technoac TDR-TA3.3T, Руководство пользователя

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Cable fault locator
TDR-TA3.3T
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COMMENT: The pulse amplitudes are given in the related proportions with the
same amplification.
The pulse of a positive polarity with the amplitude not less than 10 W is used as a
probe pulse. The probe pulse endurance is to be selected out of the given row: 10 ns, 20
ns, 30 ns, 50 ns, 100 ns, 200 ns, 500 ns, 1
µs, 1,5 µs, 3 µs, 5 µs, 10 µs – for every
subrange (window) of measurement.
The coefficient of shortening value is individual for every type of cable. It is
connected with the type of the cable jacket as follows:
0


CS
where
ε
0
– dielectric constant cable sheath
The value of coefficient of shortening can be defined experimentally, knowing the
length of cable.
The error of the distance to irregularity is to be defined with discreteness of the
indicator (320 discretes/scale) and with the error of the line shortening coefficient (CS)
setting-up. Furthermore there can appear extra errors because of the form of reflected
signal deformation inside the lines with frequency-depended losses.
The measurement error can be also caused by the type of irregularity, the error
value, presence of several irregularities inside the line. The measurement error can be
reduced with the alignment of the device with the line via
“COORD.”.
The TDR-TA3.3T allows to determine the distance automatically (depending on the
selected coefficient of shortening). The distance is equivalent to the cursor location on the
screen and is being displayed digitally at the bottom of the screen next to the cursor
location.