Electrical Engineering ⇒ Topic : Characteristics of Induction Ammeters and Voltmeters

Characteristics of Induction Ammeters and Voltmeters

The characteristics of induction ammeters and voltmeters are given below

Advantages

• There is no moving iron in the instrument.
• The moving element (i.e., disc) is not electrically connected to the circuit.
• A full-scale deflection of over 250° can be obtained.
• They provide very effective damping.
• They are not easily affected by stray magnetic fields owing to the intense concentration of instrument's own magnetic field.

Disadvantages

• They have high cost.
• They have non-linear scales.
• They can be used for a.c. measurements only.
• They introduce fairly large errors due to temperature, frequency and waveform variations.
• They consume fairly large power because of relatively large power losses in the shading coil.