A method and system for determining localized contact potential voltages
and localized clearance data between a slider body and a hard disk of a
hard disk drive. In embodiments of the present invention, a plurality of
direct current (DC) pulses are applied between said slider body and a
discreet location of the hard disk. In embodiments of the present
invention, the discreet location of the hard disk comprises a portion of
a data track of the hard disk. In embodiments of the present invention, a
variation in the clearance of the slider body is determined when a given
voltage is applied. Furthermore, a first set of DC pulses has a
positive/negative bias while a second set of DC pulses has a
negative/positive bias. The voltage of the sets of DC pulses is increased
until a contact between the slider body and the hard disk is detected.