| abstract |
A multi-zonal system and method for detecting contraband substances associated with a human subject. Objects containing such substances may be carried by the subject or in a garment worn by the subject, or as vapors entrained by the subject's garments. Alternatively, the substance may be present as small particles or residues present on skin, garment fibers, or the like that may be dislodged from the subject or his immediate effects. The system comprises: (i) an examination station through which the subject passes; (ii) sample generation means to produce a sample for analysis, comprising a plurality of air jets disposed in the examination station to impinge flowing gas onto pre-selected zones on the subject; (iii) collection means operative to acquire and convey the sample, comprising a plurality of collection ports disposed in the examination station to receive gas deflected by the subject from the air jets; (iv) analysis means in communication with the collection means to receive the sample and carry out a chemical analysis to detect the contraband substances; and (v) signal means operably connected to the analysis means for indicating detection of the contraband substances. Preferably the system employs a chemiluminescent detector based on the reaction of luminol with NO 2 produced by pyrolysis of explosive or other contraband substance and is capable of high throughput, accurate screening in real time of a large number of subjects, e.g. persons being screened in an airport. |