As one of the technologies of the EAS system, the acoustic and magnetic anti-theft system has a working principle similar to that of EAS. The working principle of EAS: a detector is installed at the exit of the supermarket or at the cashier channel. The detector includes a transmitter and a receiver. When the transmitter sends out a signal at a specific frequency, the receiver receives the signal and generates a monitoring area. . When the EAS tag that has not been processed by the cashier passes through the detection area, it will cause interference. When the receiver detects this interference, it will trigger an audio alarm.
There are two mainstream technologies used in EAS in the market: one is radio frequency technology, and the other is acoustomagnetic technology. Acousto-magnetic technology: The transmitter emits an acousto-magnetic (about 58kHz) pulse signal to activate the tags in the monitoring area. At the end of the pulse, the tag responds by emitting a single acousto-magnetic signal like a tuning fork. When the transmitter is turned off between pulses, the tag signal is detected by the receiver. The receiver checks the detected signal to make sure it is on the correct frequency, synchronized in time with the transmitter, has the proper signal level and has the correct repetition rate. If all of these criteria are met, an alert is issued.
The acousto-magnetic anti-theft system has low false alarm rate, good anti-interference performance, can be degaussed repeatedly, and can work normally even next to the POS cash register. This is also the reason why it is favored by more and more customers in the market.