Titration Patents (Class 204/405)
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Patent number: 11714059Abstract: An embodiment provides a method for measuring a characteristic of an aqueous sample, including: introducing the aqueous sample to a titration region and a reaction region of a measurement device, wherein the titration region comprises a pH electrode and a protonator electrode contacting a first portion of an aqueous sample, wherein the reaction region comprises a counter electrode contacting a second portion of the aqueous sample; placing an electrolyte reservoir in a state of electrical continuity with the titration region and the reaction region, wherein the electrolyte reservoir comprises a reference electrode, wherein the volume of the electrolyte reservoir comprises a large volume of an electrolyte; and determining a characteristic of the aqueous sample by measuring an electrochemical characteristic between the reference electrode and at least one of: the pH electrode and the counter electrode. Other aspects are described and claimed.Type: GrantFiled: December 23, 2020Date of Patent: August 1, 2023Assignee: HACH COMPANYInventor: Corey Alan Salzer
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Patent number: 11635404Abstract: Methods for manufacturing an electrochemical sensor include forming at least one electrode by printing at least one conductive ink on a surface of at least one substrate. The conductive ink may comprise, e.g., a platinum-group metal, another transition-group metal with a high-temperature melting point, a conductive ceramic material, glass-like carbon, or a combination thereof. The electrochemical sensor may be free of another material over the at least one electrode. An electrochemical sensor, formed according to such methods, may be configured for use in harsh environments (e.g., a molten salt environment). Electrodes of the electrochemical sensor comprise conductive material formed from a printed, conductive ink. In some embodiments, at least a portion of the electrochemical sensor is free of silver, gold, copper, silicon, and polymer materials, such portion being that which is to be exposed to the harsh environment during use of the electrochemical sensor.Type: GrantFiled: April 3, 2020Date of Patent: April 25, 2023Assignee: Battelle Energy Alliance, LLCInventors: Michael R. Shaltry, Prabhat K. Tripathy, David Estrada
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Patent number: 11589490Abstract: This air control device for mounter is to solve a problem of realizing an air control device for a mounter capable of providing a secured holding state by a nozzle without damaging a part by adjusting, during vacuum suction, an amount of air to be drawn suitably for the part and the nozzle. This air control device for mounter is configured such that a nozzle n detachably attached to a head module HM of a mounter is connected to a negative pressure region, and a part is suctioned at a distal end of the nozzle n. The head module HM is mounted with a variable throttle mechanism 4, and by using the variable throttle mechanism 4, an amount of air to be drawn into the negative pressure region from the nozzle is adjustable.Type: GrantFiled: January 10, 2018Date of Patent: February 21, 2023Assignee: SINFONIA TECHNOLOGY CO., LTD.Inventor: Susumu Irie
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Patent number: 11505478Abstract: The disclosure provides automated methods and systems for optimized dosing of chemicals, such as coagulants, acids, and/or bases, in water treatment processes. The methods and systems of the disclosure can provide a coagulant dosing regimen that mitigates turbidity and organic contaminant content while maintaining effective floc precipitation, agglomeration, and settling without significant human intervention.Type: GrantFiled: December 13, 2021Date of Patent: November 22, 2022Assignee: Marmac Water LLCInventor: Gregg Allan McLeod
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Patent number: 11199078Abstract: A method and system generate steam for SAGD operation wherein steam generator blowdown water is acidified, cooled and clarified before reuse. Acid Clarification Treatment, or “ACT”, mitigates organic fouling in Once-Through Stream Generators. Lab tests quantitatively and qualitatively show that ACT reduces Total organic carbon (TOC) and ‘bad actors’ TOC, respectively, in blowdown streams.Type: GrantFiled: June 1, 2016Date of Patent: December 14, 2021Assignee: CONOCOPHILLIPS COMPANYInventors: Ramesh Sharma, Travis Dinsdale, Amber J. Taylor, Babajide Kolade, Jay Locklear
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Patent number: 10668415Abstract: a filtering method, with which a fluid to be filtered is led through a filter (4), the filter (4) is back-flushed at regular time intervals and a pre-treatment agent is added to the fluid at the entry side of the filter. A process variable which describes the efficiency of the filtration is continuously computed during the filtration, and a metering quantity of the pre-treatment agent is reset on the basis of the values for the process variable or a characteristic values derived from this.Type: GrantFiled: December 28, 2016Date of Patent: June 2, 2020Assignee: GRUNDFOS HOLDING A/SInventors: Dominik Dominiak, Rikke Eriksen Gissel, Jacob Appelt Vibe Svendsen, Xing Zheng, Jan Carøe Aarestrup
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Patent number: 10473612Abstract: The present invention relates to analytical testing devices comprising a resistor for cartridge device identification and methods for assaying coagulation in a fluid sample based on the cartridge device identification, and in particular, to performing coagulation assays using a resistor for cartridge device identification in a point of care test cartridge. For example, the present invention may be directed to a chip including an analyte electrode connected to a first connection pin, a reference electrode connected to a second connection pin, and a resistor connected to the second connection pin and a third connection pin.Type: GrantFiled: September 25, 2015Date of Patent: November 12, 2019Assignee: Abbott Point of Care Inc.Inventors: Jay Kendall Taylor, Tian-Xian Zhao, Sheila Diane Ball, Kenneth Harold Hardage, Steven Roy Breeze, Joshua David Newlands
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Patent number: 10254246Abstract: A method is provided for measuring an electrolytically-active species concentration in an aqueous or non-aqueous solution for use in providing control of the concentration of the species in a source solution thereof based on the measurements. In the method, a sample containing an electrolytically-active species is added into a measurement cell that has a working electrode and an auxiliary electrode, and a constant current is applied to the measurement cell while the working and auxiliary electrodes are in contact with the sample with monitoring of voltage difference across the electrodes until a change in the voltage difference is detected. A feedback signal is generated based on a parameter of the change in the voltage difference that is directly proportional to the amount of the electrolytically-active species in the sample, which can be used for process control. An apparatus is also described.Type: GrantFiled: April 26, 2013Date of Patent: April 9, 2019Assignee: Buckman Laboratories International, Inc.Inventors: Thomas E. McNeel, Richard A. Clark, Richard D. Lusk, Jr., Chamindu Liyanapatirana
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Patent number: 9368311Abstract: A photocathode device may replenish its photoemissive coating to replace coating material that desorbs/evaporates during photoemission. A linear actuator system may regulate the release of a replenishment material vapor, such as an alkali metal, from a chamber inside the photocathode device to a porous cathode substrate. The replenishment material deposits on the inner surface of a porous membrane and effuses through the membrane to the outer surface, where it replenishes the photoemissive coating. The rate of replenishment of the photoemissive coating may be adjusted using the linear actuator system to regulate performance of the photocathode device during photoemission. Alternatively, the linear actuator system may adjust a plasma discharge gap between a cartridge containing replenishment material and a metal grid. A potential is applied between the cartridge and the grid, resulting in ejection of metal ions from the cartridge that similarly replenish the photoemissive coating.Type: GrantFiled: September 30, 2015Date of Patent: June 14, 2016Assignee: Los Alamos National Security, LLCInventors: Nathan A. Moody, David C. Lizon
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Patent number: 8858769Abstract: In the invention, a back titration and titer determination can be made using a back coulometric titration. When the iodine exists in a solution put in the titration flask with electrolytic electrodes, a back coulometric titration is performed to produce iodine ions from the iodine at the anode of the electrolytic electrodes. Where the solution is a dehydrated solvent including a Karl Fischer reagent for a volumetric titration, the titer can be determined by the back coulometric titration. Where the solution is anolyte in which the iodine remains after the coulometric titration in the coulometric titration method, the water content in the sample is found from the quantity of electricity consumed by the coulometric titration and the quantity of electricity consumed by the back coulometric titration.Type: GrantFiled: February 14, 2012Date of Patent: October 14, 2014Assignee: Kyoto Electronics Manufacturing Co., Ltd.Inventors: Ikumi Kurose, Masaaki Ishikura
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Patent number: 8778229Abstract: An electrophoretic dispersion with at least two particle species is proposed in which a minimal number (and concentration) of free compounds is present in solution. All chemicals needed to color and stabilize the pigment particles are preferably covalently attached to or within the particles. This enhances the robustness of the system and minimizes the conductivity of the dispersion so that the driving voltage for an electrophoretic display is reduced.Type: GrantFiled: May 10, 2006Date of Patent: July 15, 2014Assignee: Koninklijke Philips N.V.Inventors: Patrick John Baesjou, Lucas Josef Maria Schlangen
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Publication number: 20140001057Abstract: In the invention, a back titration and titer determination can be made using a back coulometric titration. When the iodine exists in a solution put in the titration flask with electrolytic electrodes, a back coulometric titration is performed to produce iodine ions from the iodine at the anode of the electrolytic electrodes. Where the solution is a dehydrated solvent including a Karl Fischer reagent for a volumetric titration, the titer can be determined by the back coulometric titration. Where the solution is anolyte in which the iodine remains after the coulometric titration in the coulometric titration method, the water content in the sample is found from the quantity of electricity consumed by the coulometric titration and the quantity of electricity consumed by the back coulometric titration.Type: ApplicationFiled: February 14, 2012Publication date: January 2, 2014Applicant: KYOTO ELECTRONICS MANUFACTURING CO., LTD.Inventors: Ikumi Kurose, Masaaki Ishikura
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Patent number: 8475639Abstract: A titration apparatus comprising a titration reservoir for a non-flowing sample solution to be titrated; an ion source reservoir comprising an ion source solution of selected ions; an ion exchange membrane barrier capable of passing ions from the ion source solution to the titration reservoir, but of blocking bulk liquid flow; a first electrode in electrical communication with the ion source reservoir; and a second electrode in electrical communication with the titration reservoir. Also, an electrolytic titrant generator for use in the titration apparatus.Type: GrantFiled: December 6, 2007Date of Patent: July 2, 2013Assignee: Dionex CorporationInventor: Kannan Srinivasan
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Patent number: 8123921Abstract: A method and device have an electrode rod (1; 21) for a pH meter. The electrode rod (1; 21) has a measuring end (2; 22) for immersion into a liquid test sample (31), wherein the measuring end (2; 22) has a pH measuring element, and wherein electrical feed lines (5) in the electrode rod (1; 21) extend towards the pH measuring element. A plurality of capillaries (8, 9, 10; 23) for feeding liquids and gas into the test sample (31) extend in the electrode rod (1; 21) and have outlet openings (11, 12, 13; 24) in the area of the measuring end (2; 22). The method and device facilitate and accelerate preparation of liquid test samples and adjustment of a pH value for small amounts of test samples or narrow sample containers in NMR spectroscopy applications.Type: GrantFiled: June 2, 2010Date of Patent: February 28, 2012Assignee: Bruker BioSpin GmbHInventors: Gudrun Hofmann, Martin Hofmann
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Publication number: 20110206813Abstract: A method to determine oxidative and reductive substances in food, which is realized with a testing specimen and a measuring device, and which comprises steps: pre-processing an appropriate amount of a food specimen; dissolving a given amount of the pre-processed food specimen in a buffer solution; making the buffer solution dissolving a tested material contact with a formulated layer on the testing specimen to proceed a redox reaction; the measuring device supplying a reaction potential to reaction electrodes of the testing specimen to obtain an electrical signal; and obtaining a content of the tested material from the electrical signal. Besides, the testing specimen and the measuring device used to implement the abovementioned method are also disclosed.Type: ApplicationFiled: February 22, 2010Publication date: August 25, 2011Inventors: Yen-Yuan SHEN, Hsiu-Min Lin, Edward Chen
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Publication number: 20110198239Abstract: A process for the simultaneous determination of chlorine and chlorate in sodium hypochlorite. First and second streams of sodium hypochlorite are provided. The first stream is treated to generate iodine indicative of chlorine. The second stream is treated to generate iodine indicative of chlorine and chlorate. The iodine of the first stream is subjected to an amperometric measuring cell to generate a first current proportional to a chlorine concentration of the first stream. The iodine of the second stream is subjected to an amperometric measuring cell to generate a second current proportional to the chlorine and chlorate concentration in the second stream. The first current is subtracted from the second current to determine an amount of chlorate.Type: ApplicationFiled: September 29, 2010Publication date: August 18, 2011Applicant: SIEMENS WATER TECHNOLOGIES CORP.Inventor: Kevin Anthony Foster
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Patent number: 7988876Abstract: To reduce and homogenize the thickness of a semiconductor layer which lies on the surface of an electrically insulating material, the surface of the semiconductor layer is exposed to the action of an etchant whose redox potential is adjusted as a function of the material and the desired final thickness of the semiconductor layer, so that the material erosion per unit time on the surface of the semiconductor layer due to the etchant becomes less as the thickness of the semiconductor layer decreases, and is only from 0 to 10% of the thickness per second when the desired thickness is reached. The method is carried out without the action of light or the application of an external electrical voltage.Type: GrantFiled: January 31, 2008Date of Patent: August 2, 2011Assignee: Siltronic AGInventors: Diego Feijoo, Oliver Riemenschneider, Reinhold Wahlich
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Publication number: 20100236943Abstract: A method and device have an electrode rod (1; 21) for a pH meter. The electrode rod (1; 21) has a measuring end (2; 22) for immersion into a liquid test sample (31), wherein the measuring end (2; 22) has a pH measuring element, and wherein electrical feed lines (5) in the electrode rod (1; 21) extend towards the pH measuring element. A plurality of capillaries (8, 9, 10; 23) for feeding liquids and gas into the test sample (31) extend in the electrode rod (1; 21) and have outlet openings (11, 12, 13; 24) in the area of the measuring end (2; 22). The method and device facilitate and accelerate preparation of liquid test samples and adjustment of a pH value for small amounts of test samples or narrow sample containers in NMR spectroscopy applications.Type: ApplicationFiled: June 2, 2010Publication date: September 23, 2010Inventors: Gudrun Hofmann, Martin Hofmann
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Publication number: 20090308745Abstract: A system and process for enhancing total organic carbon (“TOC”) removal from raw, untreated water while maintaining optimum membrane filter performance. The present invention overcomes many of the disadvantages of prior art water filtration systems by controlling the pH level of the water, prior to the water being directed through said membrane filter, so that the particulate charge of the water aligns with the electromagnetic surface charge of membrane filter. Maintaining the particulate charge of the water within an optimum charge window for the particular membrane filter enhances the membrane filter's performance by decreasing the fouling rate of the membrane filter.Type: ApplicationFiled: August 21, 2009Publication date: December 17, 2009Inventor: Gregg A. McLeod
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Publication number: 20090229995Abstract: Low concentrations of fluoride ion in a semiconductor processing solution containing an acid are determined via fluoride ion specific electrode measurements corrected for the effect of the acid concentration. No reagents are used for the fluoride determination.Type: ApplicationFiled: March 14, 2008Publication date: September 17, 2009Inventors: Eugene Shalyt, Michael Pavlov, Peter Bratin
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Publication number: 20090194430Abstract: A simple titration method involving a single copper ion titrant detected by a copper ion specific electrode provides the concentrations of both copper ions and bath complexing agent (ethylene diamine, for example) in alkaline copper electroplating baths of the type used to deposit or thicken copper seed layers on silicon wafers. Standard addition of an excess of a strong complexing agent (EDTA, for example) and back-titration with the copper ion titrant yields the bath copper ion concentration, and continued titration to a second endpoint, preferably after addition of hydroxide to adjust the pH of the analysis solution, yields the total concentration of bath complexing agent. Based on these analyzes, the concentration of free bath complexing agent may be calculated. The method also provides direct determination of the free bath complexing agent concentration via standard addition of excess bath complexing agent to a sample of the plating bath and titration with the copper ion titrant.Type: ApplicationFiled: January 31, 2008Publication date: August 6, 2009Inventors: Eugene Shalyt, Victor Ososkov, Michael Pavlov, Peter Bratin
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Patent number: 7438796Abstract: A sensor for measurement of free chlorine and of total chlorine in aqueous solution including a working electrode having a self-assembled monolayer (SAM) formed on the surface thereof, producing a barrier which reduces the generation of background currents when electrical potentials are applied to the electrode, and blocks the reduction or oxidation of interfering species in the solution, is described. Such SAMs have also been found to block the efficient reduction of chlorine as well. However, N,N-diethyl-p-phenylenediamine (DPD) has been found to effectively transport electrons across the SAM; that is, an oxidized form of DPD produced by a reaction with chlorine is capable of penetrating the SAM such that the reduction of the oxidized DPD species can occur. The generated reduction current is correlated with the concentration of chlorine in solution. Total chlorine may be determined by the addition of an iodide salt.Type: GrantFiled: August 28, 2006Date of Patent: October 21, 2008Assignee: Hach CompanyInventor: Corey A. Salzer
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Publication number: 20080251394Abstract: The method according to the invention consists of generating an electrochemical signature of the analyzed substance(s), obtained by carrying out a numerical pseudo-titration and to express the result of the measurements in antioxidant power units. It involves the processing of a current-potential response of the oxidation of the analyzed substance(s) by a predefined mathematical dimensionless function representing a virtual and ideal oxidizing agent. The method is useful for the identification and/or detection and/or titration of antioxidant substances in the tested material, including directly on wet biological tissues.Type: ApplicationFiled: March 11, 2005Publication date: October 16, 2008Applicant: Edel Therapeutics S.A.Inventors: Gregoire Lagger, Philippe Tacchini, Hubert H. Girault
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Patent number: 7182853Abstract: The invention is a redox control and monitoring platform that is to be used in conduction with another detection scheme. The platform includes a portion of an electrochemical control. The electrochemical control can be operated to control and measure the redox environment of a sample. The electrochemical control can be provided in a multiplicity of test regions to allow high throughput analysis of a multiplicity of samples. The present method and system allows the determination of the effect of the change in redox environment on the binding or other activity of the species in the sample that is directly affected by the redox environment.Type: GrantFiled: September 21, 2001Date of Patent: February 27, 2007Assignee: University of DaytonInventor: Jay Johnson
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Patent number: 6913686Abstract: The present invention relates to methods and apparatus for determining concentrations of various inorganic or organic components in solder plating solutions, which include titration or parallel titration methods, direct potentiometry methods, calibration methods, and/or UV-Vis absorption analysis.Type: GrantFiled: December 10, 2002Date of Patent: July 5, 2005Assignee: Advanced Technology Materials, Inc.Inventor: Monica K. Hilgarth
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Patent number: 6890715Abstract: The present invention provides a class of sensors prepared from at least a first material having a positive temperature coefficient of resistance and a second non-conductive or insulating material compositionally different than the first material that show an increase sensitivity detection limit for polar and non-polar analytes. The sensors have applications in the detection of analytes in the environment, associated with diseases and microorganisms.Type: GrantFiled: August 18, 2000Date of Patent: May 10, 2005Assignee: The California Institute of TechnologyInventors: Nathan S. Lewis, Robert H. Grubbs, Gregory Sotzing
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Publication number: 20040251133Abstract: A method for the quantitative determination of an ion in a fluid is described which comprises subjecting the fluid to voltammetry using an electrode which comprises an electrically conducting support possessing a coating of a solid capable of selecting ions when electrochemically induced during operation.Type: ApplicationFiled: August 8, 2004Publication date: December 16, 2004Inventors: Timothy James Wooster, Michael John Honeychurch, Alan Maxwell Bond
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Publication number: 20040195095Abstract: The present invention is directed to an immobilised pH gradient (IPG) gel for use in electrophoresis, the gel comprising polymerised units of (I) CH2═CR1—CO—NR2R3 and (II) CH2═CR4—CO—NR5R6 wherein R1, R2, R3, R4, R5, and R6, are the same or different and are hydrogen or C1-C4alkyl, with the proviso that at least one of R1, R2, R3, R4, R5, or R6 is C1-C4alkyl.Type: ApplicationFiled: May 17, 2004Publication date: October 7, 2004Inventors: Ben Herbert, Jasmine Grinyer, Pier Giorgio Righetti
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Publication number: 20040182704Abstract: A novel artificial muscle material and miniature valves and micropumps made therefrom are provided. The artificial muscle material bends reversibly when electroactuated by applying low voltage, in a wide pH range, even at that of physiological pH, and works without contact with electrodes. Miniature valves made from the artificial material are successfully triggered for the fluid release in a wide pH range, even at that of physiological pH. Novel fluid release devices were manufactured using this artificial muscle, and methods using the same were provided, including an implantable device optimized for trans-scleral drug delivery.Type: ApplicationFiled: March 19, 2004Publication date: September 23, 2004Inventors: Sylvia Daunert, Serban F. Peteu, Leonidas G. Bachas, Marc J. Madou, Elissavet Moschou
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Publication number: 20040178068Abstract: Methods and apparatus for preparing a smear for cytopathology or other analysis. In a representative embodiment, cells of a sample are subjected to a dielectrophoretic force to segregate the cells into two or more zones of a surface. The particles are attached to the surface, thereby defining a “segregated smear.” The segregated smear is then fixed and stained for cytopathology analysis.Type: ApplicationFiled: December 22, 2003Publication date: September 16, 2004Applicant: The University of Texas SystemInventors: Peter R.C. Gascoyne, Jody V. Vykoukal, Chandra Das, Frederick F. Becker
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Publication number: 20040065547Abstract: A multicomponent fluid composition monitoring and compositional control system, in which a component analysis is effected by titration or other analytical procedure, for one or more components of interest, and a computational means then is employed to determine and responsively adjust the relative amount or proportion of the one or more components in the multicomponent fluid composition, to maintain a predetermined compositional character of the multicomponent fluid composition. The system is usefully employed in semiconductor manufacturing photoresist and post-etch residue removal, in which the cleaning medium is a semi-aqueous solvent composition, and water is the monitored and responsively adjusted component.Type: ApplicationFiled: October 23, 2002Publication date: April 8, 2004Inventors: Russell Stevens, Thomas Kloffenstein, Todd Aycock, Joseph W. Evans, Richard Bhella
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Publication number: 20030121799Abstract: A multicomponent fluid composition monitoring and compositional control system, in which a component analysis is effected by titration or other analytical procedure, for one or more components of interest, and a computational means then is employed to determine and responsively adjust the relative amount or proportion of the one or more components in the multicomponent fluid composition, to maintain a predetermined compositional character of the multicomponent fluid composition. The system is usefully employed in semiconductor manufacturing photoresist and post-etch residue removal, in which the cleaning medium is a semi-aqueous solvent composition, and water is the monitored and responsively adjusted component.Type: ApplicationFiled: October 4, 2002Publication date: July 3, 2003Inventors: Russell Stevens, Thomas Kloffenstein, Todd Aycock, Joseph W. Evans
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Patent number: 6361670Abstract: A device for the coulometric determination of water by a Karl Fischer reaction comprising a membrane-free measuring cell that contains a liquid reagent, an iodine indicating means, an anode, a cathode and a casing around the cathode to define a cathode space. The casing has an opening through which the cathode space communicates with the liquid reagent. A maneuverable drainage device including a plunger is provided to drain-off liquid reagent in the cathode space through the opening.Type: GrantFiled: August 27, 1999Date of Patent: March 26, 2002Assignee: AB Stockholms PatentyraInventor: Anders Cedergren
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Patent number: 6315888Abstract: A constant-current polarization voltage detecting method includes step of feeding to a detecting electrode a predetermined minute current in a pulse form, and detecting sequentially a polarization voltage at each time of feeding the pulsating current, in an electrochemical analysis in solution. The polarization voltage is detected after a lapse of a predetermined time from the initiation of feeding the pulsating current at each time. A Karl Fischer's moisture content analyzing apparatus can utilize such a method.Type: GrantFiled: April 18, 2000Date of Patent: November 13, 2001Assignees: Mitsubishi Chemical Corporation, Dia Instruments Co., Ltd.Inventors: Hiromasa Kato, Masafumi Nakatani
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Patent number: 6316271Abstract: A method for generating high purity acid or base in an aqueous stream for use in analysis. For generating a base for anion chromatography, the aqueous stream is directed through a cation exchange bed having strongly acid first and weakly acidic second portions. An electrical potential is applied to the bed. Cations on the bed electromigrate into the aqueous stream while hydroxide ions are electrolytically generated to form a base-containing eluent. Analytes to be detected and the generated eluent flow through a detector.Type: GrantFiled: December 23, 1999Date of Patent: November 13, 2001Assignee: Dionex CorporationInventors: Hamish Small, Nebojsa Avdalovic, Yan Liu
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Patent number: 6315954Abstract: An apparatus for generating high purity acid or base in an aqueous stream for use in analysis. For generating a base, the aqueous stream is directed through a cation exchange bed having first strongly acidic and second weakly acidic portions. An electrical potential is applied to the bed. Cations on the bed electromigrate into the aqueous stream while hydroxide ions are electrolytically generated to form a base-containing eluent. Analytes to be detected and the generated eluent flow through a detector.Type: GrantFiled: December 23, 1999Date of Patent: November 13, 2001Assignee: Dionex CorporationInventors: Hamish Small, Nebojsa Avdalovic, Yan Liu
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Patent number: 5961801Abstract: A novel electrophoresis separation medium comprises polyacrylamide and a dioxane. An electrophoresis separation system comprises a separation channel, the separation channel including the novel separation medium. In a method for electrophoretically separating analytes by introducing analytes into a separation channel, an electric field is applied across the separation channel and the analytes are allowed to electrokinetically migrate within the separation medium. The separation channel comprises the novel electrophoresis separation medium.Type: GrantFiled: November 24, 1997Date of Patent: October 5, 1999Assignee: Beckman Instruments, Inc.Inventors: Chia Hui-Shieh, Azita Hedayati
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Patent number: 5891322Abstract: Electroanalysis of an electroactive, and especially ionized, species, in trace form, in a liquid sample, is by potentiometry with coulometric stripping (elution), and is by employing a working electrode in electrical contact with the sample. A practically exhaustive electrolysis, or a practically exhaustive complexing with adsorption, of the electroactive species, a main coulometric stripping and at least two poststripping cycles including a post-electrolysis step and a poststripping step are performed in succession. By a particular choice of the operating parameters and of the measured parameters it is possible to determine automatically the equivalent mean chemical current, for example for oxidation, competing with the current applied to the working electrode, during the stripping stage. This is done directly from the liquid sample which is being analyzed. As a result, the required concentration of the species is determined without previous calibration.Type: GrantFiled: October 22, 1996Date of Patent: April 6, 1999Assignee: Radiometer Analytical SAInventors: Daniel Jagner, Gilles Moninot
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Patent number: 5738772Abstract: An on-line method for the continuous generation of alkali metal salts includes continuously reacting a source of acidity, a liquid having a low pH value, with a source of alkalinity, a liquid having a high pH value, while continuously monitoring an electrical parameter of the resultant in salt which is indicative of its pH value. The monitored value is used to adjust the relative flow rates of the input liquids so as to dynamically maintain the pH value of the resultant salt within a predetermined range. In an apparatus, the input liquids can be continuously supplied to a reacting element and the conductance of the resultant salt monitored for purposes of providing feedback control signals to adjust one or more flow rates.Type: GrantFiled: October 25, 1996Date of Patent: April 14, 1998Assignee: FBC Industries, Inc.Inventors: James E. Bartasis, Barry Edward Carter Williams
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Patent number: 5597463Abstract: A titration electrode device for measuring the amount of a species in solution in a test liquid comprises a counter electrode and a generator electrode both in a chamber for receiving a thin layer of test liquid, the two electrodes being located in respective compartments within the chamber such that ionic conduction between the compartments is permitted but diffusion of electrogenerated reagents between the compartments is restricted, the device including reference and sensor electrodes in the chamber.Type: GrantFiled: June 7, 1995Date of Patent: January 28, 1997Assignee: Van den Bergh Foods Co., Division of Conopco, Inc.Inventors: Brian J. Birch, Nicholas A. Morris
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Patent number: 5567618Abstract: The present invention relates to a Karl Fischer reagent for the determination of water, characterized in that it contains tetrahydrofurfuryl alcohol (THFA) as alcohol component.Type: GrantFiled: May 18, 1995Date of Patent: October 22, 1996Assignee: Riedel-De Haen AktiengesellschaftInventor: Eugen Scholz
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Patent number: 5466606Abstract: The invention relates to the use of N-methylformamide as solvent in the determination of water by the Karl Fischer method.Type: GrantFiled: August 22, 1994Date of Patent: November 14, 1995Assignee: Riedel-De Haen AktiengesellschaftInventor: Eugen Scholz
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Patent number: 5312528Abstract: The invention relates to a method of determining an ion concentration with the aid of an ion-selective electrode, in which method a known quantity by volume of a sample is taken, a buffer is added and the initial potential of the electrode pair is measured, a known volume having an accurately known ion concentration is added and the potential obtained is measured, the standard solution being added stepwise, and the initial potential of the electrode pair and the slope of the relationship between potential and logarithm of the concentration is calculated for each of the quantities added from the data obtained, a small quantity of the solution to be determined is added, the potential difference is measured and the latter is compared with the required sudden change in potential, after which a sample is again taken and a quantity of the solution to be determined is added which is expected to bring the sudden change in potential into the required region, the potential is then read off and the required concentratioType: GrantFiled: June 5, 1992Date of Patent: May 17, 1994Assignee: Applikon Dependable Instruments B.V.Inventor: Robert Hoogendijk
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Patent number: 5300207Abstract: A high current coulometric titrator for the Karl Fischer determination of water in which a diaphragm is not required between the electrodes of the iodine-generating circuit. These electrodes are designed to ensure that substantially only iodine is generated at the anode while minimizing conversion of iodine to iodide at the cathode. In a preferred embodiment, the anode has a generally curved shape, all portions of which are substantially equidistant from the cathode. Increased current efficiency results wherein the amount of iodine generated at the anode increases as the magnitude of the iodine-generating current increases. Titration rates in excess of 2.5 milligrams of water per minute are achieved.Type: GrantFiled: January 14, 1993Date of Patent: April 5, 1994Inventor: Harald Dahms
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Patent number: 5296193Abstract: A titration apparatus, which operated volumetrically and/or coulometrically, includes a basic apparatus with a control and actuation arrangement for the volumetric metering of reagents, a metering unit for the volumetric titration removably attached to the basic apparatus, and mechanical coupling elements for connecting the metering unit to the actuation device. Instead of the volumetric unit or in addition thereto, a coulometric titration cell may be connected with the basic apparatus directly or by an adapter unit, while using the same control device as the metering unit.Type: GrantFiled: July 20, 1993Date of Patent: March 22, 1994Assignee: Deutsche Metrohm Gesellschaft mit beschrankter Haftung & Co. elektronische MessgerateInventors: Hubert Reger, Gunther Zimmermann
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Patent number: 5292413Abstract: The present invention relates to a catholyte for the Karl Fischer coulometric water determination, which is characterized in that it is composed of a solution of one or more salts of an organic nitrogen base and acid in a solvent.Type: GrantFiled: July 6, 1992Date of Patent: March 8, 1994Assignee: Riedel-De Haen AktiengesellschaftInventor: Eugen Scholz
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Patent number: 5286358Abstract: A method is provided for accurately determining the complexing capacity (or free HF concentration) of a pickling liquor. A sample of pickling liquor is obtained and an excess of ferric ion is added thereto to complex with all of the free HF in the sample. A back titration is performed to determine the residual free ferric ion. The difference between the amount of ferric ion added and that found by the titration is related to the free HF in the original sample.The method is useful in conjunction with an automated, on-line system which periodically monitors a pickling bath and makes any necessary adjustments thereto.Type: GrantFiled: August 1, 1991Date of Patent: February 15, 1994Assignee: The Foxboro CompanyInventors: Kenneth S. Fletcher, III, Jane K. Burdick
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Patent number: 5230785Abstract: A swimming pool water analyzer has a housing providing a coulometric titration chamber, a chlorine concentration measuring chamber, a chamber for measuring pH, and conduits connecting the several chambers, the reservoir and a discharge outlet. One or more pumps move fluid through the conduits and chambers to the discharge outlet. Electrodes in each of the chambers are connected to electrical circuitry, and a power supply is provided. A microprocessor receives and analyzes signals indicative of the activity at the electrodes and provides outputs representing values for the chemistry of the sample determined as a result of such analysis of the signals.Type: GrantFiled: May 31, 1991Date of Patent: July 27, 1993Assignee: PoolChem, Inc.Inventor: Paul A. Yager
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Patent number: 5209832Abstract: The invention relates to a process for the preparation of a metal complex dye under production conditions, which comprises reacting at least one dye with a metal donor, adding said metal donor or said dye discontinuously before the end point of the metallizing is reached, and determining the end of the metallizing voltametrically.The process makes it possible to prepare metal complex dyes in good yield and purity.Type: GrantFiled: December 11, 1991Date of Patent: May 11, 1993Assignee: Ciba-Geigy CorporationInventors: Wilhelm Schmidt, Gerhard Beck
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Patent number: 5196096Abstract: A method for measuring concentrations of addition agents in solutions of additive mixtures, namely for monitoring additives in PbSn plating solutions, comprising the steps of: (a) preparing a basis solution which contains an electroactive species whose electroreduction reaction is sensitive to the additive of interest; (b) preparing calibration standard sample solutions comprising appropriate concentrations of all species other than the additive; (c) preparing the working solution whose additive concentration is to be determined; (d) applying a pulse voltammetry technique, at a hanging Hg drop electrode, to a sample of the basis solution located in a cell of a polarographic analyzer; (e) thereafter measuring the polarographic peak height for the indicator reaction in the basis solution; (f) adding a measured amount of the working solution to the basis solution sample in the cell; (g) thereafter measuring the peak height for the indicator reaction in the mixed solution of step (f); and (h) repeating steps (f)Type: GrantFiled: March 24, 1992Date of Patent: March 23, 1993Assignee: International Business Machines CorporationInventors: I-Chia H. Chang, Wilma J. Horkans