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d) Impedance measurement
Make sure that all circuit parts, circuits and components and other objects of measurement are discon-
nected from the voltage and discharged.
Proceed as follows to measure a resistance:
- Switch on the DMM and select the measuring range “Ω”.
- Plug the red measuring line into the Ω 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 impedance value must be approximately 0 - 1.5 Ohm (inherent
impedance of the measuring lines).
- Now connect the two measuring prods to the object to be measured. As
long as the object to be measured is not high-impedance or interrupted,
the measured value will be indicated on the display. Wait until the dis-
played value has stabilised. With impedances of >1 MOhm, this may take
a few seconds.
- If “O.L.” (= overflow) appears on the display, you have exceeded the
measuring range or the measuring circuit is interrupted.
- Remove the measuring lines from the object to be measured after comple-
tion of the measurement and switch off the DMM.
If you perform a resistance measurement, make sure that the measuring points you touch with the measuring
prods are free of dirt, oil, solderable lacquer or similar. Such circumstances can falsify the measured result.
e) Acoustic continuity test
Make sure that all circuit parts, circuits and components and
other objects of measurement are disconnected from the
voltage and discharged.
- Turn the DMM on and select the measuring function .
- Plug the red measuring line into the V measuring jack (7) and the black
measuring line into the COM measuring jack (6).
- A continuity value of less than approx. 50 Ohm is identified as continuity;
in this case a beep sounds. The display shows the corresponding resist-
ance up to max. 199.9 Ohm.
- If “OL” (= overflow) appears on the display, you have exceeded the meas
-
uring range or the measuring circuit is interrupted.
- Remove the measuring lines from the object to be measured after com-
pletion of the measurement and switch off the DMM.
