Patent ID: 8717702

Claim:
A method for measuring spacing fluctuations between a dynamic flying height (DFH) controlled read/write head and the surface of a rotating disk comprising: providing a hard disk drive (HDD) or spin stand having a rotatable disk mounted therein; providing the DFH controlled read/write head having at least a heater element and a HDI sensor or its equivalent mounted therein, wherein said read/write head is flyable above said rotating disk; then, while rotating said disk, flying said read/write head over a selected track on said disk; and supplying power to said at least said heater element, stepwise, at a variable and controllable rate and time; and analyzing a high frequency component of a signal generated by said HDI sensor or its equivalent; then processing said high frequency component to determine a minimum power level step at which a detectable touchdown first occurs and a maximum power level step at which a full touchdown occurs; and then determining a touchdown power profile of said track by averaging a Ratio value over a total number of disk revolutions during each of said power steps between said minimum and said maximum and displaying said touchdown power profile in a single graph as a function of each of a sector subdivision of said track.