Delta Air Lines announced Thursday that by August RFID (radio frequency identification device) baggage tags will be in use at 84 airports, including Atlanta, where Delta is headquartered. Here’s how it works: When you check your bag, it will get an RFID tag instead of the digital bar code tag you usually get. As bags are loaded onto conveyor belts that roll up into airplane cargo holds, an electronic device reads the radio signal being broadcast from each RFID tag. It checks the tag against a database to make sure that bag belongs on that flight. If it doesn’t, the system triggers a red light on the conveyor belt and the belt automatically stops, allowing a baggage handler to remove the bag from the belt and re-route the bag to its correct destination. Another use for this RFID system: If a passenger suddenly has to de-plane and their bags have to be removed from the cargo hold, the device makes it much faster to find the passenger’s bags by tracking radio signals in the tags. Most airlines now use simple tags with digital bar codes that don’t broadcast any radio signals. That system has a rate of properly routed bags somewhere around 95%. With RFID tracking, Delta expects that number to hit 99.9%. Australia’s Qantas airline has used RFID to track bags, but Delta says no other domestic carrier has implemented an RFID baggage tracking program with this specific kind of technology on this scale. (ABC News).