Abstract: The present invention includes a microelectrode which achieves a surface-renewal advantage. The sensor and method directly controls the oxidizing and reducing nature of the electrode interface by controlling the cell potential, thereby protecting the sensing electrode's surface during periods in which the sensor is not being used. The microelectrode is biased at a small positive potential relative to the counterelectrode, except when a measurement is desired. To measure oxygen concentrations in brake fluid, the microelectrode is biased at a greater potential and the current is measured. After the current measurement, the potential is returned to the small positive potential. The oxygen concentration (and thus the amount of air) in the brake fluid is linearly related to the current measured.

Abstract: A method and device for the measurement of rheological properties of high density slurry materials and in particular high density mill tailings. A sample of the tailings is placed within a mixing tub, with either a concentric paddle or a planetarily movable paddle used to effect the mixing. A digitally controlled electric motor is used to directly drive the paddle at a constant or predetermined speed or speeds. The tub is laterally pivotable against a load cell for a direct determination of reaction torque with correlation to viscosity and other rheological properties of the mill tailing.

Abstract: A novel method and apparatus for measuring elongational viscosity are disclosed. It is shown that in a hyperbolic or semi-hyperbolic die geometry with lubricated flow, the elongational viscosity of a fluid can be obtained from pressure drop--flow rate data. Experimental data for polypropylene as core and polyethylene as skin material, and the calculated extensional viscosities are presented. Alternative embodiments of the novel elongational rheometer are described, including alternatives suitable for biaxial flow.

Abstract: A method and apparatus for detecting the flow regime of multiphase fluid flowing in a closed pipeline system utilizes an entirely passive acoustical detector means. The acoustical pattern detected by the detector means is amplified and compared to known patterns to identify the flow regime according to its acoustical fingerprint.

Abstract: A membrane filter integrity test system includes a large volume mass-flow controller for rapidly supplying a larger amount of fluid to a primary side of a membrane filter under test, a small volume mass-flow controller for supplying a relatively small amount of fluid to the primary side of the membrane filter. The operation of the large volume mass-flow controller is stopped when the pressure at the primary side of said membrane filter reaches a predetermined level. This predetermined pressure is detected by a pressure sensor which senses the pressure at the primary side of the membrane filter. The pressure sensor responsively generates a detection signal corresponding to the sensed pressure at the primary side of the membrane filter.

Abstract: To be used in a gas supply line having an upstream main on/off valve, a meter downstream of the valve, and a pressure regulator intermediate of the valve and meter, the gas supply line being used to supply gas to appliances at an installation site, a gas leak detection test station including a fitting connected in fluid communication with the line downstream of the pressure regulator, fitting having a body with a main inlet opening, a main outlet opening, and a flow path between the openings. The station further having a fixed valve body portion integrally formed with the body of the fitting, the fixed valve body having a movable valve portion which is movable between a normal valve closed position and a valve open position, the movable valve portion normally being urged towards the normal closed position, the body portion being adapted for connection with a manometer.

Abstract: A hydraulic-pneumatic cushioning device including a pressure indicator mounted on the device or remote from the device and connected to the pressure chamber within the cushioning device. The indicator includes a recess and a small pin extending into the recess. The position of the pin relative to the recess provides a tactile indication of the condition of the cushioning device.

Abstract: The invention relates to an oxygen sensor which measures the concentration of oxygen based upon ultrasonic sound waves traveling through a binary gas. The measured sound-wave delay through the gases determines the concentration level for oxygen within the transducer chamber. The invention includes an L-shaped housing where a transmitter/transducer is attached to one end of the housing and the receiver/transponder is positioned at the junction between the two substantially straight portions of the L-shaped housing. A straight transducer chamber is thereby provided, while simultaneously provided a housing design which minimizes reflected standing waves for detection by the receiver/transponder. The invention includes a sonic baffle positioned at the opposite end of the L-shaped housing from the transmitter/transducer which minimizes standing waves thereby improving the performance of the gas detection device.

Abstract: A stationary plate assembly for a rheometer that selectively provides steady state and dynamic testing of melt viscoelastic characteristics of a material sample. The stationary plate assembly has a stationary sample plate magnetically coupled to its supporting member. Therefore, after the steady state testing is complete, the movable plate, material sample and stationary plate may be moved vertically away from the stationary plate supporting member. Therefore, any spurious, erratic rotations of the movable plate when the rheometer is switched form the steady state test mode to the dynamic test mode will not cause a further working of the material sample.

Abstract: A portable leak detection system. The inventive system (10) includes a portable housing (40). The housing is equipped with a pneumatic circuit including an inlet (12) for receiving fluid from a source and an outlet (36) for communicating the fluid to an external unit under test. A flow meter (30) is disposed within the housing (40) between the inlet (12) and the outlet (36) for measuring the flow of the fluid into the unit under test. A calibration verification mechanism (50) is disposed within the housing (40) for verifying the calibration of the flow meter (30). In a specific implementation, the invention further includes a pressure regulator (22) disposed within the housing (40) between the inlet mechanism (12) and the flow meter (30).

Abstract: The invention concerns a process and a device for splitless vaporizing injection of samples into equipments of gas chromatographic analysis.The technique is applied specially when liquid samples generate volumes of vapors which cannot be housed inside the vaporizing chamber.Inside the vaporisation chamber, kept at high temperature, evaporation of the sample solvent forms a cool zone where the solutes are retained while the solvent vapors expand out of the vaporizing chamber and leave the injector. The sample liquid is kept in place within the vaporization chamber by suitable obstacles or by a packing material. At the end of solvent evaporation, i.e. when cooling ceases, the injection zone returns to the regulated injector temperature and the compounds to be analysed are transferred to the column by the carrier gas.

Abstract: On-line rheological measurements are made utilizing a rheometer of the type in which a first metering pump delivers diverted melt from a process main stream to a capillary passage and a second metering pump returns the diverted melt from the capillary passage to the process main stream and the viscosity of the diverted melt is measured by controlling the rate of flow of the melt through the capillary passage to maintain constant the pressure drop between spaced apart locations along the capillary passage and measuring the temperature of the melt in the capillary passage. The measurements may be made while controlling the speed of the second metering pump independent of the speed of the first metering pump to maintain the pressure at the exit of the capillary passage essentially constant.

Abstract: A pressure testable flexible entry boot that provides sealed piping penetration through a container wall including a first elastomeric boot which cooperates with a second elastomeric boot to form a sealed air pocket, which may be pressurized by introducing air through a port extending through one of the elastomeric boots to detect leaks.

Abstract: An explosive detection screening system used for the detection of explosives and other controlled substances such as drugs or narcotics. The screening system detects the vapor and/or particulate emissions from the aforementioned substances and reports that they are present on an individual or object and the concentration of each substance detected. The screening system comprises a sampling chamber for the collection of the vapor and/or particulate emissions, a concentration and analyzing system for the purification of the collected vapor and/or particulate emissions and subsequent detailed chemical analysis of the emissions, and a control and data processing system for the control of the overall system.

Abstract: A humidity measurement process and humidity measurement scale are derived from the physics of relative humidity. Absolute moisture content is determined independent of any measurement or knowledge of the source temperature. The humidity measurement is equivalent to the volumetric fraction of water vapor in the measured gas mixture, expressed as a percentage in a fixed range from 0 to 100%. The operating principles of the measurement process and measurement scale are described for use with an instrument suitable for humidity measurements in process ovens, product dryers, exhaust stacks, and similar environments operating at temperatures to 1250.degree. F. and near atmospheric pressure. The instrument is a point-source sampling system. A continuous sample of process air is induced to flow through the instrument for humidity measurement.

Abstract: Disclosed is a probe for determining the gas content of molten metal. The probe comprises a porous filter head permeable to gas and impermeable to the molten metal and a hollow cast iron tube or sleeve having an upper portion and a lower portion, the sleeve or tube attached to the filter head at the lower portion. A small diameter tube may be positioned in the sleeve, or the cast iron tube may be formed to provide a small diameter bore. Means for drawing a vacuum on the tube and means for measuring gas pressure in the tube is provided.

Abstract: A humidity sensing apparatus is operated by an AC power supply. The humidity sensing apparatus comprises a humidity sensing section including a humidity sensor and a divider resistor connected in parallel to the humidity sensor; a humidity sensor operating section for supplying the humidity sensor with an AC voltage within predetermined voltage levels; and, a humidity signal converting section including diodes, condensers and resistors. The humidity signal converting section converts the AC humidity signal output from the humidity sensing section into a corresponding DC humidity signal by selecting the time constants of the pair of condenser-resistor circuits and then supplies the peripheral digital circuits with the converted signals.

Abstract: A method and apparatus of leak detection for a pipeline.

Abstract: An improved leak detection method is provided that utilizes the cyclic adsorption and desorption of accumulated helium on a non-porous metallic surface. The method provides reliable leak detection at superfluid helium temperatures. The zero drift that is associated with residual gas analyzers in common leak detectors is virtually eliminated by utilizing a time integration technique. The sensitivity of the apparatus of this disclosure is capable of detecting leaks as small as 1.times.10.sup.-18 atm cc sec.sup.-1.

Abstract: A system for detecting leaks in a pipeline includes an outer containment pipe or jacket surrounding a pipe and defining an interstitial space therewith. A plurality of zone fittings are disposed within the containment pipe or jacket to divide the interstitial space into a plurality of zones. Individual external sensors are attached to the containment jacket at each of the zones for detecting the presence of fluid leakage into the interstitial space. The sensors generate an output signal which is operatively connected to visual and/or audible alarms.