Views:1 Author:Site Editor Publish Time: 2018-08-07 Origin:Site
The basic principle of EAS electronic anti-theft system and the eight major performance indicators
EAS (ElectronicArticleSurveillance), also known as electronic commodity theft prevention system, is one of the commodity security measures widely used in the large retail industry. EAS was published in the United States in the middle of the 1960s, and the following is a detailed introduction to the "basic principles of EAS electronic anti-theft system and the eight performance indicators". EAS (Electronic Article Surveillance), also known as electronic commodity theft theft (theft) system, is one of the commodity security measures widely used in the large retail industry at present. EAS was introduced in the United States in the middle of the 1960s. It was originally used in the clothing industry. Now it has expanded more than 80 countries and regions all over the world. The application fields are also extended to department stores, supermarkets, books and other industries, especially in large supermarkets (warehouses). The EAS system consists of three parts: Sensor, Deactivator and Electronic Label and Tag.
The electronic label can be divided into soft label and hard label. The cost of the soft label is low, and it is directly attached to the "hard" goods. The soft label can not be used repeatedly. The hard label is higher than the soft label, but it can be reused. Hard labels must be equipped with special nail remover, which is mainly used for soft and penetrable articles. Decoders are mostly non-contact devices, with a certain decoding height. When the cashier checks in or bags, electronic tags can be decoded without touching the demagnetization area. There is also a device that combines the decoder and the laser bar code scanner to achieve a one-time completion of the commodity collection and decoding, which is convenient for the cashier's work.
This method must be matched with the laser bar code supplier to eliminate the mutual interference between the two and improve the decoding sensitivity. When the undecoded goods are taken away from the market, the alarm will be triggered when the detector (mostly the door) is passed, which reminds the cashier, the customer and the store security personnel to deal with them in a timely manner. As far as signal carrier for EAS system is concerned, there are six or seven systems with different principles.
Because the characteristics of the detection signal carrier are different, the performance of various principles in the system is also very different. Up to now, the six EAS systems that have emerged are electromagnetic wave system, microwave system, radio / radio frequency system, frequency division system, self alarm intelligent system and acoustic and magnetic system. Electromagnetic wave, microwave, radio / radio frequency system came out earlier, but their performance was not improved greatly due to the limitation of its principle. For example, the microwave system, in spite of the wide protection of the outlet, can be installed easily and flexibly (such as hidden under the carpet or on the ceiling), but is vulnerable to the shortage of liquid, such as the human body, which has gradually withdrawn from the EAS market. The frequency division system has only a hard label, which is mainly used for the protection of clothing and clothing and can not be used in supermarkets.
The self alarm intelligent system is mainly used for valuables such as high-grade fashion, leather, fur coat and so on. The sound magnetic system is a major breakthrough in the electronic theft proof technology, which has improved the EAS misinformation. It has been introduced since 1989. It has become a favorite electronic security system for many retailers around the world. The performance evaluation index of the EAS system has the system detection rate, the system misreport, the ability to resist the environment interference, the degree of shielding of the metal, the protection width, the kind of protection commodity, the performance / size of the anti-theft label, the degaussing equipment and so on.
(1) Detection rate: Detection rate refers to the number of alarms when a unit number of valid labels pass through different locations in different directions in the detection area. Because of the directionality of the labels in some systems, the concept of detection rate should be based on the average detection rate in all directions. For the three most commonly used principles in the market, the detection rate of acoustic and magnetic systems is the highest, generally more than 95%; the detection rate of radio / radio frequency system is between 60-80%, and the detection rate of electromagnetic wave is generally between 50-70%. The system with low detection rate is more likely to be missing when the goods are taken out, so the detection rate is one of the main performance indicators to evaluate the anti-theft system.
(2) system misreporting: system misreporting refers to the alarm of the trigger system. If the alarm is triggered by unlabeled items, it will bring difficulties to the judgement of the staff, and even cause conflicts between customers and shopping malls. Because of the limitation of the principle, the common EAS systems can not completely eliminate the misinformation, but there are differences in performance. The key to the selection of the system is to see the false alarm rate.
(3) when the equipment is disturbed (mainly the interference of the power and surrounding noise), the system will send an alarm signal when no one passes through or without any triggering of the alarm. This phenomenon is called false report or self resonance. Because the radio / radio frequency system is easily disturbed by the environment, it often appears self - resonance, so some systems install infrared devices, which is equivalent to an electric switch. Only when the personnel pass through the system and block the infrared, the system starts to work and the system is in standby state when no person passes through. This solves the problem of self doubt when no one passes by, but it still can not solve the problem of being self satisfied when someone is passing through. Electromagnetic wave system is also vulnerable to environmental interference, especially the interference of magnetic medium and power supply, which affects the performance of the system. As the sound magnetic system uses the unique resonance far away, and with the intelligent technology, the system is controlled by the microcomputer and the software is driven by the software. The system can automatically detect the ambient noise, so it can adapt well to the environment and have better ability to resist the environmental interference.
(4) the degree of metal shielding in the market, the supermarket in many commodities with metal items, such as metal tin foil packaging of food, cigarettes, cosmetics, drugs, as well as their own metal products, such as batteries, CD/VCD disk, hair products, hardware tools and so on; in addition to shopping malls, shopping cart, shopping Basket and so on. The effect of metal containing articles on the EAS system is mainly the shielding effect of the induction label, so that the detection device of the system can not detect the effective label or the detection sensitivity is greatly reduced, which causes the system to not send the alarm. The most severely affected by metal shielding is the radio/RF system, which may be one of the main limitations of radio/RF performance in practical use. Electromagnetic wave system will also be affected by metal objects, when large metals enter the detection area of the electromagnetic wave system, the system will appear "stop" phenomenon. When the metal shopping cart and shopping basket are out of date, the goods inside, even if they have effective labels, will not produce the alarm because of the shielding. In addition to the pure iron products, such as iron pot, the sound and magnetic system will be affected, other metal items / foil paper, metal shopping cart / shopping basket and other common goods can work normally.
(5) The protection width of the guard-against-theft system should be taken into account in order to prevent the width between the supports from passing through the firewood and affecting the customers'entry and exit. Besides, the shopping malls all want to make the entrance more spacious.
(6) protection of goods, goods in supermarkets.In general, it can be divided into two categories. One kind is "soft" goods, such as clothing, shoes and hats, knitwear, such as the general use of hard label protection, can be used repeatedly; the other kind is "hard" goods, such as cosmetics, food, shampoo, and so on, the use of soft label protection, degaussing in the cashier, generally used in one time. For hard labels, all kinds of anti-theft systems have similar protection types. But for soft labels, the influence of metal objects varies greatly.
(7) the anti-theft label of anti-theft label is an important part of the whole electronic security system. The performance of the anti-theft label affects the performance of the whole system. Some labels are easily affected by moisture and moisture; some can not be bent; some labels can be easily concealed in the packing box of the goods; some cover the useful descriptions on the goods and so on.
(8) the reliability and ease of operation of degaussing equipment are also important factors for selecting anti-theft system. At present, the more advanced demagnetization equipment is non-contact. It produces a certain height of demagnetization area. When the effective label passes through the demagnetization of the label instantaneously, it does not need to contact the demagnetizing device, which facilitates the cashier's operation and quickens the speed of the silver collecting. EAS system is often used in conjunction with other anti-theft systems, the common closed-circuit television monitoring system (CCTV) and cash register monitoring system (POS / EM). The cash register surveillance system is designed for the cashier to touch a large amount of cash every day and is prone to theft desire. It uses the technology of stacking the operation interface of the cash register and the CCTV monitor screen to ensure that the manager of the shopping mall knows the actual situation of the cash register. The future development of EAS is mainly focused on two aspects: one is the Source Tagging, and the other is the Smart ID. Due to its technical maturity and price factors, Smart ID will not be directly used by users directly. The source tagging plan is actually an inevitable result for businesses to reduce costs, improve management and increase efficiency. The most troublesome problem of using EAS system is to attach electronic labels to various commodities, which increases the difficulty of management. The best solution to this problem is also the ultimate solution to the transfer of labelled work to the producers of the goods and to put the burglar tags into goods or packages during the production of the goods. Source tags are actually the result of cooperation between manufacturers, manufacturers, and manufacturers of anti-theft systems. The source label makes the open sale goods increase, bring more convenience to the customers, and the placement of the label is also more concealed, reduces the possibility of being destroyed, and improves the efficiency of burglar theft.