Measuring Instruments

Operation of PMMC Instrument

Operation of PMMC Instrument Most analogue (pointer-on-scale) instruments rely on three factors for their operation: a deflecting torque; a restoring torque; and a damping torque. Deflecting Torque: Essentially, a moving coil meter is a current measuring device. The current to be measured is passed through a multi-turn coil suspended between the poles of a permanent […]

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Voltmeter Loading Effect

Ammeters and voltmeters affect the operation of circuits. The degree to which the circuits are affected is called the loading effect of the instrument. For an instrument to provide an accurate indication of how a circuit operates, the loading effect should ideally be zero. In practice, it is impossible for any instrument to have zero

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