'Putting an RFID tag on a pallet is like putting license plates on a car in a demolition derby!'

That's the conclusion of Ralph Rupert, research associate at the Center for Unit Load Design at Virginia Tech in Blacksburg, Va. (www.unitload.vt.edu).

Rupert's conclusion is based on testing that the Center for Unit Load Design conducted for Rafsec, a Finnish RFID tag supplier. The group used a simulated warehouse handling test often used to test pallet designs for durability.

In the tests, it took only two hits from a lift truck to totally destroy a tag. A typical palletized load will be handled as many as 15 times per trip. "We tested four tags, and they all failed so quickly that we didn't go any further," Rupert says.

The results are important because both Wal-Mart and the Department of Defense are mandating pallet level tracking by January 2005. Moreover, many companies, including Wal-Mart, use pooled pallets in a captive system. Those are trackable assets.

"We don't think the issues around what happens to a tag when you put it on a pallet are being addressed," Rupert said.

He identified two key issues that need to be addressed if RFID tags are going to be used successfully on pallets: signal interference and tag placement.

Most shipping pallets are made from 'green' wood. The moisture content in the lumber acts like an energy sink that interferes with the signal. Read rates were cut in half when the tag was put flush on a pallet. Performance improved if the tag was off-set at least 5/16 of an inch from a runner. However, that created an easy target for the fork tines to hit.

Placing a tag inside the pallet runners reduced damage, but required two tags to get consistent read rates from either side of the lift truck.

"We're not trying to be doom sayers," Rupert adds. "We think this technology has potential. But if the durability issues aren't discussed, this could hurt everyone as they try to implement these programs."