Abstract: Sensor modules (12) including accelerometers (20) are placed on a physical structure (10) and tri-axial accelerometer data is converted to mechanical power (P) data (41) which then processed to provide a forewarning (57) of a critical event concerning the physical structure (10). The forewarning is based on a number of occurrences of a composite measure of dissimilarity (Ci) exceeding a forewarning threshold over a defined sampling time; and a forewarning signal (58) is provided to a human observer through a visual, audible or tangible signal. A forewarning of a structural failure can also be provided based on a number of occurrences of (Ci) above a failure value threshold.

Abstract: Plastic housings that are subjected to internal pressure and comprise a housing upper part, a housing lower part and a closure which connects both parts to one another. At the connecting point, the housing upper and lower part have a plurality of comb-like retaining columns shaped in a complementary manner with respect to one another such that the housing parts can be plugged together. The retaining columns are oriented in a direction in which tensile force between the housing upper part and the housing lower part is oriented when the housing is subjected to internal pressure. Retaining grooves which are oriented transversely to the effective direction of the tensile force are formed in two opposite surfaces of the retaining columns in each case. Retaining bodies which at least partially touch the areas formed by the retaining grooves and thus establish the connection can be introduced into the retaining grooves.

Abstract: A remote vision analysis system for a vessel containing a process liquid having gas bubbles or particles floating therein. A probe extends into the vessel and enables in-situ observation of the process liquid, gas bubbles or particles, and/or surfaces within the vessel. The probe has a proximal end that includes a camera for recording still or motion images of the process liquid, gas bubbles or particles, and/or surfaces within the vessel. An elongate distal end of the probe extends within an interior of the vessel and is housed within a hermetically sealed protective shroud having a lens, or window, through which images are recorded by the camera. The probe is modular and includes interchangeable parts.

Abstract: A seal is mounted in a groove around an orifice of a measuring chamber inserted in an insertion direction into a tank to form a fluid meter. The seal comprises a radially elastic torus having a shape corresponding to that of the orifice and an arrangement on at least one of its sides substantially parallel to the insertion direction for immobilizing it in a direction opposite the insertion direction.

Abstract: A reliable gaseous hydrogen detection and measuring device which is simple, easy to use, does not require any reference gas supply, and which can be of reasonably rugged construction. The device utilizes a disc comprising a solid state ceramic hydronium conductor of the general formula Na(H.sub.3 O)Zr.sub.2 Si.sub.x P.sub.(3-x) O.sub.12 together with a silver based electrode system on one side, and a catalytic noble metal electrode, such as platinum, on the other. By measurement of the output voltage across the electrodes, both the presence, and the amount, of hydrogen in a gaseous system can be determined.

Abstract: A microliter-sized metastable ionization device with a cavity, a sample gas inlet, a corona gas inlet and a gas outlet. A first electrode has a hollow and disposed in the cavity and is in fluid communication with the sample gas inlet. A second electrode is in fluid communication with the corona gas inlet and is disposed around the first electrode adjacent the hollow end thereof. A gap forming means forms a corona gap between the first and second electrodes. A first power supply is connected to the first electrode and the second power supply is connected to the second electrode for generating a corona discharge across the corona gap. A collector has a hollow end portion disposed in the cavity which is in fluid communications with the gas outlet for the outgassing and detection of ionized gases. The first electrode can be a tubular member aligned concentrically with a cylindrical second electrode. The gap forming means can be in annular disc projecting radially inwardly from the cylindrical second electrode.

Abstract: Energy efficiency of a thermal zone in an analytical instrument is improved by use of an oven cavity insert that may be removably positioned in an insulated enclosure in an oven cavity housing, whereby the combination of the oven cavity insert and one or more of the enclosure walls completely encloses a first space suitable for effecting the thermal zone. The oven cavity insert is positionable so as to separate the first space from at least a portion of the unused volume of the oven cavity, thus reducing the volume of the thermal zone, so as to reduce the amount of heating or cooling required for temperature control of a component positioned therein. When present in the oven cavity, the contemplated oven cavity insert effectively conceals a portion of the housing from the thermal zone, thus reducing the effective thermal mass of the oven cavity housing.

Abstract: A photoionization detector for a gaschromatographic apparatus includes an ionization chamber provided with a polarizing electrode and a collector electrode. The electrodes are mounted on and heated by a base portion of the detector. A lamp with a window spaced from the chamber and mounted on the base portion through supporting means having low thermal conductivity is provided. A gas curtain of a gas that is transparent to the said lamp radiation is provided at least between the window and the ionization chamber and comprises a first portion of substantially still gas acting as thermal insulant and a second portion of flowing gas also acting as sweep gas for the lamp window.

Abstract: A noise-suppressing capillary separation system for detecting the real-time presence or concentration of an analyte in a sample is provided. The system contains a capillary separation means through which the analyte is moved, a coherent light source that generates a beam which is split into a reference beam and a sample beam that irradiate the capillary, and a detector for detecting the reference beam and the sample beam light that transmits through the capillary. The laser beam is of a wavelength effective to be absorbed by a chromophore in the capillary. The system includes a noise suppressing system to improve performance and accuracy without signal averaging or multiple scans.

Abstract: A surface ionization detector for detecting organic molecules such as illicit drugs and non-organo-nitrate explosives includes a heated surface and a collector electrode. A sample containing trace amounts of the organic molecules in ambient air is directed over the heated surface maintained at a temperature in the range of 500.degree. C. to 800.degree. C., thereby causing the molecules to decompose into fragments. A polarization voltage between 18 V and 24 V is applied to ionize the fragments which are then collected by the collector electrode. An electrometer connected to the collector electrode measures the current and a change in the current indicates the presence of ionized fragments, and thereby indicates the presence of the organic molecules. The temperature of the heated surface and the polarization voltage are optimized for detection of particular organic molecules.

Abstract: A method for determining the amount of a contaminant in a refrigerant gas under pressure and the detector tube and tube holding assembly. The method involves preparing a predetermined length of refrigerant hose and connecting a pressure gauge to an exit end of the hose. The entrance to the hose is connected to a sealed detector tube which is held in a fitting which connects to conventional refrigerant hose. This fitting is connected at its other end to a source of refrigerant gas under pressure to be tested. The gas is allowed to pass through the detector tube into the known length of empty tube until the pressure gauge reaches a predetermined value depending upon the refrigerant gas to be tested. This causes a known volume of gas to pass through the detector tube and the detector tube changes color and the distance that the color change has taken place is a measure of the contaminant. Different detector tubes are used for different contaminants.

Abstract: The present invention relates to a method and a device for the detection of vessel dilatation components. The invention particularly relates to the detection of explosives, such as trinitrotoluene (TNT) and nitroglycerin. A biological detector is used, and precontracted blood vessels or parts thereof function as sensor elements.

Abstract: An analytic separation arrangement includes a system of tubes including a separation zone, preferably a separation column, which tubes upstream the separation zone are connected with reservoirs for a carrier and a chemical sample to be seperated and analyzed, and downstream the separation zone are connected with a waste container for the carrier containing the sample and also are connected with transporting means for the carrier and the sample. The tube system is associated with an optical detector for monitoring changes in the absorption, in the fluorescence or in the optical activity of the carrier when it is transported through the tube system and past the optical detector, which is arranged in the path of the carrier behind the separation zone but in front of the waste container. Between the separation zone and the optical detector there is arranged in the path of the carrier a refractive index equalizing unit.

Abstract: Apparatus and methods are provided for using a detector designed for use with liquids to detect resolved analytes in an effluent stream from a gas chromatography instrument. The gaseous stream is entrained by a flowing liquid solvent, and at least a portion of the analytes are transferred from the gas phase to the liquid phase. The liquid solvent containing the analytes is then conveyed to a detector designed for liquid analysis. Thus, the present invention gives the analyst more options for detecting an analyte or a group of analytes, thereby providing greater flexibility in optimizing the sensitivity or selectivity of the analysis. Furthermore, the present invention allows gaseous effluents to be analyzed by detectors which more readily permit sample recovery than the detectors currently being used to analyze gaseous effluents.

Abstract: A method of determining optimum operating potential in an electrochemical detector and an electrochemical detector for performing the method, particularly for use in connection with a liquid chromatograph, are disclosed. A control and data processing unit causes a plurality of different potentials to be successively applied in an electrochemical cell and a subsequent electrochemical detection of the sample to be performed at each of the potentials. After each adjustment of a new potential, the current behavior at the working electrode in the electrochemical cell is monitored by an amperometer. When the current behavior has stabilized, a trigger signal is produced by the unit which effects an injection of the sample into the separation column of the chromatograph. From the current signals at the working electrode obtained for the different potentials, it can be determined which potential gives optimum detectability of the sample.

Abstract: The presence of dangerous substances such as cocaine is detected by atmospheric samples that include the residues (such as ether) of the manufacture of the suspected substances into a gas chromatograph to remove substances other than the residues and thereafter drawing them into a proportional counter chamber having a high voltage and a signal wire. A laser passes light capable of exciting the suspected residues through the proportional counter to produce ionization and generate a photoelectron. The signal wire passes this to an analyzer which indicates the presence of the suspected residues.

Abstract: Multiple electropherograms or chromatograms representing successive stages of an electrophoretic or chromatographic separation in a capillary are obtained by training a recorder on a succession of detection windows in the capillary, spaced apart along the capillary length. A single immovable detector is used, and the capillary is either held such that each detection window is placed in alignment with the detector in succession, or is looped such that the detection windows all lie in the path of the detector at the same time.

Abstract: A method of gathering a library of response patterns for one or more sensor arrays used in the detection and identification of chemical components in a fluid includes the steps of feeding samples of fluid with time-spaced separation of known components to the sensor arrays arranged in parallel or series configurations. Modifying elements such as heating filaments of differing materials operated at differing temperatures are included in the configurations to duplicate operational modes designed into the portable detection systems with which the calibrated sensor arrays are to be used. The response patterns from the known components are collected into a library held in the memory of a microprocessor for comparison with the response patterns of unknown components.

Abstract: A hydrocarbon vapor sensor which is simple and low cost and can easily detect the existence of hydrocarbon vapor. The device is temperature compensated so that a change in resistance due to a change in temperature is avoided and an arcurate response is always provided. The sensor can be used in a system in which a number of sensors are provided at various depths to determine whether a leak or a ground spill has occurred.

Abstract: A preparative-scale gas chromatographic system has conduits and valves adapted for analysis and collection of low volatility effluent. An injection site is provided for alternately supplying liquid solvent for removing condensed effluent from the system when the flow of effluent is terminated. Conduits are joined within the thermal conductivity detector of the system to prevent condensation at the joint. Conduits are provided with copper jackets which are coupled to sources of thermal energy to prevent condensation within the conduits. A trap filter provides backpressure in the collection system wherein recovery of condensed effluent in the filter is facilitated by the smooth surface of the filter.

Abstract: The objects of the invention are attained in an apparatus for performing a method of analysis of organic compounds in chromatography, comprising a chromatographic column sealingly connected with the housing of a surface ionization detector having coaxially arranged inside, a collector and a thermoemitter with current leads, the housing of the surface ionization detector being provided with an opening for an auxiliary gas feed line and an opening for delivering the spent gases. The thermoemitter includes a closed-end sleeve with a heating element in contact with the external non-working surface of the thermoemitter. The collector includes a hollow cylinder spaced from the inner ionizing surface of the thermoemitter, and the outlet portion of the chromatographic column being received inside and throughout the length of the collector.

Abstract: A detector device for a gas chromatograph, for detecting surface ionization wherein ions will be detected which are formed upon contacting amine compounds and ammonia with the surface of metallic oxides having a large work function. The detector enables detection of poisonous amine compounds and ammonia with high sensitivity.

Abstract: A flame detector comprising a ceramic flame jet for use in a high temperature gas chromatography system is disclosed. The interior volume of the flame jet is fabricated of a highly inert ceramic material so that sample eluting from the end of a gas chromatography column located within the interior volume of the flame jet does not contact any metallic surface en route to the flame. By avoiding sample contact with metallic surfaces, interferences which are prone to occur at high temperature, such as peak tailing, are avoided. In a further aspect the flame detector is treated with a silylating reagent to further passivate the surfaces which may affect the sample.

Abstract: An open-split interface includes a connector body having four leg members projecting therefrom within a single plane, the first and third legs being coaxial and the second and fourth legs being coaxial. A tubular aperture extends through the first and third legs and a second tubular aperture extends through the second and fourth legs, connecting at a juncture within the center of the connector body. A fifth leg projects from the connector body and has a third tubular aperture extending therethrough to the juncture of the first and second tubular apertures. A capillary column extends from a gas chromatograph into the third leg with its end adjacent the juncture. A flow restrictor tube extends from a mass spectrometer through the first tubular aperture in the first and third legs and into the capillary columnm end, so as to project beyond the end of the third leg within the capillary column. An annular gap between the tube and column allows excess effluent to pass to the juncture.

Abstract: Measuring apparatus for calibrating flow meters and the like comprising a piston slidably mounted within piston cylinder means which receives gas passing through the flow meter being calibrated to cause the piston to be lifted. A precision encoder is rotated responsive to the movement of tape means aligned with the central axis of the piston and entrained about a pulley driving said encoder means. The tape is also connected to counterbalancing weight means for enhancing the sensitivity and accuracy of the measuring apparatus. The system electronics initiate operation of timer means upon the first pulse generated by the encoder means after operation of a start button and terminates the operation of the timer means upon the first encoder pulse generated after operation of stop button.Temperature and pressure in the piston cylinder are constantly monitored. These readings are employed at the time flow rate calculations are performed to correct the flow rate calculated to standard temperature and pressure.