SIST EN 50289-1-6:2002
(Main)Communication cables - Specifications for test methods -- Part 1-6: Electrical test methods - Electromagnetic performance
Communication cables - Specifications for test methods -- Part 1-6: Electrical test methods - Electromagnetic performance
This EN 50289-1-6 details four different test methods to determine the electromagnetic performance characteristics of cables used in analogue and digital communication systems. The four methods are detailed in clauses 6 to 9.
This document discusses test methods aiming to facilitate a selection of the applicable electromagnetic test method.
It is to be read in conjunction with Part 1-1 of EN 50289, which contains essential provisions for its application.
Kommunikationskabel - Spezifikationen für Prüfverfahren -- Teil 1-6: Elektrische Prüfverfahren - Elektromagnetisches Verhalten
Câbles de communication - Spécifications des méthodes d'essai -- Partie 1-6: Méthodes d'essais électriques - Performance électromagnétique
Communication cables - Specifications for test methods - Part 1-6: Electrical test methods - Electromagnetic performance (Note: Applies in conjunction with EN 50289-1-1)
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 50289-1-6:2002
01-september-2002
Communication cables - Specifications for test methods - Part 1-6: Electrical test
methods - Electromagnetic performance (Note: Applies in conjunction with EN
50289-1-1)
Communication cables - Specifications for test methods -- Part 1-6: Electrical test
methods - Electromagnetic performance
Kommunikationskabel - Spezifikationen für Prüfverfahren -- Teil 1-6: Elektrische
Prüfverfahren - Elektromagnetisches Verhalten
Câbles de communication - Spécifications des méthodes d'essai -- Partie 1-6: Méthodes
d'essais électriques - Performance électromagnétique
Ta slovenski standard je istoveten z: EN 50289-1-6:2002
ICS:
33.120.10 Koaksialni kabli. Valovodi Coaxial cables. Waveguides
33.120.20 äLFHLQVLPHWULþQLNDEOL Wires and symmetrical
cables
SIST EN 50289-1-6:2002 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN 50289-1-6:2002
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SIST EN 50289-1-6:2002
EUROPEAN STANDARD EN 50289-1-6
NORME EUROPÉENNE
EUROPÄISCHE NORM March 2002
ICS 33.120.10
English version
Communication cables -
Specifications for test methods
Part 1-6: Electrical test methods -
Electromagnetic performance
Câbles de communication - Grundnorm für Kommunikationskabel -
Spécifications des méthodes d'essai Spezifikationen für Prüfverfahren
Partie 1-6: Méthodes d'essais électriques - Teil 1-6: Elektrische Prüfverfahren -
Performance électromagnétique Elektromagnetisches Verhalten
This European Standard was approved by CENELEC on 2000-11-01. 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, Czech Republic,
Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands,
Norway, Portugal, Spain, Sweden, Switzerland and 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
© 2002 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 50289-1-6:2002 E
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SIST EN 50289-1-6:2002
EN 50289-1-6:2002 - 2 -
Foreword
This European Standard was prepared by the Technical Committee CENELEC TC 46X,
Communication cables.
The text of the draft was submitted to the formal vote and was approved by CENELEC as
EN 50289-1-6 on 2000-11-01.
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) 2002-10-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2003-11-01
This European Standard has been prepared under the European Mandate M/212 given to
CENELEC by the European Commission and the European Free Trade Association.
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SIST EN 50289-1-6:2002
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Contents
1 Scope . 5
2 Normative references. 5
3 Definitions . 5
4 Survey of electromagnetic test methods . 6
4.1 General . 6
4.2 Transfer impedance Z and capacitive coupling impedance Z . 6
T F
4.3 Screening attenuation. 7
4.4 Normalised screening attenuation . 9
4.5 Coupling attenuation. 10
5 Theoretical background. 10
5.1 General . 10
5.2 Matched inner and outer circuit . 12
5.3 Matched inner and mismatched outer circuit. 13
6 Transfer impedance, triaxial method. 16
6.1 Introduction . 16
6.1.1 Inner and outer circuit . 16
6.1.2 Transfer impedance Z . 16
T
6.1.3 Coupling length. 16
6.2 Test method. 16
6.2.1 Equipment. 16
6.2.2 Test sample . 17
6.2.2.1 General . 17
6.2.2.2 Coaxial cables. 17
6.2.2.3 Screened symmetrical cables. 18
6.2.2.4 Screened multi-conductor cables . 18
6.2.3 Calibration procedure . 19
6.2.4 Test set-up. 19
6.2.4.1 General . 19
6.2.4.2 Impedance of inner system. 19
6.2.4.3 Impedance matching circuit . 20
6.2.5 Measuring procedure. 21
6.2.5.1 General . 21
6.2.5.2 Evaluation of test results. 21
6.3 Expression of test results. 22
6.3.1 Expression . 22
6.3.2 Temperature correction . 22
6.4 Test report . 22
6.5 Non-reference measurements (informative). 22
7 Transfer impedance, line injection method . 23
7.1 Introduction . 23
7.1.1 Inner and outer circuit . 23
7.1.2 Transfer impedance Z . 23
T
7.1.3 Sample length. 24
7.2 Test method. 24
7.2.1 Equipment. 24
7.2.2 Test sample . 25
7.2.2.1 Preparation of test sample. 25
7.2.3 Calibration. 25
7.2.4 Test set-up. 27
7.2.4.1 General . 27
7.2.4.2 Impedance of inner system. 27
7.2.4.3 Impedance matching circuit . 28
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EN 50289-1-6:2002 - 4 -
7.2.5 Measuring procedure. 29
7.2.6 Evaluation of test results. 30
7.3 Expression of test results. 31
7.3.1 Expression . 31
7.3.2 Temperature correction . 31
7.4 Test report . 31
8 Screening attenuation test method, triaxial method. 31
8.1 Introduction . 31
8.1.1 Inner and outer circuit . 31
8.1.2 Screening attenuation. 32
8.1.3 Related lengths. 32
8.2 Test method. 33
8.2.1 Equipment. 33
8.2.2 Test sample . 33
8.2.2.1 General . 33
8.2.2.2 Coaxial cables. 33
8.2.2.3 Screened symmetrical cables. 34
8.2.2.4 Screened multi-conductor cables . 34
8.2.3 Calibration procedure . 34
8.2.4 Test set-up. 35
8.2.4.1 General . 35
8.2.4.2 Impedance of inner system. 35
8.2.4.3 Impedance matching circuit . 36
8.2.5 Measuring procedure. 37
8.2.6 Evaluation of test results. 38
8.3 Expression of test results. 39
8.3.1 Expression . 39
8.3.2 Temperature correction . 40
8.4 Test report . 40
9 Coupling attenuation or screening attenuation, absorbing clamp method. 40
9.1 Introduction . 40
9.1.1 Coupling Attenuation or Screening attenuation . 40
9.2 Test method. 40
9.2.1 Equipment. 40
9.2.1.1 General . 40
9.2.1.2 Balun requirements. 42
9.2.2 Test sample . 43
9.2.2.1 Tested cable length. 43
9.2.2.2 Preparation of test sample. 43
9.2.3 Calibration procedure . 44
9.2.3.1 Attenuation of the measuring set-up. 44
9.2.3.2 Insertion loss of the absorbers. 47
9.2.4 Test set-up. 48
9.2.5 Test set-up verification. 50
9.2.5.1 Determination of measurement sensitivity of the set-up. 50
9.2.5.2 Verification of test set-up calibration. 50
9.2.5.3 Pulling force on cable. 50
9.2.6 Measuring procedure. 50
9.3 Expression of test results. 51
9.3.1 Expression . 51
9.4 Test report . 52
9.4.1 General . 52
9.4.2 Evaluation of test results (informative). 52
9.4.3 Examples . 53
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SIST EN 50289-1-6:2002
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1 Scope
This EN 50289-1-6 details four different test methods to determine the electromagnetic
performance characteristics of cables used in analogue and digital communication systems. The
four methods are detailed in clauses 6 to 9.
This document discusses test methods aiming to facilitate a selection of the applicable
electromagnetic test method.
It is to be read in conjunction with Part 1-1 of EN 50289, which contains essential provisions for its
application.
2 Normative references
This European Standard incorporates by dated or undated reference, provisions from other
publications. These normative references are cited at the appropriate places in the text and the
publications are listed hereafter. For dated references, subsequent amendments to or revisions of
any of these publications apply to this European Standard only when incorporated in it by
amendment or revision. For undated references the latest edition of the publication referred to
applies (including amendments).
EN 50289-1-1 2001 Communication cables - Specifications for tests methods -
Part 1-1: Electrical test methods - General requirements
EN 50289-1-9 2001 Communication cables - Specifications for tests methods -
Part 1-9: Electrical test methods - Unbalance attenuation
(longitudinal conversion loss, longitudinal conversion
transfer loss)
1)
EN 50290-1-2 Communication cables - Part 1-2: Definitions
IEC 61196-1 1995 Radio-frequency cables
Part 1: Generic specification - General, definitions,
requirements and test methods
CISPR 16-1 1993 Specification for radio disturbance and immunity measuring
+ A1 1997 apparatus and methods
Part 1: Radio disturbance and immunity measuring
apparatus
ITU-T Recommendation 1988 Series O - Specifications of measuring equipment -
O.9 General - O.9: Measuring arrangements to assess the
degree of unbalance about earth
ITU-T Recommendation 1996 Series G - Transmission systems and media, digital
G.117 systems and networks - International telephone connections
and circuits - General recommendations on the
transmission
3 Definitions
For the purposes of this European Standard, the definitions of EN 50290-1-2 apply.
1)
At draft stage.
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SIST EN 50289-1-6:2002
EN 50289-1-6:2002 - 6 -
4 Survey of electromagnetic test methods
4.1 General
The electromagnetic performance of unbalanced cables (e.g. coaxial RF-cables) is determined
only by the quality of the screen. In the case of balanced cables the electromagnetic performance
is determined by the combined result of both unbalance attenuation and the effect of screen(s), if
any.
The quality of the screen may be evaluated by the measurement of transfer impedance (clauses 6
and 7) or screening attenuation (clauses 8 and 9). The combined result of the unbalance
attenuation and the screening attenuation (if applicable) may be evaluated using the coupling
attenuation test method (clause 9).
4.2 Transfer impedance Z and capacitive coupling impedance Z
T F
Two important properties in characterising screening effectiveness of cables are transfer
impedance Z and capacitive coupling admittance Y respectively capacitive coupling impedance
T C
Z . These properties can be used to calculate the normalised screening attenuation in dB
F
(see 4.4)
The transfer impedance Z of an electrically short uniform cable is defined as the quotient of the
T
longitudinal voltage induced in the outer circuit (environment) to the current in the inner circuit
(cable) or vice versa, related to unit length (see IEC 61196-1, 12.1.2.1).
U
2
Z = (1)
T
IL⋅
1
where
L coupling length
U
2
I
1
Figure 1 - Definition of transfer impedance Z
T
The capacitive coupling admittance Y of an electrically short uniform cable is defined as the
C
quotient of the current in the inner circuit caused by the capacitive coupling to the voltage in the
outer circuit, related to unit length (see IEC 61196-1, 12.1.2.1).
I
1
Y = =jCω (2)
C T
UL⋅
2
where
C through capacitance
T
L coupling length
U
2
CT
I
1
Figure 2 - Definition of coupling admittance
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The through capacitance C and thus the capacitive coupling admittance Y are dependent on the
T C
permittivity and geometry of the outer circuit. In order to have a quantity which is invariant on the
permittivity and the geometry of the outer circuit and is also comparable to the transfer impedance
Z we introduce the capacitive coupling impedance Z .
T F
ZZ=⋅Z⋅Y (3)
F1 2 C
where
Z characteristic impedance of inner circuit
1
Z characteristic impedance of outer circuit
2
Y capacitive coupling admittance
C
If there are no holes in the screen C and Z are zero. This is the case for a foil and for double
T F
braided screen construction. But in a single braided construction Z and Z are about the same
T F
and Z must be taken into consideration.
F
With electrically short cables, where wave propagation can be neglected, the transfer impedance
can be simply obtained as measuring current and voltage.
Therefore the transfer impedance is a suitable criteria to describe the screening effectiveness of
electrically short uniform cables.
IEC 61196-1 contains two methods - the triaxial and line injection methods - describing how to
measure the transfer impedance of coaxial RF-cables. Clauses 6 and 7 of this standard extend
these methods for symmetrical and multi conductor cables as well. In addition this standard
provides guidance on impedance matching circuits to be used if the cable impedance is different
from the impedance of the test equipment.
The triaxial method only allows measurements at low frequencies (max. 100 MHz) while the line
injection method applies for higher frequencies.
4.3 Screening attenuation
With electrically short cables, where wave propagation can be neglected, the screening quantities
related to unit length can be obtained as measurement values and directly used to calculate an
induced disturbing voltage. In the higher frequency range the transmission characteristics are
dependent on the impedance and admittance per unit length as well as on the terminating
resistors.
The screening attenuation is a suitable criteria to describe the screening effectiveness of
electrically long cables. The screening attenuation is defined as the logarithmic ratio of the power
fed into the cable and the radiated maximum peak power:
P
feed
a =⋅10 log (4)
s 10
P
rad,max
For electrically long cables - in a frequency range where the transfer impedance of the cable
screen is proportional to frequency - the screening attenuation is length and frequency
independent.
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SIST EN 50289-1-6:2002
EN 50289-1-6:2002 - 8 -
The screening attenuation is related to the transfer impedance in one of the following ways:
a) for a matched outer circuit (cable environment) for example in the absorbing clamp method
(see clause 9 or IEC 61196-1, 12.4);
� �
ω⋅⋅ZZ
� �
12
a =⋅20 log ⋅±εε (5)
s,matched 10� rr12 �
far end
cZ⋅
� �
TE
near end
� �
Z = max Z ± Z (6)
TE F T
where
“+“ applies for the near end
“-“ applies for the far end
Z transfer impedance
T
Z capacitive coupling impedance
F
Z effective transfer impedance when the capacitive coupling is present (single braided screen)
TE
or
b) for a mismatched outer circuit (cable environment) - with a short circuit at the near end - for
example in the shielded screening attenuation method (see clause 8 or IEC 61196-1, 12.6):
� �
c
ZZ− Z +Z
� �
TF TF
(7)
a =⋅− 20 log ⋅ +
� �
s, mismatched
ωεZZ⋅ 2 −εε +ε
� �
12 r1 r2 r1 r2
� �
Respectively neglecting of the capacitive coupling
� �
ωε⋅⋅ZZ −ε
� �
12 r1 r2
a2=⋅0log ⋅ (8)
s, mismatched 10� �
cZ⋅
2ε
� �
T
r1
� �
In many cases the capacitive coupling can be neglected. In this case also the near end coupling in
a matched outer circuit can be neglected (equation 5). Then the difference between these
equations is:
� �
ε
r 2
� �
Δa = a − a ≈ 20 ⋅ log 1+ − 4dB (9)
s s, mismatched s, matched 10
far end
� �
ε
r1
� �
for ε = 1,6 and ε = 1,1 this difference is Δa ≈ 1,5 dB.
r1 r2 s
where
Z transfer impedance of cable screen
T
Z characteristic impedance of cable (inner circuit)
1
Z characteristic impedance of outer circuit (environment)
2
8
.
m/s
c velocity of light, 3 10
ε resulting relative permittivity of the dielectric of the cable
r1
ε resulting relative permittivity of the environment
r2
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4.4 Normalised screening attenuation
The screening attenuation is highly dependent on the velocity difference between the inner and
outer circuit. Therefore the test results of the screening attenuation may also be presented in
normalised conditions. The normalised conditions are Δv/v = 10% or εε = 11, and Z
1 2
rr12,n
becomes the normalised impedance Z = 150 Ω.
s
The difference between the normalised screening attenuation and the measured screening
attenuation is calculated by:
aa=+Δa (10)
sn, s
where
a is the normalised screening attenuation
s,n
ωε⋅⋅ZZ⋅ −ε
11S rr2,n
a =⋅20 log (11)
sn 10
,
Zc⋅
TE
1
ω ⋅ Z ⋅150 ⋅ ⋅ ε
1 r1
11
a = 20 ⋅ log (12)
s,n 10
Z ⋅ c
TE
� �
� �
1
� 11 �
Δa=⋅20 log 2⋅ (13)
� �
ε
rt2,
� 1 − �
ε
� �
r1
where
a normalised screening attenuation
s,n
a measured screening attenuation
s
ε relative dielectric permittivity of the cable under test
r1
ε relative dielectric permittivity of the outer circuit (tube) during the measurement
r2,t
(equals 1,1)
Z equivalent transfer impedance of the cable under test
TE
Z normalised value of the characteristic impedance of the outer circuit of the cable
s
under test, Z = 150 Ω
s
ε normalised value of the relative dielectric permittivity of the environment of the cable
r2,n
Z characteristic impedance of the cable under test
1
Therefore we have for both solid PE and foamed PE dielectric of the cable (with ε ≈ 2,3
r1
respectively ε ≈ 1,6):
r1
Δa ≈ - 10 dB
The equations (8) and (9) shall be taken to calculate the normalised screening attenuation with a
measured transfer impedance.
--
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