What is a Clamp Meter?

A clamp meter, also known as a clamp-on ammeter or tong tester, is an electrical test instrument that combines a basic digital multimeter with a current sensor. It is designed to measure electrical current flowing through a conductor without the need to disconnect the circuit or make physical contact with the conductor itself.

The clamp meter works by clamping its jaws around the conductor through which the current is flowing. The jaws contain a sensor that detects the magnetic field generated by the current. Based on this magnetic field, the clamp meter can measure the current passing through the conductor.

Clamp meters are commonly used by electricians, technicians, and engineers for troubleshooting electrical systems, performing maintenance tasks, and verifying electrical loads. They are particularly useful for measuring current in situations where it may be difficult or unsafe to access the conductor directly, such as in crowded electrical panels or high-voltage environments.

In addition to measuring current, many clamp meters also offer other functions typically found in digital multimeters, such as measuring voltage, resistance, continuity, capacitance, and temperature. Some advanced models may also include features like frequency measurement, diode testing, and data logging capabilities.