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How fast can a UHF RFID reader detect tags?

HARTING’s range of UHF RFID (Radio Frequency Identification) readers have numerous uses across many industries and markets. For example, they can be employed to monitor the temperature of bearings and magnets within large gearboxes and motors and control the safe positioning of trains at stations by ensuring the carriage is correctly positioned before allowing the doors to be opened.

In addition to being robust, highly accurate devices, UHF RFID readers also have the capacity to read tags extremely quickly, which got us wondering; just how fast can a UHF RFID reader detect a tag?

In order to find out, we enlisted the help of the Ignition Racing Team (IRT) from the Osnabrück University of Applied Sciences in northwest Germany.

A need for speed

As part of their Formula Student project, the IRT have been designing, developing and building high-performance electric racing cars since 2006. These vehicles have some incredibly impressive statistics; they can accelerate from nought to 75mph down a 75m track, thanks to a hefty 1400 Nm of torque.

As HARTING is a main sponsor of the team, they seemed like the perfect partner. So, between us, we ran a series of high-speed tests to work out how fast a vehicle can be reliably detected using an RFID reader.

You can watch the tests here:

In order to accurately test the equipment, we built an RFID reader and antenna alongside the track and installed an RFID transponder in each car. To ensure a fair test, we only used standard RFID products and evaluated all the results in real time by using HARTING Ha-VIS middleware. All results and data were written to file exactly as they would be in a real-life application.

As a test run, we drove one of the IRT’s electric race cars past the antenna at around 50mph. All the RFID systems worked perfectly and the car was quickly sensed and recorded by the equipment. For pass two, we increased the pace to nearly 75mph and again the equipment had no trouble logging the data.


At this point, the IRT electric cars had maxed out on speed so we had to switch to a combustion engine vehicle. With the extra power available, we sped past the RFID reader at 100mph. Once again, the equipment didn’t let us down and we successfully achieved detection.

For our final run, we decided to test the RFID technology at maximum speed. Using a German sports car, we sped past the RFID transponder at a startling 125mph! Even at this speed, the vehicle was quickly and reliably detected.

Practical applications

Not only is UHF RFID fun to test, there are also real practical applications for this technology. For example, take the maintenance, repair and operations (MRO) of trains. Removing a train from service can be prohibitively expensive. By implementing UHF RFID as part of life cycle monitoring, the reliability of equipment can be vastly improved whilst service times are dramatically shortened.

RFID also allows the easy implementation of preventive maintenance, meaning faults or potential issues can quickly be diagnosed. This is where the speed of UHF reading plays a huge role; as the train passes predictive maintenance points any potential issues are located quickly, right down to individual component level, all whilst the train is moving.

As well as speed of reading, RFID also has many other advantages over the traditional barcode reader. For example, a barcode must be completely visible and you need to have a direct line of sight of the code. You also need to be within a short read distance and directly in front of the barcode to allow the 2D scanner to accurately decipher the code.

In contrast, with an RFID handheld, you do not need a direct line of sight and it is possible to get a good reading even if the transponder is obscured or the light conditions are not optimal. You can also be further away from the item being read and have the capability to read in excess of 300 tags per second.

Independent tests have verified the capabilities of RFID, with potential time savings of up to 94% being achieved when it comes to bulk reading.

HARTING Ltd is skilled in the fields of electrical, electronic and optical connection, transmission and networking. We use this expertise to craft solutions for the transportation, data transmission, wind energy, mechanical engineering, factory automation, automotive and robotics markets. HARTING also design and manufacture cable assemblies, box builds, kit assemblies and modified products at our UK facility in Northampton.