PeakTech 4120 Bedienungsanleitung Seite 34

Measuring Resistance
WARNING!
NEVER CONNECT THE TEST PROBES TO A SOURCE OF VOLTAGE WHEN YOU HAVE SELECTED THE
OHMS FUNCTION AND PLUGGED THE PROBES INTO THE V/Ω TERMINAL. BE SURE THAT THE CIRCUIT
UNDER TEST HAS ALL POWER REMOVED AND THAT ANY ASSOCIATED CAPACITORS ARE FULLY
DISCHARGED BEFORE YOU MAKE RESISTANCE MEASUREMENT:
Follow these steps to measure resistance:
1. Press Ω/
( )
( )
( ) / switch.
*
2. To switchover between the functions Ohm, Continuity and Diode, press the Ohm, Cont., Diode button several
times.
3. Plug the black test lead into the COM terminal and the red test lead into the V/Ω terminal.
4. Connect the probes to the device you want to measure.
Notes:
* If the measured resistance value exceeds the maximum value of the range selected. "OL" displays to indicate
overload.
The resistance in the test leads can diminish accuracy on the lowest 400 Ω range. The error is usually 1 to 0.2
*
ohms for standard pair of test leads. To determine the error, short the test leads together and read the resistance
of the leads.
* For resistance of approximately 4 MΩ and above, the display might take a few seconds to stabilize. This is normal
for high resistance readings.
Checking Continuity
1. Continuity testing verifies that circuit connections are intact. To perform audible continuity tests, press the
Ω/
( )
( )
( ) / switch.
*
2. To switchover between the functions Ohm, Continuity and Diode, press the Ohm, Cont., Diode button several
times.
3. Plug the black test lead into the COM terminal and the red test lead into the V/Ω terminal.
Warning: Never perform a continuity measurement on a circuit that has power connected.
Note: The buzzer sounds if the measured resistance is below 40 ohms.
Logic Test
The logic function lets you easily check the digital circuits to determine the logic state of different parts of the circuit.
Rather than display an absolute voltage, this function displays Hi, LO, or ---- indicated logic high, low, or undeter-
mined respectively.
Follow these steps to perform logic test:
1. Press Logic switch. The main display shows "ready".
2. Plug the back probe into your meter's COM terminal and the red probe into your meter's V/Ω terminal.
3. Connect the black probe to the ground point (GND) of the test circuit and the red probe to the supplying
voltage point (V+). While keeping the test probes firmly connected to each point.
4. While keeping a connection between the black probe and the circuit's GND point, move the red probe to
the other desired points. The meter immediately displays one of the 3 modes, as follows:
- If value exceeds 70 % of the stored (V+) value, Hi (HIGH) appears
- If value falls below 30 % of the stored (V+) value, LO (LOW) appears
- If value is between 30 % and 70 %, the segment ---- appears.
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