Hall Effect Transducers

• When a conductor is kept perpendicular to the magnetic field and a direct current is passed through it, it results in an electric field perpendicular to the directions of both the magnetic field and current with a magnitude proportional to the product of the magnetic field strength and current.

• The voltage so developed is very small and it is difficult to detect it. But in some semiconductors such as germanium, this voltage is enough for measurement with a sensitive moving coil instrument. This phenomenon is called the Hall Effect.
• Commercial hall effect transducers are made from germanium or other semiconductor materials. They find application in instruments that measure magnetic field with small flux densities.
• Hall effect element can be used for measurement of current by the magnetic field produced due to flow of current.
• Hall effect element may be used for measuring a linear displacement or location of a structural element in case where it is possible to change the magnetic field strength by variation in the geometry of a magnetic structure.

Advantages

• Non-contact device
• Small size
• High resolution

Dis-advantages

• High sensitivity to temperature changes
• Variation of hall coefficient from plate to plate, hence requires individual calibration in each case