ELECTRONIC ARTICLE SURVEILLANCE SYSTEM AND METHOD FOR DETECTING METAL

摘要

The invention relates to an electronic article surveillance system and method for detecting metal therewith. The article surveillance system for detecting, tags and metal comprises: a transmitter for emitting a first signal; a receiver placed at a distance from the transmitter for receiving the first signal and a second signal emitted by a tag; a power controller operatively connected to the transmitter for controlling the power per unit time of the first signal; a switch mechanism operatively connected to the power controller for switching between a tag detection mode, in which the first signal comprises a first power per unit time, and a metal detection mode in which the firs signal comprises a second power per unit time which differs from the first power; and a metal detector which is set to detect the presence of metal between the transmitter and receiver on the basis of first signal received by the receiver and emitted in the metal detection mode.