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14 January 2023

With thousands of RFID tag configurations to choose from, and new ones introduced almost daily, how do you sort through the sea of passive transponders to find cost effective tags that will deliver optimal performance for your application? Here are 7 items to consider when choosing the right RFID tag for any task.

 

1. Operating frequency: LH, HF or UHF

The “RF” in RFID stands for “radio frequency.” Each RFID system operates within one of three bands on the electromagnetic spectrum: low frequency (LF), high frequency (HF), or ultrahigh frequency (UHF). In general, as operating frequency increases, data processing speed increases, as does read range – or the distance between the powered reader and the passive tag it reads. However, increasing frequency tends to decrease a radio wavelength’s ability to penetrate some materials. In general:

! LF is a cost effective option for applications allowing consistent physical placement of tags on items, enabling readers to identify individual tags one at a time at close range. LF is the is almost not affected by the environment e.g. water or metal.

! HF tags can be read from distances of a few to several inches, allowing greater flexibility for tag and reader placement, and enabling higher processing speed and accuracy. In addition, HF processing enables larger memory capacity on each tag. (See more on memory capacity below.)

! UHF technology is rapidly expanding the boundaries of data collection speed and accuracy. Some UHF tags can be scanned from up to 25 feet (8 meters) or more, with readers identifying multiple tags simultaneously. Using UHF, an entire truckload of hundreds of individually tagged containers can be accounted for in the few seconds it takes for a truck to roll into or out of a distribution point. On the other side, UHF is sensitive to the environment for issues like reflection, dampening, detuning based on the surrounding materials.

If tags are to be used with an existing reader network, then select a tag whose operating frequency is compatible with your legacy system.

 

2. . Environmental conditions

While integrated chips are relatively delicate, they can be housed in materials to protect them under even the harshest conditions.

In a stable environment, such as tagging books in a library, a relatively modest housing will provide adequate protection for each tag’s electronic components.

At the other end of the spectrum, tags used in many industrial applications must perform despite repeated exposure to extreme heat or cold, physical impact, vibration, moisture and chemical agents.

Consider the conditions tags will be exposed to when deployed in your application.

During a 20-to-40-year keg life, this tag will withstand numerous high-pressure washes with high-heat sterilization; plus repeated exposure to, liquids, harsh chemicals, the rigors of distribution and collection, and sub-freezing temperatures.