What does a watt meter do?

A watt meter is specifically designed to measure the amount of electrical power being consumed by a device, measured in watts. This measurement is crucial for understanding how much energy a device uses over time, which can inform decisions about energy efficiency and cost. Unlike a voltmeter, which assesses voltage, or an ammeter, which quantifies current, a watt meter takes into account both voltage and current to calculate power usage. This capability makes it an essential tool for both residential and commercial electrical maintenance, as it provides valuable insights into energy consumption trends and helps in optimizing energy use.

In contrast, measuring voltage alone does not provide information about the power usage, nor does measuring the resistance of a wire or the current flowing through a circuit. Each of these other instruments serves a distinct purpose, highlighting the specialized function of the watt meter in energy consumption analysis.