Chapter TwoVoltage and Current Measurement
CONTINUE
بسم الله الرحمن الرحيم
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2.4. Current Measurement
Current measuring devices are selected for: Precision Stability Frequency response, including dc Galvanic isolation بعدم التام العزل من التأكد
تيار مرور Presentation of the data Effect on measured circuit
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Using an Ammeter as a Voltmeter and vice versa
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Using a Voltmeter as an Ammeter
By using a shunt resistance to reduce the large internal resistance of the voltmeter, so that it can be connected in series in the circuit
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Using an Ammeter as a Voltmeter
By using a series resistance to enlarge the small internal resistance of the ammeter , so that it can be connected in parallel in the circuit
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Figure 2.34 Changing the range of a Voltmeter using a number of high resistance resistors connected in series
with meter coil and known as multiplier
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Figure 2.35 Changing the range of a Ammeter using a number of low resistance resistors connected in parallel
with meter operating coil and known as multiplier
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Solution
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Solution guide
2.4.2. The Moving Magnet Meter
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2.4.3. The D’Arsonval Meter
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2.4.4. The Electrodynamometer
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2.4.5. The RF Ammeter and True rms
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2.4.6. The Current Transformer
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Current and potential transformers for High voltage measurements
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