Control the pivot point

Control the jewel bearing

Control the magnetic field

Control the swinging of the coil

To generate heat

To damp the oscillations

To achieve uniformity of scale

To produce magnetic attraction

FSD current

Meter coil resistance

Ohms per volt rating

Maximum voltage measurement

Calibration

Range test

Re-alignment

Testing standards

By sine wave signal

By function generator

By complex wave form

By built-in calibration signal