Abstract: A portable chemical detector, an embodiment including a material that contains a dye and is permeable to one or more chemicals that activate the dye, a light emitter to transmit light through the material and dye, a light detector to detect the light and a housing in which the material containing the dye, the light emitter, and the light detector are disposed.

Abstract: A portable gas chromatography system and method of use. The portable gas chromatograph may be used to accurately and rapidly detect low-level concentrations of chemicals, such as fixed gases, volatilized liquid samples, or toxic chemicals and transmit to a user data relating to the presence and identity of such. The portable gas chromatograph uses an onboard vacuum source to pull samples into and through the system and thus does not require the use of a carrier gas. Further, the system comprises a solenoid valve for capturing the sample and may include a short porous layer open tubular separation column, and a thermal conductivity detector. Overall size and weight of the system is small enough for a user to carry. The method of operation of the gas chromatograph includes taking rapid successive samples and analyzing the data outputs using Fourier transform techniques. Such analysis allows real-time data updates and rapid detection of hazardous environmental agents.

Abstract: A gas analysis apparatus including a sorption bed and a receiver normally spaced apart from the sorption bed. A given flow path is defined between the sorption bed and the receiver for directing a gas to be analyzed across the sorption bed for adsorption thereby in an adsorption mode of operation of the apparatus. A drive relatively moves the sorption bed and the receiver closer together from their spaced apart condition to produce a volume reduction of the defined, given flow path across the sorption bed in a desorption mode of operation of the apparatus. A heater selectively heats the sorption bed to desorb the adsorbed gas from the bed into the volume reduced flow path. A gas analyzer is connected to the receiver for analyzing the desorbed gas.

Abstract: A continuous air monitoring apparatus utilizes a solid sorbent preconcentrator to concentrate airborne sorbent compounds for gas chromatographic analysis. Direct connection between the preconcentrator and gas chromatographic column allows direct desorption of the compounds into the column with minimal dead space. Temperature control on the column allows sharp chromatographic peaks to be attained with cryogenic focussing.

Abstract: A thermochromatographic column has a fused silica capillary with a high temperature chemically inert polymer coating thereon supporting a thin heater film formed by the deposition of either a high resistance metallic compound auto-catalytically from a solution of the compound or a nichrome film sputtered onto the polymer clad capillary tubing. The electrical contacts to the heater film may be either resistance welded thereto or the electrically conductive wires may be attached to the capillary body and integrated into the heater film during the deposition of the heater film. An outer layer of an electrically insulating material is applied to the heater film to electrically isolate the heater film and to protect the heater film from damage.

Abstract: A sorption/desorption gas analysis apparatus includes a sorption/desorption bed having a thin layer of sorption material fixed to an outside surface of a first and a second adjacent tapered bed element arranged in a mutually mating configuration. The bed elements are further arranged to be selectively moved with respect to each other to produce a first flow volume therebetween past the sorptive material during a sorption mode of operation and a second substantially smaller flow volume past the sorptive material during a desorption mode of operation. The sorption/desorption bed is used in the gas analysis apparatus by first exposing the sorption bed to an impinging flow of a sample gas containing the constituent of interest which is sorbed by the sorptive material in the sorption mode of operation.

Abstract: An electrode system for an electrochemical sensor has a plurality of electrically conductive sensing segments isolated from each other and mounted on a support substrate formed from a chemically inert encapsulation material. The sensing segments are unencapsulated and are each coated with respective ones of ion conducting sensing materials to characterize each of the segments except for one of the segments which is uncoated and is arranged to be used as a reference electrode. The outer surface area of the sensing materials and the reference electrode is coated with a layer of a nonaqueous electrolyte which serves as a sorption/desorption medium. The electrolyte, in turn, is covered by a semipermeable thin film membrane secured at its peripheral edge by an O-ring to the support to form a fluid seal. Electrically conductive leads are connected to respective ones of the sensing surfaces, and a temperature measuring device is provided in the electrode structure for temperature compensation.