This paper presents an analysis of a wear debris sensor coil implemented in a Maxwell-Wien Bridge circuit used in detecting ferrous and non-ferrous particles. The sensor coil is designed to have a diameter approximately 15 times larger than the largest particle being detected. To detect particles up to 2 mm in diameter, a coil 30 mm in diameter was constructed. Simulations of the experiment indicate that the available particles should be detectable by the sensor coil. However, experimental results indicate that the Maxwell-Wien Bridge does not detect the available particles. Further simulations are presented accounting for parasitic capacitance of the sensor coil. The results from these simulations show that large parasitic capacitance affects the behavior of the bridge. The available particles were etched into smaller particles more typical of wear debris. It is expected that for a smaller coil, the effects of parasitic capacitance will be reduced.
Yang, Kue Z.; Veillette, Robert J.; and Carletta, Joan E., "Analysis of Sensor Coil Implemented in Maxwell-Wien Bridge Circuit for Detecting Ferrous and Non-Ferrous Particles" (2016). Electrical and Computer Engineering Student Research. 1.