The most effective tool for supermarkets to deal with thieves is an anti-theft alarm system, which is a widely used EAS (Electronic Commodity Surveillance) system. Although the EAS system may be replaced. But it is still very popular. The EAS system is a technology used to identify goods that pass through the supermarket. If the system finds a product that was carried without authorization, it will issue an alarm. In today's supermarkets, there are usually the following three EAS systems.
The radio frequency EAS system is the most widely used EAS system in the United States today, and its labels and signs have become smaller and smaller. The principle of the RF EAS system is very simple. A trademark is usually a small circuit or antenna that can be used arbitrarily. It is glued to the product and is responsible for receiving the special frequency sent by the transmitting antenna (usually on the side of the door). A nearby receiving antenna (the other side of the door) receives the tag's response. The receiver processes the tag's response and will trigger an alarm.
The most basic point of implementing radio frequency is that there is a spiral aluminum wire and paper stuck on the label. At the end of the antenna is a small diode or resistor that enables the tag to emit a radio signal in response to the radio signal it receives. To remove the tag, a strong RF pulse (much stronger than the one emitted on the door) burned the diode or the resistor in the system. The burnt tag will not emit a signal when passing through the door, so the door will not sound an alarm.
Electromagnetic EAS systems are more common in Europe and are often used in retail chain stores, supermarkets, and libraries. In this technique, a sticky, metal-containing magnetic strip is stuck to the back of the product. This magnetic stripe will not be removed at the cash register, just use a special high magnetic field scanner to disable it. The advantage of the magnetic stripe of the electromagnetic EAS system is its low cost. It is the ideal choice for libraries, where books will be lent out for a period of time before being returned.