A highly sensitive triple-coil inductive debris sensor based on an effective unbalance compensation circuit

摘要

Wear particles in the lubrication oil of machinery contain a considerable amount of information about the level of wear in the machinery components, which can provide very early warnings of faults. Inductive debris sensors play an important role in online oil debris detecting techniques. A large unbalance voltage in the sensing coil induced by the asymmetry of two excitation coils harms the performance of a triple-coil inductive debris sensor. This work proposes an effective signal processing system which contributes to the establishment of a high-performance triple-coil inductive debris sensor. Several experiments are conducted to test the sensor's detection performance. The results show that the sensor is sensitive, and can effectively detect 134 mu m (D) ferrous particles and 230 mu m (D) nonferrous particles in a sensing channel with an inner diameter of 43 mm.