Sensor for monitoring metal abrasive particles in oil liquid on line and application method for sensor

The invention discloses a sensor for monitoring metal abrasive particles in oil liquid on line. The sensor is a mutual inductance sensor and comprises an exciting coil and an inducting coil, wherein an oil path through which the oil liquid can pass is arranged in the center of a framework made of a magnetic inert material; the exciting coil and the inducting coil are coaxially wound on the framework; the inducing coil is positioned between the exciting coil and the framework; the axial length of the inducting coil is 1/4-1/2 of that of the exciting coil; and the axial center points of the inducting coil and the exciting coil are superposed. The sensor realizes zero compensation and adjustment by adopting a parallel measurement structure and is simple in structure, high in sensitivity, high in linearity and high in interference resistance. The sensor applied to on-line monitoring for the metal abrasive particles in the oil liquid is convenient to operate, high in instantaneity, high in measurement precision and accurate and reliable in monitored result and can be widely applied to military and civil fields and used for monitoring the pollution degree and the abrasion to the oil liquid of lubricating systems of mechanical equipment such as various air planes, naval vessels and automobiles and monitoring and diagnosing faults of the lubricating systems of the mechanical equipment to avoid safety accidents.