F Acoustic continuity testing
With this function, voltage-free wiring, fuses, circuits, etc. can be
acoustically tested for continuity. For this measurement, proceed
as follows:
1. Connect the black test lead to the COM socket and the red test
lead to the V/Ohm socket.
2. Turn the rotary switch to "•)" (acoustic continuity test), then
connect the test probes to the completely voltage-free object
being tested.
3. If the continuity resistance is less than 30 Ohm, then an acoustic
signal sounds.
Do not measure charged capacitors because a
possible discharge may damage the measuring
instrument.
G Transistor test
The transistor connector is not protected against
overload.
To measure the amplification of a transistor, proceed as follows:
1. Position the rotary switch to "hFE".
2. Plug the transistor to be tested into the measuring connector.
When doing so, pay attention to the following points:
- observe the pin configuration (i.e. C-B-E) of the transistor
(given in transistor comparison tables/lists).
20
- some types of transistor include base-emitter resistors, which
can distort the measurement result.
- the measured hFE value is not absolutely accurate. It only
confirms whether the transistor is working or not. The actual
amplification of a transistor depends on its working current.
This multimeter can deliver a base current up to 10 µA with a
Vce of 3 V. The collector current flowing during measurement
is captured and from this the hFE value is calculated.
- no transistor can be measured which is incorporated into a
circuit.
- the hFE values of FETs or other unipolar transistors cannot be
measured with this multimeter.
- when the connecting "legs" of the item to be measured do
not fit into the socket (too "thick"), do not use force, other-
wise the socket can thereby be damaged.
- the measurement of hFE reacts to temperature variations. As
soon as the transistor is picked up and plugged into the
connector and thereby warmed with the fingers, the measu-
red value can alter. If an unstable display occurs, remove the
transistor and allow it to cool down to room temperature.
Disposal
Dispose of an unusable, irreparable digital multimeter in accordan-
ce with applicable statutory regulations!
21