How Acousto-Magnetic Technology Works?

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Acousto-magnetic EAS systems use a transmitter to create a surveillance area where tags and labels are detected. The transmitter sends a radio frequency signal at a frequency of 58 kHz (thousands of cycles per second), but the frequency is sent in pulses. The transmit signal energizes a tag in the surveillance zone. When the transmit signal pulse ends, the tag responds, emitting a single frequency signal like a tuning fork.

The tag signal is at about the same frequency as the transmitter signal.While the transmitter is off between pulses, the tag signal is detected by a receiver. A microcomputer checks the tag signal detected by the receiver to ensure it is at the right frequency, occurs in time synchronized to the transmitter, at the proper level, and at the correct repetition rate. If the criteria is met, an alarm occurs.