Pit Detection Using a Contact Sensor

Pit detection study of a thermal contact sensor was carried out by both experiments and simulation. The experimental results showed that the thermal contact sensor was able to detect a small pit with fairly good sensitivity. And the simulation study revealed that the mechanism of pit detection is due to worse cooling, which results in higher sensor temperature, because the sensor/disk spacing is larger on the pit compared with at nominal flying state. And the temperature increase of sensor can be attributed to worse heat flux due to both larger spacing and air-bearing pressure drop when the sensor is above the pit.