EAS (Electronic Article Surveillance), also known as electronic commodity theft prevention system, is one of the widely used commodity security measures in the large retail industry. EAS was introduced in the United States in the mid-1960 s, originally used in the clothing industry, has expanded more than 80 countries and regions around the world, and applications to department stores, supermarkets, book industries, especially in large supermarkets (warehousing) applications. EAS system consists of three parts: Sensor, Deactivator, Electronic Label and Tag. Electronic labels are divided into soft and hard labels, soft labels have low cost, directly attached to more “hard” goods, soft labels can not be reused; hard labels have higher one-time cost, but can be reused. Hard labels must be equipped with special nail traps for soft, penetrating items. Decoders are mostly contactless devices with a certain decoding height. When the cashier registers or bagged, the electronic label can be decoded without contact with the demagnetization area. There are also equipment that synthesize the decoder and the laser barcode scanner together to complete the goods collection and decoding one-time to facilitate the work of the cashier. This way must cooperate with the laser barcode supplier to eliminate the mutual interference between the two and improve the decoding sensitivity. Undecoded goods are taken away from the mall, and the alarm after the detector device (mostly door) will trigger the alarm, so as to remind the cashier, customers and mall security personnel to deal with them in time.
In terms that the EAS system detects the signal carrier, there are six or seven different systems with different principles. Due to the different characteristics of the detection signal carrier, the performance of the system is also very different. So far, the six EAS systems that have emerged are electromagnetic wave systems, microwave system, radio / radio frequency system, frequency division system, self-alarm intelligent system, and acoustic magnetic systems. Electromagnetic wave, microwave, radio / RF systems appeared earlier, but limited by their principle, there is no major improvement in performance. For example, the microwave system although wide protection exit, convenient and flexible installation (e. g. hidden under the carpet or hanging on the ceiling), but vulnerable to liquid such as human shielding, has gradually withdrawn from the EAS market. The frequency sharing system is only hard label, mainly used for the protection of clothing, can not use for the supermarket; since the alarm intelligent system is mainly used for valuables such as premium fashion, leather, fur coat, etc.; acoustic magnetic system is a major breakthrough in electronic anti-theft technology, has improved the electronic theft system for many retailers since its launch in 1989.
The performance evaluation indicators of EAS system include system detection rate, system false report, anti-environmental interference ability, degree of metal shielding, protection width, type of protection goods, performance / size of anti-theft labels, demagnetization equipment, etc.

(1) Test rate:
Detection rate refers to the number of alarms when a unit number of valid labels pass through different locations in the detection area in different directions.
Due to the orientation of some systems, the concept of detection rate should be based on the average detection rate in all directions. In terms of the three most commonly used principles in the market, the detection rate of acoustic magnetic systems is the highest, generally exceeding 95%; radio / RF systems is between 60-80%, and electromagnetic waves are generally between 50 and 70%. The system with low detection rate is likely to have the leakage rate when the commodity is brought out, so the detection rate is one of the main performance indicators to evaluate the quality of the anti-theft system.

(2) System Misstatement:
System false alarm refers to an alarm that the non-theft label triggers the system. If a non-labeled item triggers the alarm, it will bring difficulties to the staff to judge and handle it, and even cause conflicts between customers and the mall. Due to the principle limitation, the current common EAS systems cannot completely exclude the false alarm, but there will be differences in performance, the key to choosing the system is to see the false alarm rate.

(3) Ability to resist environmental interference
When the equipment is disturbed (primarily by the power supply and the surrounding noise), the system sends an alarm signal when no one passes or no triggered alarm item passes, a phenomenon called false report or self-alarm.
Radio / RF system is prone to environment interference, often self-singing, so some systems installed infrared devices, equivalent to adding an electric switch, only when the personnel through the system, block the infrared, the system began to work, no one passes, the system is in the standby state. Although this solves the confession when no one passes, but still can not solve the confession situation when someone passes.
Electromagnetic wave system is also vulnerable to environmental interference, especially the magnetic media and power supply interference, affecting the performance of the system.
The acoustic magnetic system adopts a unique resonance distance away and cooperate with intelligent technology, the system is controlled by microcomputer and software to automatically detect the ambient noise, so it can well adapt to the environment and have good anti-environmental interference ability.

(4) The degree of metal shielding
Many goods in shopping malls and supermarkets carry metal items, such as food, cigarettes, cosmetics, drugs, etc., and their own metal products, such as batteries, CD/VCD plates, hairdressing supplies, hardware tools, etc.; and shopping carts and shopping baskets provided by shopping malls. The impact of metal-containing items on the EAS system mainly is the shielding effect of the induction label, so that the detection device of the system cannot detect the effective label existence or that the detection sensitivity is greatly reduced, leading to the system does not issue an alarm.
The most heavily affected by metal shielding is the radio / RF RF system, which may be one of the main limitations of radio / RF performance in actual use. The Electromagnetic wave system will also be affected by the metal items. When the large metal enters the detection area of the electromagnetic wave system, the system will appear “stop” phenomenon. When the metal shopping cart and shopping basket pass by, even if the goods in it will have valid labels, they will not produce an alarm because of the shielding. In addition to pure iron products such as iron pot, the acoustic magnetic system will be affected, and other metal items / metal foil, metal shopping cart / shopping basket and other common supermarket items can work normally.

(5) Protection width
Shopping malls need to consider the protection width of the anti-theft system, so as not to avoid the width between the supports over firewood, affecting customers in and out. Besides, shopping malls all want to have more spacious entrances and exits.

(6) Protection of the types of commodities
Goods in the supermarket can generally be divided into two categories. One kind is “soft” goods, such as clothing, shoes and hats, knitting goods, this kind of generally using hard label protection, can be reused; the other kind is “hard” goods, such as cosmetics, food, shampoo, etc., using soft label protection, antimagnetization in the cashier, generally disposable use.
For hard labels, the various principles of anti-theft systems protect the same types of goods. But for soft labels, they vary widely due to different influences from metals.

(7) Performance of the anti-theft labels
Anti-theft label is an important part of the whole electronic anti-theft system. The performance of the anti-theft label affects the performance of the whole anti-theft system. Some labels are susceptible to moisture; some do not bend; some can easily hide in the boxes of the commodity; some will cover useful instructions on the item, etc.

(8) Demagnetic equipment
The reliability and ease of demagtization equipment are also important factors in the selection of anti-theft system. At present, more advanced demagnetization devices are contactless, which produces a certain degree of demagmagnetization area. When the effective label passes through, the label demagnetization is instantly completed without contact with the demagmagnetization, which facilitates the convenience of the cashier’s operation and accelerates the cashier speed.
EAS systems are often used in conjunction with other anti-theft systems, common with CCTV monitoring (CCTV) and cashier monitoring (POS/EM). The cashier monitoring system is designed for cash collectors to contact large amounts of cash every day and is prone to theft. It uses the technology of overlapping the cashier operation interface and the CCTV monitoring screen to ensure that the mall management knows the actual situation of the cashier.
The future EAS will mainly focus on two aspects: the burglar Source Label Program (Source Tagging) and the other is the Wireless Recognition Technology (Smart ID). Because Smart ID is influenced by its technology maturity and price factors, it will not be used directly by users very quickly.
The source label plan is actually an inevitable result of the business in order to reduce costs, improve management and increase benefits. The most troublesome use of EAS system is the electronic labeling on various kinds of items, increasing the difficulty of management. The best solution to this problem is also the final solution is to transfer the labeling work to the manufacturer of the product, and put the anti-theft label in the product or packaging in the production process of the product. The source label is actually the result of a collaboration between the sellers, the manufacturers, and the manufacturers of the anti-theft systems. The source label makes the increase of marketable goods, bringing more convenience to customers. In addition, the placement of the label is also more hidden, reduce the possibility of damage, and improve the anti-theft efficiency.