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To check up the result, it is better to make measurements from two ends (including K) and to
ensure the indications sum is equal to the cable length.
The factor K shows the attitude of an additional error
Δ
К
, receiving during the calculations to
a measurement passport error
Δ
:
Δ
К
= K
×
Δ
The accurate distance de
fi
nition is possible if K<10. Measurement accuracy is close to passport
then K<0,1 for high-resistance defects (above 100kOm). For defects with resistance below
100kOm the method gives an additional error. If contact resistance of rather “good” wire Ra less
than 20kOm then the error is sharply increases and a method can be used only for approximate
orientation in faulted splice searching. In this case we recommend to use TDR measurements
or to use an auxiliary cable.
Cable selection
To measure distance up to isolation fault, it is necessary to choose the necessary cable in the
LIST before starting the measurements. How to make a right choice in different situations?
How to
fi
nd distance in percentage length
This is mode «Cable 100%». It is by default at turning on of the device. Therefore it is possible
to make a measurement immediately. The result shows in % of length.
Only for a cable without sections!
Distance in meters. Input of the cable length without sections
To receive result in meters, it is necessary to enter a known cable length into «Cable 100%».
Only for a cable without sections!
How to calculate a cable length on Cable Type and temperature
In the item <cable selecting> choose <Cable Type>. Choose the necessary cable type. Now it is
necessary to establish a ground temperature. It is possible to enter it manually, and it is possible
to it take from the reference book which is stored in the device memory. For this purpose in
item <Zone>
fi
nd your climatic zone. The device will work with the temperature value, taken
from the reference book according to the date of measurement.
Only for a cable without inserts!
Cable consist from different Cable Type sections
Such cable should be preliminary written in < Cable List >. Enter into the Menu 2 and in item
<cable sampling> select the necessary cable from the List. Press [
О
K]. The distance up to a
place of fault will be automatically calculated on cable parameters from the device memory. To
change or see them is possible in the item <Cable parameters>.