What device is used to measure power factor?

A power factor meter is specifically designed to measure the power factor of an electrical system, which quantifies how effectively electrical power is being converted into useful work output. The power factor is a dimensionless number between 0 and 1, representing the ratio of the real power flowing to the load to the apparent power in the circuit. This measurement is crucial for assessing the efficiency of electrical systems, especially in industrial and commercial applications.

While other devices like an amperemeter, multimeter, and oscilloscope can be used to gather various types of electrical measurements (current, voltage, and waveforms), they do not inherently calculate the power factor. An amperemeter measures current flow, a multimeter can measure voltage and resistance, and an oscilloscope visualizes waveforms. None of these instruments are equipped to derive the power factor directly from the relationship between current and voltage in an AC circuit, making the power factor meter the most appropriate choice for this function.