The basic principle and triggering conditions of supermarket anti-theft doors (commonly known as electronic article surveillance systems, EAS) are as follows:
Basic principle:
Electromagnetic field: The anti-theft door forms a monitoring area by transmitting and receiving electromagnetic signals. When an item passes through this area, if it carries an unremoved anti-theft tag, it will cause an alarm.
Tag type:
Magnetic tag: Using magnetic materials, when an unremoved tag enters the electromagnetic field, the system will identify and trigger an alarm.
Radio frequency tag (RF): Using radio frequency technology, the tag responds at a specific frequency and triggers an alarm.
Detection device: The anti-theft door is equipped with a transmitter and a receiver, which can monitor in real time whether the goods passing through the door carry an unremoved tag.
Triggering conditions:
Unremoved tags: When an item carrying an unremoved anti-theft tag passes through the anti-theft door, the system will detect and trigger an alarm.
Distance and position: The distance between the tag and the door is too close or too far, which may affect the detection effect. Make sure the tag is within the effective range.
Interference factors: Interference from other electromagnetic devices may cause false alarms or no alarms.
Fault status: Faults or improper maintenance of the equipment itself may also affect its normal operation.
Through the above principles and conditions, supermarket anti-theft doors can effectively prevent the theft of goods and improve safety.