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