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12.12 Resistance measurement
Ensure that all objects that you want to measure (including circuit compo-
nents, circuits and component parts) are disconnected and discharged.
Proceed as follows to measure the resistance:
1. Switch the DMM on and select the
Ω
measurement mode.
2. Insert the red test lead into the
Ω
measurement socket and the black
test lead into the
COM
measure-
ment socket.
3. Check the test leads for continu-
ity by connecting both measuring
probes to one another. The multim-
eter should then show a resistance
value of approx 0 - 0.5 Ω (inherent
resistance of the test leads).
Æ
For low-impedance measure-
ments of <600 Ω, hold down
the
REL
button for approximately one second when the measuring probes
are short circuited. This ensures that the inherent resistance of the test leads
does not affect the resistance measurement. The display should show 0 Ω.
Auto range is thereby disabled.
4. Connect the measuring probes to the object that you want to measure. The
measurement will be indicated on the display (provided that the object you are
measuring is not highly resistive or disconnected). Wait until the display stabi-
lises. This may take a few seconds for resistances greater than 1 MΩ.
Æ
“OL” (overload) indicates that the measurement range has been exceeded
or that the circuit is broken.
5. After taking a measurement, remove the leads from the measured object and
switch the DMM off.
When taking a resistance measurement, ensure that the points that come
into contact with the measuring probes are free from dirt, oil, solder and
other impurities. These substances may distort the measurement.
The
REL
button only works when a measurement is displayed. It cannot
be used when “OL” is displayed.
R
