F) Diode Test; G) Contact-Free Ac Voltage Recognition (Ncv) - VOLTCRAFT VC165 Operating Instructions Manual

f) Diode test

Make sure that all circuit parts, circuits and components and other objects of measurement are discon-
nected from the voltage and discharged.
- Switch on the DMM and select the measuring range
- Press the "SELECT" button to switch to the measurement function "diode
test". The diode symbol" appears in the display.
- Plug the red measuring line into the V measuring jack (7) and the black
measuring line into the COM measuring jack (6).
- Check the measuring lines for continuity by connecting the two measuring
prods. The value must be approximately 000 V.
- Connect the two measuring prods with the object to be measured (diode).
- The display shows the continuity voltage "UF" in volt (V) (example value in
the sketch: 0.621 V). The measuring range goes to 1.999 V.
- If "OL" appears, the diode is measured in reverse direction (UR) or the di-
ode is faulty (interruption). Perform a counter-pole measurement to check.
- Remove the measuring lines from the object to be measured after comple-
tion of the measurement and switch off the DMM.

g) Contact-free AC voltage recognition (NCV)

This function is not admissible to determine voltage freeness in electrical systems. For this, a 2-pole
measurement must be performed at all times.
The NCV function ("non-contact-voltage detection") leads to contact-free detection of the
presence of an alternating voltage in electrical conductors. The NCV sensor (11) is attached
to the front of the meter and marked with the symbol
A possible alternating voltage is displayed purely acoustically and increases in the sound
sequence with increasing height of the voltage. The display shows only the measuring func-
tion "NCV" and the letter abbreviation "EF" (for "Electromagnetic field").
- Remove all measuring lines from the meter. This function needs no measuring lines.
- Turn the DMM on and select measuring function "NCV".
- Move the meter with the front to a known AC voltage source. Always perform this test to
avoid wrong detection. The meter starts to beep if there is an alternating voltage.
- Perform the test at the intended line, etc.
- Switch off DMM after completing the test.
The highly sensitive NCV sensor may also cause a voltage recognition at static
charge. This is normal and not a malfunction.
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