Advantages and Disadvantages of Electrostatic Instruments

      The various advantages of electrostatic instruments are,

1) The give correct measurement in both  a.c. as well as d.c. circuits.

2) They are most useful in high voltage measurements.

3 ) There are no frequency and waveform variations as the deflection is proportional to the square of voltage.

4) As there is no iron part in the working system of these instruments, they are free from errors due to eddy currents and hysteresis.

5 ) The power loss in these instruments is very small.

6 ) Costly resistance wires are not used in this instruments.

7) The operating current is very small hence does not affect the performance of other circuits connected to the same supply.

      The various disadvantages of electrostatic instruments are,

1 ) they are not suitable for low voltage measurements.

2) These are large in size, bulky and not very robust.

3 ) These are expensive instruments

4 ) The scale is not uniform