Considerations When Picking UHF RFID

If you’ve attempted to implement an ultra-high frequency (UHF) RFID system into your facility, you might have run into some headaches in the process of getting things to work properly. If you are looking to implement UHF RFID, but haven’t had the chance to set things up yet, then this blog might be beneficial to keep in mind during the process.

UHF RFID and what it can do

UHF RFID is a long-range system with a focus on gaining visibility in the supply chain or manufacturing process. It can track multiple ID tags in a set area/distance (depending on the read/write head you select). The RFID field is emitted by an antenna that propagates an electromagnetic field, which will “ping and power up” a tag with data saved on it. Commonly, warehouses use it for logistics, supply chain tracking, warehouse pallet tracking, equipment tracking, or even for luggage tracking. As amazing as this technology sounds, there are environmental factors that can cause the system to not work to its full potential.

Factors affecting RFID system performance

Different materials or environments can affect the performance of your RFID system. Each tag antenna is set to a specific frequency, and some materials or environments can influence the radiation pattern. This can be something as simple as the material on which the tag is mounted to something more complex, such as how the signal is going to bounce off the walls or the ground. Below are some common issues people run into when implementing RFID.

    • Absorption: Absorption occurs when an object in the field absorbs part of the radio frequency energy emitted from the reader antenna. Cardboard, conductive liquids, and tissue (human bodies or animals) are examples of materials that can absorb some of the RF energy. One way to think of this is to imagine a sound booth in a recording studio. The booth is covered in foam to absorb sound. This is a similar philosophy for UHF RFID. You need to consider materials that absorb that energy.
    • Reflection: When there are distortions of the RF field, reflection can occur. As you may imagine, certain materials, such as metals, can cause the waves emitted from the antenna to distort or “reflect” in ways that cause performance losses. This could be metal machinery or fixings between the reader and the tags, a group of metal pipes, and mounting on metal containers. If you choose to do a deeper dive, there are other performance factors that can be impacted by the path of the signal, such as zones in which the tag can’t be reached (even if the tag is in the reader’s field), or the tag and the reader are not aligned properly.
    • Detuning: Detuning occurs when the radio frequency between the tag and reader is changed in the process. Since you pair specific readers to specific tags at a specific frequency, you don’t want your environment to cause a change in the specific frequencies. Certain materials, such as cardboard, metals, tissue, and plastics, can cause an impedance that can “un-match” your reader and tags based on the RF not matching up.

Luckily for you, many companies who specialize in RFID can help ensure you pick the right system for your application. Some will even go visit your site to evaluate the environment and materials that will be involved in the process and recommend the right readers, antennas, tags, and accessories for you.

Although not all UHF RFID applications seem complex, there are many small things that can affect the entire operation. When you are picking your system, make sure you keep in mind some of these effects, and if you are unsure, call in a professional for some assistance.

Securing Your Supply Chain and Beefing Up Traceability


Snake oil is one of the most maligned products in all of history. Synonymous with cure-alls and quackery, it is a useless rip-off, right? Well, no, it’s actually high in the Omega 3’s, EPA, and DHA.

Snake oil fell from prominence because it was all too easy for charlatans to brew up fake oil and pass it off as the genuine article, with sometimes dangerous outcomes.

Today’s customers are smarter than ever and waking up with ever-evolving knockoffs. We are more aware of fake reviews and fake products. Brands that can prove their products are genuine can command higher prices and forge long-standing customer relationships. This starts with securing your supply chain and beefing up traceability.

Securing your brand

Many roads lead to Rome and no single technology will be the one silver bullet to secure your supply chain. That said, RFID technology is likely to play an important role. RFID allows for multi-read without a line of sight, making it a great choice in both production and warehouse/logistics environments. Perhaps more importantly, RFID tags can be encrypted. This adds protection against would-be cheats. The ability to both read and write provides additional flexibility for tracking and tracing in production.

RFID is not the only traceability solution and smart companies will use a combination of technologies to secure their brands. We’ve seen holograms on baseball cards and QR codes on underwear. We’ve seen authorized retailer programs … and RFID on coffee cups and medical devices. As you think through the various options, it’s worth keeping in mind the following 4 questions:

      1. Is the technology secure? Does it support modern cryptographic methods?
      2. Does the solution add value – i.e. improve current processes?
      3. Is the technology future-proof?
      4. Is the technology robust?

Any technology that answers yes to these questions will be well-suited to meet this new market. Brands that stay ahead of the curve will grow and those who fall behind the curve risk ending up in the dustbin – right next to the snake oil.

Protecting photoelectric and capacitive sensors

Supply chain and labor shortages are putting extra pressure on automation solutions to keep manufacturing lines running. Even though sensors are designed to work in harsh environments, one good knock can put a sensor out of alignment or even out of condition. Keep reading for tips on ways to protect photoelectric and capacitive sensors.

Mounting solutions for photoelectric sensors

Photoelectric sensors are sensitive to environmental factors that can cloud their view, like dust, debris, and splashing liquids, or damage them with physical impact. One of the best things to do from the beginning is to protect them by mounting them in locations that keep them out of harm’s way. Adjustable mounting solutions make it easier to set up sensors a little further away from the action. Mounts that can be adjusted on three axes like ball joints or rod-and-mount combinations should lock firmly into position so that vibration or weight will not cause sensors to move out of alignment. And mounting materials like stainless steel or plastic can be chosen to meet factors like temperature, accessibility, susceptibility to impact, and contact with other materials.

When using retroreflective sensors, reflectors and reflective foils need similar attention. Consider whether the application involves heat or chemicals that might contact reflectors. Reflectors come in versions, especially for use with red, white, infrared, and laser lights, or especially for polarized or non-polarized light. And there are mounting solutions for reflectors as well.

Considering the material and design of capacitive sensors

Capacitive sensors must also be protected based on their working environment, the material they detect, and where they are installed. Particularly, is the sensor in contact with the material it is sensing or not?

If there is contact, pay special attention to the sensor’s material and design. Foods, beverages, chemicals, viscous substances, powders, or bulk materials can degrade a sensor constructed of the wrong material. And to switch perspectives, a sensor can affect the quality of the material it contacts, like changing the taste of a food product. If resistance to chemicals is needed, housings made of stainless steel, PTFE, and PEEK are available.

While the sensor’s material is important to its functionality, the physical design of the sensor is also important. A working environment can involve washdown processes or hygienic requirements. If that is the case, the sensor’s design should allow water and cleaning agents to easily run off, while hygienic requirements demand that the sensor not have gaps or crevices where material may accumulate and harbor bacteria. Consider capacitive sensors that hold FDA, Ecolab, and CIP certifications to work safely in these conditions.

Non-contact capacitive sensors can have their own special set of requirements. They can detect material through the walls of a tank, depending on the tank wall’s material type and thickness. Plastic walls and non-metallic packaging present a smaller challenge. Different housing styles – flat cylindrical, discs, and block styles – have different sensing capabilities.

Newer capacitive technology is designed as an adhesive tape to measure the material inside a tank or vessel continuously. Available with stainless steel, plastic, or PTFF housing, it works particularly well when there is little space available to detect through a plastic or glass wall of 8mm or less. When installing the tape, the user can cut it with scissors to adjust the length.

Whatever the setting, environmental factors and installation factors can affect the functionality of photoelectric and capacitive sensors, sometimes bringing them to an untimely end. Details like mounting systems and sensor materials may not be the first requirements you look for, but they are important features that can extend the life of your sensors.