This test method is applicable to the measurement of capacitive coupling and ground capacitance unbalance of symmetrical cable and coaxial cable in length using capacitive coupling bridge. The test step rate is 800～1000Hz. GB 5441.3-1985 Communication cable test method Capacitive coupling and ground capacitance unbalance test GB5441.3-1985 standard download decompression password: www.bzxz.net

Scope of application
National Standard of the People's Republic of China
Test methods for communication cable
Capacitance coupling and capacitance unbalance test to ground
UDC 621.315.2
: 621. 39 : 621
.317.3.08
GB5441.3—85
This test method is applicable to the capacitance end combination and capacitance unbalance to ground of symmetrical wire groups in manufactured length cables and old integrated cables using capacitance paste bridge.
Test frequency is 800～1000 Hz u
2Symbols and their definitions
See Table 1.
Unbalanced
Real "/Real Road II
Real Road Road
Real Road E/Illusion Road
Lack of Road "Road"
Hong Road "/Ji Road 1
Down [Road and
Real Road Use Taoge"
Real Illusion Road
Road ", Road
Buy Road "Channel Road is
Double Road Real Road Sichuan
Real Road [/Road I
Real Road I/Total other core wires and gold must be well set, Real Road II/Other core wires are gold-insulated and protected, including civil wires and read protection, National Bureau of Standards 1985
09-29 issued
Approximate formula
(Cig+C+) - (CHI()
(C: +(:) -(C23 - C2) +
(c+r2) -(c:+C)
Cie -C2r
G.-CuCs -Gar.
C, +(e+ 2 +r'2r4 +(: +( 38 +Cs-(--: -(45 -(6-3: --C30
CC-( I.:-(r-
-i -C -t
Gh +Ce +C a+Ca: - G -Cas - 36C.. +.. +.
+C36 -r
--C--G-
CC-C46-C
r'a C2u+(h. -Cet
Ca. C+at. Ch
C+Ca-Ci.tC C Cm GtG.t:
1986-06-01 implementation
external meter "eal
unbalanced" 3
real line 1/metal sheath ground
real line 1I/metal sheath, ground
to Lu I/metal expansion sheath, ground
GB 5441-3
approximate formula
tia i Gun -Csp- In the table: Gn
, the actual circuit "is a pair of 1 wires in the tested four-wire group, whose cores are numbered 1 and 2; the actual circuit 11 is a working pair of the tested four-wire group, whose cores are numbered 3 and 4; the actual circuit 12 is a working pair of another tested four-wire group, whose cores are numbered 5 and 6; the actual circuit 13 is a working pair of another tested four-wire group, whose cores are numbered 7 and 8; 3, (11(, is the partial capacitance of the cable cores 1, 2, 3, 4 phase return; C2, (, is the partial capacitance between the cable cores 1, 2, 3, 4, etc. and all non-tested cores. Cm, C, (, C……… is the partial capacitance between the cable cores 1, 2, 3, and ground. 3 Test equipment
The test wiring schematic diagram is shown in Figures 1 to 4,
is formed by (an
or [ +{
Connect metal sheath
Wire core pattern shield
Figure 1K, test principle diagram
(u Cu+ C.
4a→
Connect metal sheath
Core design shield
Figure 2A or human test original diagram
Metal sheath
GB 5441.3—85
All other non
Tested core
Figure 3 Line pair to external capacitance unbalance eul
:?Test principle diagram
—Two pairs of wire cores in the group;
Figure: 1.2.3.4—
a,b,c,d-
Th, T2-
Four items of the bridge;
Bridge capacitance:
Transformer point #
Oscillator:
Indicator;
A transformer,
The test instrument should meet the following requirements:
Figure 1 Line pair to external capacitance unbalance
P test principle diagram
To other non-
tested line cores
3.Oscillator: Single-frequency output within the frequency range of 8~100Hz, the frequency error should not be less than 10!, the nonlinear loss coefficient should not be less than,
3.2 Indicator: The sensitivity of the indicator should be guaranteed to be no less than the [/5-] resolution of the test error, and the meter head of the zero-pointing device or other sound devices (including H machine) can be used.
3.3 Bridge: The test recognition error should not be greater than 3% of the measured value or more than 2.5pF. Standard narrow gauges should be used regularly on small bridges to connect the lines to ad, be and db in Figure 1 on one bridge arm for calibration. 4 Sample preparation
The sample is a finished cable of manufacturing length.
5 Test steps
5. Select the test wiring schematic.
A is tested according to the wiring schematic in Figure 1.
K, K, are tested according to the wiring schematic in Figure 2
GB5441.3-85
K,~K,2 are tested according to the wiring schematic in Figure 1, but at this time, the actual connection method of the wire cores and the correction body of the four actual circuits should comply with the wiring schematic in Figure 2. 2.
ea, ea2, ej, ez are tested according to the wiring schematic in Figure 3; when measuring ei and ez, the provisions of Article 5.2.2 should be met. ea3, e are tested according to the wiring schematic in Figure 4.
5.2 When testing K and e values, the connection of the non-tested wire cores shall meet the following requirements: d
5.2.1 When measuring K and e values, the cores of the non-tested wires in the cable except the tested wire shall be connected to the metal sheath or cable shield. 5.2.2 When measuring e1 and e, the other two wire cores in the same four-wire group shall be automatically transferred to point F by the instrument, and the other non-tested wires in the cable shall be connected to the metal sheath or cable shield. 5.2.3 When testing eal~ea3, all non-tested wires in the cable shall also be connected to point F of the instrument. 5.3 Connect the tested wire core of the cable directly or through the lead to the test terminal of the bridge, and the other end of the tested wire should be connected to the normal circuit. The test lead should use a drum soft wire, and the connector end of the lead should ensure good electrical contact. 5.4, when the inspection is correct, turn the conversion plate of the tester to the required value. e value or e value, and test. 5.5 When measuring overflow, the "conductance" and "capacitance" parts of the electric correction should be balanced repeatedly until the indicator has sufficient sensitivity, and then the measurement results should be read.
6 Test results and calculations
The test results are converted to the value of standard length according to the following formula: K(1 ~12)=K(1 ~12) )
K -12) = K(1 ~
e(1-31 =e(1~3)x
e(1-3)=e(1-9)x
ea(1 -3) =ea(l ~3) x
（4）
GB5441.3—85
ee( ~3) =ea(1 ~3) X*
L\Standard manufacturing length determined when the indicators are specified in the product standard, m! Where:
Lx——The length of the cable under test, m,
K(1 ~ 12)——
--K1~12 value between cable pairs of standard manufacturing lengthKa1-12)x
K(1~12)x
e(1-3)www.bzxz.net
e(1~3)x
e(1~3)
e(1~3)x
ea(1~3)
ea(1~3)X
Ea(1~3)
ea(1~3)x
·7 Notes
Measured value of K1~12 between cable pairs on the measured cable length: The arithmetic mean value of K~1 between cable pairs of standard manufacturing length, K between cable pairs on the measured cable length,~12 Arithmetic mean of measured values, e1~3 values ​​between cable pairs and ground on standard manufacturing length: measured values ​​of e1~3 between cable pairs and ground on the measured cable length; the arithmetic mean of e1~3 between cable pairs and ground on standard manufacturing length; the arithmetic mean of e1~3 measured values ​​between cable pairs and ground on the measured cable length; the arithmetic mean of ea(1~3) measured values ​​of cable pairs to the outside on the standard manufacturing length; the arithmetic mean of ea(1~3) measured values ​​of cable pairs to the outside on the measured cable length; - the arithmetic mean of ea1~3) measured values ​​of cable pairs to the outside on the standard manufacturing length; the arithmetic mean of ea(1~3) measured values ​​of cable pairs to the outside on the measured cable length. 7.1 The K value, e value and ea value of the lead wire should be deducted from the test result respectively, or balanced out during bridge pre-balancing. (6)
7.2 Pay attention to the "positive" and "negative" signs of the capacitance coupling value during testing. When using an external additional capacitor, the test result should be the algebraic sum of the reading on the bridge and the additional capacitance value. 7.8 Under normal circumstances, the remaining non-tested cores specified in Articles 5.2.1 and 5.2.2 are allowed to be reduced to non-tested cores connected to metal sheaths or cable shields around the tested cores. However, in case of disputes, Articles 5.2.1 and 5.2.2 must be followed. Additional Notes:
This standard was proposed by the Ministry of Machinery Industry of the People's Republic of China. This standard is under the jurisdiction of the Shanghai Cable Research Institute of the Ministry of Machinery Industry. This standard was drafted by the Shanghai Cable Research Institute of the Ministry of Machinery Industry and others. The person in charge of drafting this standard must learn from Fan.
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