The electrical measuring instrument is classified into following the type
1. Indicating instrument
2. Integrating instrument
3. Recording instrument
Indicating instrument
The instruments which directly indicate the value of the electrical quantity at that time when it is being measured are called as Indicating instrument, eg- voltmeter, ammeter, and wattmeter. In this measuring instrument a pointer moving over a scale directly proportional to the electrical quantity.
Integrating instrument
Those instruments which measured the total quantity of electrical energy in (Wh or Ah) in a given time is called as Integrating instrument.
Recording instrument
Those instruments which give a continuous record of the variation of the electrical quantity to be measured is called the recording instrument.
Principles of operation of Electrical Instruments
Electrical measuring instruments work on the principle of operation of a different effect such as Magnetic effect, Electro-dynamic effect, Electromagnetic Induction, thermal Effect, Chemical Effect, Electrostatics Effect, etc.
The principle of operation of the different electrical instrument is given in the table below-
