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    What is a Clamp Meter?

    Clamp meter is an electronic instrument that measures current and is widely used in electrical engineering, electronic maintenance, energy management and other fields. Clamp meters measure electrical current non-invasively by clipping around a current conductor without interrupting the circuit or directly touching the conductor. This design makes it a safe, convenient and efficient tool, especially suitable for measuring AC current.

    The working principle of the clamp meter is based on Faraday's law of electromagnetic induction. When an electric current passes through a wire, it creates a magnetic field around it. The clamp part of the clamp meter contains an iron core and an induction coil, which captures changes in the magnetic field around the wire. By measuring these changes, the clamp meter can accurately determine the strength of the current without requiring direct contact with the wire, making it a non-invasive tool for measuring current.

    Clamp meters usually have a digital display that shows the strength of the current. Some advanced clamp meters are also equipped with data logging, peak hold, and automatic range switching functions, making them more flexible and suitable for different measurement scenarios. In addition to current measurement, some digital clamp meters can measure AC voltage, DC voltage, resistance, temperature, and more, making them versatile tools for electricians, engineers, and technicians.

    DC leakage current clamp meter

    How does a Clamp Meter Work?

    • Principle of electromagnetic induction: A clip-on ammeter uses the magnetic field generated when the current passes through a conductor to measure current. According to Ampere's law, when an electric current passes through a conductor, it creates a magnetic field around it. The collet of a clip-on ammeter contains an iron core that enhances the surrounding magnetic field. When clamped near a current conductor, this magnetic field affects the sensor within the collet.
    • Sensor: Inside the chuck, there are one or more magnetic sensing elements, usually Hall effect sensors. These sensors detect the strength of the magnetic field around the chuck and convert it into a voltage signal.
    • Current measurement: The chuck senses the magnetic field caused by the current passing through the conductor into the sensor and converts it into a corresponding voltage signal. A measuring instrument measures the magnitude of this voltage signal and converts it into a current value.
    • Display and reading: Finally, the measuring instrument displays the measured current value on the meter so that it can be read by the user.


    • Non-intrusive measurement: The clamp ammeter measures by clamping an electrical conductor without interrupting the circuit, providing electricians with a safe and convenient method of measurement. This non-invasive feature means no direct contact with wires is required when making current measurements, reducing the risk of electric shock.
    • High safety: Since the clamp meter does not require direct contact with wires when measuring current, it is safer to use. This reduces the risk of electric shock or electric shock in high voltage or high current environments, making it an important tool in industrial and power systems.
    • Fast and convenient: The clamp meter can measure quickly, and the current value can be obtained quickly by clamping the wire without cutting off the circuit. This increases the efficiency of troubleshooting and maintenance, making it an important tool in fieldwork.
    • Versatility: The clamp meter is capable of measuring not only current, but also voltage, resistance, frequency, temperature, and more. Its versatility makes it a universal tool for electricians and maintenance personnel in different application scenarios, saving the cost and space of carrying multiple instruments.
    • Suitable for large current measurement: A clamp meter can measure a wide range of current and is suitable for environments such as industrial equipment and power systems that require high current measurement. Its high current measurement capabilities make it widely used in engineering and maintenance.
    • Portable design: The clamp ammeter is lightweight and portable, making it easy to carry to different job sites. This design makes it ideal for electricians, engineers and maintenance personnel when working on the move.
    • Accuracy: When used correctly, the clamp meter provides highly accurate current measurements. They ensure the reliability of measurement results through sophisticated sensors and electronic components, making them highly reliable in scenarios where accurate measurements are required.


    • Current measurement: The most common use of clamp meters is to measure current in AC circuits. By clamping the current wire, it can accurately measure the magnitude of the current without interrupting the circuit.
    • Fault diagnosis: A clamp meter can be used to diagnose faults in an electrical circuit. By measuring the current in different parts, it is possible to determine whether there is an abnormal current distribution and thereby locate the fault.
    • Load testing: In industrial and commercial electrical systems, clamp meters can be used to test loads. This helps ensure that the electrical system is functioning properly and that loads are within specifications.
    • Energy management: Use the clamp meter to monitor current usage, aiding in energy management. By regularly monitoring the current flow, potential energy efficiency issues can be identified and appropriate measures taken.
    • Installing and maintaining electrical equipment: When installing new electrical equipment or performing maintenance work, use a Clamp Meter to ensure that the current is within normal limits and that the equipment's electrical system is functioning properly.
    • Current balance detection: In a three-phase power system, a clamp meter can be used to detect whether the three-phase current is balanced. Unbalanced current flow may indicate a problem with the system that requires further investigation and repair.
    • Ground fault detection: By measuring the ground current in the current loop, the earth leakage clamp meter can detect the presence of a ground fault. This is very important to ensure the safety of the electrical system.
    • Current monitoring and recording: Some clamp meters have a data logging function that can be used to monitor changes in current and record the data for subsequent analysis and reporting.

    In general, the clamp meter is a very important electronic measuring instrument. It achieves accurate measurement of current through advanced electromagnetic induction technology, providing electricians, engineers and technicians with a convenient and effective tool to ensure Proper operation of the circuit and stability of the equipment.

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