What does a clamp-on multimeter primarily measure?

A clamp-on multimeter is primarily designed to measure the root mean square (RMS) current flowing through a conductor without needing to disconnect it from the circuit. Its clamp feature allows it to encircle a wire, sensing the magnetic field generated by the current flow. This capability enables it to provide real-time readings of AC current, which is particularly useful for diagnostics and monitoring in electrical systems. While many clamp-on multimeters can also measure voltage and resistance, their standout functionality lies in accurately measuring the RMS values of alternating current, making them invaluable tools for electrical professionals.