Abstract: A highly selective, sensitive, fast detection system and method are disclosed for detecting vapors of specific compounds in air.

Abstract: A highly selective, sensitive, fast detection system and method are disclosed for detecting vapors of specific compounds in air. Vapors emanating from compounds such as explosives, or stripped from surfaces using heat and suction from a hand-held sample gun, are collected on surface coated with gas chromatograph (GC) material which trap explosives vapors but repel nitric oxide, then are desorbed and concentrated in one or more cold spot concentrators. A high speed gas chromatograph (GC) separates the vapors, after which specific vapors are decomposed in two pyrolyzers arranged in parallel and the resulting nitric oxide is detected. A low temperature pyrolyzer with silver produces NO from nitramines or nitrite esters; a high temperature pyrolyzer decomposes all explosives vapors to permit detection of the remaining explosives. Also disclosed is a series arrangement of pyroloyzers and gas chromatographs and an NO detector to time-shift detection of certain vapors and facilitate very fast GC analyses.

Abstract: A highly selective, sensitive, fast detection system and method are disclosed for detecting vapors of specific compounds in air. Vapors emanating from compounds such as explosives, or stripped from surfaces using heat and suction from a hand-held sample gun, are collected on surfaces coated with gas chromatograph (GC) material which trap explosives vapors but repel nitric oxide, then are desorbed and concentrated in one or more cold spot concentrators. A high speed gas chromatrograph (GC) separates the vapors, after which specific vapors are decomposed in two pyrolyzers arranged in parallel and the resulting nitric oxide is detected. A low temperature pyrolyzer with silver produces NO from nitramines or nitrite esters; a high temperature pyrolyzer decomposes all explosives vapors to permit detection of the remaining explosives. Also disclosed is a series arrangement of pyrolyzers and gas chromatographs and an NO detector to time-shift detection of certain vapors and facilitate very fast GC analyses.

Abstract: An electric force motor includes two movable and independently actuatable coils energized by a single magnetic circuit. Air gaps are formed at respective ends of a tubular permanent magnet between a core of magnetically permeable material mounted within the magnet and pole pieces attached to opposite ends of the magnet. Such a configuration thus establishes a serial magnetic circuit connecting the magnet and the core through each of the air gaps. The two coils, each positioned within the respective air gaps, receive independent electrical input signals to develop corresponding output forces. Interactions between each coil that would tend to affect accuracy are minimized by choosing a magnet of high coercivity and by limiting the amount of input current applied to each coil.