Contactless Distance Sensor for small air-gap (<10 mm) using Linear Hall Effect Sensor

摘要

This paper presents a contactless method to measure small air-gap distance (<;10 mm) using linear Hall effect sensor. The method exploited measurement of changes in magnetic field intensity as a function of Hall sensor displacement. The results showed that the displacements were exponentially correlated with output signal from Hall sensor. The empirical equation of the displacement as a function of the output signal was generated using the exponential regression agreement analysis. The statistical analysis of the predicted displacement in comparison to the actual displacement indicated strong correlation coefficient R² = 0.9932 and low absolute percentage mean error of 4.6784%. In addition, a potential application of surface crack detection on ferromagnetic materials is also discussed in this paper.