A clamp meter also known as a clamp-on meter or tong tester, is an electrical test tool that combines a basic digital multimeter with a current sensor. Clamp meters measure current, voltage, resistance, continuity, and, with some models, capacitance, temperature, frequency, and more and are considered essential tools for electrical diagnostics, system maintenance and safety assurance,

Clamp meters have a hinged jaw allowing users to clamp onto a wire or cable at any point in an electrical system to measure the current without disconnecting it. These current clamps are extremely popular due to safety reasons as they provide a non-contact method of measuring current, eliminating the need for direct contact with live wires. They identify issues when installations occur and are cost effective for ongoing tester, maintenance, and service requirements. You can find out more in our clamp meters guide.

Our range of clamp meters including calibrated clamp meters, have been sourced from leading brands such as: Beha-Amprobe, Chauvin Arnoux, Fluke, FLIR, Keysight Technologies, Megger, RS PRO and many more. Our product range is easy to browse and supported with technical information to ensure you choose the right solution for your needs. RS has technical advisers on hand to provide you information not only on the product, but also on our calibrated services.

What are clamp meters used for?

• Measuring Current - AC and DC Current, and high currents that multimeters cannot measure safely
• Voltage Measurement
• Resistance Testing
• Continuity Testing - checks for the integrity of electrical connections
• Frequency Measurement - advanced clamp meters can measure the frequency of an electrical signal.
• Earth Leakage Testing - specialised clamp meters detect small leakage currents in circuits, ensuring safety and compliance with regulations.
• Troubleshooting Electrical Systems - ideal for identifying overloads, shorts, or imbalanced circuits in industrial, commercial, or residential settings.

How to test for earth leakage

Testing for earth leakage involves using specific tools such as an earth leakage clamp meter to measure the unintended current flow from a live conductor to the earth.

• Set the earth leakage clamp meter to the lowest AC current range for precision.
• Clamp the meter around all live conductors, including neutral (not the earth wire). This measures the net current flow.
• Read the leakage current displayed. Any significant value (above 30mA in residential setups) indicates a potential issue.

Popular Clamp Meters

• AC Current Clamp Meters
• DC Current Clamp Meters
• AC/DC Clamp Meters
• Earth Leakage Clamp Meters
• HVAC Clamp Meters
• Power Clamp Meters
• Hall Effect Clamp Meters
• True RMS Clamp Meters
• Bluetooth Clamp Meters
• Wireless Clamp Meters

Why would you need a clamp meter?

• Safety: Clamp meters allow electricians to bypass the old-school method of cutting into a wire and inserting a meter's test leads into the circuit to take an inline current measurement. The jaws of a clamp meter do not need to touch a conductor during a measurement.
• Convenience: During measurement, it is not necessary to shut off the circuit carrying current—a large boost inefficiency.
• Service: Repair existing systems on an as-needed basis.
• Installation: Troubleshooting installation problems, perform final circuit tests and supervise apprentice electricians while installing electrical equipment.
• Maintenance: Perform scheduled and preventative maintenance and system troubleshooting.