Portal trace detection systems for detection of imbedded particles

Abstract

A portal trace detection apparatus is provided for detecting minute particles of interest, such as traces of narcotics, explosives and other contraband. The apparatus includes a portal through which a human suspect will pass. A detection apparatus is disposed at least partly in the ceiling of the portal, and hence above the human subject in the portal. Particles of interest will be entrained in the human thermal plume that exists in the boundary adjacent the suspect, and will flow upwardly from the suspect to the detection apparatus in the ceiling of the portal. The ceiling is coated with an anti-static material so that particles are more likely to flow towards the detector and less likely to be affixed electrostatically to the ceiling.

Description

[0001] This application is a divisional of U.S. patent application Ser. No. 10 / 774,004 filed Feb. 6, 2004, which is a divisional of U.S. patent application Ser. No. 10 / 033,874, filed Dec. 20, 2001, now issued as U.S. Pat. No. 6,708,572.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The subject invention relates to a detection apparatus for dislodging particles from clothing and skin of a person and then testing the dislodged particles for the presence of substances of interest. [0004] 2. Description of the Related Art [0005] Detection systems exist for detecting traces of materials, such as narcotics and explosives. Such systems are marketed by Ion Track Instruments, Inc. and are shown, for example, in U.S. Pat. No. 5,491,337. [0006] Prior art detection systems rely upon the fact that trace amounts of contraband will be transferred to the body of a person who handled the contraband, and subsequently will be transferred from the body to any article that the perso...

AI Technical Summary

Benefits of technology

The invention is a portal detection system that uses a fan or other device to generate an air flow that matches the air flow of a typical human body. The system has a plurality of air jets directed at the area where a human suspect will stand. The air jets are connected to a high-pressure air supply and are operated sequentially to disturb the clothing of the human suspect and release trapped particles. The air jets have a minimal effect on the human thermal plume and can detect vapors that would be below the system's sensitivity. The system also reduces or eliminates the static electricity that causes particles to accumulate on the hood or ceiling of the portal.

Problems solved by technology

The air flow created by the jets necessarily disturbs the body plume somewhat, and hence conceivably could cause a turbulence that could direct particles of interest out of the portal.

It has been determined that longer periods of operation for the respective jets adversely affects the human thermal plume without significantly increasing the release of particles from the clothing of the human suspect passing through the portal.

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