RFID Tags Provide Ultra Reliable Monitoring
Today’s car buyers typically order a number of custom options for their vehicles at the time of purchase. In turn, the automaker must identify and track each vehicle throughout the production process to ensure that all options are installed. Volvo Car Corp. uses RFID tags to meet this challenge.
For many years, the Swedish automaker used three methods to identify and track each vehicle: bar code technology during general manufacturing, active RFID in the paint shop, and large bar codes on the final-assembly line. Besides being costly to maintain, this approach lacked reliability and often caused production disturbances throughout the factory.
Several years ago, Volvo began using Corona ultra high frequency (UHF) tags in all its manufacturing plants. To date, the company has installed tags on 2 million Volvo cars, along with more than 600 UHF readers to read the tags during production. Plant managers say the tags, which are made by Confidex Ltd., have demonstrated 99.96 percent reliability over the past six years.
Each tag measures 3.15 by 1.97 by 0.02 inch and is mechanically mounted on the car chassis prior to production. It is read at various points during the manufacturing process to identify the vehicle. Mounting is permanent, eliminating the need for collecting, cleaning and testing used tags.
Volvo plant managers like that the plastic tag is durable enough to withstand extreme temperatures and harsh conditions throughout production. It operates in temperatures from -100 to 430 F and can tolerate 430 F for at least 30 minutes.
After leaving the welding shop, car bodies proceed to the paint line. There, the car is immersed in an electrolyte bath for corrosion prevention, before receiving several layers of paint and enduring a series of high-temperature drying ovens. The tag’s performance is unaffected by these conditions.
Managers also like that the tag does not hinder production, while providing time-stamped records of check-in and check-out times and assigned personnel. These records are storable and auditable. To simplify distribution of finished automobiles, Volvo encodes each vehicle’s electronic product code (ID number) on the tag.
Because it is passive, the Corona tag is powered by radio frequency energy transferred from the reader. In contrast, an active RFID tag relies on an internal power source (battery).
The tag has a radio frequency range of 865 to 928 megahertz and a read range of up to 10 meters. It complies with ISO 18000-6C.
For more information on RFID tags, call 301-641-7408 or visit www.confidex.com.