High-precision magnetic plug type sensor

The invention provides a high-precision magnetic plug type sensor, which comprises a probe structure and a signal conditioning circuit, and is characterized in that the probe structure comprises an external excitation coil, an internal induction coil group and a permanent magnet, and the external excitation coil is used for providing an excitation signal; the internal induction coil group comprises a plurality of induction coils, and each induction coil is connected in series with a capacitor to form an LC resonance circuit; the permanent magnet is used for capturing ferromagnetic metal particles in oil to the end face of the probe structure; the signal conditioning circuit comprises a half-wave rectifying circuit, a low-pass filtering circuit, a lock-in amplifier and a post-amplifier and is used for monitoring the characteristics of abrasive particles in the lubricating oil system by analyzing the size and the number of the wave crest signals. The invention designs a magnetic plug sensor probe structure, the