What is the primary use of a voltmeter?

A voltmeter is specifically designed to measure the electrical potential difference, or voltage, between two points in an electrical circuit. This is crucial in assessing how much electrical energy is available to drive current through a circuit and understanding how electrical devices are functioning. By measuring the voltage, a technician can determine whether a voltage supply is adequate for the components in use, diagnose issues, or confirm that power levels are within the required specifications.

The voltmeter operates on the principle of measuring potential difference without significantly affecting the circuit itself, which distinguishes its function from devices that measure current or resistance. While a current meter measures the flow of electricity, or ampacity, and an ohmmeter measures resistance, these tools serve different purposes entirely. Additionally, a voltmeter does not provide power to devices; its primary function is purely measurement, making it a fundamental tool for anyone working with electrical systems.