The wattmeter is an instrument for measuring the electric power(or the supply rate of electrical energy) in watts of any given circuit.It consists of current coil and voltage coil(pressure coil).It is used for power measurement of ac as well as dc circuits.They are also used in industries to check the power rating and consumption of electrical appliances,Basically,There are three types of wattmeters viz Dynamometer type, Induction type, and electrostatic type Wattmeter.
The energy meter is a device that measures the amount of electric energy consumed by a residence, a business, or an electrically powered device.They are typically calibrated in billing units, the most common one being the kilowatt hour [kWh].The energy meters divided into two basic categories, electromechanical and electronic.Induction type energy meters are most commonly a form of an electromechanical A. c. KWh meter used to measure the energy consumed in any a.c. the circuit in a prescribed period when su
A frequency meter is an instrument that displays the frequency of a periodic electrical signal. Digital frequency meter is a general purpose instrument that displays the frequency of a periodic electrical signal to an accuracy of three decimal places. It counts the number events occurring within the oscillations during a given interval of time.Deflection type and Resonant Reed (Non-deflection) type are the two types of frequency meter.
Power Factor Meter
A power factor meter is a type of electrodynamometer movement when it is made with two movable coils set at right angles to each other.There are two types of Power factor meter as Electrodynamometer type and Moving iron type.Electrodynamometer type is further classified as single phase and three phase.
Instrument transformers are high accuracy class electrical devices used to isolate or transform voltage or current levels. The most common usage of instrument transformers is to operate instruments or metering from high voltage or high current circuits. Instrument transformers are classified as Current and voltage transformers.