Measured fields and performance of recording heads

A method is presented for obtaining the longitudinal magnetic field produced by recording heads. The method entails the use of a microloop to directly measure the perpendicular field Hy across the gap region of the head and the calculation of the longitudinal field Hx using a transform of Hy(x). This method has been applied to the study of narrow-track, thin-film heads. The ability to predict the shape of the readback waveform from a measurement of the head field is demonstrated.