Embodiments of the invention generally provide a method for detecting
air contamination within a fluid dynamic bearing used with a disc drive. In one
embodiment, the invention provides a method to determine the amount of air contamination
with hydrodynamic fluid by comparing the differential displacement of the fluid
dynamic bearing between vacuum and non-vacuum conditions. In another aspect, the
invention provides an air-contamination detecting apparatus adapted to detect air
contamination within the fluid of a fluid dynamic bearing. In another aspect, the
invention provides a method to determine air contamination within fluid dynamic
bearings using the change in fly height of one or more probes disposed above the
surface of a rotating surface of the disc drive.
