Wattmeter

A wattmeter is a device that measures power, or the amount of energy being used, in a given space or system. In short, it is used to measure active electric power. It is a helpful device for comparing the power use of different systems, such as lamps and computers, and for measuring the power of systems that operate at power levels too low to be measured by other instruments. Wattmeters are also used in the field of energy efficiency to measure the energy efficiency of buildings, appliances and other systems. 

Wattmeter

A wattmeter is an instrument used to measure and estimate electrical power. It is typically used to determine the amount of power flowing through a circuit and can be used to estimate the electrical load of a system. It is commonly used to determine the power supply of a system and is often the first instrument of a power supply unit (PSU) to be tested. It is also an important instrument in the field of power electronics, where it is used to measure, monitor and control power flow in power electronic devices such as converters and power splitters. It measures the average rate of flow of electrical energy in watts. 

The working mechanism of a wattmeter is based on the principle that the amount of electricity consumed by an appliance is proportional to the power consumed by the appliance. Thus, an appliance that consumes more electricity will use more energy than a similar-sized appliance. The formula used for the calculation of power with a wattmeter is:

       P = IVCosθ

Key points about wattmeter

• It displays the electric power of devices
• It monitors power consumption
• It can measure voltage, current, power, power factor and energy consumption with an accuracy of 1% to 5%
• It can be damaged by excessive current
• It consumes energy, although the amount consumed is very little
• Both electric and digital wattmeters are available in the market

Types of wattmeters

There are two types of wattmeters: Electrodynamometer Wattmeter and Induction Wattmeter.

1. Electrodynamometer wattmeter

Electrodynamometer, or wattmeter, is used to measure the amount of energy being transferred by an electric current. It consists of a pair of wires with current running between them. The current creates a magnetic field, which can be measured using a voltmeter. The voltmeter reads the current in voltage, which can be used to calculate the energy being transferred by the current, and subsequently, the distance travelled by the current in a wire. The most common application of electro dynamometers is in electric motors and generators. Electric motors rely on current flowing through a wire to generate force.

2. Induction wattmeter

Induction wattmeters are used to measure the number of watts of electricity flowing in a circuit or wire. They are used in electric power generation, electric power distribution, and electric power transmission systems to measure power and energy. They are also used in electric power monitoring and control systems, electric power quality testing, and electric power quality measurement. Induction wattmeters are a type of variable-speed wattmeter.

Uses of wattmeter

1. Electric companies use watt meters to record the amount of electricity and energy their customers use.
2. Wattmeters are typically used to measure the power output of small-scale photovoltaic arrays to determine the amount of electrical energy generated by the system.
3. They are also used to measure the power being generated by a renewable energy system, such as a solar panel or wind turbine, so that the system can be sized appropriately.
4. Wattmeters have broad applications in laboratories and industries, and for the measurement of transmission or distributed power.
5. Wattmeters are most commonly used to measure the power output of a motor. They help determine whether a motor is functioning properly or whether it needs to be replaced. 
6. Wattmeters are used to monitor the amount of power used by electrical equipment and to help ensure that the power is being used properly.
7. Wattmeters are used to monitor power consumption (mostly of electrical appliances) and help consumers optimise their electricity usage by reducing energy waste.

Conclusion

A wattmeter is a device that measures the power being used by a device or system.  It is also known as a watt-hour meter, watt, watt-hour, or watt. Wattmeters are used for various purposes, like determining the energy used by a device or the power needed by a system to operate. They are a common household device, but they can also be used in public or commercial buildings, vehicles, and industrial equipment.