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MEGOHMMETER (MEGGER) | Up
Neets Module 03-Introduction to Circuit Protection, Control, and Measurement | Next
HOOK-ON TYPE VOLTAMETER |
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A MULTIMETER is a single meter that combines the functions of a dc ammeter, a dc voltmeter, an
ac ammeter, an ac voltmeter, and an ohmmeter. It is more convenient to have one meter with several
functions than several meters each with a single function. The various functions of a multimeter are
selected by use of the appropriate function switch positions, jacks, and meter scales. A mirror may be
used on the scale of a multimeter to eliminate parallax error.
The following SAFETY PRECAUTIONS should be observed when using a multimeter.
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Deenergize and discharge the circuit completely before connecting a multimeter.
·
Never apply power to the circuit while measuring resistance with a multimeter.
·
Connect the multimeter in series with the circuit for current measurements and in parallel for
voltage measurements.
·
Be certain the multimeter is switched to ac before attempting to measure ac circuits.
·
Observe proper dc polarity when measuring dc circuits.
·
When you are finished with a multimeter, switch it to the OFF position, if available. If there is
no OFF position, switch the multimeter to the highest ac voltage position.
·
Always start with the highest voltage or current range.
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Select a final range that allows a reading near the middle of the scale.
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Adjust the "0 ohms" reading after changing resistance ranges and before making a resistance
measurement.
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