What Are Hall Effect (AC, DC) Clamp Meters?

In measuring both ac and dc current, Hall Effect clamp meters can measure up to the kilohertz (1000 Hz) range. With the same current transformer types, Hall Effect clamp meters use rigid iron jaws to deliberate the magnetic field that encompasses the conductor being measured.

The jaws are not wrapped by copper wires, not the same as current transformer clamp meters. In addition, the magnetic field produced by the conductor is absorbed across one or more gaps in the core after the jaws are clamped around the conductor. The point where the jaw tips of a Hall Effect clamp meter meet.

When the jaw tips of a Hall Effect clamp meter meet, a gap exists. It creates an air pocket that the magnetic field (aka magnetic flux) must jump. The core will not saturate when the gap limits the magnetic flux.

In contrast, the jaws of an ac-only current transformer clamp are flush when closed. When opened, the tips of the jaws show bare metal core faces.

Within the gap, there’s a thin plastic molding covering the semiconductor known as a Hall Effect sensor – it is a transducer that differs its output voltage when reacting to magnetic fields, in this case, the magnetic field of the conductor or wire being measured. The objective is to measure the magnetic flux directly. The output voltage from the sensor then improved and mounted to represent the current flowing through the conductor that lies inside the jaws of the clamp.

How the Hall Effect clamp meters work

While the current flow within the conductor is being measured. The iron core is formed by the jaws of a Hall Effect clamp meter that permits the magnetic field to effortlessly pass through easily.

In the case of the magnetic field (flux) that comes to that small air gap in the tips of the jaw, the field must jump that gap. When the gap is small, the field stays determined across the gap. Therefore, the Hall Effect sensor, which sits in the gap—produces a voltage proportional to the magnetic flux. The gap that the clamp transforms into a current reading.

Of all Hall Effect devices, the dc magnetic fields are concentrated through the core – like a permanent magnet sticking iron. Clamps require the reading to be “zeroed” before taking a measurement to eliminate offsets. The dc magnetic field of the earth and the possibility of other magnetic fields near the measurement site.

To learn more about clamp meters, visit https://presidium.ph/product-category/products/fluke-industrial-group-tools/clamp-meters/.