A Sensitive Large-Flow Debris Sensor Based on Dual-Excitation and Multi-Induction

Traditional sensors for monitoring oil wear debris do not integrate the advantages of high sensitivity and large flow, limiting the performance of the sensors. Thus, in this work, we design a sensitive and large-flow sensor based on the dual-excitation and multi-induction structure. The finite element analysis (FEA) shown that the impact of width of the L-shaped magnetic poles (L-MPs) on magnetic field is not serious and the influence of crosstalk among multiple medium-sized induction elements (MIEs) can be ignored. Therefore, for our sensor structure, the short distance between two excitation elements (EEs) can generate a strong symmetrically gradient magnetic field, which ensures the high sensitivity of the sensor. Meanwhile, thanks to the wide L-MPs, multiple MIEs can be arranged side by side, effectively increasing the flow of the sensor. Finally, a sensor containing four MIEs with an equivalent inner diameter of 20mm is made. The experiment shown that our sensor had no obvious crosstalk phenomenon during the work and successfully detected the iron debris of $25~\mu \text{m}$ , showing a better performance than existing sensors.