A Differential Hall Effect Based Pressure Sensor

Abstract

This paper presents the design and simulation of a pressure sensor integrated with two identical hall effect sensors and permanent magnets arranged in a differential configuration for measuring pressure in the range of 0–20 bar. The sensor uses the deflection of a circular diaphragm with a simple rigid mechanical structure to convert the applied pressure to a differential hall voltage output. A complete analytical modelling was carried out by assuming the rigid mechanical structure as a central circular boss structure on the circular diaphragm. Numerical simulations were also carried out in COMSOL Multiphysics FEM tool to support the analytical results. Before going for actual fabrication, the optimum sensor dimensions were also fixed from both analytical modelling and numerical simulation analysis. The sensor was planned to be fabricated completely using different grades of stainless steel and hence can be used in high temperature and corrosive environments. The fabricated sensor can be of low cost, self-packaged and the differential arrangement helps in compensating for any ambient temperature variations.