What do watt meters measure?

Watt meters are designed specifically to measure active power, which is the actual power consumed by an electrical device to perform work. Active power is measured in watts and represents the portion of electricity that results in useful work, such as lighting, heating, or running machinery.

When an electrical current flows through a circuit, energy is utilized in a productive manner, and this is quantifiable using a watt meter. The measurement reflects the rate at which energy is being converted into work by the device. It does not account for reactive power or apparent power, which involve different aspects of electrical energy in AC circuits.

Understanding that watt meters directly measure the work done or energy consumed over time is crucial. This is an important concept in electrical engineering and power management, as it enables energy efficiency assessments and effective power distribution within systems.