| 摘要 |
An apparatus for securing objects located in a room, in particular a (self-service) place of sale such as a supermarket, against theft. The objects to be secured are each equipped with at least one magnetically activatable sensor metal element. A first apparatus to be arranged at each room outlet generates a magnetic field, in the area of which field, the sensor metal element generates a signal when a field strength limit value is exceeded. A second apparatus associated with the first apparatus detects the signal and conducts it to an alarm apparatus, so as to trigger an alarm. The sensor metal elements are in each case configured so that in the active state they generate, in a region of the magnetic field in which the field strength is greater than a lower limit value, an atypical signal which is not generated by other metallic objects under magnetic excitation, but rather is only generated by a magnetizable object which has been purposefully subjected to a special treatment. The first apparatus consists of at least one field coil which surrounds the room outlet in an annular form, and whose height and breadth are so configured that a person can pass through it. The sensor metal element is preferably a Wiegand wire.
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