Key Takeaways
- Wattmeters measure instantaneous power consumption in electrical circuits, while energy meters measure the total amount of electrical energy consumed over time.
- Wattmeters help determine the efficiency of electrical devices, while energy meters are used for billing purposes in residential and commercial settings.
- Energy meters are integrated into the electrical distribution system, while wattmeters can be standalone devices or integrated into other instruments.
What is Wattmeter?
The wattmeter is a device that measures the active electric power (or the average rate of flow of electrical energy) of any given circuit in watts. Electromagnetic wattmeters measure utility and audio frequency power; radio frequency measurements require other types.
An electrodynamic device is the traditional analog wattmeter. The gadget comprises two fixed coils, the current coils, and one movable coil, the potential coil. The current coils are linked to the circuit in series, while the potential coil is connected in parallel. In addition, on analog wattmeters, the potential coil contains a needle that moves around a scale to represent the measurement.
An electromagnetic field is created around the current coil when current flows through it. Electronic wattmeters are used for direct, low-power measurements or power measurements at frequencies above the range of electrodynamometers. A modern digital wattmeter takes thousands of voltage and current readings per second.
Measuring power with inexpensive wattmeters or any meters not optimized for low-power readings has limits, especially true for low-power applications such as standby; readings may need to be more precise. The issue stems mainly from the difficulty of accurately measuring alternating current rather than voltage and the relatively low demand for low-power measurements.
What is Energy Meter?
An electricity meter, also known as an electric meter, electrical meter, energy meter, or kilowatt-hour meter, is a device that monitors the amount of electric energy consumed by a home, a business, or a gadget that is powered by electricity. An electric or energy meter measures the total power consumed over time.
Electric utility bill and track customers using electric meters installed on their premises. Meters for less essential services, such as small residential customers, can be installed directly between the source and the client. Current transformers are used for more oversized loads so that the meter can be placed anywhere other than in line with the service conductors. The meters are classified into two types: electromechanical and electronic.
The electromechanical watt-hour meter is the most prevalent form of the electricity meter. Electronic meters display the amount of energy consumed on an LCD or LED display; some may send readings to remote locations. In addition to measuring energy, electronic meters can also record various loads and supply information such as rapid and maximum rate of usage demands, voltages, power factor, and reactive power consumed, among others.
Difference Between Wattmeter and Energy Meter
- The Wattmeter monitors the power in a circuit, whereas the energy meter measures how much energy the load consumes.
- The significant parts of a wattmeter are the current coil, pressure coil, damping system, control mechanism, scale, and pointer.
- In contrast, the essential elements of an energy meter are the current coil, voltage coil, rotating aluminum disc, breaking system, and counting mechanism.
- Wattmeter measures the active and reactive power of the circuit, while an energy meter only measures the active power.
Comparison Between Wattmeter and Energy Meter
| Parameters of comparison | Wattmeter | Energy Meter |
|---|---|---|
| Used for | Measuring the total energy consumed by the load. | Measuring the power in a circuit. |
| Work principle | Conversion of electrical energy into mechanical energy. | The force acts on the current-carrying conductor when placed in an electromagnetic field. |
| SI Units | Energy in joules. | Power in watts. |
| Instrument type | Indicating type instrument. | Integrating type instrument. |
| Application | Determining the power rating of the appliances. | Measuring electrical energy in homes and industries. |
- Materials | Free Full-Text | Electronic Energy Meter Based on a Tunnel Magnetoresistive Effect (TMR) Current Sensor (mdpi.com)
- Power and energy measurement devices: A review, comparison, discussion, and the future of research – ScienceDirect
Last Updated : 29 July, 2023
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Piyush Yadav has spent the past 25 years working as a physicist in the local community. He is a physicist passionate about making science more accessible to our readers. He holds a BSc in Natural Sciences and Post Graduate Diploma in Environmental Science. You can read more about him on his bio page.
