Performance Of Resistance Measurements Continuity Tests; Performance Of Cable Length Measurements In Cables Installed - Unitest 3000 Bedienungsanleitung

6.5 Performance of Resistance Measurements
Continuity Tests
" Switch on UNITEST Cable Length Meter by
pressing the key.
" Set measurement range selection dial to posi-
tion [Ω].
" Connect the red test leads to red sockets and the
black test leads to black sockets.
" Connect both ends of the resistance to be mea-
sured. The resistance value measured is dis-
played.
If the resistance is below approx. 10 Ohm an
acoustic signal is audible.
The UNITEST Cable Length Meter 3000 is
equipped with special Kelvin clamps. I.e. the
contact surfaces and the contact bottom sides
of the alligator clamps (Kelvin clamps) must be
connected to the resistance to be measured.
6.6 Performance of Cable Length
Measurements for Cables Already Installed
Never apply voltage to any of the instrument
measurement ranges. Always verify that the
circuits are not live using a dual-pole voltage
tester (e.g. UNITEST 2000 alpha)! For failure to
comply with this prescription the safety of the
user can no longer be guaranteed and there is
danger of instrument damage.
" Switch on the UNITEST Cable Length Meter
pressing the key.
" Perform the temperature compensation of the
UNITEST Cable Length Meter as described in
section 6.1.
Performance of Measurements
To comply with specified accuracy values the
temperature of the cable already under ground
must be determined exactly, as the cable tem-
perature (e.g. earth cable, conductors in ceil-
ings and walls...) may differ considerably from
the temperature of the UNITEST Cable Length
Meter 3000 (internal temperature compensa-
tion).
" Connect the red test leads to red sockets and the
black test leads to black sockets.
" Connect two leads of the conductor to be mea-
sured with the alligator clamps.
" Short circuit both leads at the cable end to be
measured (close the loop).
" Select the material (copper / aluminium) of the
cable or conductor to be measured. The mes-
sage ''Cu'' or ''Al'' is indicated on the display.
" The measurement unit (m/ft) is selected by
pressing the and
Shift Shift
sage ''m'' or ''ft'' is indicated on the display.
" Set the measurement range selection dial in
compliance with the conductor cross section in
Table I or II. The cable and conductor cross sec-
tions are briefly displayed.
The key is used to switch to the mea-
surement ranges of Table II. The message
''TAB II'' is indicated on the display.
The message display ''- - -'' indicates that the
UNITEST Cable Length Meter is ready for measure-
ment.
" Start the measurement by pressing the
key.
The double measurement value of the cable length
is displayed in the previously selected unit (m/ft).
The correct length of the conductor to be measured
is obtained when dividing the displayed value by
two.
keys. The mes-
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