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General Information
4.0 General Information regarding
UNITEST Echometers 3000
The UNITEST Echometers are measurement instru-
ments for swift, easy and precise determination of
the length of a cable or a conductor as well as for
resistance measurements.
The cable length determination is carried out in
accordance with the pulse reflection procedure.
Hereby, pulses are send into a cable which "travel”
at a certain velocity along the cable. If these pulses
hit the cable end they are reflected and return to the
starting point.
The UNITEST Echometer 3000 calculates the cable
length on the basis of time difference between emis-
sion and reception of the pulses.
If a short-circuit or an interruption is present in the
conductor to be measured the digital display indi-
cates the length of the conductor up to the fault lo-
cation. This allows an easy and fast fault localiza-
tion.
The travel time required only depends on the dis-
persion velocity of the travelling pulse. In turn, the
dispersion velocity is determined by the make and
structure of a cable. This means, that every cable
has a certain characteristic dispersion velocity and,
thus, different travel times.
The cable characteristics saved in the Echometer
(TAB range) represent a cable mean value estab-
lished by the various manufacturers and ensure ap-
proximate measurements. To carry out precise
measurements, the user may calibrate the cable
supplied by a certain manufacturer and permanent-
ly store the cable characteristics in the instrument
memory for subsequent measurements (REF
range).
The UNITEST Echometer 3000 enables the mea-
surement of the most conventional cable and con-
ductor cross sections. Additionally, 87 freely ad-
justable cable and conductor cross sections are
available for programming and measurement.
Simply connect the instrument alligator clamps to
the ends of a cable or a conductor and set the re-
spective measurement range. The conductor length
is clearly indicated on the digital instrument display.
The built-in memory is used to save measurement
results and to transfer the data via interface to a PC.
