Extracting 3D Magnetic Field Components With Two Hall Plates on a Piezoelectric Nano Rotary Positioner System

In light of a 3-D Hall sensor that is being designed at the Magnet Section of the Paul Scherrer Institute (PSI), a new calibration scheme is under development. As a preparation to this, a single Hall plate is calibrated for perpendicular and in-plane field directions by rotation of the Hall plate in a calibration magnet. A piezoelectric nano rotary positioner system that fits into the 38 mm aperture of the calibration magnet will be applied. In addition, two Hall plates glued back-to-back and rotated 90 ° around the normal axis with respect to each other are used which have the clear advantage that the planar Hall effect is nearly cancelled out. It will be shown that the full 3-D field vector of a magnetic field can be extracted by rotation of the probe(s) in the to-be-measured magnetic field. Hence, the setup can be used efficiently to measure the (inhomogeneous) magnetic field of large aperture magnets. The paper describes the calibration results and the scheme to measure the full field vector using a piezoelectric nano rotary positioner system.