Experimental study of dropout signal loss

Thin layers of magnetic medium are burnished away from a flexible disk surface to study the read signal loss as a function of decreasing medium thickness. Substantially larger signal loss is observed as compared to the case when reading over scratches of equivalent depths. The results are found to be consistent with Iwasaki and Suzuki's write field model, which shows that a significant reduction in the recorded magnetization occurs due to the presence of a demagnetizing field within the medium. In addition, the results are used to predict qualitatively the variation of the recorded magnetization with depth.