Abstract: A fluxgate including at least two ferromagnetic or ferrimagnetic, flexible cores, and at least two sets of a plurality of windings of an electrically conductive material. At least one set of windings is wound around each of the cores. The fluxgate further includes an electrically conductive, flexible shield enclosing the cores and the windings.

Abstract: A flexible fluxgate including: at least two ferromagnetic or ferrimagnetic, flexible cores; at least two sets of a plurality of windings of an electrically conductive material, at least one set of windings being wound around each of the cores; and an electrically conductive, flexible shield enclosing the cores and the windings. The fluxgate may have a considerable length, e.g. several hundreds of metres, and can be arranged in an open loop. The fluxgate may be used in an access control system. Various fluxgate magnetometers are disclosed as well.