Testing the Writeability of a Magnetic Head
Original Publication Date: 1986-Aug-01
Included in the Prior Art Database: 2005-Mar-09
In a magnetic disk storage, the writeability of a magnetic head can be tested by erasing the disk in one magnetic direction and by writing a low-frequency pulse track on the disk by means of the head. The head then reads the amplitudes of the positive and the negative pulses on the disk, the ratio of these amplitudes being indicative of the head's symmetry (writeability). It has been found that the accuracy of the above-described method is impaired by small signal offsets in the electronic signal path and by small magnetic fields in the vicinity of the head. For improved accuracy, it is suggested that two measurements of the above-described kind be made, but with opposite DC saturation.