ISSN: 0022-1198
CODEN: JFSCA
Page Count: 8

The Natural Sampling of Airborne Trace Signals from Explosives Concealed upon the Human Body
Settles, GS
Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, PA

Gowadia, HA
Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, PA

(Received 29 August 2000; accepted 13 March 2001)

Abstract

An experimental study of the natural sampling of trace signals from explosives concealed upon the human body was performed by taking proper account of the thermal behavior of the air surrounding the human body and the particles therein. Experiments were conducted in a dispersal chamber to identify variables affecting the detectibility of concealed RDX and TNT patches. Movement by human volunteers was found to enhance the available explosive trace signal above a baseline level. Clothing blocked some of this movement-generated trace signal. The detected signal levels were also found to vary significantly from volunteer to volunteer, indicating that human variability is an issue in explosive trace detection. Further, under the conditions studied here, the detectibility of RDX and TNT was dependent upon the efficient sampling of contaminated particulate matter, not the vapor phase. The present results are now being applied to the design of a practical, nonintrusive trace detection portal for aviation security screening and related applications.

Keywords:
forensic science, explosive detection, natural sampling, RDX, TNT, human body, human thermal plume, aerobiology, heat transfer, flow visualization

Paper ID: JFS15153J
DOI: 10.1520/JFS15153J
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