Ferromagnetic particle sensor

摘要

A ferromagnetic particle sensor includes a housing having a first electromagnet and a second electromagnet attached to the interior surface thereof. A mass sensitive surface acoustic wave (SAW) sensor is disposed between the electromagnets. The sensor is submerged in lubricating fluid and as the electromagnets are energized they produce magnetic forces that draw fluid-borne ferromagnetic particles past the SAW sensor. The SAW sensor is used measure the mass of the ferromagnetic particles and determine when the volume of particles in the lubricating fluid increases.