A new approach to linear displacement measurements based on Hall effect sensors

Authors: İSMAİL YARİÇİ, YAVUZ ÖZTÜRK

Abstract: Since displacement is a vital variable to be considered in many industrial applications, displacement sensing devices have been extensively studied both theoretically and experimentally. There have been also many studies on Hall effect-based displacement measurement, but for many systems linearity still remains a problem. This paper discusses different approaches to calculate the magnetic field due to a cylindrical permanent magnet and proposes a new setup geometry with 2-Hall effect sensors and a permanent magnet between them to overcome the linearity problems. Furthermore, theoretical and experimental studies of the discussed displacement sensor were presented by focusing on the linear range and the sensitivity of the system. These parameters were investigated for different sensor-to-sensor distances. As this value decreases, it is found that sensitivity increases, and yet the linear range decreases as well. For the 25.5 mm sensor-to-sensor distance linear range was determined as around 3 mm, and the sensitivity and maximum error in displacement measurement was calculated as 351 mV/mm and 0.029 mm, respectively. We believe that by using the results of our study, it is possible to develop Hall sensor-based approaches that can be used for sensitive displacement measurements in a certain range and can meet the needs of researchers and industry in many applications.

Keywords: Displacement measurement, Hall effect, linearity, magnetic sensors

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