Wattmeter
Overview
Electric power
Electric power is the rate at which electric energy is transferred by an electric circuit. The SI unit of power is the watt.-Circuits:Electric power, like mechanical power, is represented by the letter P in electrical equations...
(or the supply rate of electrical energy) in watt
Watt
The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...
s of any given circuit
Electrical network
An electrical network is an interconnection of electrical elements such as resistors, inductors, capacitors, transmission lines, voltage sources, current sources and switches. An electrical circuit is a special type of network, one that has a closed loop giving a return path for the current...
.
An instrument which measures electrical energy
Energy
In physics, energy is an indirectly observed quantity. It is often understood as the ability a physical system has to do work on other physical systems...
in watt hours (electricity meter
Electricity meter
An electricity meter or energy meter is a device that measures the amount of electric energy consumed by a residence, business, or an electrically powered device....
or energy analyser
Energy analyser
An instrument for measuring various parameters of an electrical power distribution system is often called an energy analyser. The term is also used for computer software for analysing the use of electrical or other energy use, for example determining how electrical power is consumed in a building...
) is essentially a wattmeter which accumulates or averages readings; many such instruments measure and can display many parameters and can be used where a wattmeter is needed: volts, current ,in amperes, apparent instantaneous power, actual power, power factor, energy in [k]Wh over a period of time, and cost of electricity consumed.
The traditional analog wattmeter is an electrodynamic instrument.
