Abstract: Disclosed are a method and apparatus for high speed, selective detection of vapors of specific compounds, particularly nitrogen-containing compounds, utilizing a bypass branch and high speed gas chromatography for improved selectivity and sensitivity of detection. A system with two gas chromatographs (GC's) alternating in series with two pyrolyzers provides two time intervals of detection in a downstream detector, with the second time interval containing signals delayed and further separated relative to signals from the first time interval. The bypass branch, in diverting a portion of the flow of gas samples from passage through the second gas chromatograph and second pyrolyzer, avoids interferences in the first time interval of detection from non-GC-retained compounds decomposed in the second pyrolyzer. Also disclosed is an arrangement for rapid, precise heating of vapor concentrator tubes in which vapors are rapidly focussed and then injected into a GC, and for rapid, precise heating of the GC's.

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: Disclosed are a method and apparatus for high speed, selective detection of vapors of specific compounds, particularly nitrogen-containing compounds, utilizing, a bypass branch and high speed gas chromatography for improved selectively and sensitivity of detection. A system with two gas chromatographs (GC's) alternating in series with two pyrolyzers provides two time intervals of detection in a downstream detector, with the second time interval containing signals delayed and further separated relative to signals from the first time interval. The bypass branch, in diverting a portion of the flow of gas samples from passage through the second gas chromatograph and second pyrolyzer, avoids interferences in the first time interval of detection from non-GC-retained compounds decomposed in the second pyrolyzer. Also disclosed is an arrangement for rapid, precise heating of vapor concentrator tubes in which vapors are rapidly focussed and then injected into a GC, and for rapid, precise heating of the GC's.

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 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 pyrolyzers 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 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 pyrolyzers 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: Disclosed is a walk-in inspection apparatus for active production of air samples containing vapors of explosives, drugs, or other substances carried by a person. The apparatus includes a U-shaped booth with an open end through which a person walks past walls which may contain a metal detector, then stands facing a vertical end wall. In the collection of an air sample a blower outside the booth sucks a large volume of air around the person and horizontally through a vertical array of shaped funnels in the end wall and through ducts connected to a collection manifold for subsequent analysis. Infrared heaters in the end wall heat the clothing and skin of the person during sampling, and many small nozzles extending through the end wall direct low volume, high momentum pulsed jets of puffs of air at the person to dislodge vapors, expel air from beneath clothing, and disrupt stagnant boundary layers of air near the person.

Abstract: Disclosed is a walk-in inspection apparatus for active production of air samples containing vapors of explosives, drugs, or other substances carried by a person. The apparatus includes a U-shaped booth with an open end through which a person walks past walls which may contain a metal detector, then stands in front of a mesh screen facing a vertical end wall containing a vertical array of shaped funnels. Light-transmissive wall sections near the end wall help encourage entry of the person into the booth, and the light colored mesh screen draws attention of a person in the booth away from the darker funnels. In the collection of an air sample a blower outside the booth sucks a large volume of air around the person and horizontally through the funnels in the end wall and through ducts into a collection manifold for subsequent analysis.

Abstract: An improved nephelometer for immunochemical complex assay measures forward light scatter in samples. The angle of forward scatter, about 30.degree., is small enough to result in a large amount of forward scatter from the immunochemical complex particles which are to be assayed, whose size is of the order of the wave length of the light used in the optical system. Forward scattering from smaller particles, such as from molecules of buffer, antibody and serum, is constant during the course of a test, and is compensated for by the use of subtraction circuits which are readily and semiautomatically adjusted to subtract proper values, in accordance with the readings taken on standard or "blank" samples of buffer, antibody and serum. Forward scattering from large particles, such as dust, is variable, and results in fluctuating signals, which are electrically processed to ignore the spurious peaks. The results of a test are displayed on a digital read out meter.

Abstract: An improved nephelometer for immunochemical complex assay measures forward light scatter in samples. The angle of forward scatter, about 30.degree., is small enough to result in a large amount of forward scatter from the immunochemical complex particles which are to be assayed, whose size is of the order of the wave length of the light used in the optical system. Forward scattering from smaller particles, such as from molecules of buffer, antibody and serum, is constant during the course of a test, and is compensated for by the use of subtraction circuits which are readily and semiautomatically adjusted to subtract proper values, in accordance with the readings taken on standard or "blank" samples of buffer, antibody and serum. Forward scattering from large particles, such as dust, is variable, and results in fluctuating signals, which are electrically processed to ignore the spurious peaks. The results of a test are displayed on a digital read out meter.

Abstract: A controller is disclosed for controlling the operation of selected electro-mechanical devices without the use of a microprocessor or similar computing machines. The controller includes a memory programmed to output a data word each time the memory is advanced to its next successive memory address. Responsive to the data word, an electro-mechanical device, identified by the data word, is actuated to perform its function. As the function of an electro-mechanical device is completed, a sensor develops a control signal for altering the internal count of a counter. The counter, in turn, advances the memory to its next address for outputting its next data word. The cycle continues as the memory is advanced through its addresses and selected electro-mechanical devices are successively actuated to perform their assigned functions.

Abstract: The modular chemical analysis system includes a first module or sample preparation apparatus for preparing sample solutions, a second module including a nephelometer apparatus comprising a stationary flow cell, mechanisms for moving sample solutions into and out of the flow cell, light generating means for passing light through the flow cell, electric circuitry for sensing the relative light scattered (R.L.S.) by the solution or particles in the solution in the flow cell and a third module comprising a microprocessing/calculator having a tape cartridge program. The microprocessor is coupled to the nephelometer apparatus (and, if desired, is also coupled to the sample preparation apparatus) for controlling operation of the nephelometer apparatus (and, if desired, to control the sample preparation apparatus). Also, the output from the nephelometer apparatus is coupled to the microprocessor which receives R.L.S. values and known concentration values for some solutions from which R.L.S. values were obtained.

Abstract: An apparatus and method for deriving an oxygen association curve for a blood sample wherein the sample is placed on a transparent support and is covered by a gas-permeable membrane element. The support is mounted in a gas treatment chamber with transparent windows on opposite sides of the support to provide an optical path through the support normal to the sample. Radiant energy is directed along this optical path, said radiant energy including two light frequencies, one having a wavelength at which there is substantially no change in absorbance as between oxygenated and deoxygenated blood and the other having a wavelength at which there is a relatively large change in absorbance as between oxygenated and deoxygenated blood. A controlled source of deoxygenating gas, such as nitrogen, and a controlled source of oxygen are connected to the chamber. An oxygen electrode is mounted in the chamber and generates the X component, corresponding to oxygen in the chamber, in an X-Y recorder.

Abstract: An apparatus for incubating and analyzing blood samples while the samples are measured for oxygen association. The apparatus includes a controlled atmosphere chamber in which humidity, temperature and carbon dioxide may be maintained at a predetermined level while the level of oxygen concentration is varied. The samples are received in an apparatus which includes at least two slides having pockets therein for receiving the samples. The slides are arranged so that the specimens may be inserted in the holders, indexed to desired positions within the chamber for incubation and analysis, respectively, and removed from the chamber without affecting the controlled atmosphere within the chamber.