25
5.7 Frequency Measurement
Follow these steps to measure frequency:
1. Connect the black test-lead with the COM-socket (11) and the red tst-
lead with the V/
Ω
socket (12).
2. Set the rotary function switch (7) to "FREQ" and connect the test-lead
tips with the frequency source (generator, etc.).
Attention!
Observe the max. input limits. Never connect voltages over 50 VDC/
VACrms (rms = eff). It is life dangerous to touch the terminals or probe
tips when measuring voltages over 25 VAC or 35 VDC.
Disconnect the test-leads from the contact points before changing the
meter function and range. The sensitive electronic of the measuring unit
might be destroyed and you expose yourself to severe shock hazard.
If there are voltages below 50 mVrms (at 1 Khz) no frequency measure-
ment is possible.
During continuity check the voltage measuring socket and the current
sockets must not be connected.
During frequency measurement the right sub-display shows dB-value of
AC voltage, the middle sub- display the AC voltage "V".
~
~
~
24
5.6 Diode Test
To test diodes proceed as follows:
1. Connect the lack test lead with the COM-socket (11) and the red test-
lead with the V/
Ω
-socket (12).
2. Set the measuring function switch to "
/
". No connect the test-lead
tips with the object under measurement to an off-circuit semiconduc-
tor line, the RED probe-tip to the anode, the BLACK test-lead tip to
the cathode (as a rule it is marked with a coloured ring, point etc.)
If you check a diode's forward voltage, you will measure voltage of
approx. 0.25 V (Germanium) or 0.7 V (Silicium) to 2.5 (or 250 mV, 700 mV
to 2500 mV), if the diode is not defective. The middle sub-display will
show 9ood for "good".
If you reverse the probe-tips, this means red to the cathode and black
to the anode, you check the so called reverse direction.
If "OL" is displayed and "Open" in the middle sub-display, the diode
is good. However, if any voltage is displayed, you connected the
object wrong or the diode is defective.
Attention!
During diode test, observe that the diode or the circuit in which it is
built in, must be without voltage. All existing capacities must be
discharged. During continuity check the measuring socket and the cur-
rent terminals not be connected.
Forward Direction
Reverse Direction
