Passive ultrahigh-frequency (UHF) tags can be read from 20 or 30 feet away when mounted properly on an asset (certain products composed of metal, or containing high water content, require special tags or careful tag placement). So it is usually not a problem to read tags on goods moving through a dock door that is 15 feet wide. However, if you had a pallet with, say, 60 tagged cases of canned goods, you would not be able to read the cases at the center of the pallet, because energy from the reader would not reach the tags.
It is possible to utilize RFID to secure products, but the system would need to be well-designed. In 2006, Sony Europe installed a tracking system that links RFID-tagged items with closed-circuit video, in an effort to help the company reduce shrinkage, increase the efficiency of its shipping processes and resolve shipping disputes with its retailer customers in Germany. The solution links the unique serial numbers on tagged DVD players to video recordings made by a closed-circuit television (see Sony Europe Implements Video-RFID Tracking System).
Depending on the type of product you wish to secure, you might have to read the tags as a pallet is being built, then shrink-wrap it and place a pallet tag on the pallet. If you need more information, I would be happy to discuss this by phone. I can also provide the names of a few system integrators that can help you.
—Mark Roberti, Founder and Editor, RFID Journal
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