A High-Sensitivity and High-Precision Debris Sensor Based on Multiple Excitation Coil Structure for Online Wear Monitoring

To address the inconsistent measurements of debris sensors, a precision and sensitivity debris sensor based on a multi-excitation-coil structure (MECS) is proposed. By tailoring a multi-excitation-coil array for magnetic field homogeneity and separately optimizing the induction coil, this sensor enhances both precision and sensitivity. To validate the design concept, a sensor prototype and signal processing system were constructed. Experimental results demonstrate that under identical turn conditions, the sensor’s output consistency surpasses that of traditional three-coil design by 55%. In a 12 mm diameter channel, the theoretical detect limits of 95 μm for ferromagnetic debris and 283 μm for non-ferromagnetic debris are achieved, with errors attributable to debris motion variations not exceeding 3%. The design concept of this sensor is readily ported to online diagnostic systems, where it can systematically improve measurement consistency, and enhance the credibility of downstream health-management decisions.