The Optimization of Parallel Resonance Circuit for Wear Debris Detection by Adjusting Capacitance

Wear debris in lubrication oil provides important information for marine engine condition monitoring and faults diagnosis. Inductive sensors have been widely used to detect wear oil. To improve the sensitivity, inductive coil is always connected with a capacitor parallel form LC resonance-sensing circuit. A previous study optimized resonance circuit by adjusting excitation frequency. However, multiple parameters (namely, signal, signal detection circuits, signal-processing program, etc.) need be adjusted accordingly series of testing frequencies. simplify optimization, we propose method based on capacitance this work. The impedance (inductance internal resistance) sensing its variation induced particles are first measured, which necessary establishing function relationship between relative variation. With relationship, calculated directly, optimal located at highest absolute value it. experimental results ferrous nonferrous match calculation well. Interestingly, particle was larger than that particle. We speculate difference generated due increased resistance eddy current effect.