Get that dynamite out of your pants.
New drug and explosives scanners, so sensitive that they can tell if you even touched a dangerous object days ago, may soon be coming to airports. The walk-through scanners are faster, more accurate and less invasive then any technology currently out there.
“Little has been accomplished for examining people themselves since metal detectors some 30 years ago,” said Ken Wood, president of Barringer Technologies of Warren, N.J., which built the Sentinel device launched this week. “The Sentinel will non-invasively detect and identify microscopic amounts of over 30 explosive or narcotic substances,” he said.
Barringer’s main competitor, Ion Track Instruments of Wilmington, Mass. is building a similar portal, spokeswoman Joanne Arsenault said. Still formally unnamed, the company’s calling it the “Entryscan 3” for now.
The Sentinel will come onto the market at the end of this year, Wood said. The company didn’t give a price for the machine, but systems for checking baggage for explosives cost around $1 million each, according to the FAA.
Winds of Change
When you step into a Sentinel, which looks like a larger than usual metal detector, a light puff of air ruffles your clothes. That air is sucked into vents in the machine, which separates out heavy molecules like those that make up drugs and explosives. (The active ingredient in marijuana, THC, weighs 314 atomic mass units. Water, a simple molecule, weighs 18.) The process uses a sample-preconcentration technique developed by Sandia National Labs, a Department of Energy installation in Albuquerque, N.M.
ITI’s Entryscan device relies on body heat, which warms up air near a traveler’s body and lifts it to the top of the device. The Entryscan collects a smaller amount of air, and doesn’t require the Sentinel’s puff, Arsenault said. Their system was developed with the Gas Dynamics Lab at Pennsylvania State University.
“You have heat rising off your body all the time, and it tends to carry particles off your body,” FAA spokeswoman Becky Trexler, who’s familiar with both devices said. On an infrared camera, “it looks very karmic.”
Extremely Sensitive Systems
Both the Sentinel and the Entryscan 3 then use ion mobility spectrometry, which relies on analyzing the rate of movement of a particular molecule, to determine exactly what substances the heavy molecules form. If they find something on their list of problem substances, an alarm sounds. If the system finds a suspicious substance, a red light shines and the substance name appears on a video screen. The process takes about seven seconds.
The Sentinel also includes a metal detector, so travelers don’t have to pass through two checkpoints.
The systems are so sensitive, they can detect a few parts per trillion of explosives or drugs, microscopic traces which cling to clothes and skin even when people think they’re clean.
“If you emptied a packet of sugar into an Olympic-sized swimming pool and then mixed that up, this thing is the equivalent of drawing in that much water and detecting one of those particles of sugar,” said Sandia spokesman John German.
The systems’ sensitivity is two-edged — they can find explosives previously thought undetectable, but they raise the specter of false positive results.