Mastering Security Tags: Technology and Application

There is a separate large-scale industry that specializes solely in retail security offering multiple ways (security tags, surveillance cameras, etc.) to protect inventory from theft and preserve profit for businesses. ADT, Eagle Security, Exacq, and Plugout can be found among the top players in the industry in 2017.

According to the study conducted by the National Retail Federation (2017), retail shrinkage or theft costs the U.S. economy almost USD 49 billion in 2016, and these costs are certainly increasing.

Shoplifting accounts for over 36 percent of retail theft, the study says. These figures speak for themselves. It is the biggest cause of retail shrinkage in the U.S. 

The retail security industry proves its significance and importance.

Businesses are presented with so many options to secure inventory and prevent shoplifting such as:

But security tags are probably the most popular choice among many retailers. (Needless to say, without a detection system all tags would be useless.) 

Let us look through types of security tags, technology behind, application in various industries, and the future in order to better understand as to why security tags are so desirable. 

A great variety of different types of security tags

The following definition gives a general overview of the fundamental concept of security tags:

EAS (Electronic Article Surveillance)

All types of security tags can be distinguished by technology and variation. From the technological point of view, there are:

Security System is a technology-based method dedicated to prevent shoplifting. It combines three main components: electronic antenna, tag, and detacher or deactivator. Electronic tags should be attached to various merchandise, including books, and later removed or deactivated by a cashier upon a successful purchase. Otherwise, a detection system would trigger the alarm at the exit of the store.


Technology for security tags has been developed over time starting 1960’s. Since Ronald Assaf and Jack Welch first came up with a foil tag taped to a cardboard which made an alarm carried out through special electronic boxes in 1964. Their invention was build based on microwave technology (UHF, which reads Ultra High Frequency). 

In this system, a detector has two transmission antennas, which send two high and low signals, and a high-frequency receiver. A hard plastic tag holds a diode, and antenna, that receives both high and low signals, as well as sends a high-frequency signal.

By the detector, the tag reads two frequencies, combines them (diode), and transmits a new joint high-frequency signal. The detector then checks if the signal has the right high frequency, and triggers the alarm.

Ronald Assaf founded Sensormatic Electronics Corporation, which developed a microwave-based EAS security system at the time. It is the oldest technology for retail security tagging, however, IHF has practically been withdrawn from use.

Radio Frequency (RF)

In the year 1966 Arthur Minasy designed a security tag and detection system based on radio frequency technology. It is also the year surveillance tags were widely marketed to retailers.

The detection system comprises two pedestals that form the gate. One is a transmitter which sends out the signal, and another one is a receiver. Security tags, in this case, are actually flat labels which have an integrated electronic circuit including a capacitor and inductor. When the label receives the signal from the transmitter detector, it activates the capacitor and inductor. They bounce the energy back and forth at a specific frequency.

The label then sends a new signal to the receiver detector, which also obtains the signal from the transmitter detector, and compares two signals. Having a certain difference between the two signals, the alarm goes off. Radiofrequency based tags are deactivated by a very strong radiofrequency pulse that destroys the electronic circuit.

There are two types of detection systems in RF technology. Swept RF has a separate transmitter and receiver, whereas Pulse RF combines the transmitter and receiver into one pedestal. It gives a choice of a greater variety of retail store layouts.

Arthur Minasy is the founder of Knogo Corporation, which was the second-largest EAS security system manufacturer for many years. Nowadays, RF technology is one of the most popular security tagging methods due to tag variation, relative cheapness, remote deactivation capability, and time efficiency.


Electro-Magnetic (EM)

In the 1970’s the industry developed electromagnetic EAS security systems due to a need for even smaller labels. The technology was adopted by many European supermarkets.

In electromagnetic security systems, two pedestals generate a low-frequency electromagnetic field between them. This field constantly changes strength and polarity back and forth from positive to negative. Labels have an embedded wire which switches a magnetic state in exposure to the changing electromagnetic field at the gate.

When the wire switch from positive to negative, it sends a signal to a receiver in the detector. Electromagnetic labels can easily be deactivated by the magnet, and reactivated by demagnetization.

Today electromagnetic security systems are no longer used in many retail industry sectors. Given reactivation capacity, however, the technology seems to be perfect for rental items. Thus, EM EAS is widely used in libraries all around the world.


Acousto-Magnetic (AM)

In the 1980’s acause magnetic technology was developed to overcome limitations of Swept RF. Alongside the development of the EAS security system, people have come up with ways to trick retail security systems.

Shoplifters have made use of the foil-lined bags that could shield tagged items from detectors in stores. Even though additional metal detection systems could sense metal surfaces, and tackle the foil-lined bags, retailers had to look for better ways to prevent ever-evolving shoplifting. Thus, acouso magnetic technology operating with low-frequency radio waves that are not blocked by metal foil wrappings has been introduced.

These are similar to magnetic tags in that they are made of two strips:

  • A strip of magnetostrictive, ferromagnetic amorphous metal
  • A strip of a magnetically semi-hard metallic strip, which is used as a biasing magnet (to increase signal strength) and to allow deactivation.

These strips are not bound together but free to oscillate mechanically. An acousto-magnetic sends out a radio frequency signal in short bursts… AM system labels have a resonator and a magnetic strip. The radiofrequency burst makes the resonator vibrate, initiating a signal that is tuned to match the original signal from the transmitter.

The resonator works like a tuning fork, sending out a sustained signal and if the receiver continues to detect the proper radio frequency in between pulses, the alarm is triggered. The label can be turned off by demagnetizing it. AM uses many different technologies to achieve very wide exit detection combined with small tags and labels, consistent performance in the retail environment, greater immunity to false alarms and greater detection performance against shielding

AM uses many different technologies to achieve very wide exit detection combined with:

  • Small tags and labels,
  • Consistent performance in the retail environment,
  • Greater immunity to false alarms and greater detection performance against shielding AM is the second popular choice among retailers.

acousto magnetic


A professional blogger with a high passion for technology and security niches. Technologies are spinning our world to the future. All articles are created for an educational purpose.

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