System for Synchronous Detection Trace of Explosives and Drags Substances on Human Fingers

AbstractThe sampling unit of the device, based on ion mobility spectroscopy technique, for detection of ultra small (trace) substances concentration on human fingers and documents is described. The vapor pressure of many dangerous substances is very small; so the heating of an investigated surface is needed for effective detection. However the direct heating of the human fingers by irradiation of the gas-discharge lamp is not effective because a small concentration of the melamine (pigment of the black or brown color) in the skin of the human palm. Therefore in this work the combination of the two methods is used: a grid is heated by the irradiation of the gas-discharge lamp and a grid heats the surface of the finger which is pressed to a grid