Electronic article surveillance is a tool for combating shoplifting, book pilferage from libraries, and property removal from office buildings. When an item is correctly bought or checked out, then the special tags attached to it will remove or deactivated by the salesperson. When a detection system detects active tags near the store’s exits, it sounds an alarm or otherwise warns the employees. EAS antenna and EAS tags or labels are the two most common types of EAS Systems.
In 1966, Arthur Minasy invented surveillance tags that could be affixed to merchandise in stores. The notion of pilferage becoming a genuine worry for merchants began in 1964 when a shopkeeper in Ohio established a requirement after experiencing pilferage in his business. Following that, an extensive study was conducted, and it has now progressed to the point that visual deterrent has progressed to the point where a merchant does not even need to build pedestals in a store.
Types of Electronic Article Surveillance (EAS) Systems
The most common types of EAS Systems are;
- Electro-Magnetic systems
- Acousto-magnetic systems(AM)
- Radio Frequency (RFID, 8.2 MHz)
- Video surveillance systems
- Concealed EAS Surveillance Systems
Among these 5 the most popular EAS systems are AM and RF systems. Let’s check these all in detail.
EM tags are popular for library security to protect books and media. The tags are made with an amorphous metal that has a low magnetic saturation value. Unlike AM and RF, EM may protect tiny or round things and products with foil wrapping or metal objects in the retail sector, such as cosmetics, infant milk cans, pharmaceuticals, DIY equipment, homeware, and so forth. Objects placed in foil bags or metal briefcases can also be detected by EM devices.
There are no visible pedestals or obstructions in the storefront with these systems. These devices are positioned underneath the floor and attached to the ceiling, and they can safeguard store products from theft. There are site circumstances and other characteristics that enable them to be implemented properly, but malls are increasingly requiring hidden systems as a mandate to improve the shopping experience.
Same as magnetic tags AM tags are made up of two strips: a magnetostrictive, ferromagnetic amorphous metal strip and a magnetically semi-hard metallic strip that serves as a biasing magnet and allows deactivation. These strips are not mechanically connected and are free to oscillate. Because of their high magnetoelastic coupling, amorphous metals are employed in such systems because they can efficiently transform magnetic energy into mechanical vibrations.
The tag is triggered when the semi-hard magnet is magnetized. Because the DC magnetic field produced by the strip offsets the magnetic anisotropy inside the amorphous metal, the magnetized strip makes the amorphous strip respond much more strongly to the detectors. The tag can also be disabled by demagnetizing the strip, which reduces the reaction to a level that is undetectable by detectors.
In RF systems sensing is achieved by sweeping around the resonant frequency and detecting the dip.
These tags are an LC tank circuit (L for inductor, C for capacitor) with a resonance peak ranging from 1.75 to 9.5 MHz 8.2 MHz is the standard frequency for retail applications. Sweeping around the resonant frequency and detecting the dip is how sensing is done.
Typically, a deactivation pad is used to deactivate 8.2 MHz label tags. Labels can be turned inactive in the absence of such a device by punching a hole in them or covering the circuit with a metallic label, known as a “detuner.” The capacitor is partially destroyed by the deactivation pad. Despite the fact that this sounds aggressive, both the procedure and the end product are imperceptible to human sight.
A non-linear element (a diode) is connected to one microwave and one electrostatic antenna in these permanent tags. One antenna emits a low-frequency (approximately 100 kHz) field, while the other emits a microwave field at the exit. The tag functions as a mixer, combining signals from both fields and re-emitting them. The alarm is triggered by this modulated signal. These tags are both permanent and pricey. They’re usually found in apparel stores and have all but disappeared from the market.
Electronic article surveillance systems, tags, and labels come in a wide range of designs. While pedestal-style EAS systems are the most prevalent, there are other ones that are buried in the floor at the store entry, put on the ceiling, or even embedded in the door frame (concealed EAS).
There are simple pin tags and lanyard tags that are used on garments, purses, and accessories, but there are also numerous specialized versions for golf clubs, liquor bottles, eyeglasses, packaged products, shoes, waterproof things, and so on.
Technology grows day by day, the features and properties of EAS systems are getting improved with technology. Nowadays EAS systems can count the store visitors count in addition to providing security. Same way tags are developed to be tamper-resistant, easier to detect, and some can be surprised by the shoplifters by spilling ink on the garments while trying to detach/remove.