Abstract: A portal is provided with a detector for detecting trace amounts of substances of interest that may be retained on the surface or interior of a vehicular subject. The portal relies upon the continuous process by which microscopic flakes of dust, dirt, pollen, and other surface and interior contaminants as well as adsorbed analyte media and analyte vapors continuously separate from the surface of vehicular subjects and escape from the interior of vehicular subjects. The portal further leverages the existence of a vehicular thermal plume consisting of a layer of warm air adjacent to the vehicular subject. The warm air rises in the cooler surrounding air and transports the microscopic flakes of surface contaminants, desorbed analyte, and analyte vapors upwardly. The portal capitalizes on this phenomenon by providing at least a partial enclosure with a funnel-shaped collector above the vehicular subject.

Abstract: A portal is provided with a detector for detecting trace amounts of substances of interest that may be retained on the surface or interior of a vehicular subject. The portal relies upon the continuous process by which microscopic flakes of dust, dirt, pollen, and other surface and interior contaminants as well as adsorbed analyte media and analyte vapors continuously separate from the surface of vehicular subjects and escape from the interior of vehicular subjects. The portal further leverages the existence of a vehicular thermal plume consisting of a layer of warm air adjacent to the vehicular subject. The warm air rises in the cooler surrounding air and transports the microscopic flakes of surface contaminants, desorbed analyte, and analyte vapors upwardly. The portal capitalizes on this phenomenon by providing at least a partial enclosure with a funnel-shaped collector above the vehicular subject.