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d) Resistance measuring
Make sure that all the circuit parts, switches and components and other objects of
measurement are disconnected from the voltage and discharged.
Measuring socket selection and assignment of the black and red measuring cable
DMM
black
red
VC130
COM (5)
mA/
Ω
(7)
VC150
COM (5)
mA/
Ω
(7)
VC170
COM (5)
V/
Ω
(8)
Proceed as follows to measure the resistance:
-
Turn the DMM on and select measuring range “
Ω
”.
-
Insert the measuring cables in line with the model into the corresponding measuring sockets as
shown in the table.
-
Check the measuring leads for continuity by connecting both measuring prods to one another. After
that the resistance value must be approximately 0.5 Ohm (inherent resistance of the measuring
leads).
-
While the measuring tips are short-circuited, press the button “SELECT” (only with the VC170)) to not
let the inherent resistance of the measuring leads flow into the following resistance measuring. The
display shows 0 Ohm
-
Now connect the measuring prods to the object to be measured. As long as the object to be mea-
sured is not high-resistive or interrupted, the measured value will be indicated on the display. Wait
until the display has stabilised. With resistances of >1 MOhm, this may take a few seconds.
-
As soon as “OL” (overload) appears on the display, you have exceeded the measuring range or the
measuring circuit has been broken. Select a larger measuring range if necessary.
-
After measuring, remove the measuring leads from the measuring object and turn the DMM off. Turn
the rotary switch to the position “OFF” or turn the device off via the “POWER” switch.
☞
If you carry out a resistance measurement, make sure that the measuring points which you
contact with the measuring prods are free from dirt, oil, solderable lacquer or similar. An
incorrect measurement may result under such circumstances.
e) Diode test
Make sure that all the circuit parts, switches and components and other objects of
measurement are disconnected from the voltage and discharged.
