EM Systems

What is a electromagnetic anti-theft system?

EM system uses electromagnetic wave as detection signal, which is mainly composed of anti-theft antenna, degausser, magnetic strip and; The auxiliary is also composed of magnetic stripe detector.
Electromagnetic system uses electromagnetic wave as detection signal. It came out almost at the same time as radio system, and has a history of more than 30 years. The detection rate of electromagnetic wave system is generally about 60%. The system is prone to false alarm or non alarm due to the influence of magnetic or metal substances. The utility model has the advantages that the EM soft label is the smallest, the label price is also cheap, and can be degaussed repeatedly. It is suitable for the protection of specific products such as books. There are two types of electromagnetic wave systems: vertical and channel, and the outlet width is generally 0.8m. The application environment is mostly in libraries, bookstores, audio-visual stores, etc.
There are two types of electromagnetic wave anti-theft systems, vertical and channel, which are mostly used in bookstores, cosmetics stores, libraries and pharmacies. The channel electromagnetic wave system is an electronic anti-theft system controlled by software. It uses digital processing technology to integrate with degaussing system, cashier monitoring and closed-circuit television monitoring system. Actility’s electromagnetic wave anti-theft system is fashionable and high-end, It is very popular with consumers. Its electromagnetic wave anti-theft system adopts high-quality materials, and the whole shape is also very pleasing.
Compared with RFID anti-theft system and acoustic magnetic anti-theft system, it is the most cost-effective to buy EM system. The label of electromagnetic anti-theft system is the smallest, and the label price is also very cheap. It can be degaussed repeatedly. The anti-theft performance of RFID anti-theft system is not as good as that of electromagnetic anti-theft system, and the cost of acoustic magnetic anti-theft system is very high, The anti-theft performance is similar to that of the EM system.
When you buy the electromagnetic wave anti-theft system, you must make a good comparison and choose the one you are satisfied with.

Technical principle of electromagnetic wave anti-theft system

Its basic principle is to detect the magnetic change of the magnetic strip through the alternating magnetic field to distinguish whether the protected object has a magnetic strip, so as to achieve the purpose of anti-theft. The principle technology is electromagnetic identification technology.
The electromagnetic method uses the detection antenna (transmitting antenna and receiving antenna) to detect the alternating magnetic field generated at a low frequency of 10Hz to 20kHz. The detection object is a magnetic stripe attached to the protected object. Magnetic stripe is a permalloy soft magnetic stripe with steep hysteresis loop. When the magnetic stripe is located in the alternating magnetic field generated by the transmitting antenna, its polarity is periodically magnetized repeatedly. The magnetic flux density in the magnetic stripe jumps near the span of the applied magnetic field strength (nonlinear characteristic), resulting in harmonics with the frequency of the fundamental frequency of the transmitting antenna. These harmonics are received and processed by the receiving antenna to generate an alarm signal.

Implementation steps of electromagnetic wave anti-theft system

1. Magnetic stripe pasting: each book is pasted with anti-theft magnetic stripe, and the composite magnetic stripe is magnetic (the size of the magnetic stripe is 12cm * 3mm), which does not affect the normal reading of the book and is very hidden.
2. Detection door installation: the detection antenna is installed at the exit. If the thief takes the book out, he will pass through the detection antenna, and the detection antenna will sense the existing alarm.
3. Detection method:

• (1) After completing the formalities, the borrower will pass through the detection channel, and the librarian will pass through other channels to avoid alarm. Both “people and goods have been divided”.
• 2) After the borrower completes the formalities, the administrator demagnetizes the books with a charge desensitizer, and the borrower and the books pass through the detection channel at the same time.

4. Return of books: after the return of books, the administrator needs to check the books with the book return detector to determine the effectiveness of the magnetic stripe in the book. If the book is effectively put back to the original shelf, if it is invalid to prove that the magnetic stripe is torn off or non-magnetic, it is necessary to add a magnetic stripe or magnetize with a charge desensitizer.
5. If books are still damaged, it is recommended to install surveillance cameras in combination with the site conditions.

Characteristics of electromagnetic wave anti-theft system

The label of electromagnetic wave system is the smallest, the label price is also cheap, and it can be degaussed repeatedly, but it is easy to be affected by magnetic or metal substances. The outlet width of the protection is generally about 0.9m. The system will not affect magnetic items (such as audio tape, video tape and magnetic card). The new generation of channel electromagnetic wave system is an electronic anti-theft system controlled by software. The use of fast degaussing plate can degausse repeatedly, and the system cost is high.
The installation distance is 75-85cm, with stable performance, high alarm rate, strong metal resistance, plastic steel materials, mold manufacturing, strong technical pertinence and high cost performance. It is suitable for small and medium-sized bookstores, libraries, pharmacies, audio-visual stores, cosmetics stores, etc. Specific description:

• Channel width: single channel 85CM.
• High sensitivity: it can detect 6cm magnetic stripe at the shortest time and detect all magnetic stripes on the market with high guarantee.
• Good stability: it has the world’s most advanced DSP technology to perfectly ensure the stability and reliability of the system.
• Strong anti metal ability: the self-developed intelligent digital microcomputer control technology and three ring synchronous recursive filtering technology have unprecedentedly improved the anti metal interference ability of the system and adjusted freely against metal interference.
• Strong technical pertinence: designed for the installation requirements of small and medium-sized bookstores, libraries, pharmacies, audio-visual stores, cosmetics stores, etc.
• Meet the green environmental protection standard: the product power is less than 5 watts, with long service life, low power consumption and no radiation to human body.
• High cost performance: international quality and domestic price.

China EM system manufacturer www.tractility.com offers electromagnetic anti-theft system.