D) Measuring Frequency " (Only Vc270 And Vc290); Measuring Resistance - VOLTCRAFT VC250 Bedienungsanleitung

d) Frequency Measurement " (only VC270 and VC290)
The DMM can measure and display the frequency of a signal voltage between 10 Hz and 10 MHz.
Proceed as follows to measure frequencies:
- Turn the DMM on and select measuring range "Hz". The display
reads "Hz".
- Plug the red measuring lead into the Hz measuring socket (7) and the
black measuring lead into the COM measuring socket (8).
- Now connect the two measuring probes to the object to be measured (sig-
nal generator, switch etc.).
- The frequency and corresponding unit are displayed.
- After measuring, remove the measuring leads from the measured object
and turn the DMM off.
e) Measuring Resistance
Make sure that all the circuit parts, switches and components and other objects of
measurement are disconnected from the voltage and discharged.
Proceed as follows to measure resistance:
- Turn the DMM on and select measuring range "Ω".
- Plug the red measuring lead into the Ω measuring socket (7) and the
black measuring lead into the COM measuring socket (8).
- Check the measuring leads for continuity by connecting both measuring
probes with one another. The resistance value must be approximately
0 - 0.5 Ohm (inherent resistance of the measuring leads).
- When conducting low-Ohm measurements on the VC270 and VC290, press the button "REL" (3) to
not let the inherent resistance of the measuring leads influence the following resistance measure-
ment. The display shows 0 Ohm The automatic range selection (Autorange) is deactivated. The
Autorange function can be reactivated by changing the measurement function (e.g. press the
"SELECT" button twice).
- Now connect the measuring probes to the object to be measured. As long as the object to be mea-
sured is not high-Ohm or interrupted, the measured value will be indicated on the display. Wait until
the displayed value has stabilised. With resistances of >1 MOhm, this may take a few seconds.
- If "OL" (overload) appears on the display, you have exceeded the measuring range or the measur-
ing circuit has been broken.
- After measuring, remove the measuring leads from the measured object and turn the DMM off.
If you carry out a resistance measurement, make sure that the measuring points which
you contact with the measuring probes are free from dirt, oil, soldering paint or similar. An
incorrect measurement may result under such circumstances.
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