Abstract: An injection assembly for short path thermal desorption apparatus used in a gas chromatography-detector unit (GC-DET) for systems, methods and techniques such as a gas chromatography-mass spectrometry system. The short path thermal desorption apparatus has a housing defining an upper compartment, and a desorption compartment. The injection assembly is disposed exterior of the housing and is actuated from a disengaged position to an engaged position with the gas chromatography unit by a suitable gas powered cylinder assembly mounted in the upper compartment and includes a desorption tube for collecting and storing the sample compound to be analyzed, means for passing a carrier gas therethrough to desorb the sample component when the desorption unit is heated, and a needle injector for passing the desorbed sample component to the GC-DET system for identification and quantification of the sample component.

Abstract: Pressure sensing device having a housing (12) with a bottom wall (14) and interior surface (16) and having upstanding edge wall (18) around the periphery of said housing (12). A layer (22) supports a pressure sensing element (30) and its circuitry. A porous gas permeable support layer (40) overlies said pressure sensing element (30) and includes a gas chamber (42) adjacent to the pressure sensing element (30). A gas permeable membrane (50) is supported on said support layer (40). The elements are sealed with respect to the housing as is wire or cable (32) leading from the pressure sensing element (30) to instrumentation remote from the sensing device for readout of measurements by the sensor device (10).

Abstract: A semiconductor accelerometer including a weight, a support frame surrounding the weight with a gap therebetween, at least one beam for connecting the weight to the support frame, a piezoresistor attached onto the beam for detecting acceleration, and stoppers for restricting the movement of the weight relative to the support frame, in which at least one first projection integrally mounted to the weight and at least one second projection integrally mounted to the support frame cooperate to function as the stoppers. At least one first cross member and at least one second cross member may cooperate with the first and second projections. First and second stopping members may also cooperate with the first and second projections.

Abstract: Apparatus (10) for incorporating blowing agents into a liquid material provides a high pressure liquid storage and mixing tank (20) containing a mixture of liquid material (M) under pressure; means for delivering (59) a pre-determined quantity of at least one blowing agent into the mixture in minute bubbles having an average diameter of from about less than 0.5 micron up to about 100 microns; and means for uniformly distributing (60) the blowing agent throughout the liquid material. Apparatus (100) for measuring the volumetric expansion potential of a mixture of blowing agent and liquid material is also provided.

Abstract: A method is described for enabling leak detection of an underground storage tank surrounded by a water table. The method begins by sealing a test probe in the tank, the test probe having an elongated substantially hollow core with first and second ends, a housing for receiving the second end of the hollow tube and being vented to the fluid product, a low temperature coefficient medium supported in the substantially hollow core of the elongated tube, and a liquid seal supported in the housing between the medium and the fluid product. The method continues by then establishing and maintaining a pressure equilibrium between the hollow core of the test probe and the head space. An inert gas such as nitrogen is then introduced into the head space to overpressurize the head space by an amount sufficient to reestablish a leak at any break in the storage tank despite presence of the water table surrounding the storage tank. Once the tank contents are stabilized, the precision leak test is performed.

Abstract: First and second thresholds are established which define a pressure difference relative to a maximum pressure level for a fluid under pressure, which maximum pressure level is detected by a pressure detecting device, and a third threshold is also established which is lower than the maximum pressure level and higher than the first and second thresholds. While a pressure detected by the pressure detecting device ranges between the first and second thresholds, an output signal is supplied to a drive member. When a pressure lower than the third threshold is detected by the pressure detecting device, an output signal indicative of a predicted failure is produced. The output signal indicative of a predicted failure is produced when a pressure lower than the third threshold is detected a plurality of times by the pressure detecting device.

Abstract: A leak detection system for monitoring an evacuated space which includes a vacuum pump, a low vacuum gauge for continuously monitoring the magnitude of the vacuum in said space, and a vacuum control switching assembly responsive to the vacuum in the space for periodically starting the pump when the vacuum in the space is lost to a predetermined extent, and thereby restoring the vacuum to a certain magnitude. A counter is provided to count cycles of the vacuum pump. An alarm device provides an alarm responsive to execessive running of the pump. A high vacuum test line is connected between the evacuated space and the vacuum pump. The high vacuum test line and vacuum pump are used concurrently with a switching system which opens to allow atmospheric air to be drawn into the evacuated space between the confining walls to sweep out and purge this space when high vacuum is applied to the evacuated space, and which isolates the sensitive low vacuum gauge at this time.

Abstract: A test device for assessing low temperature performance of a wax-containing fuel which compriss: a vessel for containing a fuel to be assessed, having cooling and heating elements, for cooling and heating the fuel in the vessel and a filter element wherein the fuel is caused to pass through the filter of the filter element and the cooling and heating elements are so arranged that a stable convection current is set up in the fuel and the filter is so positioned that it receives wax settling from the fuel.

Abstract: A simple acoustic detection system is described for measuring leaks from long gas pipelines. Microphones are strung along (and attached to) the pipeline exterior. The outputs of the microphones are spectrally analyzed. A peak at a frequency f.congruent.V.sub.s /(2d) and its harmonics indicates a leak in the vicinity of the recording microphone, where V.sub.s is the velocity of sound in the gas and d is the thickness of the pipe wall.

Abstract: A low pressure, low energy measuring device for indirectly and non-invasiy measuring the pressure of a gaseous medium in a sealed system, such as gas discharge lamp, is disclosed. The measuring device and method measures the luminance of an externally-induced, high-frequency glow discharge of a gas in the lamp by non-invasive means. Comparison of the measured luminance with calibrated luminance vs. pressure data provides the pressure for the gas. In one embodiment, the components of the measuring device form a stand-alone unit useful for testing multiple sealed systems. In another embodiment, certain components of the device are integrated into the lamp's discharge system to facilitate measurement in the field. A separate peripheral unit is required with this latter embodiment.

Abstract: A method is disclosed for determining the composition of a two-phase fluid, such as saturated steam. In that method, the transit times of sound are measured within the two-phase fluid, the speed of sound of the two-phase fluid is calculated from the measured transit times, and the composition of the two-phase fluid is calculated from the calculated speed of sound. From the calculated linear velocity and the calculated composition, one can calculate at least one fluid property of the two-phase fluid, such as mass flow rate or energy flow rate. All of these calculations can be performed by a microprocessor.

Abstract: A method and apparatus for leak testing a sealed package having at least one flexible wall portion and a sealed flange wherein at least one flexible wall portion of the package spaced from at least a seal-exposing edge of the sealed flange is gripped and pulled outwardly from the package to stress the package in tension while at least the seal-exposing edge of the sealed flange is exposed to a gas pressure equal to or greater than atmospheric pressure. The reaction of the sealed package to the stressing is then detected. The method and apparatus are useful for testing retort or aseptic pouches, cups and multi-layered trays with heat sealed lids, etc., with or without head space. Leaks in the seal and also in areas adjacent the seal can advantageously be detected quickly and with a high degree of reliability.

Abstract: A method and apparatus for dynamic measurement of rates of absorption from solutions. The method has the advantage of avoiding the use of solvent normally used to establish a baseline. The method involves pre-evacuating the adsorbent contained in an adsorbent cell and thereafter rapidly contacting the adsorbent with analytical solution, all without prior exposure of adsorbent to pure solvent. The result is a sharp characteristic adsorption line.

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: The actual flow rate of gas to the solid-sample container or to the gas reservoir can be precisely obtained according to variances in the pressure of the gas reservoir without directly adjusting the flow rate precisely. The volume of gas not adsorbed in the sample container can be obtained from the pressure in the sample container. The adsorption can easily be determined from the difference between the flow rate of gas and the volume of gas not adsorbed in the sample container. Even if the flow rate fluctuates, the adsorption can precisely be obtained. The desorption can easily be obtained in the same way. Gas is exhausted from the gas reservoir in advance. When desorbed gas in the sample container is continuously exhausted to the gas reservoir, the pressure in the gas reservoir is measured.

Abstract: An injector port assembly for direct injection of a solid filter test sample for gas chromatography analysis comprising and elongated thermally conductive injector tube having a perforated sample holding portion, and an injection port having a sealable entry opening into which the elongated injector tube is moveably inserted, a hot zone, a cool zone thermally insulated from the hot zone, a purge valve and a conduit for connecting said injection port in fluid communication with a gas chromatography column.

Abstract: An apparatus for in situ testing of an internal combustion engine for vacuum leaks is provided. In accordance with the present invention, smoke is generated from a suitable smoke-generating fluid in chamber means, and then sealably communicated through conduit means to the intake manifold of a vacuum system in an internal combustion engine. By visibly observing smoke exiting from any of the hoses, flanges and gaskets contained within a vacuum system, leaks therein may be readily located.

Abstract: A tracer gas leak detection system for: a first duct provided with a pre-evacuation valve, enabling a test chamber to be connected to the suction of a pre-evacuation pump. A gas analyzer is connected to the suction of a mechanical secondary pump whose delivery is connected by a second duct to a primary pump. At least one connection is provided with an inlet valve connecting of the text chamber to the mechanical secondary pump and the system further includes a second mechanical secondary pump situated on the first duct downstream from the pre-evacuation valve.

Abstract: A volumetric leak detector. An overfilled storage tank has at its upper end a fill pipe predetermined surface area. An area converter reservoir is connected at this upper end with the storage tank, so that some liquid from the fill pipe flows into the reservoir. The area converter reservoir has a surface area which is larger than the surface area of the fill pipe. An almost constant minimum level is provided in the area converter reservoir, and the height difference between that minimal level and the actual level of the tank are as determined.

Abstract: A fluid separation system applicable to gas chromatography includes a separating column in the form of a coiled tube in a thermally insulated enclosure. The ends of the coiled tube are connected by snap-action couplings to the outlet of an injector and the inlet of a detector which generates an electrical signal corresponding to the component of the fluid being separated. Snap action couplings also connect the thermally insulated enclosure to a thermal control system which circulates a heat exchange fluid to define the temperature in the enclosure.