Pressure activated sampling system
First Claim
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 by slowly increasing the pressure in a chamber from the atmospheric pressure to a selected pressure level;
rapidly decompressing the item to the atmospheric pressure;
collecting a sample of a substance comprising at least one of vapors or particles removed from the item by the rapid decompression; and
testing the sample to determine whether a predetermined contaminant is present in the sample.
3 Assignments
0 Petitions
Accused Products
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.
24 Citations
45 Claims
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1. A method for screening an item for the presence of contaminants, the method comprising:
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subjecting an item to a pressure substantially in excess of atmospheric pressure conditions by slowly increasing the pressure in a chamber from the atmospheric pressure to a selected pressure level;
rapidly decompressing the item to the atmospheric pressure;
collecting a sample of a substance comprising at least one of vapors or particles removed from the item by the rapid decompression; and
testing the sample to determine whether a predetermined contaminant is present in the sample. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A system for screening items for contaminants, the system comprising:
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a pressure chamber adapted to contain at least one item;
a pressurized gas source connected to provide pressurized gas to the pressure chamber;
a valve for venting the pressure chamber to an ambient atmosphere;
a controller operable to control a pressurization of the pressure chamber by the pressurized gas source and to control the valve to initiate a rapid decompression of the pressure chamber;
a sample collector positioned to collect samples of substances removed from the at least one item by the rapid decompression; and
a trace-level contaminant detector operable to detect whether at least one contaminant is sampled by the sample collector. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23)
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24. A method for screening luggage for prohibited materials, the method comprising:
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placing an item of luggage in a pressure chamber;
pressurizing the pressure chamber up to a predetermined pressure level;
rapidly decompressing the pressure chamber by venting the pressure chamber to an ambient atmosphere;
collecting samples of substances removed from the luggage by the rapid decompression; and
testing the collected samples for prohibited materials. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31)
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32. A method for screening an item for the presence of contaminants, the method comprising:
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subjecting an item to a pressure substantially in excess of atmospheric pressure conditions;
decompressing the item to the atmospheric pressure at a rapid rate relative to a rate of compression;
collecting a sample of a substance comprising at least one of vapors or particles removed from the item by the rapid decompression; and
testing the sample to determine whether a predetermined contaminant is present in the sample. - View Dependent Claims (33, 34)
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35. A method for screening an item for the presence of contaminants, the method comprising:
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subjecting an item to a pressure substantially in excess of atmospheric pressure conditions;
decompressing the item to the atmospheric pressure by venting a chamber containing the item to allow air to escape the chamber at a high velocity;
collecting a sample of a substance comprising at least one of vapors or particles removed from the item by the decompression; and
testing the sample to determine whether a predetermined contaminant is present in the sample. - View Dependent Claims (36, 37, 38, 39, 40, 41)
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42. A method for screening luggage for prohibited materials, the method comprising:
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placing an item of luggage in a pressure chamber;
pressurizing the pressure chamber up to a predetermined pressure level;
decompressing the pressure chamber at a rapid rate relative to a rate of pressurization;
collecting samples of substances removed from the luggage by the rapid decompression; and
testing the collected samples for prohibited materials. - View Dependent Claims (43, 44, 45)
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Specification