Magnetic Simulations and Measurements for Designing Stray Field Robust Sensors

The presentation will comprise the development of two stray field immune magnet-sensor systems. It will cover the methods in their pre-design process as specific FEM simulations and 3D-Hall sensor measurement before realizing any hardware. Stray field immune sensors are often built by sensor pairs using the gradient principle. So, first stage tests including simulations and Hall measurements on different traces close the magnet and calculating potential sensor pair outputs are very valuable. Both can prove the viability of a devised systems and when successful the practical realization can be initiated. The whole way from pre-design investigations up to the hardware realization of a first sensor will be sketched in the presentation. For some sensors relatively fastidious mappings of parameters near the magnet, like partial derivatives of field components and related mathematical operations, can lead to reliable predictions of the real performance too. This is valid for respective field simulations as well as for multidimensional Hall sensor measurements. Both will be shown

on a second magnet-sensor system, where a sufficient magnet for an already commercially available sensor was developed. Related subjects will be explained in detail in the talk. Also here, results of the sensor system will be provided and compared to the predications of the first development stages.