CISPR 22:2008/ISH3:2012

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SC CIS/I/Publication CISPR 22 (2008), Sixth edition/I-SH 03
INFORMATION TECHNOLOGY EQUIPMENT –
RADIO DISTURBANCE CHARACTERISTICS –
LIMITS AND METHODS OF MEASUREMENT

INTERPRETATION SHEET 3
T3his interpretation sheet has been prepared by subcommittee I: Electromagnetic compatibility
of information technology equipment, multimedia equipment and receivers, of IEC technical
committee CISPR: International special committee on radio interference.
The text of this interpretation sheet is based on the following documents:
ISH Report on voting
CISPR/I/402/ISH CISPR/I/408/RVD

Full information on the voting for the approval of this interpretation sheet can be found in the
report on voting indicated in the above table.
___________
Introduction:
At the CISPR SC I plenary, held on the 19th October 2011, it was noted that some
laboratories and manufacturers are having difficulty understanding Figure C.5 in the standard
and are applying the wrong branch in the decision tree to identify the correct method for
testing different types of equipment with a telecommunication port .
This information does not change the standard; it serves only to clarify the point noted.
CISPR SC I WG3 hopes that these clarifications will be of use to users and especially
laboratories testing to CISPR 22, Edition 6.0 or Edition 5. The document is based on the
comments received on CISPR/I/402/ISH.
Interpretation:
Figure C.5 provides a flowchart to correctly identify the process and limits for measuring
conducted emissions on a telecommunications port.
The first question to be answered is “Is the EUT port a telecommunications port as defined in
clause 3.6?” The following interpretation assumes the response to this first question is “yes”.
The intention of the next part of the flow chart is to relate the telecommunication port being
measured to the type of cable or network to which it is to be connected. The purpose here is
to guide the user to the appropriate test method(s) that are defined in the standard for these
cable/network types.
The user should determine which of the options given best describes the type of cable or
network that the telecommunication port is ultimately connected to. The following
interpretations provide further guidance on the cable or network options given:
April 2012 ICS 33.100.10
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“Unscreened balanced pair” should be interpreted as a cable or network consisting of a single
pair or multiple pairs of balanced unscreened twisted pair conductors, for example those
categorized as CAT5, CAT6 etc in accordance with ANSI/TIA/EIA-568-A.
“Screened or Coaxial” should be interpreted as a cable or network where there is an outer
metallic foil or braid that encompasses all the other conductors within the cable.
“Mains” should be interpreted as any cable or network that is intended to carry AC mains
power, whether or not it carries other signals; generally these contain 2 or 3 untwisted
conductors.
“Other” should be interpreted as a cable or network whose definition is not covered by the
other three definitions. You will note that within the flowchart the user may also be directed to
this option when suitable test methods do not exist within the Unscreened balanced pair
option.
April 2012 ICS 33.100.10
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SC CIS/I/Publication CISPR 22 (2008), Sixième édition/I-SH 03
APPAREILS DE TRAITEMENT DE L'INFORMATION –
CARACTÉRISTIQUES DES PERTURBATIONS RADIOÉLECTRIQUES –
LIMITES ET MÉTHODES DE MESURE
FEUILLE D'INTERPRÉTATION 3
Cette feuille d’interprétation a été établie par le sous-comité I: Compatibilité
électro
...