`Gradiometer´ head pulse shapes

Simple analysis of the isolated voltage pulse response expected for normal ring heads, single-pole heads, naked and shielded single-element magnetoresistive heads, and naked and shielded two-element differentially sensed gradiometer heads for the cases of longitudinal (x) and perpendicular (y) magnetization transitions are given. These analyses, which hold only to the first-order for small signals, yield simple results which can be written in closed form. The results appear to match the published experimental data on many of these types of heads considerably better than do the results of much more elaborate numerical studies of these problems. It is noted that a normal inductive ring head functions as a gradiometer since it actually measures the first differential of a scalar, the head flux. The two recently introduced magnetoresistive gradiometer heads discussed here have presumably been so named because they, too, measure the difference between the fluxes flowing in the magnetoresistive elements