Transition profile measurement

The signal read by an inductive head from a recorded transition is proportional to the convolution of the head sensitivity functions with the gradient of the transition profile. With a known sensitivity function, the Fourier transform of the gradient of the transition profile, averaged over the medium thickness and track width, can be recovered from the transform of the signal by dividing it by the head sensitivity function transform. To assess the performance of the technique for thin-film heads, the sensitivity functions of several heads with different geometries have been measured. The signal read from a single transition with each of these heads is deconvolved, and the resulting inferred transition profiles are compared. Results are also shown for measurements using a single read head on transitions written with a series of different write currents and flying heights