Abstract: A small-sized and inexpensive coating material feeding apparatus capable of feeding even a coating material comprising less miscible main agent and curing agent as in an aqueous two component mixed coating material, while uniformly mixing them, to a coating machine or a coating material tank under extremely simple control, the apparatus comprising a measuring unit having a measuring cylinder for delivering the coating material ingredients each by an amount in accordance with the mixing ratio individually and simultaneously to the coating material tank, a storage unit having a transfer cylinder for storing the coating material prepared by mixing each of the coating material ingredients previously and then delivering the same to the coating machine or the coating material tank, and a valve unit formed with a switching valve for conducting channel switching, in which the coating material ingredients delivered from the measuring cylinder are pre-mixed in the channel stirring pre-mixer and a coating material deliv

Abstract: A pressure proving gas valve insures safe and efficient operation of a fuel-burning appliance by monitoring combustion air pressure and appropriately controlling the valve based upon this air pressure. An air pressure sensor is incorporated into a pressure proving valve housing itself thus providing integrated solution for the control of the combustion process. Consequently, when heat is called for, no fuel is provided to the combustion chamber unless appropriate combustion air pressure is sensed. Further, by monitoring the actual air pressure, additional control capability is provided. That is, a variable speed blower associated with the combustion apparatus can be controlled to provide very precise fuel to air mixtures.

Abstract: A rotary liquid mixing solenoid valve comprises a valve casing, a cold and/or hot water inletpipes, a mixed water outlet pipe, a temperature sensor installed in the mixed water outlet pipe, and a guardless rotary electromagnet mounted on a side of the valve casing. Both side faces of a regulating block mounted on an epitaxial end of a rotary armature shaft of the electromagnet may fit with the end faces of cold, hot liquid inlet openings respectively. After a coil is energized, the regulating block causes the temperature of mixed liquid to be stable via regulating the flow of cold, hot liquids in proportion according to a preset temperature. The valve has the advantages as follows: e.g. a simple structure, a miniature volume, a small power consumption, a high working efficiency, a fast regulating response, a high accuracy, and a stable and reliable operation, etc.

Abstract: A flow monitoring system (14) for and method of monitoring the flow of processing gases in a wafer processing system (10) during the manufacturing of microelectronic devices. The wafer processing system includes a wafer processing chamber (12) in fluid communication with a gas delivery system (18) via a common conduit (32). The gas delivery system includes a plurality of gas sources (22) each having a flow regulator (24) and a flow meter (26). The flow monitoring system includes a total flow meter (36) in fluid communication with the common conduit between the gas delivery system and the processing chamber. When a gas is flowed into wafer processing chamber from one of the gas sources, the comparator compares a first flow signal from the total flow meter to a second signal from the flow meter corresponding to the active gas source to determine whether or not the corresponding flow regulator is properly calibrated.

Abstract: A device for introducing a first fluid into a second fluid stream comprising an enclosure and a member which causes release of a first fluid. The enclosure releasably retains the first fluid. The release causing member causes the release of the first fluid from the enclosure into the second fluid stream upon detection of a predetermined condition associated with the second fluid stream.

Abstract: Disclosed is a method for transporting blended crude oils comprising the steps of; (a) admixing a first crude oil with a second, different crude oil to form a crude oil admixture; (b) determining a first value representing the content of unprecipitated asphaltenes in the admixture; (c) holding the admixture for a period of time at standard conditions; (d) determining a second value representing the content of unprecipitated asphaltenes in the admixture; and (e) either: (i) transporting the admixture if the second value is the same as or within a predetermined range of the first value; or (ii) taking remedial action to prevent asphaltene precipitation prior to transporting if the second value is outside a predetermined range from the first value. Also disclosed is a method for estimating the storage stability of stored crude oils and crude oil admixtures.

Abstract: An apparatus for preparing dialysate concentrate includes a vessel, a controllable valve for regulating water flow to the vessel, a first sensing device for detecting when the liquid has reached a lower level, a second sensing device for detecting when the liquid has reached an upper level, a controller selectively responsive to one of the sensing devices, and a positionable switch for selecting to which of the sensing devices the controller is responsive.

Abstract: Apparatus for the preparation of gas mixtures includes cylinder which is divided into two chambers by means of a fixed central barrier. This barrier has a central orifice for receiving a rod which has central portion of diameter corresponding with the diameter of the orifice. The rod has end portions which pass through end plates of the cylinder and these end portions have a small diameter than that of the central portion, the diameters of the end portions being equal. A valved passage for the gases of either chamber to be transferred to the other chamber is provided in the barrier and a stepper motor is used to move the rod over small distances; with means to introduce or withdraw gas from either chamber.

Abstract: Gas mixtures having precise compositions are prepared by separately pumping the components in liquid phase through piping, vaporizing the components, blending the components and analyzing the mixture for composition. A signal sent to a control unit causes any necessary change in the rate of pumping of the liquid components to reduce the difference between the measured concentration and the desired concentration. When the composition is within desired limits it is charged into gas cylinders.

Abstract: A process for the dynamic manufacture and packaging of gas mixtures containing a first component and a second component in predefined proportions, the first and second components being chosen from the group formed by O2, N2, He and N2O, in which predetermined proportions of the first and second components are dynamically mixed in order to obtain a gas mixture of the desired composition and the temperature of the mixture is adjusted in order to keep it above the demixing threshold temperature of the mixture. This process is particularly suitable for the production of analgesic gas mixtures that can be used in the medical field, particularly a mixture formed from 50% oxygen and 50% nitrous oxide.

Abstract: The present invention provides apparatus, systems, and methods related to the manufacture of integrated circuits. Specifically, embodiments of the present invention include apparatus designed to provide thorough and reliable fluid mixture for gases used in a semiconductor processing system. In one embodiment of the invention, the gas mixing apparatus comprises a gas mixer housing having a gas inlet, a fluid flow channel, and a gas outlet. The fluid flow channel is fluidly coupled to a plurality of gas sources. The majority of the gas mixture occurs in the fluid flow channel which comprises one or more fluid separators for separating the gas into two or more gas portions and one or more fluid collectors for allowing the gas portions to collide with each other to mix the gas portions. This separation and collection of the gas portions results in a thoroughly mixed gas.

Abstract: An object of this invention is to provide a hydraulic brake control device which has a simple structure for the effective holding of the coil unit, for preventing breakage of the electric connection of the lead wire, and for assuring a long lasting electric connection. The coil holding board 80 has protuberances 83, 84 elastically contacting the bottom portion of the coil unit 52. The board is assembled with the opening side of the cover 60. The coil unit 52 is frictionally engaged with the cover 60 to be held only by the elastic force of the coil holding board 80 or with elastic material 22 inserted between the cover 60 and the top portion of the coil 52.

Abstract: A system for blending two-blend components to form a blended final product including a first supply line for supplying a first blend component at a first flow rate and a second supply line for supplying a second blend component at a second flow rate. The first supply line and the second supply line intersect to form a blended product line. The system further includes a blended product measuring device positioned in the blended product line for measuring the flow rate of the blended product and an auxiliary measuring device positioned in the first supply line for measuring the flow rate of the first blend component. The auxiliary measuring device may have a degree of accuracy less than that of the blended product meter. Alternatively, the auxiliary measuring device may have the same level of accuracy as that of the blended product meter.

Abstract: A method for preparing a welding fluid consisting of a mixture of at least two components. The method including the steps of withdrawing the mixture components from respective tanks and feeding them into a mixing zone at substantially identical pressures, monitoring the composition of the mixture formed, and if the composition is correct, feeding the mixture into a buffer tank to be stored.

Abstract: A method of manufacturing a system for mixing fluids for providing a flow of a fluid product having a certain pre-established quality or characteristic, from a flow of a first fluid component and a flow of a second fluid component, wherein the fluid components do not meet the pre-established quality standards of the fluid product. The system includes a mixing reservoir; first and second fluid conduits connected to the mixing reservoir for flowing the first fluid component and the second fluid component, respectively into the reservoir; and a third fluid conduit connected to the mixing reservoir for discharging a flow of fluid product from the mixing reservoir, and sensors connected for sensing the flow rates and qualities of the first and second fluid components, flowing into the mixing reservoir and of the fluid product discharged from the mixing reservoir.

Abstract: A device for introducing a first fluid into a second fluid stream comprising an enclosure and a member which causes release of a first fluid. The enclosure releasably retains the first fluid. The release causing member causes the release of the first fluid from the enclosure into the second fluid stream upon detection of a predetermined condition associated with the second fluid stream.

Abstract: A system for injecting chemicals, e.g., odorants, from a chemical supply into a conduit or container includes three primary components, a pump for injecting the odorant, a metering device, and a programmable controller. The controller is preferably powered by a solar panel to facilitate use of the system in remote areas for long periods of time. A removable data carrier, such as a memory module, is connected to the controller to collect odorant system event data. The data carrier is removable from the controller and the data therein may be downloaded into an auxiliary audit computer for generation of summary audit reports. The system precisely monitors how much odorant is used per pump stroke and insures that the odorant injection rate remains constant irrespective of environmental or equipment variations which might otherwise cause inaccuracies in the measurement of odorant usage data and/or the fluctuation of the odorant injection rate.

Abstract: Apparatus for removing gases from a container used to prepare concentrates of a powder in water are disclosed including a supply conduit for supplying water to the container, a removal conduit for removing the concentrate from the container, a pump including a negative pressure side, an evacuation conduit for connecting the negative pressure side of the pump with the container, an actuatable valve disposed in the evacuation conduit whereby upon actuation the actuatable valve connects the container with the negative pressure side of the pump, an indicator for indicating when the container includes a predetermined amount of the gases, and a control mechanism for actuating the valve in response to the indicator to eliminate the gases from the container.

Abstract: A process for monitoring and controlling an aqueous system. At least one performance parameter relating to conditions within the aqueous system is selected. A value of the at least one performance parameter is measured to serve as a baseline value. A capacity of the aqueous system is determined and flow rates of water into and out of the system are measured and monitored. The value of the at least one performance parameter is measured and compared the value to the baseline for the performance parameter. Flow rates of water into and out of the system are factored in. At least one controllable variable within the aqueous system is altered based upon a deviation of the value of the at least one performance parameter from the baseline value.

Abstract: A coating apparatus according to the invention comprises a spin chuck for holding a substrate, resist solution tanks which contain a primary resist solution, a thinner tank which contains thinner, a confluence valve communicating with the thinner tank and the resist solution tanks, first pumps each for supplying the confluence valve with the primary resist solution from a corresponding one of the resist solution tanks, a second pump for supplying thinner from the thinner tank to the confluence valve, a mixer for mixing the primary treatment solution and thinner supplied from the confluence valve, a nozzle for applying a solution from the mixer, to the substrate held by the spin chuck, and a controller for controlling the first and second pumps to adjust the mixture ratio of the primary resist solution to be supplied from each of the resist solution tanks to the confluence valve, to thinner to be supplied from the thinner tank to the confluence valve.

Abstract: A system and method for mixing and/or diluting ultrapure fluids, such as liquid acids, for semiconductor processing. The system includes first and second chemical dispensers, the first and second chemical dispensers adapted to contain first and second fluids to be mixed, respectively; a process connection between the first and second chemical dispensers which allows the first and second fluids to flow therethrough and intermingle to form a mixed fluid, the process connection further allowing the mixed fluid to flow to a location needed by the operator; and an ultrasonic wave emitting device provided in a location sufficient to transmit an ultrasonic wave through the mixed fluid, the device including means to measure the velocity of the wave through the mixed fluid, and thus indirectly measure a ratio defined by a quantity of the first chemical to a quantity of the second chemical in the mixed fluid.

Abstract: The invention relates to a metering device for the metered admixture of a first fluid in a second fluid. The device comprises a housing (10) with a first inlet (15, 16), a second inlet (11), and an outlet (14) for a mixture of the two fluids. The housing (10) also contains a moving body (18) which is so arranged as to be influenced by a flow of fluid through the housing and exhibits means for regulating the first fluid, in such a way that a change in the flow at the outlet (14) produces a change in the flow of the first fluid. The inlet (15, 16) for the first fluid is connected to a tubular channel (17), which is centered essentially coaxially inside the outlet (14). The body (18) is mounted so that it is capable of displacement along the outside of the tubular channel (17), against the effect of a spring device (21) acting in a direction downstream.

Abstract: A system and method for dispensing a fuel derived from one or more fuels having different octane ratings respectively stored in a plurality of storage tanks. The fuels are passed from their respective tanks to a mixing zone for mixing to form a blended fuel. The blended fuel is passed from the mixing zone to a dispensing nozzle while the octane rating of the blended fuel is sensed. The flow of each fuel from its tanks to the mixing zone is controlled accordingly to establish and maintain a predetermined octane rating of the blended fuel.

Abstract: Methods for the central preparation and distribution of a concentrate to a plurality of medical treatment devices are disclosed comprising supplying a stream of substantially only water to a central container which includes a single salt composition at least partially in solid form, producing a substantially saturated solution of the salt composition in the central container, and distributing the salt solution to a distribution conduit which includes a plurality of concentrate connectors whereby the salt solution can be distributed to the plurality of medical treatment devices. Methods for disinfecting this apparatus, the apparatus itself, and containers for use in the apparatus are also disclosed.

Abstract: A thermostatic regulator (30) for a single handle mixer valve (12) has a sensor (32) mounted in a mixed water chamber (34) for sensing the temperature of the outlet water. The sensor is connected to a valve (20) that is mounted in the cold water supply line (18) to restrict the availability of cold water when the water in the hot water line (16) is down below a set temperature.

Abstract: A substrate processing apparatus does not allow sudden boiling of supplementary liquid but rather sufficiently diffuses the supplementary liquid into processing liquid so that the temperature of the processing liquid does not decrease largely. De-ionized water (PW) is ejected through a plurality of de-ionized water blow-off openings (Ha) which are formed in a de-ionized water injection nozzle (10a). Inside an internal bath (1), which is located immediately below the de-ionized water blow-off openings, and close to a overflow part (20a) which is a top edge of a side surface (1a) of the internal bath (1), the de-ionized water reaches the surface of a phosphoric acid solution (PA). The de-ionized water thereafter reaches a gutter part (30a) of an external bath (2), as it is mixed with the phosphoric acid solution (PA), and flows into a reservoir part (30d) of the external bath (2).

Abstract: Apparatus and methods for precision batch or continuous flow blending of gases are described. Pulsatile precision metering valves having substantially zero dead space are employed to introduce gases to a mixing chamber or manifold in predictable uniform quantities to achieve precision gas blends according to predetermined criteria. During batch processing, gases to be blended are repeatedly characterized by the change in mixing vessel pressure with respect to time immediately after blending. Estimates of additional amounts of a given gas to be added to achieve a desired final partial pressure of the given gas in the mixing vessel are based on empirical data previously measured and stored for the gas in question.

Abstract: The invention is directed to a process for providing a gas having a minimum pressure and a composition that includes a major component to an end application, said process comprising the following steps:a) providing a first gas having said major component in a first concentration to said end application;b) providing means for measuring the pressure of said first gas being delivered to said end application;c) providing a second gas having a second concentration of said major component of said first gas which exceeds said first concentration;d) providing a third gas having a third concentration of said major component of said first gas which is less than said first concentration;e) providing means for mixing said second and said third gases so as to produce a fourth gas at at least said minimum pressure and which has said major component in a fourth concentration; wherein,f) when said means for measuring the pressure of said first gas to be received at said end application detects a deficiency with respect to sa

Abstract: A method for detecting and controlling cooling system characteristics. A flow rate of make-up cooling medium is measured. A conductivity of the make-up cooling medium is measured. A conductivity of a recirculating cooling medium is measured. A treatment material feed rate is determined based upon the formula: ##EQU1## where X is a treatment feed rate of a treatment compound, .OMEGA. is a desired concentration of the treatment compound, and K is a constant. A corrosion rate of the recirculating cooling medium is measured. A desired corrosion rate of the recirculating cooling medium is determined. A feed rate of a corrosion inhibitor is calculated according to the following formula:Y=(X)?1+.alpha.(CORR.sub.MEASURED /CORR.sub.SETPOINT)!,where .alpha. is a cascade factor that varies in a step-wise manner depending upon the value of CORR.sub.MEASURED /CORR.sub.SETPOINT and has a value between about 0.1 and about 8.0. A corrosion inhibitor is then fed at the corrosion inhibitor feed rate.

Abstract: A method and apparatus for treating nuisance odor streams is provided. One embodiment of the invention is directed to a method and apparatus in which deodorizing chemical agents are applied to an evaporative reaction pack situated within a gas chamber having an air stream running therethrough. The evaporative reaction pack provides a reaction zone within which the chemical agent is evaporated to facilitate a gas-gas or vapor phase interaction between the chemical agent and odoriferous compounds contained in the air stream. Another aspect of the present invention relates to a method and apparatus for batch processing of sewage treatment agents within a wet well to prevent the formation of undesired compounds. In one embodiment, a predetermined amount of chemical agent, sufficient for treating the amount of sewage that the well can hold, is added to an evacuated wet well in coordination with the pumping of sewage from the wet well.

Abstract: A gas flow rate controller arranged between a gas burner and a flammable gas source and a combustion-assisting gas source includes a gas flow rate setting means for producing a flow rate setting signal corresponding to a preset flow rate of gas flowing toward the gas burner. A ratio setting means produces a flammable gas setting reference signal and a combustion-assisting gas flow rate setting signal at a predetermined ratio, based on the flow rate setting signal produced by the gas flow rate setting means. The flow rate of the flammable gas detected is compared with the flammable gas setting reference signal produced and the flow rate of the combustion-assisting gas detected is compared with the combustion-assisting gas flow rate setting reference signal produced. Control valves are feedback controlled so that any differences therebetween will become zero. Thus the mixing ratio between the gases is kept constant even if the gas pressures change.

Abstract: A method and an apparatus for preparation of a medical solution from water and a plurality of concentrates, including at least one acid in gaseous form, comprises the steps of transporting the water from a source through a main conduit and successively adding the plurality of concentrates to the water in the main conduit at a plurality of predetermined points positioned along the main conduit. The apparatus for preparing the medical solution includes a source for supplying the gaseous acid and other concentrates to the plurality of predetermined points along the main conduit, wherein the plurality of predetermined points includes a gas inlet for injecting the acid in gaseous form supplied from the gas source into the main conduit.

Abstract: The invention is a system for drawing off multiphase effluents. The system includes a drum; at least one assembly, located in the drum, for drawing a multiphase fluid contained in the drum to outside the drum, the at least one assembly including a section through which the multiphase fluid is drawn to flow outside the drum, and extending over a substantial portion of a height of the drum; at least one sensor for sensing at least one flow condition of the multiphase fluid and for providing a signal representing each sensed flow condition of the multiphase fluid; and a mechanism, coupled to the at least one sensor, for modifying the section of multiphase flow as a function of each signal representing a sensed flow condition.

Abstract: An apparatus is disclosed for mixing ambient air and a hazardous gas with the gas being admitted to the apparatus via an inlet conduit. A rake disposed for travel within said conduit periodically dislodges deposits from the conduit interior with rake travel being along conduit affixed guides. Openings defined by the rake permit a gas flow at all times. Projections on a conduit end wall dislodge deposits from disc edges defining openings. A rake actuator is in communication with a solenoid valve in circuit with a timer and controller for automatic operation of the actuator.

Abstract: Apparatus and methods for precision batch or continuous flow blending of gases are described. Pulsatile precision metering valves having substantially zero dead space are employed to introduce gases to a mixing chamber or manifold in predictable uniform quantities to achieve precision gas blends according to predetermined criteria. During batch processing, gases to be blended are repeatedly characterized by the change in mixing vessel pressure with respect to time immediately after blending. Estimates of additional amounts of a given gas to be added to achieve a desired final partial pressure of the given gas in the mixing vessel are based on empirical data previously measured and stored for the gas in question.

Abstract: A combination faucet compensates for a temperature deviation between a target temperature and actual temperature of a water mixture by utilizing a temperature-sensitive coil spring (80) to press a movable cylinder or axially elongated valve disc (70) that controls a mixing ratio of hot water to cold water. The temperature-sensitive coil spring (80) is constructed of a material that varies the spring constant of spring (80) according to a temperature change. When the temperature-sensitive coil spring (80) by itself cannot provide sufficient correction to compensate for the temperature deviation, feed-back control is utilized for completely eliminating the temperature deviation. To prevent hunting, control gain K of the feed-back control is determined according to variation in the spring constant of coil spring (80).

Abstract: A system for continuously filling a plurality of cylinders with a precise concentration of a vaporized liquid component blended into a gas is disclosed wherein the concentration of the liquid component of the resultant final blended mixture is continuously analyzed, and immediately adjusted, during the filling process. Due to the constant analysis and adjustment, any error in the concentration of a component is typically realized before the concentration is outside an acceptable range. The inventive system allows for a large number of cylinders to be accurately and quickly filled with the compressed, final blended mixture.

Abstract: The present invention is directed to methods and apparatus for effectively proportioning a mixture of compressible and non-compressible fluids, wherein the resulting mixture has an almost constant density. The present invention is particularly useful for admixing supercritical fluids with polymeric coating compositions for various spray applications.

Abstract: A thermostatic mixing valve and method of use thereof. The thermostatic mixing valve is controlled by the incoming hot and cold fluids, which are mixed in a mixing chamber, by a thermally responsive element disposed in the flow of the fluid mixture in a fluid outlet from the mixing chamber. A distributor for distributing the flow is controlled by the thermally responsive element. A drive is activated by pressure of the fluid and is connected to the distributor for controlling the position of the drive. The distributor is used to control the hot and cold fluid flows. Channels are provided to connect the distributor with one of the fluid inlets, to connect the distributor with the outside of the valve body to conduct away used operating fluid and to connect the distributor with the drive.

Abstract: A control system for supplying a gas flow to a gas consumption apparatus, comprising a gas supply pipe which can be connected to the apparatus and which has an electrically controlled gas control valve, and an electronic control unit. The control unit comprises a mathematical module, model-related to the control valve, for adjusting the valve position, and the gas control valve has in-built sensors for gas variables and valve position, the control system adjusting the control valve in linear proportion to a desired gas-flow signal to be supplied to the control unit. The mathematical module comprises a flow submodule, a mechanical submodule and a valve-position submodule, and the flow submodule receives, at its inputs, the desired gas-flow signal and gas variables originating from the valve sensors and supplies, at its output, a signal relating to the through-flow area of the valve, to the mechanical submodule.

Abstract: An apparatus for analyzing particles in a sample liquid which classifies or counts components in the sample liquid by image processing. The liquid sample can be urine or the like and is passed in a flattened flow. The apparatus comprises sheath liquid supply apparatus sample liquid discharge apparatus a, temperature sensor for detecting the ambient temperature and temperature measuring circuit for measuring the temperature depending on the output of the temperature sensor, and a driving circuit for driving the sample liquid discharge apparatus by correcting the sample liquid discharge flow rate depending on the signal from the temperature measuring circuit. The sheath liquid is supplied at a specific pressure, and the sample liquid discharge quantity is corrected depending on the ambient temperature. When changed to the high scale factor taking state or low scale factor taking state, a different correction rate is set.

Abstract: An apparatus and process for simulation of field fluid flow conditions under elevated temperature and pressure conditions of oil and gas production, refining, cooling towers, desalinization. The process involves evaluating inhibitor action in reduction of a specified chemical reaction under simulated field aqueous flow conditions by forming first and second aqueous flow streams having a preset concentration of anions and cations, respectively, for the specified chemical reaction with at least one of these streams having a concentration of the inhibitor to inhibit the specified chemical reaction. These streams are combined to form a single process stream where the specified chemical reaction may take place. The process is repeated with successive reductions in inhibitor until detecting the specified chemical reaction in the process stream.

Abstract: A housing receives ambient air through an inlet located so as to direct the airflow against blades of a rotor which disperses the airflow. A gas inlet conduit discharges hazardous gas into a chamber of the housing. The dispersed airflow acts on the hazardous gas entering the chamber to disperse and mix with the gas. The mixed air and hazardous gas flow impinges against a wall surface of the housing prior to discharge from the housing via an outlet conduit. A source such as the intake side of a blower induces the flow of air and hazardous gas through the housing and the outlet conduit. The rotor is located near an air inlet of the housing for rotor operation by airflow drawn into the housing. A flow sensor and damper control system are provided.

Abstract: The present invention discloses a method for identifying the concentration of fuels or gases in air, particularly in the intake of motor vehicle motors, with ultrasound measurement, comprising the steps of conducting an air/vapor mixture whose concentration is to be identified through an ultrasound measuring section of known length, directing ultrasound through the mixture in the measuring section, determining the speed of sound through the air/vapor mixture; and identifying the concentration of the mixture on the basis of the speed of sound through the mixture in the measuring section.

Abstract: Gas generating apparatus in which a supply of carrier gas is mixed with an impurity gas that permeates through the membrane of an impurity gas generator. A dopant gas is supplied to the impurity gas generator through a pressure controller which operates in response to a pressure monitor that monitors the pressure of the dopant gas supplied to the impurity gas generator. As the monitored pressure of the supplied dopant gas changes, the pressure of that supplied gas likewise changes in a manner which maintains a substantially constant flow rate of the impurity gas through the membrane to be mixed with a carrier gas.

Abstract: To prepare a flow of gas at a high temperature of operation, a flow of gas which has previously been heated to a temperature much lower than the operating temperature is divided into two elementary flows, which are thereafter individually heated at higher temperatures, one of which is higher than the operating temperature and the other being lower than the operating temperature. The two flows thus differently heated are each sent to a buffer container which is heat insulated and two elementary gas flows are withdrawn from the containers and are thereafter combined in regulated proportion by means of a mixing valve adjusted at a control mixing position by means of a correcting signal which differentiates between the effective temperature of the gas prepared and a control temperature. Application for example to the manufacture of articles made of expanded foam material utilizing carbon dioxide.

Abstract: A method of welding in which an inert gaseous shield at a welding zone is provided by a mixture of gases of different densities. The proportions of the individual gases in the mixture are controlled to ensure that the density of the gas mixture is about the same as the density of the surrounding atmospheric air. Cryogenic means may be used to form a condensed gas plug in a pipe or the like to be welded.

Abstract: This invention further provides an improved system of fluid transport, including a fluid source and a fluid transport connected to the source. The system includes means for monitoring the concentration of a friction reducing material in the system and means for adding friction reducing material to the fluid transport when the fluid transport could handle a greater throughput, i.e. there is an excess of fluid available at the fluid source and the throughput in the fluid transport limits the amount of fluid which can be transported through the system.

Abstract: To supply a programmed gradient to a high pressure pump for introduction into a column, a mixer, degasser and accumulator communicates with the high pressure pump to supply fluid thereto, having a volume no more than 150 times the chamber volume of the high pressure pump. The mixer, degasser and accumulator includes temperature sensors which sense when the mixer, degasser and accumulator has been emptied to a level where it cannot respond to a demand for fluid from said high pressure pump and provides a signal to a low pressure pump which responds by cycling to again fill the mixer, degasser and accumulator. Upon receiving a demand signal, the low pressure pump fills by drawing fluid from a plurality of fluid sources to compose the gradient being used at that time, with the pump slowing during valve opening and closing so as to avoid cavitation.

Abstract: Apparatus for preparation of calibration gas mixtures comprises an accurate cylinder divided into first and second chambers for two gases to be mixed in exact proportions by a piston which can be displaced by a precise linear distance by a stepper motor driven micrometer; the piston has a valved passage to allow transfer of a thus precisely determined volume from the second chamber to gas in the first chamber at balanced pressures; stirrers, temperature and pressure sensors are provided, a device for introducing vaporized drops to the gas in the first chamber is provided. The apparatus can provide mixtures in the parts per million and parts per billion ranges and one or more apparatuses can be linked to a personal computer.