Abstract: A monitoring system for use in combination with, in particular a ferromagnetic, detection system of the kind that generates a warning signal to indicate a detection event when the detection system detects movement of a door protecting an entrance to a protected area. The monitoring system may include a processor configured to present information to a user to alert the user when the warning signal indicates a detection event; and a user interface configured to accept a user input in response to the presentation of the detection event that generates a user generated signal indicative of whether the detection event was the result of an unintentional action or an intentional action. The processor may be configured to automatically store data relating to the detection event in a memory unit when the user generated signals indicates that the detection event was the result of an unintentional action.

Abstract: A low magnetic signature motor system (1) comprises a plurality of electric motors (2), a first shield (9) and a second shield (13). The electric motors are arranged with their associated magnetic moments (6, 7) forming a closed loop such that their net external magnetic field (5) is minimized The first shield comprises a material with a high electrical conductivity and substantially surrounds the electric motors such that the a.c. component of the magnetic field is reduced; and the second shield comprises a material with a high magnetic permeability and substantially surrounds the first shield such that the d.c. magnetic field is reduced.