Extech Instruments 470 - Manual (Page 13)

V5.0 5/04 13
CONTINUITY CHECK
WARNING: To avoid electric shock, never measure continuity
on circuits or wires that have voltage on them.
1. Set the function switch to the green
Ω position.
2. Insert the black lead banana plug
into the negative COM jack.
Insert the red test lead banana
plug into the positive
Ω jack.
3. Press the SELECT button to
indicate” "and “Ω” on the display
4. Touch the test probe tips to the
circuit or wire you wish to check.
5. If the resistance is less than
approximately 150 Ω, the audible
signal will sound. If the circuit is
open, the display will indicate “OL”.
DIODE TEST
1. Set the function switch to the
green Ω position.
2. Insert the black test lead banana
plug into the negative COM jack
and the red test lead banana plug
into the positive V jack.
3. Press the SELECT button to
indicate and V on the display.
4. Touch the test probes to the diode
under test. Forward voltage will
typically indicate 0.400 to 0.700V.
Reverse voltage will indicate “OL”.
Shorted devices will indicate near
0V and an open device will
indicate “OL” in both polarities.