Ahura spokeswoman Kerstin Barr said that First Defender has an accuracy rate of about 95 percent.
Kudwa also noted that many passengers carry several containers of fluid in carry-on bags. The First Defender would require about 15 seconds to identify the contents in each, resulting in a slowdown at security checkpoints.
Ahura's director of operations Mark Spillane agreed that using the First Defender on every passenger is impractical. Instead, it would be used on people who had already been tabbed as suspicious. "Somehow, the security people have got to identify the threat," Spillane said.
Kudwa said AS&E's SmartCheck is "something we're a little closer to testing operationally." But there are questions about public acceptance of the system because some passengers may worry about the health effects of an X-ray scanner. But both AS&E and the TSA say the radiation emitted by SmartCheck is roughly equal to the increased radiation exposure a person receives from flying at 20,000 feet for about five minutes.
The newest generation of SmartCheck has been modified to cope with another concern -modesty. Early versions generated a very revealing image of the passenger's anatomy. AS&E software engineers came up with a program that covers up the contours of passengers' bodies, making them resemble chalk outlines of a person. Only the objects carried can be clearly seen.