High-sensitivity distinguishing and detection method for wear debris in oil of marine machinery

Oil debris distinguishing and detection is to characterize the wear position, rate and degree of mechanical system by detecting the properties, count and size of debris in the oil, which contributes to the health status monitoring and fault diagnosis of marine machinery. To improve the sensitivity of inductive detection method, especially for the detection of non-ferromagnetic particles, a double-wire solenoid coil and an inductance-resistance detection method are presented in the paper. The frequency characteristics of inductance and resistance detection are discussed, which shows that the first method is sensitive to ferromagnetic metal particles, and the second method is sensitive to non-ferromagnetic metal particles. We demonstrated that the double-wire solenoid coil sensor can detect iron particles with diameter of 20 mu m onwards and copper particles with diameter of 60 mu m onwards with inductance-resistance detection method.