Detection equipment exploding
With terrorist awareness at an all-time high, government security experts are searching for the state-of-the-art in bomb detection technology.
From airports to courthouses and other facilities falling under the blanket of governmental protection, the demand for sophisticated bomb searching technology is surging.
“Recognition of [explosives detection] technology came about through its use in aviation applications,” says Brook Miller, vice president of Barringer Technologies Inc., Warren, N.J., a provider of advanced technology for security, law enforcement and other applications.
Explosives detection equipment ranges greatly in size and can be used in conjunction with already-installed X-ray, CCTV and other access control systems.
Ion Mobility Spectrometry (IMS), used in many of the devices, is capable of separating ionic species at atmosphere pressure. A machine analyzes particles collected off a surface to test for explosive residue or drug residue and gives a positive or negative response. Every element — explosive or not — has its own “signature” that can be read by the machine.
“It vaporizes the samples, and those vapors are charged,” Miller explains. “Everything has a different signature — TNT has its own particular one, as does heroin and everything else. The system is very accurate in reading the signatures.”
IMS equipment can range from a handheld device weighing about eight pounds, to a 47-pound industrial system commonly found in airports throughout the country. The systems can continuously scan the air and sample it for explosive and drug residue, and there are conveyor belt-type automated machines used to scan baggage.
IMS can scan either particles (as from a wand brushed along a surface) or vapors collected from the surrounding air.
Radio waves. Quadruple resonance uses carefully tuned pulses of low intensity radio waves that probe the molecular structure of targeted items, such as explosives or narcotics. The waves momentarily disrupt the alignment of targeted nuclei, which produces a characteristic signal picked up by a receiver and sent to a computer for rapid analysis.
“The signal emitted by the explosive or drug is unique,” says Lowell J. Burnett, president and CEO of Quantum Magnetics Inc., a subsidiary of InVision. “Specialized radio frequency pulse sequences have been developed for the optimal detection of such explosives as Semtex, C-4, Detasheet, TNT, tetryl, ANFO, and black powder, and such narcotics as cocaine or heroin.”
Magnetic resonance uses a steady magnetic field that causes nuclei to rotate at a characteristic frequency. The technology is key for scanning liquids to detect any explosive or narcotic contents. Magnetic sensors can also be used to scan people for explosives or illegal weapons.
Bomb detector dogs, familiar to law enforcement officials everywhere, can track the type of odor they are trained on even when it's masked with harsh odors.
