Effects of Humid Air on Air-Bearing Flying Height

The pressure distribution in a squeeze film air bearing depends on the water vapor pressure and the saturation vapor pressure of water at ambient temperature. When the water vapor pressure is compressed beyond the saturation vapor pressure, a portion of the water vapor condenses, thus reducing the total gas pressure in the air bearing. This condensation mechanism thus reduces the flying height of the slider. Using a magnetic recording system for experiments, we quantified the effect of condensation on flying height by measuring the dependence of magnetic spacing on relative humidity. We developed a numerical model based on the proposed mechanism that matches the experimental data and provides a detailed view of the air-bearing response to humidity.