With Integrating Or Differentiating Means Patents (Class 422/77)
  • Patent number: 8945939
    Abstract: The invention is directed towards methods and compositions for identifying the amount of hydrofluoric acid in a buffered oxide etching composition. In buffered oxide etching compositions it is very difficult to measure the amount of hydrofluoric acid because it has varying equilibriums and it is toxic so it hard to handle and sample. When used to manufacture microchips however, incorrect amounts of hydrofluoric acid will ruin those chips. The invention utilizes a unique method of spectrographically measuring the hydrofluoric acid when in contact with added chromogenic agents to obtain exact measurements that are accurate, immediate, and safe.
    Type: Grant
    Filed: November 18, 2013
    Date of Patent: February 3, 2015
    Assignee: Ecolab USA Inc.
    Inventors: Amy M. Tseng, Brian V. Jenkins, Robert Mack
  • Patent number: 8932874
    Abstract: The invention is directed towards methods and compositions for identifying the amount of ammonium acid in a buffered oxide etching composition. In buffered oxide etching compositions it is very difficult to measure the amount of ammonium acid because it has varying equilibriums and it is toxic so it hard to handle and sample. When used to manufacture microchips however, incorrect amounts of ammonium acid will ruin those chips. The invention utilizes a unique method of spectrographically measuring the ammonium acid when in contact with added chromogenic agents to obtain exact measurements that are accurate, immediate, and safe.
    Type: Grant
    Filed: July 2, 2014
    Date of Patent: January 13, 2015
    Assignee: Nalco Company
    Inventors: Amy M. Tseng, Brian V. Jenkins, Robert M. Mack
  • Patent number: 8920825
    Abstract: The present application is directed to a novel composition which acts as a barrier to noxious agents while adding self-detoxifying catalytic treatments to neutralize the noxious and harmful warfare agents when applied for example on a fabric, or other solid support.
    Type: Grant
    Filed: January 2, 2014
    Date of Patent: December 30, 2014
    Assignees: Stedfast, Inc., U.S. Army Natick Soldier Research, Development and Engineering Center, Chemical Technology Team
    Inventors: Hamid Benaddi, Heidi Schreuder-Gibson
  • Patent number: 8716028
    Abstract: The invention is directed towards methods and compositions for identifying the amount of hydrofluoric acid in a buffered oxide etching composition. In buffered oxide etching compositions it is very difficult to measure the amount of hydrofluoric acid because it has varying equilibriums and it is toxic so it hard to handle and sample. When used to manufacture microchips however, incorrect amounts of hydrofluoric acid will ruin those chips. The invention utilizes a unique method of spectrographically measuring the hydrofluoric acid when in contact with added chromogenic agents to obtain exact measurements that are accurate, immediate, and safe.
    Type: Grant
    Filed: December 31, 2012
    Date of Patent: May 6, 2014
    Assignee: Nalco Company
    Inventors: Amy Tseng, Brian V. Jenkins, Robert M. Mack
  • Patent number: 8658098
    Abstract: A portable detection system for allergic diseases includes a filtration-based inspection module and a reader module. The filtration-based inspection module includes an FPW sensor and a liquid sample filtration apparatus, wherein the liquid sample filtration apparatus includes an injection opening, a passage module, a filtering membrane and a gathering aperture. The injection opening is in communication with the gathering aperture. The FPW sensor comprises a frame body, a carrier and a sensing chip having an accommodating slot in communication with the gathering aperture. The carrier comprises a plurality of conductive terminals, and the conductive terminals are electrically connected with the sensing chip. The reader module comprises a connection slot capable of being inserted by the conductive terminals of the carrier.
    Type: Grant
    Filed: July 13, 2012
    Date of Patent: February 25, 2014
    Assignee: National Sun Yat-Sen University
    Inventors: I-Yu Huang, Yu-Cheng Lin, Chua-Chin Wang, Ying-Chung Chen
  • Patent number: 8642058
    Abstract: The present application is directed to a novel composition which acts as a barrier to noxious agents while adding self-detoxifying catalytic treatments to neutralize the noxious and harmful warfare agents when applied for example on a fabric, or other solid support.
    Type: Grant
    Filed: March 26, 2010
    Date of Patent: February 4, 2014
    Assignees: U.S. Army Natick Soldier Research, Development and Engineering Center Chemical Technology Team, Stedfast Inc.
    Inventors: Hamid Benaddi, Heidi Schreuder-Gibson
  • Patent number: 8349614
    Abstract: Alkalinity determination, including an alkalinity determination process and/or alkalinity determinator. An alkalinity determination process may include providing a known value of volume of an acidic fluid, forming a titration system by providing one or more additions of a known value of volume of a relatively alkaline fluid to an acidic fluid, determining a pH value and/or a temperature value for one or more additions and/or determining an alkalinity value of a system by calculating a transformation including one or more determined pH values and/or temperature values of one or more additions. An alkalinity determination process may include modeling, such that an informed determination may be made with reference to relevant and/or irrelevant factors, as well as parameters to maximize likelihood of alkalinity determination. In embodiments, an alkalinity determinator may include one or more titration cells, one or more sensors and/or one or more alkalinity value determinators.
    Type: Grant
    Filed: February 17, 2010
    Date of Patent: January 8, 2013
    Assignees: George Mason Intellectual Properties, Inc., University of South Carolina
    Inventors: Christopher Hintz, Kenneth J. Hintz
  • Publication number: 20100247379
    Abstract: A reagent preparing apparatus capable of being connected to a sample measuring section for measuring a sample using a diluted reagent prepared by the reagent preparing apparatus, comprising: a reagent preparing section for preparing a diluted reagent containing a predetermined reagent and pure water; a pH measuring section for measuring hydrogen ion concentration of the diluted reagent prepared by the reagent preparing section; and a controller for performing predetermined processing, wherein the controller is configured to change the process to be performed based on the hydrogen ion concentration measured by the pH measuring section, is disclosed. A sample analyzer is also disclosed.
    Type: Application
    Filed: March 22, 2010
    Publication date: September 30, 2010
    Inventor: Carola Schmidt
  • Publication number: 20100210026
    Abstract: Alkalinity determination, including an alkalinity determination process and/or alkalinity determinator. An alkalinity determination process may include providing a known value of volume of an acidic fluid, forming a titration system by providing one or more additions of a known value of volume of a relatively alkaline fluid to an acidic fluid, determining a pH value and/or a temperature value for one or more additions and/or determining an alkalinity value of a system by calculating a transformation including one or more determined pH values and/or temperature values of one or more additions. An alkalinity determination process may include modeling, such that an informed determination may be made with reference to relevant and/or irrelevant factors, as well as parameters to maximize likelihood of alkalinity determination. In embodiments, an alkalinity determinator may include one or more titration cells, one or more sensors and/or one or more alkalinity value determinators.
    Type: Application
    Filed: February 17, 2010
    Publication date: August 19, 2010
    Inventors: Christopher Hintz, Kenneth J. Hintz
  • Patent number: 7205153
    Abstract: Embodiments of the invention provide an analytical method and analytical reagent solutions for determining the concentration of electrolyte components, such as copper, acid and chloride constituents in an acid or basic metal plating bath using a chemical analyzer. Common methods for measuring the concentration of copper general require two reagent solutions/two steps. This invention provides a novel analytical reagent solution that simplifies the chelating, buffering, and cleaning functions of separate regent solutions required for measuring electrolyte concentration. This has the benefits of reducing chemical inventory and associated dispensing equipment, and thus reducing chemical consumption.
    Type: Grant
    Filed: April 11, 2003
    Date of Patent: April 17, 2007
    Assignee: Applied Materials, Inc.
    Inventor: Todd Alan Balisky
  • Patent number: 7153690
    Abstract: 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: Grant
    Filed: October 23, 2002
    Date of Patent: December 26, 2006
    Assignee: Advanced Technology Materials, Inc.
    Inventors: Russell Stevens, Thomas Kloffenstein, Todd Aycock, Joseph W. Evans, Richard Bhella
  • Patent number: 7093431
    Abstract: The present invention relates to an exhaust gas treatment device (1), in particular for an internal combustion engine, preferably in a motor vehicle, comprising a housing (2) as well as a substrate body (3) which is situated therein and through which exhaust gases can flow in an axial direction (5). The substrate body (3) is supported axially on the housing (2) via an axial bearing (8) on at least one axial end face (11). To improve the axial support of the substrate body (3), the axial bearing (8) has a supporting ring (10) mounted on the housing and having a U-shaped profile (12), which is open axially toward the end face (11). A bearing ring (17) made of bearing material engages into the U-shaped profile (12) of the supporting ring (10) on its axial end, which faces away from the substrate body (3) and is supported thereon axially. With its axial end facing the substrate body (3), the bearing ring (17) is supported on the end face (11).
    Type: Grant
    Filed: January 6, 2004
    Date of Patent: August 22, 2006
    Assignee: J. Eberspächer GmbH & Co. KG
    Inventors: Andreas Balle, Bernd-Peter Scherer, Georg Wirth
  • Patent number: 6846639
    Abstract: The use of impedance measurements to detect the presence of pathogens attached to antibody-coated beads. In a fluidic device antibodies are immobilized on a surface of a patterned interdigitated electrode. Pathogens in a sample fluid streaming past the electrode attach to the immobilized antibodies, which produces a change in impedance between two adjacent electrodes, which impedance change is measured and used to detect the presence of a pathogen. To amplify the signal, beads coated with antibodies are introduced and the beads would stick to the pathogen causing a greater change in impedance between the two adjacent electrodes.
    Type: Grant
    Filed: November 15, 2001
    Date of Patent: January 25, 2005
    Assignee: The Regents of the University of California
    Inventors: Robin R. Miles, Kodumudi S. Venkateswaran, Christopher K. Fuller
  • Patent number: 6821790
    Abstract: A method of separating a cell-containing sample into a substantially cell-depleted portion, and a cell-containing portion comprising at least one of a stem cell, a lymphocyte, and a leukocyte comprises a step in which the sample is received in a vessel with at least one flexible wall. In another step, an additive and particles are added to the sample, wherein the additive substantially binds to the at least one of the stem cell, lymphocyte, and leukocyte, and the particles and wherein the particles substantially bind to the at least one of the stem cell, lymphocyte, and leukocyte, and the additive, thereby producing a cell-containing network. In a further step, the network is separated from the substantially cell-depleted portion by applying a magnetic force.
    Type: Grant
    Filed: September 7, 2001
    Date of Patent: November 23, 2004
    Inventors: Vijay Mahant, Byron Doneen
  • Patent number: 6576460
    Abstract: The present invention relates to a filtration-detection device for detecting or quantifying an analyte in a test sample including a filtration device having a first binding material immobilized thereto, wherein the first binding material is capable of binding to a portion of the analyte, and a detection assembly positioned relative to the filtration device to detect or quantify analyte bound to the first binding material. The present invention also relates to methods of using the filtration-detection device.
    Type: Grant
    Filed: October 27, 2000
    Date of Patent: June 10, 2003
    Assignees: Cornell Research Foundation, Inc., Innovative Biotechnologies International, Inc.
    Inventors: Antje J. Baeumner, Richard A. Montagna
  • Patent number: 6537822
    Abstract: Free fluorine is measured in a hydrofluoric acid-containing solution with a coexistent metallic ion based on a total fluorine concentration, a total acid concentration, a metallic ion concentration, the equilibrium constant of hydrofluoric acid, and equilibrium constants of metal fluoride complexes. It is possible to accurately analyze free fluorine in a hydrofluoric acid-containing solution without being affected by a coexistent metal and by the passage of time. This technique may be used to accurately control the concentration of free fluorine in a hydrofluoric acid-containing mixed acid pickling solution at the production site of a stainless steel so that improvement in descaling capability as well as reduction in the amount of chemical materials can be achieved.
    Type: Grant
    Filed: July 5, 2000
    Date of Patent: March 25, 2003
    Assignee: Kawasaki Steel Corporation
    Inventors: Hisao Yasuhara, Makoto Shimura
  • Patent number: 6495372
    Abstract: A test method and apparatus for determining the content of carboxylic acid-based corrosion inhibitors in a coolant or heat exchange fluid. The amount of acidic reagent added to the coolant or fluid between two pH equilibrium points is measured to determine the amount of inhibitors. The refractive index can be measured to determine the amount of freezing point depressant.
    Type: Grant
    Filed: September 27, 1999
    Date of Patent: December 17, 2002
    Assignee: Texaco Inc.
    Inventors: Jean-Pierre Maes, Peter Roose, Filip Van Kenhove
  • Patent number: 6372505
    Abstract: In a process for titrating substances by adding increments of a titrant in time intervals, the course of the reaction is monitored in its approach toward the end point (EP), and the addition of titrant is controlled. At least one differential component is determined from the course of the reaction and used for controlling the addition of titrant. The process can be performed by an apparatus that includes a delivery unit for the titrant and suitable devices for performing the monitoring, differentiating and control functions.
    Type: Grant
    Filed: October 26, 1999
    Date of Patent: April 16, 2002
    Assignee: Mehler-Toledo GmbH
    Inventors: Albert Aichert, Gregor Amrein
  • Patent number: 6315888
    Abstract: 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: Grant
    Filed: April 18, 2000
    Date of Patent: November 13, 2001
    Assignees: Mitsubishi Chemical Corporation, Dia Instruments Co., Ltd.
    Inventors: Hiromasa Kato, Masafumi Nakatani
  • Patent number: 6291249
    Abstract: A cell containing sample is separated into a cell containing portion and a substantially cell depleted portion, by mixing the sample with particles to produce a cell containing network, and separating the network from the remaining substantially cell depleted portion within a plurality of confining walls, wherein at least one of the walls is flexible. While in some aspects the separation is performed employing a magnetic force, in other aspects the separation is performed using two forces, wherein one force is a magnetic force and the other force is a mechanical force. It is contemplated that whole blood may be used as the sample, and that the cell-containing portion largely comprises a network of inter-linked red blood cells. It is especially contemplated that separation involves antiligands, preferably primary antibodies that bind to a ligand such as antigen on or in red blood cell membranes, and secondary antibodies that bind to the primary antibodies.
    Type: Grant
    Filed: February 28, 2000
    Date of Patent: September 18, 2001
    Assignee: Qualigen, Inc.
    Inventors: Vijay Mahant, Byron Doneen
  • Patent number: 6183695
    Abstract: An improved apparatus and method is disclosed utilizing hydrogen absorption in combination with photolysis and/or electrolysis for in situ generation, i.e., without the need for adding chemical oxidizing agents, or enhancement of oxidizing conditions used to promote oxidation of organic compounds to form carbon dioxide, and the use of the same in connection with high-accuracy determination of even extremely low levels of organic and/or inorganic carbon compounds both in flowing aqueous streams and in bulk solutions.
    Type: Grant
    Filed: May 11, 1998
    Date of Patent: February 6, 2001
    Assignee: Sievers Instruments, Inc.
    Inventors: Richard D. Godec, Paul P. Kosenka, Richard S. Hutte
  • Patent number: 5853352
    Abstract: A reduced vertical impact exercise platform is provided having a frame structure which, at least in part, encloses a platform assembly comprised of a plurality of distinct layers including a durable, resilient outer contact layer; a resilient padding layer; a reinforcing stiffening layer; a plurality of resilient cushioning members and a foundation layer. An optional stretch cord assembly and harness assembly are also provided for use with the exercise platform.
    Type: Grant
    Filed: August 7, 1997
    Date of Patent: December 29, 1998
    Assignee: Steven Login
    Inventor: Steven Login
  • Patent number: 5766552
    Abstract: Red blood cells are removed from whole blood or a fraction thereof by agglutinating whole blood with a mixture of a free agglutinating agent and nucleating particles having agglutinating agent intimately associated therewith to form clusters of red blood cells. High molecular weight polyethylene glycol may be added further to enhance agglutination. The clusters of red blood cells are much larger than the size of individual red blood cells, so that the clusters can easily be filtered through a porous medium. The plasma, which is substantially free of red blood cells, is further passed through a filter that optionally contains an additional agglutinating agent. Flow-delay additives may be provided to retain the fluid sample in contact with a reagent for a predetermined time.
    Type: Grant
    Filed: February 5, 1996
    Date of Patent: June 16, 1998
    Assignee: ActiMed Laboratories, Inc.
    Inventors: Sonal R. Doshi, John K. McGeehan, Wai Tak Law
  • Patent number: 5618495
    Abstract: The invention relates to colorimetric titration method, a titrator and colorimeter device. The titrating apparatus comprises radiant energy means for producing radiant energy. The device includes means for modulating an amplitude of an intensity of the radiant energy at a modulation frequency. The radiant energy is partially absorbed by an adjacent solution within a sample beaker having a color indicator dissolved therein. Radiant energy focusing means focuses the modulated radiant energy transmitted through the sample and beaker on radiant energy detection means. The radiant energy detection means produces a transmitted signal wherein an intensity of the transmitted signal is directly proportional to the intensity of transmitted energy. Filtering means filters the transmitted signal, such that a center frequency of the filtering means matches the modulation frequency of the radiant energy means.
    Type: Grant
    Filed: April 5, 1995
    Date of Patent: April 8, 1997
    Inventors: Andrew S. Mount, Douglas Paul, Alfred P. Wheeler
  • Patent number: 5567625
    Abstract: An apparatus and method are described for determining the relative concentrations of the constituent chemical components of a chemical combination. The spectral response of the composite sample, measured at a number of wavelengths .lambda..sub.i, is represented by a vector C. The relative concentration of the jth constituent is X.sub.j, and the relative concentrations of each of the chemical constituents are represented by the vector X. The vector X can be determined from the vector C by the following matrix equation:X=(A.sup.T A).sup.-1 A.sup.T Cwherein the matrix A has elements A.sub.ij, which is the spectral response of the jth component at wavelength .lambda..sub.i. Since the matrix A is a predetermined set of numbers, the elements of vector X are readily determined from the above equation. Such a determination is rapid; a profile of each of the constituents X.sub.j in the sample is readily and rapidly determined.
    Type: Grant
    Filed: October 19, 1994
    Date of Patent: October 22, 1996
    Assignee: International Business Machines Corporation
    Inventors: Jerome M. Kurtzberg, John S. Lew
  • Patent number: 5389546
    Abstract: The total alkalinity of an aqueous metalworking fluid is monitored and controlled by a continuous titration method that continuously supplies a stream of the metalworking fluid, at a known, controllable flow rate, to a flow through chamber having therein a static mixing element. Simultaneously and separately a stream of acid titrant, of known acid concentration is injected into the flow through chamber at a known controllable flow rate. The acid titrant and metalworking fluid mix and react in the chamber and the reacted metalworking fluid exiting the chamber passed over the tip of a pH electrode. The pH of the reacted metalworking fluid is continuously monitored and the output of the pH electrode used to adjust the flow of acid titrant to the chamber until an endpoint pH valve (typically a pH of 4) is reached.
    Type: Grant
    Filed: April 20, 1994
    Date of Patent: February 14, 1995
    Assignee: Cincinnati Milacron Inc.
    Inventor: Giles J. P. Becket
  • Patent number: 5254461
    Abstract: A method of determining populations of live, whole bacteria electrochemically. The bacteria are filtered, and the filtrate is employed in association with an electrochemical measuring unit to determine the bacteria density. In accordance with a flow-through method, the average signal over the predetermined time period of the test is employed, in conjunction with a constant, to determine the population. In accordance with the bypass method, reagent is passed through a bypass line to the electrochemical measuring unit, and the resulting signal is subtracted from the signal resulting from the filtrate, a constant being employed to correlate the resulting remainder with bacteria count. A changing-concentration method employs a changing concentration of bacteria in the same fluid to determine populations of bacteria. A saved-sample method employs a second test of the same filtrate, after a predetermined time period, to compensate for any contaminants that may be present.
    Type: Grant
    Filed: November 30, 1990
    Date of Patent: October 19, 1993
    Assignee: Infometrix, Incorporated
    Inventors: Gilson H. Rohrback, Elmond A. Holmes
  • Patent number: 5006312
    Abstract: A gravimetric method for determining the iodine adsorption number of carbon black is disclosed. The concentration of an accurately weighed iodine solution is determined by titrating with a standardized titrant and determining the concentration of the iodine solution by the weight of the standardized titrant needed to reach the titration endpoint. An appropriate amount of accurately weighed iodine solution is mixed with an accurately weighed amount of carbon black, and the mixture is equilibrated. The concentration of the resulting supernatant is determined by determining the weight of the standardized titrant needed to reach the titration endpoint. The iodine adsorption number is then determined based on the gravimetrically determined concentrations of the solutions. Preferably, the method is semi-or fully automated, and an apparatus for accomplishing the same is disclosed.
    Type: Grant
    Filed: June 18, 1990
    Date of Patent: April 9, 1991
    Inventor: Lawrence J. Murphy, Jr.
  • Patent number: 4950610
    Abstract: Titration apparatus includes two cells that receive and contain liquids and are transparent to light. A liquid having an unknown characteristic and mixed with an indicator that is optically responsive to a titrant is disposed in the cells. Light is transmitted through each cell to separate photosensors. The photosensor signals are compared and a titrant is added to one of the cells in known-volume increments until the difference between the signals reaches or exceeds a prescribed threshold. The characteristic of the liquid is calculated from the quality of known concentration titrant added in order to reach or exceed the prescribed threshold.
    Type: Grant
    Filed: September 28, 1987
    Date of Patent: August 21, 1990
    Assignee: Man-Gill Chemical Company
    Inventor: Douglas L. Tittle
  • Patent number: 4859608
    Abstract: In a new method for the titrimetric determination of the contents in a chemical solution, wherein a quantity of a reaction component, corresponding in each case to the change of a certain physical-chemical magnitude or a value derived from that, is added to a reaction component and this added quantity is so regulated that it will be a function of the prior and/or predetermined magnitude change or changes and the already added total quantity of one of the reaction components. In the method mentioned, the minimum quantity added is not allowed to fall below a predetermined percentage, e.g., 1.0 percent, or even 0.5 to 0.1 percent, of the already added quantity. The apparatus for performing the method therefore contains devices operable to regulate the quantity to be added as a function of the magnitude change and the already added total quantity of one of the reaction components. Potentiometric titration is the most important area of application of the new determination method.
    Type: Grant
    Filed: August 31, 1987
    Date of Patent: August 22, 1989
    Assignee: Mettler Instrumente AG
    Inventor: Peter Frueh
  • Patent number: 4582572
    Abstract: An end point of polarization titration is detected by the steps of passing constant DC pulse having a magnitude of 0.1-100 .mu.A between a pair of detection electrodes immersed in a solution to be titrated, detecting a polarization state generated between the detection electrodes at each current passage before the polarization reaches an equilibrium state and judging the end point based on the detected polarization state. The polarization state is detected by integrating a polarization potential generated at each current passage and the polarization is eliminated by short circuiting the detection electrodes before passing the next DC pulse.
    Type: Grant
    Filed: May 10, 1984
    Date of Patent: April 15, 1986
    Assignee: Mitsubishi Kasei Kogyo Kabushiki Kaisha
    Inventor: Seiji Ishikawa
  • Patent number: 4279863
    Abstract: An apparatus (10,50) is provided for physically retaining a reagent (17) in a blood collection tube (11) separate from a blood sample until the tube (11) is centrifuged. The apparatus includes a cup-shaped flexible barrier (10,50) placed over the reagent (17) disposed in the bottom of the tube (11). The barrier (10,50) seals with the inner wall of the tube (11) and prevents the reagent (17) from entering the tube's upper evacuated chamber (12,55) into which the blood sample is drawn. The seal maintains the barrier (10,50) in position until the tube (11) is centrifuged whereupon the barrier (10,50) moves to the bottom of the tube (11) causing the reagent (17) to flow past the barrier (10,50) to mix with the blood sample.
    Type: Grant
    Filed: September 12, 1979
    Date of Patent: July 21, 1981
    Assignee: Sherwood Medical Industries, Inc.
    Inventor: William R. Friehler
  • Patent number: 4266942
    Abstract: A method for the automatic, electro-chemical determination of the end point of titration utilizing an initial, continuous addition of the titrant, up to a predetermined value, followed by a step-by-step addition with a resting time inserted therebetween for stabilization of the solution is disclosed. As the titrant is being added to the bath sample in constant volume units, a measured value is formed after every such addition. The difference to the preceding measurement is determined and the three consecutive differences of greatest magnitude are utilized in a mathematical formula for calculating the end point. The titration ceases when the greatest difference lies between two lesser values.
    Type: Grant
    Filed: January 21, 1980
    Date of Patent: May 12, 1981
    Assignee: Siemens Aktiengesellschaft
    Inventors: Chris Vandenbossche, Jacky Vanhumbeeck
  • Patent number: 4120657
    Abstract: The invention relates to a process of and equipment for a selective, quick and accurate analysis of liquid samples. According to the process of the invention a liquid or a gas sample absorbed by a liquid is allowed to flow at a constant volume rate and overtitrated with an amount of a reagent adequate to the measurement in a definite time. Then the flow of the reagent is decreased to zero in a definite time, meanwhile continuously following, in a known way, the changes occurring in the reaction mixture. The determination of the concentration is carried out by comparing the time elapsed between the appearances of the two chemical equivalence points with calibration curves prepared with standard solutions, said time having a well defined functional relationship with the concentration of the sample.
    Type: Grant
    Filed: April 18, 1977
    Date of Patent: October 17, 1978
    Assignee: EGYT Gyogyszervegyeszeti Gyar
    Inventors: Geza Nagy, Erno Pungor, Klara Toth, Jeno Havas, Zsofia Feher