Elma BM 251s-257s
side 41
CAUTION
Discharge capacitors before making any measurement. Large value capacitors should be
discharged through an appropriate resistance load.
CAUTION
Using resistance and continuity function in a live circuit will produce false results and may
damage the instrument. In many cases the suspected component must be disconnected
from the circuit to obtain an accurate reading
Continuity function is convenient for checking wiring connections and operation of
switches. A continuous beep tone indicates a complete wire.
Normal forward voltage drop (forward biased) for a good silicon diode is between 0.400V
to 0.900V. A reading higher than that indicates a leaky diode (defective). A zero reading
indicates a shorted diode (defective). An OL indicates an open diode (defective). Reverse
the test leads connections (reverse biased) across the diode. The digital display shows OL
if the diode is good. Any other readings indicate the diode is resistive or shorted
(defective).
DCmV, ACmV, Temperature oC & oF functions
Press the SELECT button momentarily to select the subject functions in sequence. Last
selection will be saved as power up default for repeat measurement convenience.
