An improved cylindrical magnetometer sensor

An improved cylindrical flux-gate magnetometer sensor element has been constructed by electrodepositing permalloy films on solid copper rod substrates with the magnetic easy-axis in the axial direction. The cylindrical films were fabricated by a three-bath electrodeposition process which resulted in a film composition of 81% Ni and 19% Fe adjusted to zero magneto-striction. The optimum ambient field during deposition was determined to be 17.5 Oe in the axial direction. Hysteresis in the resulting Longitudinal Magnetization Characteristic was minimized by tapering the edges of the films.