SIST EN 55016-1-3:2007
Specification for radio disturbance and immunity measuring apparatus and methods -- Part 1-3: Radio disturbance and immunity measuring apparatus - Ancillary equipment - Disturbance power
Specification for radio disturbance and immunity measuring apparatus and methods -- Part 1-3: Radio disturbance and immunity measuring apparatus - Ancillary equipment - Disturbance power
This part of CISPR 16 is designated a basic standard, which specifies the characteristics and calibration of the absorbing clamp for the measurement of radio disturbance power in the frequency range 30 MHz to 1 GHz.
Anforderungen an Geräte und Einrichtungen sowie Festlegung der Verfahren zur Messung der hochfrequenten Störaussendung (Funkstörungen) und Störfestigkeit -- Teil 1-3: Geräte und Einrichtungen zur Messung der hochfrequenten Störaussendung (Funkstörungen) und Störfestigkeit - Zusatz-/Hilfseinrichtungen - Störleistungsmessung
Spécifications des méthodes et des appareils de mesure des perturbations radioélectriques et de l'immunité aux perturbations radioélectriques -- Partie 1-3: Appareils de mesure des perturbations radioélectriques et de l'immunité aux perturbations radioélectriques - Matériels auxiliaires - Puissance perturbatrice
La présente partie de la CISPR 16 est une norme fondamentale qui spécifie les caractéristiques et l'étalonnage de la pince absorbante pour la mesure de la puissance perturbatrice radioélectrique dans la gamme de fréquences de 30 MHz à 1 GHz. Cette deuxième édition annule et remplace la première édition parue en 2003. Elle constitue une révision technique. Cette édition spécifie une méthode d'étalonnage plus détaillée pour la pince absorbante. De plus, de nouvelles méthodes d'étalonnage possibles sont introduites, qui sont plus praticables que celle qui était spécifiée auparavant. Des paramètres additionnels pour décrire la pince absorbante sont définis, tels le facteur de découplage pour l'absorbeur large bande DF et le facteur de découplage pour le transformateur de courant DR
Specifikacija za merilne naprave in metode za merjenje radijskih motenj in odpornosti - 1-3. del: Merilne naprave za merjenje radijskih motenj in odpornosti - Pomožna oprema - Moč motenj (CISPR 16-1-3:2004)
Ta del standarda CISPR 16 je osnovni standard, ki določa lastnosti in umerjanje absorbirnih klešč za merjenje moči radijskih motenj v frekvenčnem območju med 30 MHz in 1 GHz.
General Information
Relations
Standards Content (Sample)
SLOVENSKI SIST EN 55016-1-3:2007
STANDARD
marec 2007
Specifikacija merilnih naprav in metod za merjenje radijskih motenj in
odpornosti - 1-3. del: Merilne naprave za merjenje radijskih motenj in
odpornosti - Pomožna oprema – Moč motenj (CISPR 16-1-3:2004)
Specification for radio disturbance and immunity measuring apparatus and
methods - Part 1-3: Radio disturbance and immunity measuring apparatus -
Ancillary equipment - Disturbance power (CISPR 16-1-3:2004)
ICS 17.220.20; 33.100.20 Referenčna številka
SIST EN 55016-1-3:2007(en)
© Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno
---------------------- Page: 1 ----------------------
EUROPEAN STANDARD
EN 55016-1-3
NORME EUROPÉENNE
November 2006
EUROPÄISCHE NORM
ICS 33.100.10;33.100.20 Supersedes EN 55016-1-3:2004
English version
Specification for radio disturbance
and immunity measuring apparatus and methods
Part 1-3: Radio disturbance and immunity measuring apparatus -
Ancillary equipment -
Disturbance power
(CISPR 16-1-3:2004)
Spécifications des méthodes Anforderungen an Geräte
et des appareils de mesure und Einrichtungen sowie Festlegung
des perturbations radioélectriques der Verfahren zur Messung
et de l'immunité aux perturbations der hochfrequenten Störaussendung
radioélectriques (Funkstörungen) und Störfestigkeit
Partie 1-3: Appareils de mesure Teil 1-3: Geräte und Einrichtungen
des perturbations radioélectriques zur Messung der hochfrequenten
et de l'immunité aux perturbations Störaussendung (Funkstörungen)
radioélectriques - und Störfestigkeit -
Matériels auxiliaires - Zusatz-/Hilfseinrichtungen -
Puissance perturbatrice Störleistungsmessung
(CISPR 16-1-3:2004) (CISPR 16-1-3:2004)
This European Standard was approved by CENELEC on 2006-07-01. 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 references 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 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, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels
© 2006 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 55016-1-3:2006 E
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EN 55016-1-3:2006 - 2 -
Foreword
The text of the International Standard CISPR 16-1-3:2004, prepared by CISPR SC A, Radio-interference
measurements and statistical methods, was submitted to the CENELEC Unique Acceptance Procedure
and was approved by CENELEC as EN 55016-1-3 on 2006-07-01.
This European Standard supersedes EN 55016-1-3:2004.
In this EN 55016-1-3:2006, a more detailed calibration method for the absorbing clamp is specified.
Furthermore, new alternative calibration methods are introduced which are more practicable than the one
that was specified previously. Additional parameters to describe the absorbing clamp are defined, like the
decoupling factor for the broadband absorber (DF) and the decoupling factor for the current transformer
(DR), along with their validation methods. A procedure for the validation of the absorbing clamp test site
(ACTS) is also included in the document.
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) 2007-07-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2009-07-01
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard CISPR 16-1-3:2004, including the corrigendum February 2006, was
approved by CENELEC as a European Standard without any modification.
__________
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- 3 - EN 55016-1-3:2006
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
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 (including any amendments) applies.
NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.
Publication Year Title EN/HD Year
CISPR 16-1-2 2003 Specification for radio disturbance and EN 55016-1-2 2004
immunity measuring apparatus and methods
Part 1-2: Radio disturbance and immunity
measuring apparatus - Ancillary equipment -
Conducted disturbances
CISPR 16-2-2 2003 Specification for radio disturbance and EN 55016-2-2 2004
immunity measuring apparatus and methods
Part 2-2: Methods of measurement of
disturbances and immunity - Measurement of
disturbance power
1) 2)
CISPR 16-4-2 - Specification for radio disturbance and EN 55016-4-2 2004
immunity measuring apparatus and methods
Part 4-2: Uncertainties, statistics and limit
modelling - Uncertainty in EMC
measurements
IEC 60050-161 1990 International Electrotechnical Vocabulary - -
+ A1 1997 (IEV) - Chapter 161: Electromagnetic - -
+ A2 1998 compatibility - -
1)
Undated reference.
2)
Valid edition at date of issue.
---------------------- Page: 4 ----------------------
INTERNATIONAL
CISPR
ELECTROTECHNICAL
16-1-3
COMMISSION
Second edition
2004-06
INTERNATIONAL SPECIAL COMMITTEE ON RADIO INTERFERENCE
Specification for radio disturbance and immunity
measuring apparatus and methods –
Part 1-3:
Radio disturbance and immunity measuring
apparatus – Ancillary equipment –
Disturbance power
IEC 2004 Copyright - all rights reserved
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 the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch Web: www.iec.ch
PRICE CODE
V
Commission Electrotechnique Internationale
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
For price, see current catalogue
---------------------- Page: 5 ----------------------
CISPR 16-1-3 IEC:2004 – 3 –
CONTENTS
FOREWORD.5
1 Scope.9
2 Normative references.9
3 Terms, definitions and abbreviations .9
4 Absorbing clamp instrumentation.11
Annex A (informative) Construction of the absorbing clamp (Subclause 4.2) .35
Annex B (normative) Calibration and validation methods for the absorbing clamp and
the secondary absorbing device (Clause 4).39
Annex C (normative) Validation of the absorbing clamp test site (Clause 4) .59
Figure 1 – Overview of the absorbing clamp measurement method and the associated
calibration and validation procedures.27
Figure 2 – Schematic overview of the absorbing clamp test method.31
Figure 3 – Schematic overview of the clamp calibration methods .33
Figure A.1 – The absorbing clamp assembly and its parts.35
Figure A.2 – Example of the construction of an absorbing clamp.37
Figure B.1 – The original calibration site .51
Figure B.2 – Position of guide for centering the lead under test .51
Figure B.3 – Side view of the calibration jig .53
Figure B.4 – Top view of the jig .53
Figure B.5 – View of the jigs vertical flange .53
Figure B.6 – Test set-up for the reference device calibration method .55
Figure B.7 – Specification of the reference device .55
Figure B.8 – Measurement set-up of the decoupling factor DF .57
Figure B.9 – Measurement set-up of the decoupling factor DR.57
Figure C.1 – Test set-ups for the site attenuation measurement for clamp site
validation using the reference device .63
Table 1 – Overview of the characteristics of the three-clamp calibration methods and
their relation .29
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CISPR 16-1-3 IEC:2004 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
INTERNATIONAL SPECIAL COMMITTEE ON RADIO INTERFERENCE
___________
SPECIFICATION FOR RADIO DISTURBANCE AND IMMUNITY
MEASURING APPARATUS AND METHODS –
Part 1-3: Radio disturbance and immunity measuring apparatus –
Ancillary equipment – Disturbance power
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard CISPR 16-1-3 has been prepared by CISPR subcommittee A: Radio
interference measurements and statistical methods.
This second edition cancels and replaces the first edition published in 2003. It constitutes a
technical revision. In this edition a more detailed calibration method for the absorbing clamp is
specified. Furthermore, new alternative calibration methods are introduced which are more
practicable than the one which was specified previously. Additional parameters to describe
the absorbing clamp are defined, like the decoupling factor for the broadband absorber (DF)
and the decoupling factor for the current transformer (DR), along with their validation
methods. A procedure for the validation of the absorbing clamp test site (ACTS) is also
included in the document.
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CISPR 16-1-3 © IEC:2004 – 7 –
The text of this standard is based on the following documents:
FDIS Report on voting
CISPR/A/517/FDIS CISPR/A/532/RVD
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 ISO/IEC Directives, Part 2.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site 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
• amended.
The contents of the corrigendum of February 2006 have been included in this copy.
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CISPR 16-1-3 IEC:2004 – 9 –
SPECIFICATION FOR RADIO DISTURBANCE AND IMMUNITY
MEASURING APPARATUS AND METHODS –
Part 1-3: Radio disturbance and immunity measuring apparatus –
Ancillary equipment – Disturbance power
1 Scope
This part of CISPR 16 is designated a basic standard, which specifies the characteristics and
calibration of the absorbing clamp for the measurement of radio disturbance power in the
frequency range 30 MHz to 1 GHz.
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 (including any amendments) applies.
CISPR 16-1-2:2003, Specification for radio disturbance and immunity measuring apparatus
and methods – Part 1-2: Radio disturbance and immunity measuring apparatus – Ancillary
equipment – Conducted disturbances
CISPR 16-2-2:2003, Specification for radio disturbance and immunity measuring apparatus
and methods – Part 2-2: Methods of measurement of disturbances and immunity –
Measurement of disturbance power
CISPR 16-4-2, Specification for radio disturbance and immunity measuring apparatus and
methods – Part 4-2: Uncertainties, statistics and limit modelling – Uncertainty in EMC
measurements
IEC 60050-161:1990, International Electrotechnical Vocabulary (IEV) – Chapter 161: Electro-
magnetic compatibility
Amendment 1 (1997)
Amendment 2 (1998)
3 Terms, definitions and abbreviations
3.1 Terms and definitions
See IEC 60050-161, where applicable.
3.2 Abbreviations
ACA Absorbing clamp assembly
ACMM Absorbing clamp measurement method
ACRS Absorbing clamp reference site
ACTS Absorbing clamp test site
CF Clamp factor
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CISPR 16-1-3 IEC:2004 – 11 –
CRP Clamp reference point
DF Decoupling factor
DR Decoupling factor that specifies the decoupling of the current transformer from the
common mode impedance of the measurement receiver
JTF Jig transfer factor
LUT Lead under test
RTF Reference transfer factor
SAD Secondary absorbing device
SAR Semi-anechoic room
SRP Slide reference point
4 Absorbing clamp instrumentation
4.1 Introduction
The measurement of disturbance power using an absorbing clamp is a method for the
determination of the radiated disturbance in the frequency range above 30 MHz. This
measurement method represents an alternative approach to the measurement of the
disturbance field strength on an OATS. The absorbing clamp measurement method (ACMM) is
described in Clause 7 of CISPR 16-2-2.
The ACMM uses the following measurement instrumentation:
– the absorbing clamp assembly;
– the secondary absorbing device;
– the absorbing clamp test site.
Figure 1 gives an overview of the absorbing clamp measurement method including the
instrumentation required for this method and the calibration and validation methods for the
instrumentation. The requirements for the instrumentation necessary for the ACMM are
specified in this clause. Details of the absorbing clamp calibration method, and validation of
other properties of the clamp and the secondary absorbing device, are described in Annex B.
Details of the absorbing clamp test site validation are described in Annex C. Absorbing
clamps are suitable for the measurement of disturbances from some types of equipment,
depending on construction and size. The precise measuring procedure and its applicability is
to be specified for each category of equipment. If the EUT itself (without connecting leads)
has a dimension that approaches 1/4 of the wavelength, direct cabinet radiation may occur.
The disturbance capability of an appliance having a mains lead as the only external lead may
be taken as the power the appliance could supply to its mains lead, which acts as a
transmitting antenna. This power is nearly equal to that supplied by the appliance to a
suitable absorbing device placed around the lead at the position where the absorbed power is
at a maximum. Direct radiation from the appliance is not taken into account. Equipment
having external leads other than a mains lead can radiate disturbance energy from such
leads, whether shielded or unshielded, in the same manner as radiation from the mains lead.
Measurements using the absorbing clamp can be made on these types of lead as well.
The application of the ACMM is specified in more detail in 7.9 of CISPR 16-2-2.
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CISPR 16-1-3 IEC:2004 – 13 –
4.2 The absorbing clamp assembly
4.2.1 Description of the absorbing clamp assembly
Annex A describes the construction of the clamp and gives a typical example of such a
construction.
The absorbing clamp assembly consists of the following five parts:
– a broadband RF current transformer;
– a broadband RF power absorber and impedance stabilizer for the lead under test;
– an absorbing sleeve and assembly of ferrite rings to reduce RF current on the surface of
the coaxial cable from the current transformer to the measuring receiver;
– a 6 dB attenuator between the output of the absorbing clamp and the coaxial cable
connecting to the measuring receiver;
– a coaxial cable as receiver cable.
The clamp reference point (CRP) indicates the longitudinal position of the front of the current
transformer within the clamp. This reference point is used to define the position of the clamp
during the measurement procedure. The CRP shall be indicated on the outside housing of the
absorbing clamp.
4.2.2 The clamp factor and the clamp site attenuation
An actual measurement of an EUT using the ACMM is depicted schematically in Figure 2.
Details on the ACMM are given in Clause 7 of CISPR 16-2-2.
The disturbance power measurement is based on measurement of the asymmetrical current
generated by the EUT, which is measured at the input of the absorbing clamp using a current
probe. The absorbing ferrites of the clamp around the lead under test isolate the current
transformer from disturbances on the mains. The maximum current is determined by moving
the absorbing clamp along the stretched lead, which acts as a transmission line. The
transmission line transforms the input impedance of the absorbing clamp to the output of the
EUT. At the point of optimal adjustment, the maximum disturbance current at the current
probe or the maximum disturbance voltage at the receiver input can be measured.
For this situation the actual clamp factor CF of an absorbing clamp relates the output signal
act
of the clamp V to the measurand of interest, i.e. the disturbance power P of an EUT as
rec eut
follows:
P = CF + V (1)
eut act rec
where
P = the disturbance power of the EUT in dBpW;
eut
V = the measured voltage in dBμV;
rec
CF = the actual clamp factor in dBpW/μV.
act
Ideally, the received power level P in dBpW at the receiver input can be calculated using
rec
the following formula:
P =V − 10 ⋅ log()Z = V − 17 (2)
rec rec i rec
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CISPR 16-1-3 IEC:2004 – 15 –
where
Z = 50 Ω, input impedance of the measuring receiver, and
i
V = measured voltage level in dBμV.
rec
Using Equations (1) and (2) one can derive a relation between the disturbance power P
eut
emitted by the EUT and the power P received by the receiver as follows:
rec
17P − P = CF + (3)
eut rec act
This ideal relation between the disturbance power of the EUT and the power received by the
measuring receiver is defined as the actual clamp site attenuation A (in dB).
act
17A ≡ P − P = CF + (4)
act eut rec act
This actual clamp site attenuation depends on three properties:
– the clamp response properties,
– the site properties and
– the EUT properties.
4.2.3 Decoupling functions of the absorbing clamp
Whereas the current transformer of the absorbing clamp measures the disturbance power, the
decoupling attenuation of the ferrites around the lead under test establishes an asymmetrical
impedance and separates the current transformer from the far end of the lead under test. This
separation reduces the disturbing influence of the connected mains and of the impedance of
the far end and its influence on the measured current. This decoupling attenuation is called
the decoupling factor (DF).
A second decoupling function is needed for the absorbing clamp. The second decoupling
function is the decoupling of the current transformer from the asymmetrical (or common
mode) impedance of the receiver cable. This decoupling is achieved by the absorbing section
of ferrite rings on the cable from the current transformer to the measurement receiver. This
decoupling attenuation is called the decoupling factor to the measurement receiver (DR).
4.2.4 Requirements for the absorbing clamp assembly (ACA)
Absorbing clamps used for disturbance power measurements shall meet the following
requirements:
a) The actual clamp factor (CF ) of the absorbing clamp assembly, as defined in 4.2.1 shall
act
be determined in accordance with the normative methods described in Annex B. The
uncertainty of the clamp factor shall be determined in accordance with the requirements
given in Annex B.
b) The decoupling factor (DF) of the broadband RF absorber and the impedance stabilizer for
the lead under test shall be verified in accordance with the measurement procedure as
described in Annex B. The decoupling factor shall be at least 21 dB for the whole
frequency range.
c) The decoupling function from the current transformer to the measuring output (DR) of the
absorbing clamp shall be determined in accordance with the measurement procedure as
described in Annex B. The decoupling factor to the measurement receiver shall be at least
30 dB for the whole frequency range. The 30 dB contains 20,5 dB attenuation from the
absorbing clamp and 9,5 dB from the coupling/decoupling network (CDN).
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CISPR 16-1-3 IEC:2004 – 17 –
d) The length of the clamp housing shall be 600 mm ± 40 mm.
e) A 50 Ω RF attenuator of at least 6 dB shall be used directly at the clamp output.
4.3 The absorbing clamp assembly calibration methods and their relations
The purpose of the clamp calibration is to determine the clamp factor CF in a situation that
resembles an actual measurement with an EUT as much as possible. However, in 4.2.2 it is
stated that the clamp factor is a function of the EUT, the clamp properties and the site
performance. For standardization (reproducibility) reasons, the calibration method shall use a
test site with a specified and reproducible performance, and a signal generator and receiver
with reproducible performance. Under these conditions, the only variable left is the absorbing
clamp under consideration.
Three absorbing clamp calibration methods are developed below, each with their own
advantages, disadvantages and applications (see Table 1). Figure 3 gives a schematic
overview of the three possible methods.
In general, each of the calibration methods comprises the following two steps.
First, as a reference, the output power P of the RF generator (with 50 Ω output impedance)
gen
is measured directly through a 10 dB attenuator using a receiver (Figure 3a). Secondly, the
disturbance power of the same generator and 10 dB attenuator is measured through the
clamp using one of the following three possible methods.
a) The original method
The original absorbing clamp set-up calibration method uses a reference site including a
large vertical reference plane (Figure 3b). By definition this method gives the CF directly,
because this is the original calibration method, which is used for the determination of the
limits and therefore considered as the reference. The lead under test is connected to the
centre conductor of the feed-through connector in the vertical reference plane. At the back
of this vertical plane, the feed-through connector is connected to the generator. For this
calibration configuration, P is measured while the clamp is moved along the lead under
orig
test, in accordance with the procedure described in Annex B such that for each frequency
the maximum value is obtained. The minimum site attenuation A and the absorbing
orig
clamp factor CF can be determined using the following equations:
orig
A = P − P (5)
orig gen orig
and
CF = A − 17 (6)
orig orig
The minimum site attenuation A is in the range of about 13 dB to 22 dB.
orig
b) The jig calibration method
The jig calibration method uses a jig that can be adapted to the length of the absorbing
clamp under calibration and the secondary absorbing device (SAD). This jig serves as a
reference structure for the absorbing clamp (see Figure 3c). For this calibration
configuration P is measured as a function of frequency while the clamp is in a fixed
jig
position within the jig. The site attenuation A and the absorbing clamp factor CF can
jig jig
be determined using the following equations:
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CISPR 16-1-3 IEC:2004 – 19 –
A = P – P (7)
jig gen jig
and
CF = A – 17 (8)
jig
c) The reference device method
The reference device method uses a reference site (without vertical reference plane) and
a reference device that is fed through the lead under test, which is a coaxial structure for
this purpose (see Figure 3d).
For this calibration configuration, P is measured while the absorbing clamp is moved
ref
along the lead under test in accordance with the procedure described in Annex A such that
for each frequency the maximum value
...
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