"EAS Showdown: AM 58 KHz vs. RF 8.2 MHz - Choosing the Right Retail Security

Comparison on Technology -  AM 58 KHz (Acousto Magnetic) or RF Radio Frequency) 8.2 MHz

Since EAS first rolled out in the 1960s, Electronic Article Surveillance has become one of the most effective and popular methods of securing valuable retail merchandise against theft.

Its usage is so widespread, that it is estimated almost three quarters, 73%, of retailers harness its power.

Meanwhile, the past 40 years have seen major developments and improvements in both its detection capability and visual appeal, with a range of tags and pedestals available to suit any environment.

If you are a retailer looking to employ the loss prevention strategy that is EAS, here’s what you need to know…

The lowdown on EAS

Electronic Article Surveillance works on the premise that merchandise is fitted with an electronic tag or label that communicates with an instore antenna, usually positioned near the entry/exit to a store.

When that tag comes into range of the antenna, an alarm sounds, alerting store management that an item is illegally leaving the store.

When items are sold legitimately, the cashier either deactivates a label or physically removes the tag, meaning no alarm will sound when an item has been correctly deactivated or untagged.

Some frequency facts

There are two commonly used types of EAS – radio frequency (RF) and acousto magnetic (AM), and the difference between them is the frequency at which they operate. This frequency is measured in hertz (this will be seen as KHz)

Acousto Magnetic systems operate at 58 KHz, which means a signal is sent out in pulses or bursts between 50 and 90 times a second while Radio Frequency or RF operates at 8.2 MHz

Each type of EAS has benefits, making some systems more suited to specific retailers than others.

So, let us look into the pros and cons of each.

Radio Frequency (RF) technology – swept or pulsed

RF electronic article surveillance comprises hard tags or soft labels that communicate with one or more antenna. These antennas can be positioned in pedestals in the shop doorway or even under the floor.

The tags/labels have miniscule circuits that resonate between 7.4 to 8.8 MHz, with the most popular frequency being 8.2 MHz.

RF antenna

RF antenna can operate in several ways based on whether they use swept or pulsed technology.

Using Swept RF Technology, one pedestal acts as a transmitter, sending out a signal. If an intact tag or label comes into the pedestal vicinity, it will resonate and this is detected by the second pedestal acting as a receiver. An alarm will then sound.

In the case of pulsed RF Technology, a single pedestal antenna both sends and receives the signal, sounding an alarm when a tag is detected within range.

If you are looking to protect a wide doorway, multiple swept or pulsed pedestals can be used, depending on the width of the doorway being guarded.

RF tags and labels

Tags and labels range from an array of small ultra-thin adhesive labels through to a variety of hard tags, and are suitable for a numerous application, including clothing, food and pharmaceutical products.

Historically RF has been considered more affordable to install and is often most popular with retailers who use adhesive security labels over security hard tags. 

RF tag and label deactivation

Labels are deactivated by using a Label Deactivator to overload the integrated capacitor and effectively break the label’s circuit, while hard tags are removed at the point of sale normally by a powerful magnetic security tag detacher.

Why retailers select it

RF is often favoured due to the flat footprint of its paper labels that make it suitable for high volumes of packaged products, and for the easy integration of Deactivation into Point of Sale Scanners.

Probably due to its perceived lower price, RF remains the most widely adopted EAS technology worldwide.

Although RF EAS is not to be confused with RFID (Radio Frequency Identification), some RF antennas can easily be upgraded to RFID where RF and RFID technology work side by side in the same antenna.

RF limitations

RF does have some limitations. The technology has traditionally been more sensitive to electrical interference caused by other local electronic fixtures that often do not affect alternative EAS technologies.

Although in the real world it is not a problem, RF Security Labels cannot be reactivated once the circuit is broken.

Detection systems are generally limited to doorway pedestals, although recently some RF floor-based systems have become popular.

Who uses RF EAS

Radio Frequency EAS is perfectly suited to retailers with a high volume of packaged products due to the convenience of adhesive, flat tags.

That makes RF the system of choice for supermarkets, discount stores, chemists and video stores.

That said, the ability to upgrade some RF EAS systems to RFID means its usage has recently grown in apparel stores.

RF benefits at a glance

• Affordability: Price can range from very low cost for more basic RF systems to high cost for advanced RF systems.
• Available as flat paper labels
• Wide range of label shapes, sizes and presentation
• Labels can be printed on
• Potential for upgrade path to RFID with some RF antenna systems
• Easy high-speed security label deactivation including possible integration with POS scanners
• Available from many manufacturers

RF disadvantages

• Labels cannot be reused once the circuit is broken
• Limited range of detection systems traditionally limited to pedestals
• More susceptible to electronic and metallic interference

Acousto Magnetic (AM)

Acousto Magnetic EAS sees a transmitter send out a signal in bursts which energize tags within the pedestal zone. When the pulse ends, the tag responds.

Between bursts, the tag’s signal is detected by a receiver. Therefore, if an active tag passes between the pedestals, an alarm will sound.

AM Antenna

One of the major drawcards of Acousto Magnetic technology is that it offers an extended detection range to RF and is normally less susceptible to external electronic interference.

For retailers this provides greater flexibility for installation of the antennas, which can be pedestal-based, concealed within door frames or housed under the floor at the entry of the store.

Meanwhile, AM adhesive security labels can often work on or near metals where other technologies fail.

AM tags and labels

AM hard tags are available in a range of sizes, and can be reused.

Although smaller than RF labels, AM labels are not paper thin and instead have a raised profile. Labels can potentially be deactivated and reactivated, although this is not common practice. They are activated when magnetized and deactivated when demagnetized.

AM tag and label deactivation

AM tags and labels are activated and deactivated using purpose-built magnets that match the strength of the tags.

AM Limitations

AM was traditionally more expensive to install than RF, however due to increased competition, system costs have come down in recent years.

The raised profile of AM labels has also been seen as a drawback for retailers like grocery stores who sell small, high-turnover goods.

Who uses AM?

AM is more often seen in small to large clothing apparel outlets, large department stores, DIY shops, electronic shops, and pharmaceutical retailers where products have metallic components in their packaging.

AM benefits at a glance

• Larger detection area so antenna can be positioned further apart
• Less susceptible to electronic interference
• Systems can be concealed in door structures or under flooring
• Security labels can be reused and reactivated
• Accurate detection of tags and labels

AM disadvantages

• Often the cost is higher than RF
• Labels can’t be bent around merchandise and can’t be easily printed on
• Antennas are not easily upgradable to RFID

The bottom line

EAS is a highly effective way of protecting merchandise against theft. The key to selecting the right system for your retail outlet involves considering the type of items sold, their value, the physical layout of the entryway and further considerations such as any future upgrade to RFID.