In the comics, the Phantom is a masked crimefighter who protected the innocent from pirates, hijackers and other evildoers. While not as dashing or exciting as its costumed namesake, this electromagnetic phantoma carbon and polymer mixture that simulates the human bodyis being readied by the National Institute of Standards and Technology (NIST) for its upcoming role as a different kind of protector. The NIST phantom serves as a mannequin in a standardized performance test for walk-through metal detectors or WTMDs such as those used at airports.
Metal detectors currently are evaluated by using clean testers (human subjects) who walk through the detector adorned with different types of innocuous metal objects, such as eyeglasses, belt buckles, watches, jewelry and coins, or by a piece of plywood pushed through the metal detector with the same items mounted on it. The disadvantage of using human subjects is that person-to-person variability in physical makeup and walking style and changes in a particular persons gait or position at each pass makes standardization impossible. The second method is reproducible, but it cant tell evaluators how a human body may impact the WTMDs ability to discriminate between weapons and innocuous objects.
The solution for both problems came from the lab. With funding from the U.S. Department of Justices National Institute of Justice (NIJ), researchers in NISTs Electromagnetics Division mixed a polymer with carbon blacka fine powder made almost entirely of elemental carbonto yield a low-cost, easily molded compound that can mimic the average electrical conductivity of the human body (which includes blood, bone, fat, organs, muscle and skin). The material is shaped into brick-like blocks and then arranged on a non-conductive fiberglass frame in a form that simulates the mass and height of the average American adult male.
Once assembled, the NIST phantom is placed atop a low-friction nonmetallic cart and pas
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| Contact: Michael E. Newman michael.newman@nist.gov 301-975-3025 National Institute of Standards and Technology (NIST) Source:Eurekalert |