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 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. The maximum temperature increase is significant initially with increasing pit depth but saturates when the depth is larger than 60 nm.