Remote identification system

A system for remote identification of objects, an identification marker for use in the system, a method of remote identification of objects and a device for generating a magnetic field for use with the invention. In the system for remote identification of objects each object has an identification marker (1), said marker (1) including at least one elongate soft ferromagnetic element (3), each said object being arranged to pass through an interrogation zone (12), said system comprising: means (10,11) for generating a magnetic field in said interrogation zone (12) having a magnetic field vector with a substantially constant magnitude, means (10,11) for varying the relative orientation between the magnetic field vector and said object; and means (11) for detecting a change in the magnetising direction of the elongate soft ferromagnetic elements (3). The marker (1) includes a plurality of elongate soft ferromagnetic elements (3) arranged in a spatial relationship to each other to define a code. Each of the soft ferromagnetic elements (3) may be provided with a keeper or control element which is magnetically coupled thereto. The field generating means (10,11) generates a magnetic field having a substantially constant magnitude in an interrogation zone (12). The orientation of the magnetic field vector is varied. Means (10,11) are provided for determining the magnitude of the magnetic field.