What device would be used to measure AC current flow in a large diameter conductor?

What device would be used to measure AC current flow in a large diameter conductor?

• A. Clamp-on type ammeter
• B. Voltmeter
• C. Ohmmeter
• D. Multimeter

Answer: (A)

Measuring AC current in a large diameter conductor is best done with a clamp-on ammeter. Its clamp surrounds the conductor without the need to disconnect or thread the wire through a meter. Inside the clamp, a current transformer (or a Hall effect sensing element) responds to the magnetic field produced by the conductor’s current. For AC, the magnetic field continually changes, and the device outputs a reading proportional to the current flowing in the wire. This non-contact method handles large conductors easily and safely, which is why it’s the go-to choice. A voltmeter measures voltage, not current. An ohmmeter measures resistance by applying a test voltage/current to a component and reading the response. A multimeter can measure current, but typically requires placing the meter in series with the circuit, which is less practical for a large, possibly hazardous conductor without modifying the circuit.

Measuring AC current in a large diameter conductor is best done with a clamp-on ammeter. Its clamp surrounds the conductor without the need to disconnect or thread the wire through a meter. Inside the clamp, a current transformer (or a Hall effect sensing element) responds to the magnetic field produced by the conductor’s current. For AC, the magnetic field continually changes, and the device outputs a reading proportional to the current flowing in the wire. This non-contact method handles large conductors easily and safely, which is why it’s the go-to choice.

A voltmeter measures voltage, not current. An ohmmeter measures resistance by applying a test voltage/current to a component and reading the response. A multimeter can measure current, but typically requires placing the meter in series with the circuit, which is less practical for a large, possibly hazardous conductor without modifying the circuit.