| 摘要 |
<p>1. An article surveillance system and method, wherein the system comprises an alternating magnetic field generator (60, 62, 64, 20), a sensor element (30) in the form of an elongated strip of a soft magnetic material and characterized by a magnetic hysteresis curve having a different slope in one direction of magnetization than in the opposite direction of magnetization, the sensor element being attachable to articles of merchandise (14) to be protected, and a receiver (22, 66-86) responsive to magnetic waves generated by the generator (60, 62, 64, 20), the receiver including a signal processor (66-86) constructed and arranged to produce electrical signals corresponding to received magnetic waves which have been disturbed by the sensor element (30) and to produce an alarm in response thereto. <MATH></p> |
