Clas Ohlson UT33D - DC Current Measurement; Resistance Measurement

7
English
DC current measurement
1. Connect theblack test lead to
and thered test lead to
(for 0–200 mA) or to (for therange
200 mA – 10 A).
2. Setthemultifunction selector to 
.
3. Connect thetest leads in series with
thecurrent source to be measured.
Readthevalue.
Warning!
Do not connect theleads in parallel with
thevoltage source when measuring current!
If in doubt about thecorrect range, start with
thehighest and work downwards.
When measuring high currents, themeter should only be connected briefly (less than
10 seconds for currents over 5 A). Thisis to prevent theshunt in theinstrument from
overheating.
The interval between two readings must be greater than 15 minutes.
Resistance measurement
1. Connect theblack test lead to and
thered test lead to .
2. Setthemultifunction selector to
and
therequired range for resistance measurement.
3. Connect thetest leads across thecircuit to
be tested. Readthevalue.
Warning: Ensurethat thecircuit to be tested is
not “live” before taking any measurements.
In order to avoid therisk of personal injury, never
measure components with avoltage higher than
60 V DC or 30 V AC.
The test leads can add 0.1–0.2 Ω to theactual resistance measured. Toobtain accurate
readings of low-resistance components, short-circuit theinput sockets beforehand,
record theshort-circuited reading and use it to remove thelead resistance error from
thereading on thedisplay.
If theshort-circuited reading is higher than 0.5 Ω, check whether any connection/test
lead is loose or damaged.
For high-resistance measurement (>1 MΩ), it is normal for thereading to take several
seconds to stabilize.
For maximum accuracy, leads that are of thehighest possible quality and as short as
possible should beused.