as they provide a relationship between the voltage and current quantities on one port of the circuit and those at the other port With reference to Figure E 5, the chain param eter relationship can be expressed as (see [35]) V1 A B V2 I = C D I 1 or, by its inverse Copyright International Electrotechnical Commission (E ) I EC 61 000-4-23: 201 © I EC 201 – 93 – V2 = D − B V1 I − C A I 2 (E 2) I t should be noted that in these expressions, there is a requirement that the ABCD param eters shall satisfy the relationship AD - BC = for a linear, bilateral system I1 I2 V1 (ABCD) Param eters V2 IEC Figure E.5 – Two-port representation of a circuit Letting the variables V1 and I1 represent the tangential E- and H-fields on the illuminated side of the slab ( E1tan and H1tan ) and V2 and I2 denote the fields E2tan and H 2tan on the shielded side, reference [8] has developed the following chain parameter representation for the slab: E1tan A B E2tan tan = C D tan H2 H1 cosh jωt d R jωt d sinh jωt d = − R jωt d sinh jωt d cosh jωt d ( ( ) ( ) ) ( ( ) ) E tan H2tan where t d is a diffusion time and R is the d c slab surface resistance (in t d = mσd and R = σd (E 3) Ω ), given by (E 4) I n these expressions, d is the slab thickness, σ = /ρ is the electrical conductivity of the m aterial and m is the permeability of the sample E.3.3 E.3.3.1 Circuit responses Expression for the surface fields Using standard circuit anal ysis techniques, the responses for E and H an ywhere in the problem can be determ ined Specificall y, the surface fields on the illuminated side of the slab can be evaluated as E1tan = ( AZc + B ) E inc Z c ( A + Z c C ) + (B + Z c D ) (E 5) H1tan = (CZc + D ) E inc Z c ( A + Z c C ) + (B + Z c D ) (E 6) and Copyright International Electrotechnical Commission – 94 – I EC 61 000-4-23:201 © I EC 201 where A, B, C and D are the slab chain parameters defined in equation (E 3) The limiting cases of Equations (E 5) and (E 6) are instructive When the conductivity of the slab vanishes, or equivalentl y, when d = 0, the chain param eters become A = , B = 0, C = 0, D = , and these equations are reduced to the free-space case where E1tan = Einc and H1tan = inc E Zc (E 7) Another case of interest is when the slab becomes perfectl y conducting (i e σ → ∞) For this case, the chain parameters are A = , B = 0, C = ∞, D = , and the fields in Equations (E 5) and (E 6) take on the required values E1tan = and H1tan = inc E = Hinc Zc (E 8) on the surface of the conductor E.3.3.2 Expression for the penetrating fields I n a similar m anner, the fields penetrating into the shield region, E2tan and H 2tan , can be determ ined by circuit anal ysis These fields have the form E2tan = Zc E inc Z c ( A + Z c C ) + (B + Z c D ) (E 9) H 2tan = E inc Z c ( A + Z c C ) + (B + Z c D ) (E 0) and Checks of these fields for the limiting cases described in E.3 indicate that for no slab present the fields becom e the free-space incident fields, and for a perfectly conducting slab, the fields are zero, indicating perfect shielding E.3.3.3 The surface impedance Using the general field expressions in Equations (E 5) and (E 6), it is possible to develop an expression for the surface impedance on the illuminated side of the slab This quantity is useful, in that it permits the anal ysis of problem s on the illum inated side of the slab without requiring a further analysis of fields inside the slab or in the shielded region beyond This im pedance is defined as the ratio of E and H on the surface as: E tan (AZc + B ) (Ω ) Zs = 1tan = (Zc C + D ) H1 (E 1 ) For a thin slab of finite conductivity at low frequencies, the chain param eters become A = , B = 0, C = /R and D = I n this case, the surface im pedance becomes: Copyright International Electrotechnical Commission I EC 61 000-4-23: 201 © I EC 201 – 95 – Zs = 1 R + Zc () ≈R Ω (E 2) for cases where the surface resistance of the material is m uch less than the im pedance of free space (377 Ω ) At higher frequencies, the chain parameters in Equation (E 1 ) should be evaluated using Equation (E.3) The general expression for Zs becomes: Zs = (Z cosh jωt + R jωt sinh jωt ) (Ω) Z (R jωt )− sinh jωt + cosh jωt c c d d d d d (E 3) d For m an y types of conducting m aterials in the H EMP frequency range, it is possible to use a low-frequency sim plification to Equation (E 3): Zs ≈ R jωt d = (1 + j ) ωm ≡ R s + jωL s (E 4) σ where the surface resistance R s and the surface inductance L s are given in terms of the frequency f = ω /2 π as: Rs = 2πfm σ and Ls = Rs (E 5) 2πf Table E presents the surface resistance for several materials Table E.1 – Surface resistance and electrical parameters for selected materials M aterial Conductivity σ S/m Permeability Skin depth δ 6, × 07 π × -7 Copper 5, 80 × 07 π × -7 Alum inim um 3, 72 × 07 π × -7 Brass , 57 × 07 π × -7 Tin 0, 90 × 07 π × -7 Solder 0, 71 × 07 π × -7 0, 0642 / Surface resistivity R s Ω m H/m Silver Copyright International Electrotechnical Commission m f 2, 52 × -7 f 0, 066 / f 2, 61 × -7 f 0, 826 / f 3, 26 × -7 f 0, 27 / f 5, 01 × -7 f 0, 68 / f 6, 62 × -7 f 0, 85 / f 7, 73 × -7 f – 96 – Conductivity σ M aterial Permeability S/m m Skin depth δ 3, × 04 π × -7 Plexi glas 5, × 0-3 π × -7 Surface resistivity R s Ω m H/m Graphite E.3.3.4 I EC 61 000-4-23:201 © I EC 201 2, 91 / 7, 05 f × 03 / ,1 f × -5 f 0, 028 f Shield transfer impedance The transfer im pedance of the plate is defined as the ratio of E2tan / H 2tan , or equivalentl y, the ratio of the internal E-field to the external surface current density This is slightl y different from the transfer im pedance of a cable in which the impedance is defined as the ratio of the internal E-field (a distributed voltage source) to the total shield current I n this case, the transfer impedance has the units of Ω /m I ts units are in Ω A circuit anal ysis of provides the following expression for the transfer im pedance of the plate: Zt E2tan H1tan = = (Zc Cc+ D ) (Ω ) Z (E 6) or, equivalentl y: Zt = ( ) Z R jωt d c −1 Zc sinh jωt d + cosh jωt d (Ω ) (E 7) and for good conductors in the H EMP frequency range, this is approximated as: ≈ Zt R jωt d Ω sinh jωt d () (E 8) I t should be noted that at low frequencies, the transfer impedance is Zt ≈ R , which is the d.c surface resistance of the slab I t is interesting to note that this is the same value as the surface impedance in Equation (E 2) Thus, a low-frequency m easurem ent of the surface impedance on the front side of the plate can serve to characterize the transfer im pedance of the plate at low frequencies E.3.3.5 Transfer admittance The transfer adm ittance of the planar sheet is defined as Yt = = H2tan E1tan ( = )( ) S Zc A + B ( Zc cosh jωt d + R jωt d sinh jωt d ) (E 9) For a thin slab of finite conductivity at low frequencies, the chain parameters are A = , B = 0, C = /R and D = and in this transfer adm ittance impedance becom es Yt ≈ / Zc = 0,002 (S) Copyright International Electrotechnical Commission I EC 61 000-4-23: 201 © I EC 201 – 97 – An n e x F (informative) I n s i d e -t o - o u t m e a s u re m e n t m e t h o d F P u rp o s e Some HEM P protection facilities in practical use not have enough space available outside the electromagnetic barrier (due to ph ysical constraints such as concrete walls or soil) to allow for the correct application of the m easurement m ethod described wi thin the m ain bod y of this docum ent (outside-to-in); practical experience has shown that m any facilities have up to m of available separation space Territorial regulatory constraints can also be a prohibiting factor for conducting outside-to-in m easurem ents Therefore, in man y practical cases it is not possible to measure shielding effectiveness according to the standard outside-to-in test m ethod The constructors for H EMP protection facilities are also unwilling to build facilities with extra space for this m easurement outside of the barrier due to the great expense and inefficiency of the operational working area for the existing building Annex F provides som e experimental data that dem onstrates the feasibility of placing the transm itting antenna inside the enclosure and the receiving antenna placed a short distance outside (‘inside-to-out’ method) I t is important to note that there is a risk to equipment and other materials inside the facility using this m ethod; therefore, rem oval of equipment is recommended With this m ethod, it may be difficult to determine whether the transmitter is actually transm itting; therefore, it is recommended that a field measurement probe with a read-out outside the chamber is utilized to confirm a field is actuall y present inside F C o m p a ri s o n o f e x i s t i n g S E t e s t m e t h o d s Table F provides a com parison of existing SE test methods from a variety of standards including the previous edition (Edition 0) of this standard Copyright International Electrotechnical Commission – 98 – Tabl e F S t a n d a rd P u b l i c a ti o n – C o m p a ri s o n I EC 61 000-4-23:201 © I EC 201 w i t h o t h e r s t a n d a rd s I EC 61 000-4-23: 2000 (Edition 0) I EEE-STD-299 MI L-STD-1 88-1 25-1 2000 2006 2005 kHz to kH z: point 40 kH z to 60 kH z: point MH z to M Hz: poi nt kHz to 30 kH z: point 300 kH z to 500 kH z: point T e s t fr e q u e n c y M Hz to 20 MH z: point 50 MH z to 200 MH z: poi nts 20 MH z to 00 MH z: point 00 MH z to 300 M Hz: poi nt 300 MH z to 600 M Hz: poi nt 600 MH z to GH z: point GH z to GHz: poi nt GH z to GHz: poi nt kHz to 00 kHz: 20 points 00 kH z to M Hz: 20 points M Hz to MH z: 40 poi nts MH z to 00 MH z: 50 points 00 MH z to GH z: 50 points GH z to GHz: poi nt GH z to GH z: point Loop antenn a An t e n n a t yp e Loop antenn a Biconical anten na Dipole anten na Dipole anten na Horn antenna TX/RX a n te n n a d i s ta n c e /l o c a ti o n U n i t t e s t a re a TX: ≥ m (outside) TX: ≥ , m (outside) Loop antenn a Biconical anten na Log period ic antenna TX: 2, 05 m (outside) RX: cm to 60 cm RX: 0, m RX: , m 2, m 2, m 3, 05 m × 2, m × 2, m × 3, 05 m kHz to M Hz P a s s / fa i l c ri t e ri a - By owner : F.3 20log f -60 dB MH z to GHz : F ≥ ≥ 80 dB I n s i d e - t o - o u t S E t e s t o f s h i e l d e d ro o m s M e a s u re m e n t s o f t h e i n s i d e - t o - o u t S E The conditions of testing real exam ples of H EM P protected facilities are shown in Table F Copyright International Electrotechnical Commission I EC 61 000-4-23: 201 © I EC 201 – 99 – Table F.2 – Test shielded rooms Shielded room #1 Shielded room #2 IEC Chamber size 2, m × 3, m × 2, m Door, wavegui de, h on eycom b, Shielded room #3 IEC IEC 3, m × 5, m × 3, m 9, m × 6, m × 3, m ,1 m × 2, m × 2, m 2, m × 3, m × 3, m filter, connector panel Door, wavegui de, h on eycom b, filter Door, wavegui de, h on eycom b, filter SE Approxim atel y 60 dB to 70 dB Approxim atel y 60 dB to 70 dB 80 dB Door type Single I nterl ocks I nterl ocks Filter type EMI EMI EMP PoE a) Test set-up for the inside-to-out SE m easurement I n the outside-to-in case, the transmitting antenna was placed outside the electromagnetic barrier and the receiving antenna was placed inside I n contrast, for the inside-to-out, the transm itting antenna was placed inside the electrom agnetic barrier and the TX equipment was placed in another shielded room to protect from EM disturbances The receiving antenna was placed outside the barrier I t was then retested under the equal separation distance placing the transm itting antenna outside The results were then com pared Using the basic test method of MI L-STD-1 88-1 25-1 to m easure the shielding effectiveness, the nominal distance from the transmitting antenna reference point to the test area surface is 2, 05 m, and the nominal distance from the receiving antenna reference point to the test area surface is m Test points for the shielded room #1 and #2 are selected at the door, and the test point of the shielded room #3 is selected at the wall Regarding frequencies of 200 kH z, 50 M H z, 200 MH z, 400 MH z, and GH z, outside-to-in measurement results were compared with inside-to-out m easurem ent results The shielded RF cables of m were used both for calibration and measurement The test set-up for outside-to-in and inside-to-out SE m easurement is shown in Figure F Copyright International Electrotechnical Commission – 00 – I EC 61 000-4-23:201 © I EC 201 IEC a) Shielded room #1 IEC b) Shielded room #2 IEC c) Shielded room #3 Figure F.1 – Test set-up for the outside-to-in and inside-to-out SE measu rement Copyright International Electrotechnical Commission I EC 61 000-4-23: 201 © I EC 201 – 01 – b) Test results for the inside-to-out SE m easurem ent The m easurement results are shown in Table F Table F.3 – Comparison of the SE measurement results Freq Shielded room #1 - Door Shielded room #2 - Door Shielded room #3 - Wall - 200 kHz 50 M Hz 200 M Hz 400 M Hz (Un it: dB) GHz Outside-to-in SE 42 83 46 54 52 I nside-to-out SE 42 84 47 51 52 +1 +1 -3 Difference Outside-to-in SE 37 81 56 52 45 I nside-to-out SE 46 79 57 50 42 +9 -2 +1 -2 -3 Difference Outside-to-in SE > DR > DR 92 82 93 I nside-to-out SE > DR > DR 95 77 89 ? ? +3 -5 -4 Difference NOTE " > DR" m eans the shi eldin g effecti ven ess is superior to the DR (d yn am ic rang e) val ue DR is the rang e in which the test system is able to m easure th e SE The actual measurement results of outside-to-in and inside-to-out shielding effectiveness for each shielded room are not identical This is probabl y due to the different shielded room conditions Care should be taken to ensure that sufficient d ynamic range above the noise floor is available for the inside-to-out method or, at test frequencies where this is not possible, an alternative test frequency should be specificall y selected to avoid this issue F.3.2 Summary The inside-to-out method produces very comparable results to the traditional outside-to-in m ethod, particularl y where the shielding effectiveness of the installation is anticipated to be lower than a high quality shielded room ( > 80 dB) For cases where radiated HEM P protection is required to be m uch less than 80 dB, the insideto-out m ethod clearly has m erit This does not preclude the m ethod being applied to high quality shielded room s; however, d ynamic range may be a limiting factor Copyright International Electrotechnical Commission – 02 – I EC 61 000-4-23:201 © I EC 201 Bibliography [1 ] I EC 61 000-4-20, me asurem e nt Electroma gne tic techn iques – compa tibility Em ission and (EMC) – Pa rt im mun ity 4-20: testin g in Testing a nd tra nsverse e lectroma gn etic (TEM) wave guides [2] I EC 61 000-4-25, Electroma gne tic com patib ility (EMC) – Part 4-25: Testing a nd me asureme nt techn iques – HEMP immun ity test m eth ods for e quipme n t an d syste ms [3] I EC 61 000-2-1 0, Electroma gne tic compa tibility (EMC) – Part 2-1 0: En viron men t – Description of HEMP e nviron men t – Con ducte d disturbance [4] I EC 61 000-4-24, Electroma gne tic comp atib ility (EMC) – Part 4-24: Testing a nd me asureme nt tech n iques –Test m e th ods for protective devices for HEMP conducte d disturba nce [5] I EC TR 61 000-2-5, Electroma gne tic compa tib ility (EMC) – Pa rt 2-25: En viron men t – Description an d cla ssification of e lectroma gne tic environm e nts General EM P references: [6] Baum, C E., "EMP Sim ulators for Various Types of Nuclear EMP Environm ents: An I nterim Categorization, " I EEE TRAN S EMC, Vol EMC-20, N o , Feb 978 [7] Bell Laboratories, "EMP Engineering and Design Principles", Technical Publications Department, Bell Laboratories, Whippan y, N J , 975 [8] EMP I nteraction: "Principles, Techniques and Reference Data", K S.H Lee, editor, Hemisphere Publishing Co N ew York, 989 [9] Ghose, R., "EMP Environm ent and System Hardness Design", DWCI Publication, Gainesville, VA, 984 [1 0] Joehl, W , "A General and Systematic Survey of N EMP Protection Measures", Research I nstitute for Protective Construction (FMB), Zurich, Rep FMB 78-1 , J an 978 [1 ] Joint Special I ssue of the Nuclear Electrom agnetic Pulse, I EEE Trans EM C, Vol EMC20, N o , Feb 978 [1 2] Vance, E F , "Electromagnetic-Pulse Handbook for Electric Power Systems," Report DN A 3466F, Defense N uclear Agency, Washington, D.C , Feb 4, 975 Electromagnetic topology: [1 3] Baum, C E , "Electromagnetic Topolog y for the Anal ysis and Design of Com plex Electromagnetic Systems," pp 467-547 in Fast Electrica l a nd Optica l Mea sure me nts , Vol I , eds I E Thompson and L.H Luessem, Martinus N ijhoff, Dordrecht, 986 [1 4] Baum, C E , "Electromagnetic Topology: A Form al Approach to the Anal ysis and Design of Complex Electronic Systems", of the 4th Sym posium and Technical Exhibition on EMC Zurich, pp 209-21 4, March 981 [1 5] Baum, C E., "The Role of Scattering Theory in Electrom agnetic I nterference Problems", in Electromagnetic Scattering, P L E Uslenghi, editor, Academ ic Press, 978 [1 6] Karlsson, T , "The Topological Concept of a Generalized Shield, " AFWL I nteraction Note 461 , Kirtland AFB N M, Jan 988 [1 7] Karlsson, T., "On Grounding – Practical Procedures Based on Electrom agnetic Theory", Proceedings of the 9th I nternational Zurich Technical Exhibition on EMC, 3-5 March 987 Copyright International Electrotechnical Commission I EC 61 000-4-23: 201 © I EC 201 – 03 – [1 8] Tesche, F M , "Topological Concepts for I nternal EM P I nteraction, " I EEE Trans EMC, 20 (1 ), Feb 978 [1 9] Tesche, F.M , "I ntroduction to Concepts of Electrom agnetic Topolog y as Applied to EMP I nteraction With System s", N ATO/AGARD Lecture Series Publication 44, I nteraction Between EMP, Lightning and Static Electricity with Aircraft and Missile Avionics Systems , May 986 [20] Vance, E F , "EM P Hardening of Systems, " Proceeding of the 4th Sym posium and Technical Exhibition on Electrom agnetic Compatibility, Zurich, 0-1 March 981 [21 ] Vance, E F., and W Graf, "The Role of Shielding in I nterference Control", I EEE Trans EMC, Vol 30, N o 3, August 988, pp 294-297 Electromagnetic compatibility references: [22] Christopoulos, C., "Principles and Techniques of Electromagnetic Com patibility", CRC Press, Boca Raton, 995 [23] Degauque, P and J Hamelin, eds , "Electrom agnetic Compatibility", Oxford U niversity Press, Oxford, 993 (also in French) [24] Goedbloed, J.J , "Electrom agnetic Compatibility", Prentice H all, N ew York, 992 [25] Gravelle, L B., and P F Wilson, "EMI /EMC in Printed Circuit Boards – A Literature Review", I EEE Trans EMC, Vol 34, No 2, May 992, pp 09-1 [26] I anovici, (I anoz) M and J.J Morf, eds., "Com patibilité Électrom agnétique", Presses Pol ytechniques Rom andes, Lausanne, 983 [27] Keiser, B E , "Principles of Electrom agnetic Compatibility", Artech House, I nc Dedham, Mass 979 [28] Morgan, D., "A H andbook for EMC Testing and Measurement", Peter Peregrinus Ltd., I EE Electrical Measurem ent Series 8, London, 994 [29] Ott, H.W., "Noise Reduction Techniques in Electronic System s", J ohn Wiley & Sons, New York, 988 [30] Paul, C.R., "Prediction of Crosstalk in Ribbon Cables: Comparison of Model Predictions and Experimental Results", I EEE Trans EMC, Vol EMC-20, No 3, Aug 978, pp 394-406 [31 ] Paul, C.R , "Transm ission-Line Modeling of Shielded Wires for Crosstalk Prediction", I EEE Trans EMC, Vol EMC-23, N o 4, N ov 981 , pp 345-351 [32] Paul, C R , "I ntroduction to Electrom agnetic Compatibility", John Wiley & Sons, New York, 992 [33] Perez, R , ed , "Handbook of Electromagnetic Com patibility", Academ ic Press, 995 [34] Ryser, H , "Electromagnetic Com patibility, " H asler Review, Vol 7, N o 2, 984, pp 33-40 [35] Tesche, F.M., M V I anoz and T Karlsson, "EM C Anal ysis Methods and Computational Models", John Wiley & Sons, N ew York, 996 Electromagnetic shielding: [36] Casey, K F., "Electrom agnetic Shielding Behaviour of Wire-Mesh Screens", I EEE Trans EMC, Vol 30, N o 3, Aug 988, pp 298-31 Copyright International Electrotechnical Commission – 04 – I EC 61 000-4-23:201 © I EC 201 [37] Dahlberg, E., Electromagnetic Shielding, "Some Sim ple Form ulæ for Closed Uniform Shields", TRI TA–EPP–75–27, KTH Stockholm, Dec 975 [38] Kaden, H , "Wirbelstroem e und Schirmung in der Nachrichtentechnik", Springer-Verlag, Berlin, 959 [39] King, L V , "Electrom agnetic Shielding at Radio Frequencies", Vol 5, N o 97, Feb 933, pp 201 -223 [40] Lee, K S H , Ph il Ma g an d J Sci , "Electromagnetic Shielding", Ch 1 in Rece nt A dva nces in , H.N Kritikos and D L Jagard, eds., Springer-Verlag, New Electroma gne tic Th e ory York, 990 [41 ] Schelkunoff, S A , "Theory of Lines and Shields, " 3(1 934)4, pp 522-579 [42] Vance, E F , "Coupling to Shielded Cables", Krieger Publishing, 987 [43] Savage, E B , J L Gilbert and W A Radasky, “Expedient Building Shielding Measurem ent M ethod for H EMP Assessm ents, ” I EEE Transactions on Electrom agnetic Compatibility, Vol 55, No 3, June 201 3, pp 508-51 Be ll Syste m Tech n ical Journa l , Related specifications and standards: [44] MI L-STD-1 88-1 25-1 : 2005, High-A ltitude Electroma gn etic Pulse (HEMP) Protection for Groun d-Base d C4I Facilities Performin g Critical, Time-Urgen t Missions – Part : Fixe d Facilities [45] I EC 621 53-4-x (all parts), Me tallic commun ication cab le test meth ods – Part 4-x: Electrom a gne tic compatibility (EMC) [46] I EC TR 61 000-5-4, Electroma gn etic compa tibility (EMC) – Pa rt 5: Insta lla tion a nd mitiga tion guide lin es – Section 4: Immun ity to HEMP – Specifica tions for protective devices a ga inst HEMP dia te d disturbance [47] I EEE-Std-299: 2006, IEEE Sta n dard Me th od for Measuring th e Effectiven ess of Electrom a gne tic Shie ldin g Enclosures [48] AN SI /I EEE Std 488.1 :1 987, Stan dard IEEE Progra mma ble Instrume n ta tion _ Copyright International Electrotechnical Commission Sta ndard Digita l In terfa ce for Copyright International Electrotechnical Commission INTERNATIONAL ELECTROTECHNICAL COMMISSI ON 3, rue de Varembé PO Box 31 CH-1 21 Geneva 20 Switzerland Tel: + 41 22 91 02 1 Fax: + 41 22 91 03 00 info@iec.ch www.iec.ch Copyright International Electrotechnical Commission