Friends, today in this article we will learn about electrostatic voltmeter. I am going to give information about all these in a very good way. So let’s start.
Electrostatic Voltmeter –
Electrostatic instruments can be used as voltmeters. They are used for high voltage measurement. They can be used on both types of supply (AC and DC).
It has many metal plates in between which concentric plates of light metal rotate between the fixed plates mounted on the spindle. The spindle rests on Joule bearing on which the indicator is mounted which gives indication on the graduated scale on the dial. Electrostatic voltmeters are of two types –
- Quadrant type electrostatic voltmeter
- Attraction disc type static voltmeter
Advantages of electrostatic instruments –
(i) They can be used on AC and DC circuits.
(ii) Suitable for high voltages.
(iii) Due to high capacitance in AC circuit, very little current flows in the instrument.
(iv) Since there is no iron in this type of instrument, there is no magnetic field, hence hysteresis and eddy currents errors are not present.
(v) These instruments do not take any current from the circuit. Hence power consumption in them is negligible.
(vi) Due to no power consumption, there is no thermal error.
(vii) The wave shape and frequency of these instruments have no effect on accuracy. Hence, they can be used up to 100 kHz without any loss of accuracy.
(viii) These instruments can be manufactured for high voltage measurement for first class accuracy. Many special types of instruments are designed to be sealed in vacuum which can be used as standards.
Disadvantages of electrostatic instruments-
(i) These instruments are heavy, expensive and not strong.
(ii) Their scale is not uniform. The quadrant and the wave can be made uniform by shaping it.
(iii) High voltage (pd) is required to generate proper deflection torque. Such instruments cannot be used at low voltage but Kelvin multi-cellular voltmeter is designed up to a low voltage of at least 30 volts.
What did you learn today:-
Now you must have known what is electrostatic voltmeter. You must have got the answer to all these questions well.
I hope you liked the information given by me. If you have any question/suggestion in your mind, then you can tell me by commenting below, I will definitely answer your comment. If you liked this post, then you can also share it with your friends and relatives.