Abstract: The invention relates to an electrochemical gas sensor having both a reference sensor and an active sensor, whereby each reference and active sensor includes a substrate, a counter electrode deposited on a surface of the substrate, a sensing electrode also deposited on the surface, and an electrolytic material in electrical contact with both electrodes for carrying a flow of ions between them, which measures a concentration of a gas and compensates for relative humidity differences between sample gas and surrounding atmosphere. The sensor also includes a layer of electrolytic material on the sensing electrode of the reference sensor and a film of electrolytic material on the sensing electrode of the active sensor, whereby the layer is thicker than the film. The invention may further include a reference electrode in both the reference and active sensors for improving sensor accuracy and/or repeatability.

Abstract: The invention relates to a method and apparatus for providing a reactor having a heater, a passage for transporting a reactant, and a chamber containing a gas sample and being coupled to the passage for receiving the reactant and mixing the reactant with the gas sample. The reactor further includes a connector leading from the chamber to the heater for transporting a mixture of the reactant and gas sample, and wherein the heater heats the mixture of the reactant and gas sample.

Abstract: The invention relates to an electrochemical gas sensor having improved response time and sensitivity. The electrochemical gas sensor includes a substrate for providing a surface upon which an electrode may be placed, a first electrode placed on the surface, a thin film of electrolyte support for receiving electrolyte and having a predetermined porosity, and a second electrode deposited on the thin film for permitting a measurement of current between the first and second electrodes.

Abstract: The invention relates to an electrochemical gas sensor having a substrate, substrate surface for depositing electrodes thereon, counter and sensing electrodes for measuring current flow, an electrolyte for providing an electrical connection between the electrodes, and an electrode surface having minimal porosity, pore size, and thickness for deterring flooding.

Abstract: The invention relates to an instrument and method for measuring minute quantities of weight, including a pan for holding a sample to be weighed, a chamber for forming an enclosure about the pan, and a hang-down wire coupled to the pan for suspending the pan within the chamber. The pan has volume less than 0.020 cm3 and the hang-down wire has a volume less than 0.01 cm3. The invention may also include a carrier gas, placed within the chamber, having a generally consistent density over changes in temperature.

Abstract: The invention relates to an electrochemical gas sensor having improved response time and sensitivity. The electrochemical gas sensor includes a substrate for providing a surface upon which a film of conductive material may be deposited, a pair of electrodes deposited on the substrate for permitting a measurement of current, and an electrolytic material for providing an electrical connection between the electrodes. The electrochemical gas sensor further includes a passage in the surface for holding or transporting gas received from a gas source, whereby sensing occurs at a three way interface where the gas, electrolytic material, and electrodes come in direct contact with one another.

Abstract: A method and apparatus is provided for detecting an impurity in a sample where an index can be calculated to assess purity in the presence of n major components with signal averaging or noise-filtering automatically built-in. The method and apparatus can be applied to liquid chromatography impurity detection using UV-VIS spectrophotometry based on robust matrix algebra representing the entire spectral space generated by the sample.

Abstract: A housing for a material holder includes an intermediate housing member having a generally horizontal member, an upper recess and a lower recess, an upper housing member having a generally horizontal member and a wall defining a material holding chamber, the upper housing member being seated within the upper recess of the intermediate housing member, and a lower housing member having a generally horizontal member, the lower housing member being seated within the lower recess of the intermediate housing member. The upper recess, the generally horizontal member of the intermediate housing member and the generally horizontal member of the upper housing member define a first cavity adapted to receive a first winding assembly, and the lower recess, the generally horizontal member of the intermediate housing member and the generally horizontal member of the lower housing member define a second cavity adapted to receive a second winding assembly.

Abstract: The invention relates to an electrochemical gas generator including a substrate for providing a surface for electrode deposition, a first electrode deposited on the surface for providing an electrical connection with a conducting medium, a second electrode deposited on the substrate for generating a gas, and a plurality of members extending from at least one side of the first electrode placed alternately with a plurality of extensions protruding from at least one side of the second electrode for improving generator efficiency.

Abstract: An analyte pre-concentrator for gas chromatography is disclosed generally comprising a tube having a restricted outlet and packed with an adsorbent, wherein the tube serves as the liner of a chromatographic injector, as an adsorbent trap coupled to a chromatographic column, and/or as an adsorbent trap coupled to a headspace sampler. Preferably, a heating device allows the tube to be heated. In a preferred embodiment, the analyte pre-concentrator further comprises a column isolating accessory so that a chromatographic column can be temporarily isolated from substances flowing through the tube.

Abstract: A method of measuring the effective temperature inside a sealed container having a headspace is provided. A liquid solvent is added to the container, and a solid compound is added to the liquid solvent to create a saturated solution. Vapor of the saturated solution is allowed to equilibrate in the headspace of the sealed container, and a volume thereof is transferred to a chromatographic column, where chromatographic readings of the equilibrated vapor are taken. A temperature within the sealed container is then calculated based upon the chromatographic readings of the equilibrated vapor, wherein the temperature calculation is based upon the concentrations of the liquid solvent and the solid compound in the equilibrated vapor.

Abstract: A method and apparatus is provided for detecting an impurity in a sample where an index can be calculated to assess purity in the presence of n major components with signal averaging or noise-filtering automatically built-in. The method and apparatus can be applied to liquid chromatography impurity detection using UV-VIS spectrophotometry based on robust matrix algebra representing the entire spectral space generated by the sample.

Abstract: Torch glassware for use with inductively coupled plasma-optical emission spectrometers is provided. The glassware includes an outer tube and a stream of cool inert gas flowing radially within the inner surface thereof such that the cool inert gas creates a cushion between the tube and hot plasma contained within the stream of cool inert gas. The outer tube includes a sidewall having an open end and having a slot passing therethrough. The slot extends longitudinally along the sidewall from the open end thereof and is defined at least in part by a first longitudinal edge and a second longitudinal edge. The first longitudinal edge is offset radially inwardly from the second longitudinal edge. Stated another way, the tube includes a fixed center, and a distance between the fixed center and the first longitudinal edge is smaller than a distance between the fixed center and the second longitudinal edge.

Abstract: The effects of unwanted components such as H2O and CO2 in spectral data measured by a spectrometer such as an FT-IR spectrometer are suppressed by a technique in which data representing high resolution spectra of the unwanted component is acquired, this data is modified so that its resolution matches that of the instrument, the results data is filtered to allow for perturbing effects of the sample and the resulting data is subtracted from the measured sample sectrum to provide corrected output data.

Abstract: The invention relates to an apparatus and method for providing a modifiable headspace for measuring a concentration of volatile releases from a sample. The invention includes a collapsible housing for containing the air sample and a plurality of spacers between the housing and the sample surface for separating them from one another. The plurality of spacers permit the distance between the housing and the sample to be adjustable.

Abstract: A method of measuring the absolute value of thermal conductivity of low thermal conducting solid materials is disclosed. Thermal conductivity and heat capacity of the sample are determined simultaneously in a single measurement with the prerequisite that these values are frequency independent. This method is realized on power-compensated differential scanning calorimeters without any modification in the measuring system. DSC is calibrated in a standard way for temperature and heat flow. The method uses temperature-time profiles consisting of one fast temperature jump of 0.5 to 2 K and an isotherm. The measuring time for each temperature is less than 1 min. As input parameters only sample thickness and contact area with the DSC furnace (or sample diameter if the sample is disk shaped) are needed together with sample mass. In addition to the sample thermal conductivity and heat capacity the effective thermal contact between sample and DSC furnace is determined.

Abstract: A gas chromatography split injector including a housing having a carrier gas inlet port and a vent port and an injector liner is provided. The injector liner includes a substantially cylindrical outer liner member disposed within the housing and an inner liner member disposed within the outer liner member. The inner liner member has substantially cylindrical upper and lower portions and a constriction therebetween. The constriction includes an inner surface having an inner diameter smaller than a diameter of inner surfaces of the upper and lower portions. The injector also includes a chromatographic column passing through the lower portion of the inner liner member and is in sealing engagement with the constriction of the inner liner member. A transfer line passing through the upper portion of the inner liner member and has an end located proximate to the constriction of the inner liner member.

Abstract: An autosampler for manipulating a specimen container into and out of a furnace of a parent instrument is disclosed. The autosampler has upper, lower and middle gripping fingers which grip and stabilize a crimped wire, which has a large bend therein. The middle gripping finger is positioned between and opposed to the upper and lower gripping finger and has a portion at one end thereof sized and shaped to receive the bend of the crimped wire. The gripping fingers grip and hold the crimped wire while a tray table moves to place the specimen container on a hook at the bottom of the crimped wire. If the specimen container is sealed, a hole may be punctured therein by a puncturing apparatus, which has a housing which is movable between an upper and lower position and biased toward the lower position. A pin is positioned inside the housing.

Abstract: Constituents such as oxy- and deoxy-hemoglobin are monitored non-invasively in an animal organ such as a brain with a spectrometric instrument by passing radiation through the organ. Concentrations are computed from the spectral intensities and from a statistical correlation model. To predetermine the correlation model, the procedures are effected for a plurality of organs of a same type with each organ having established concentrations of the selected constituents, and the correlation model is statistically determined from the concentrations and corresponding intensities. For more accuracy computations are normalized to path length which may be determined by utilizing several discrete wavelengths with RF modulations.

Abstract: An iterative method and apparatus for correction and compensation of analytical signals, such as spectrometric data, is provided which corrects for spectral cross-talk; compensates for spectral shift; and reduces error propagation. The method and apparatus can be applied to a multicomponent sample analysis using least squares procedure with differentiation while reducing noise propagation.