Write Head Measurement Tool
Original Publication Date: 1988-Jul-01
Included in the Prior Art Database: 2005-Feb-15
The thickness of the accumulated Bitter particles over a written transition on magnetic recording media is related to the strength of the gradient of the magnetic field. By quantifying the thickness, the recording characteristics of a write head can be directly observed independent of the read process. Recorded magnetic media is immersed in an aqueous suspension of colloidal magnetic particles under a controlled condition of concentration and exposure time. After air drying, the transitions are viewed using a Mirau interferometer to determine the height and shape of the accumulated Bitter particles. The shape and height of the accumulated particles determine the saturation current of the write head, and can be used to observe the differences between infinite and thin film pole pieces.