A Hall sensor works via the Hall effect. In a conductor, when current is following and a magnetic field is perpendicular to the current, a Hall effect voltage difference is generated perpendicular to both.
Hall sensor may be unipolar, sensing only a north pole or only a south pole, or bipolar, sensing either. The figures illustrate some functional interactions between Hall sensor and magnets. The graphs represent the behaviour of the flux density at the sensor position.
We also offer you the opportunity to calculate automatically the flux density of disc, ring, and rectangular magnets.
If a Hall sensor and magnet are mounted in place, the flux density changes are caused by moving an iron plate between the Hall sensor and magnet. The iron plate shields the magnetic flux.