Pressure Activated Sampling System

Abstract

Screening of items for the presence of contaminants, such as explosives residue, is accomplished by subjecting an item loaded into a pressure chamber to a pressure substantially in excess of atmospheric pressure conditions and rapidly decompressing the item to the ambient atmospheric pressure. The rapid decompression serves to scavenge vapors and particles from the exterior and interior of the item and any objects it contains. A sample of the vapors and particles removed from the item by the rapid decompression is sampled and is tested to determine whether a predetermined contaminant is present in the sample. Depending on the types of contaminants for which the sample is tested, it is possible to detect whether explosives, biological or chemical agents, and/or narcotics residues are present on or in the item being screened.

1 . A method for screening an item for the presence of contaminants, the method comprising:
 subjecting an item to a pressure substantially in excess of atmospheric pressure conditions;   rapidly decompressing the item to the atmospheric pressure;   collecting a sample of a substance comprising at least one of vapors and particles removed from the item by the rapid decompression;   testing the sample to determine whether a predetermined contaminant is present in the sample.