A method for simultaneously measuring contact potential and slider body
clearance in a hard disk drive. In embodiments of the present invention,
a plurality of direct current (DC) pulses are applied between a slider
body and a hard disk of a magnetic disk drive. The contact potential
voltage between the slider body and the hard disk is determined in
response to applying the plurality of direct current (DC) pulses. The
voltage of the plurality of direct current (DC) pulses is increased until
a contact between the slider body and the hard disk is detected.