Sthor 81772 Manual Original página 13

If the measurement cable plugs are capped, remove the caps before plugging the measurement cables into
the jacks. Connect the measurement cables in accordance with the instructions provided in the manual. Next,
remove the measuring section caps (if any) and proceed with the measurements.
Built-in buzzer
The meter has a built-in buzzer that emits a short sound signal each time the button is pressed to confi rm the
action has taken place. The buzzer will emit several sound signals per minute before the meter is automatically
switched off and one long signal immediately before it is automatically switched off . The meter switches off
automatically 15 minutes after the button has last been pressed or the selector's position has been changed.
MEASUREMENT PROCEDURE
NOTE! Do not allow the measurement range of the meter to be smaller than the measured value. This
can damage the meter and cause electrocution. Special care should be taken when measuring within the
highest voltage range in order to avoid electrocution.
The correct connection of the cables:
The red cable goes in the jack marked VΩ or A mA.
The black cable goes in the jack marked COM.
Ensure the optimum measurement conditions in order to achieve the highest possible accuracy of measurement.
The ambient working temperature should be in the range from 18 to 28
Example of accuracy determination
Accuracy: ± (% of the indication + weight of the least signifi cant digit)
Measurement of DC voltage: 1.396 V
Accuracy: ±(0.8% + 5)
Calculation of error: 1.396 x 0.8% + 5 x 0.001 = 0.011168 + 0.005 = 0.016168
Measurement result: 1.396 V ± 0.016 V
Voltage measurement
Caution! The meter will only display the measurement value if the voltage is higher than 0.8 V.
Connect the red cable to the jack marked VΩ. Connect the black cable to the jack marked COM. The meter
will recognise whether DC or AC voltage is being measured. Connect the measurement cables in parallel to
an electrical circuit and read the voltage measurement result. Never measure voltage that is higher than the
maximum measurement range. This can damage the meter and cause electrocution.
Measurement of resistance
Connect the red cable to the jack marked VΩ. Connect the black cable to the jack marked COM. The meter
will recognise that resistance is being measured. Connect the measurement cables to the terminals of the
measured element and read the measurement result. It is absolutely forbidden to measure the resistance
of elements through which electric current is fl owing.
Current intensity measurement
Connect the red cable to the jack marked A mA. Connect the black cable to the jack marked COM. The meter
will recognise that current intensity is being measured. Connect the measurement cables in series with the
electrical circuit to be tested and read the measurement result. The measurement time for currents higher
than 2 A must not exceed 3 seconds, followed by a break of at least 15 minutes before the next measurement.
It is forbidden to exceed the maximum values of current and voltage for a given jack.
Caution! Do not exceed 36 V DC or 25 V AC for current measurements.
O R I G I N A L
EN
I N S T R U C T I O N S
C and relative air humidity <75%.
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