Abstract: The present invention relates to an electroanalytical instrument for determining by amperometry (eg chronoamperometry) the presence or quantity (eg concentration) of an analyte in an aqueous sample, comprising a sealed housing, an elongate pivotal arm mounted on the sealed housing, wherein the elongate pivotal arm houses a potentiostat, and a pivotal forearm joined pivotally to the elongate pivotal arm, which is connectable to an electrochemical sensor. By flexing the pivotal forearm, the electrochemical sensor may be electrically connected to the potentiostat. By flexing the elongate pivotal arm, the electrochemical sensor is immersed in the aqueous sample in the sealed housing.

Abstract: A system for monitoring cell-substrate impedance of excitable cells at millisecond time resolution and methods of assessing cell beating by monitoring cell-substrate impedance of beating cells at millisecond time resolution.

Abstract: Apparatuses, systems, method, reagents, and kits for conducting assays as well as process for their preparation are described. They are particularly well suited for conducting automated analysis in a multi-well plate assay format.

Abstract: A semiconductor module includes a housing, a circuit carrier having an insulation carrier and a metallization layer applied to a side of the insulation carrier, and a connection lug having a first and second load connection sections and a shunt resistor region. The shunt resistor region is electrically arranged between the first and second load connection sections and connected in series with the first and second load connection sections. The shunt resistor region has an ohmic resistance with a temperature coefficient having an absolute value of less than 0.00002/K at a temperature of 20° C. The connection lug in the region of the second load connection section is electrically conductively connected to a first section of the metallization layer by a first cohesive connection. The first load connection section is led out from the housing and has a free end arranged on the outer side of the housing.

Abstract: The present invention relates to a device and a method for parallel recording of impedance spectra and field potential of cells in vitro.

Abstract: Measurement devices, systems, and methods to measure a high field conductivity of a fluid are provided herein. The measurement device includes a fluid cell, a pair of electrodes, a voltage switch, and a measurement unit. The fluid cell is on an inclined plane to receive the fluid. The pair of electrodes are connected to the fluid cell. The pair of electrodes are spaced apart from one another to receive the fluid therebetween and positioned parallel to one another to pass an electrical current therethrough. The power unit provides a high voltage power supply to one electrode of the pair of electrodes. The measurement unit measures the electrical current that passes between the pair of electrodes through the fluid.

Abstract: A container for measuring cellular electric potential after being mounted on an electric potential measuring device is provided comprising a container and an electrode substrate, the electrode substrate being attached to a lower end of the container so as to form a plurality of wells, wherein the container comprises a plurality of cylindrical portions whose upper and lower ends are open, the electrode substrate comprises a substrate and a plurality of measurement electrodes and a plurality of reference electrodes disposed on one surface of the substrate, the measurement electrodes and the reference electrodes at least comprise metal-plated copper wiring, a pair of a measurement electrode and a reference electrode are disposed on a bottom of each well, and the measurement electrodes and the reference electrodes are formed by a pre-plating method.

Abstract: A contact structure for inspection that is installed on a bottom surface of a circuit board includes a ground conductor that is grounded; an elastic contact member that is brought into contact with an inspection target object; and a conductive line that electrically connects the circuit board and the elastic contact member. Here, the elastic contact member may be provided on a bottom surface of the ground conductor that is grounded. The elastic contact member may include an insulating layer, a wiring layer, a contactor and an elastic body provided at a position corresponding to the contactor. The elastic body provides the elastic contact member with elasticity when the contactor is brought into contact with an electrode. The elastic contact member is provided in parallel with the ground conductor. The wiring layer and the ground conductor form a microstrip line.

Abstract: A measurement cell provides electrochemical characterization of a sample. The cell includes a container in which a sample is located, the container having walls and a base defining an interior region for containing a conductive media. A base electrode is located adjacent a base of the container, a counter electrode is spaced from the base electrode and a reference electrode is located between the base and counter electrodes. Samples that may be characterized include the conductive media, an element forming the base electrode or a surface of the base electrode, an element in contact with the conductive media, or any two or more of these. The reference electrode contacts the conductive media between the base electrode and the counter electrode such that electrical paths are is established through the sample between the base electrode and the counter electrode and between the base electrode and the reference electrode.

Abstract: A tissue monitoring system includes an introducer having an inflatable section and a plurality of electrodes disposed thereon. The electrodes are alternatively connected to an electrode contact system which includes at least one signal line and at least one measurement line for taking readings about a circumferential segment of tissue encompassed by the electrodes.

Abstract: A method for identifying a selective persistent Na+ channel blocker by measuring the ability of the blocker to reduce or inhibit a persistent Na+ current to a greater degree than a transient Na+ current. Aspects of the present method provide Na+ depletion/repletion methods for identifying a selective blocker of a persistent Na+ channel, hyperpolarization methods for identifying a blocker of a persistent Na+ channel, and Na/K ATPase pump inhibitor methods for identifying a selective blocker of a persistent Na+ channel.

Abstract: A method for identifying a selective persistent Na+ channel blocker by measuring the ability of the blocker to reduce or inhibit a persistent Na+ current to a greater degree than a transient Na+ current. Aspects of the present method provide Na+ depletion/repletion methods for identifying a selective blocker of a persistent Na+ channel, hyperpolarization methods for identifying a blocker of a persistent Na+ channel, and Na/K ATPase pump inhibitor methods for identifying a selective blocker of a persistent Na+ channel.

Abstract: A method for identifying a selective persistent Na+ channel blocker by measuring the ability of the blocker to reduce or inhibit a persistent Na+ current to a greater degree than a transient Na+ current. Aspects of the present method provide Na+ depletion/repletion methods for identifying a selective blocker of a persistent Na+ channel, hyperpolarization methods for identifying a blocker of a persistent Na+ channel, and Na/K ATPase pump inhibitor methods for identifying a selective blocker of a persistent Na+ channel.

Abstract: A method for identifying a Na+ channel blocker, including providing a cell containing a Na+ channel, demonstrating both a transient and a persistent current. The cell includes a potassium (K+) channel and a Na/K ATPase (Na+ pump). A fluorescent dye is disposed into the well. The fluorescent dye is sensitive to change in cell membrane potential in order to enable optical measurement of cell membrane potential. A Na+ channel blocker, to be identified, is added to the well and a stimulating current is passed through the cell in an amount sufficient to generate an action potential before and after the addition of the Na+ channel blocker. Thereafter, a change in cell membrane potential is optically measured.

Abstract: Methods and apparatus employ the use of arrays (301, 902) of two or more electronically-discrete electrodes (1, 2, 3 . . . ) to facilitate high-throughput preparation and testing of materials comprising two or more elements. High rates of deposition, synthesis and/or analysis of materials are achieved with the use of arrays of electrodes whereby desired materials are developed. The high rate synthesis and/or analysis of an array of materials uses deposition control techniques in conjunction with the electrode array to develop a meaningful array of materials and to analyze the materials for desired characteristics to develop one or more materials with desired characteristics. The use of an array of electrodes enables high-throughput development of materials having scientific and economic advantages.

Abstract: A highly time resolved impedance spectroscopy that enhances the measurement of the dynamics of non-stationary systems with enhanced time resolution. The highly time resolved impedance spectroscopy includes an optimized, frequency rich a.c., or transient, voltage signal is used as the perturbation signal, non-stationary time to frequency transformation algorithms are used when processing the measured time signals of the voltage and current to determine impedance spectra which are localized in time; and the system-characterizing quantities are determined from the impedance spectra using equivalent circuit fitting in a time-resolution-optimized form. Methods and apparatus for processing impedance spectra data are also provided.

Abstract: A process for producing a thermoplastic resin composition is disclosed and comprises melt-kneading a resin composition containing from 40 to 90 parts by weight of (A) a polyamide resin, from 5 to 50 parts by weight of (B) a polyphenylene ether resin, from 5 to 30 parts by weight of (C) an aromatic vinyl compound-aliphatic hydrocarbon copolymer and from 0 to 30 parts by weight of (D) a polyolefin resin, per 100 parts by weight in total of the components (A), (B), (C) and (D), and further containing from 0.01 to 1.5 parts by weight of (E) an &agr;,&bgr;-unsaturated carboxylic acid or a derivative thereof per 100 parts by weight of the component (B), wherein the components (B), (C) and (E) are added from the upstream end of a melt-kneading machine and the component (A) is added part-way through the melt-kneading machine.

Abstract: A combination battery, light bulb, fuse tester having novel features. In particular, the tester includes a novel probe apparatus comprising an actuator, a pair of opposed probe arms, each of the probe arms having an electrical contact on an end thereof, the probe arms being adapted such that operation of the actuator biases the ends of the probe arms away from each other to an open position allowing the electrical poles of a battery, light bulb, or fuse to be tested to be contacted by the contacts on the probe arms. Additional features include magnetic probe contacts to facilitate the testing of a battery, light bulb, or fuse.

Abstract: An orientation sensor especially suitable for use in an underground device is disclosed herein. This orientation sensor includes a sensor housing defining a closed internal chamber, an arrangement of electrically conductive members in a predetermined positional relationship to one another within the chamber and a flowable material contained within the housing chamber and through which electrical connections between the electrically conductive members are made such that a comparison between an electrical property, specifically voltage, of a first combination of conductive members to the corresponding electrical property of a second combination of conductive members can be used to determine a particular orientation parameter, specifically pitch or roll of the sensor.

Abstract: Biologically active compounds are classified according to their effect on ion channels, changes in membrane potential and ionic currents, and the frequency content of action potentials that the compound(s) evoke in excitable cells. The spectral density changes of such evoked membrane potential or action potential are a characteristic for each channel type that is modulated by the test compound. A pattern of spectral changes in membrane potential is determined by contacting a responsive cell with a compound, and monitoring the membrane potential or ionic currents over time. These changes correlate with the effect of that compound, or class of compounds, on the ion channels of the responding cell. This pattern of spectral changes provides a unique signature for the compound, and provides a useful method for characterization of channel modulating agents.

Abstract: A method of observing a physical and chemical property of a tissue or cell by using an apparatus which comprises at least a cell culturing means, an environment conditioning means, an observing means and a comparing means, comprising the steps of (A) culturing the tissue or cell by the cell culturing means, (B) maintaining a first physical and chemical environment around the tissue or cell by the cell culturing means, (C) observing a first physical and chemical property of the tissue or cell in the first physical and chemical environment by the observing means, (D) changing the first physical and chemical environment to a second physical and chemical environment by the environment conditioning means, (E) observing a second physical and chemical property of the tissue or cell in the second physical and chemical environment by the observing means, and (F) comparing the first physical and chemical property of the tissue or cell with the second physical and chemical property of the tissue or cell by the comparing

Abstract: A measuring system with a measuring body (2) mounted on a rotatable shaft (1) and being provided with electrodes (16) for measuring electrical currents obtained through chemical reactions within an analyte solution. In the rotatable shaft is housed an electronic unit (14) for converting the electric current to a measuring signal which is, via a transferring means (6), transferred in an analogue or digital representation to a measuring signal registrating means placed outside of the rotatable shaft.

Abstract: The invention relates to an apparatus and method for monitoring cells and to a method for monitoring changes in cells upon addition of an analyte to the cell's environment, comprising a device which includes an array of microelectrodes disposed in a cell culture chamber, upon which array a portion of cells adhere to the surfaces of the microelectrodes. The diameter of the cells are larger than the diameters of the microelectrodes. A voltage signal is applied across each of the microelectrodes and a reference electrode. Detection and monitoring of the signals resulting from the application of the voltage signal provides information regarding the electrical characteristics of the individual cells, including impedance (combined cell membrane capacitance and conductance), action potential parameters, cell membrane capacitance, cell membrane conductance, and cell/substrate seal resistance. Such an invention is useful in detecting or screening a variety of biological and chemical agents.

Abstract: During voltammetric analysis of liquids, the indicator electrode must be frequently changed in order to prevent memory effects and resultant changes to basic conditions during measurement. In order to be able to change the indicator electrodes simply, a plurality of indicator electrodes are arranged on a common carrier. For accommodation of the liquid (2) to be analysed, a vessel (1) is provided and the carrier (5) is mounted to move in relation to this vessel (1) in such a way that one of the indicator electrodes (6) can be selectively brought into the area intended for the liquid. The reference electrode (8) necessary for the measurement is arranged in the vessel (1) and likewise connected with the measuring device (20). With that, changing of the selected electrode (6) ensues by moving the carrier (5) relative to said vessel (1).

Abstract: A cell potential measurement apparatus, which uses a planar electrode enabling a multi-point simultaneous measurement of potential change arising from cell activities, is provided which can conduct measurements accurately and efficiently as well as can improve convenience of arranging measurement results.

Abstract: An apparatus and method for measuring electrical parameters of a medium such as electrical conductivity and dielectric constant between a pair of electrodes are disclosed. The medium can be a liquid, gas, powder, etc., and the electrodes can be coaxial metallic circular cylinders. To compute electrical conductivity, the device is immersed in the medium to an immersion depth and the conductance across the electrodes is determined. The measurement is repeated at at least one additional immersion depth. By obtaining a differential conductance measurement with respect to the immersion depth, the effects of fringe conductances are eliminated from the measurement. The device can also be used to determine dielectric constant of the material by obtaining a differential capacitance measurement with respect to immersion depth. The device need not be calibrated by performing resistance measurements in a known standard solution.

Abstract: Impedance measurements from an array of cells containing microorganisms whose growth or multiplication are to be measured in terms of the impedance, utilizes electrodes which can be introduced into the cells and have contact pieces engageable by one or more probes of a measuring head displaceable by an x, y carriage system into alignment with the successive contact pieces. The system avoids the need for voluminous conductor arrangements and multiplexing systems.

Abstract: A conductivity sensor adapted for use in the conductimetric analysis of liquids includes a pair of conductivity electrodes incorporated into a conductivity cell assembly having a liquid flow control chamber, sensing chamber, and liquid exit chamber. Liquids to be measured are pumped into the liquid flow control chamber, where any turbulence in the liquid is dampened. The non-turbulent liquid is passed from the liquid flow control chamber to the sensing chamber, where the conductivity of the liquid is determined. The sensing chamber is adapted for changing the height of a column of liquid between the pair of conductivity electrodes in order to vary the cell constant of the sensor. The non-turbulent liquid is passed from the sensing chamber to the liquid exit chamber, where it exits the sensor. The sensor is well-suited for use in measuring conductivities of plating bath solutions and monitoring concentrations of major constituents of plating bath solutions.

Abstract: A conductivity meter usable in solutions where the path of the electric lines of force between two electrodes is altered. In one embodiment, detachable guard rings alter the path length based upon their own conductivity. In another embodiment, the physical distance between the electrodes is altered while maintaining a constant electrode configuration.

Abstract: A streaming current detector has a reciprocating piston with a sensing region having a uniform clearance from the casing which is sufficiently large to avoid significant shearing of the particles in the fluid of the sample stream. A separate guiding region of the piston has a sufficiently tight fit in the casing for smooth reciprocation. A relief region of the piston has the largest clearance from the casing to provide a sufficiently large area to control a constant low velocity of the sample fluid.

Abstract: In a streaming current signal, a zero crossing circuit tracks the phase of the streaming current signal. A latch is clocked in response to the outputs of the zero crossing signal to compensate the piston direction signal for change of phase of the streaming current signal.

Abstract: A low pressure ion-chromatograph for the analysis of cations comprises eluent reservoirs, pump, sample injection valve, sampler, column, flow conductivity cell, electrical conductivity detector and recorder, wherein the pump is a low pressure electronic micropump, the angle included between the inlet and outlet of eluent in the cell is 45.degree.-135.degree., and the flow conductivity cell is oriented in such a position that the eluent inlet is either horizontal or sloping upwardly. There is no leakage in this instrument. No special demands are needed for seal and material. Very good precision and high sensitivity up to ppb level can be obtained, and with low cost.

Abstract: An apparatus for providing a precise, continuous, and dynamic measurement of the electrical resistivity of a liquid medium. A dynamic measurement cell is provided with at least one conduit of electrically insulating material in which a conductive electrode slides with a motion of given amplitude. The lower portion of the conduit is calibrated over a length equal to at least the given amplitude, and has a known cross-section. The cell is immersed in a crucible containing the liquid medium for test at constant temperature to monitor various electric parameters. The monitoring system provides devices for controlling, adjusting, and measuring the amplitude and speed of the displacement of the electrode; measuring and adjusting the depth of immersion of the electrodes; and, measuring the variation, in ohmic resistance, of the cell as a function of the displacement of the electrodes. The conductivity is determined by an equation proportional to the ratio of the change in amplitude to the change in resistance.

Abstract: A streaming current detector includes an optical shutter rotated by the shaft of the motor which reciprocates a piston between electrodes in a bore containing sample fluid. An electronic synchronous detector is controlled by the output of a light detector whose source is interrupted by the optical shutter. The alternating current signals from the electrodes are connected to an operational amplifier having its inverting input connected to its output solely by a capacitor so that the output voltage is proportional to the charge of the fluid.

Abstract: A method and apparatus are disclosed for measuring the current distribution in an alumina reduction cell. The apparatus includes sensors attached to the anodes of the cell, a remote computer system for receiving and correlating data received from the sensors and a means for transmitting and receiving the data from the sensors to the remote computer.

Abstract: A conductivity cell is presented having a solid inner electrode and a hollow electrode whereby the inner electrode is adjustably mounted. The adjustable feature allows the cell to be accurately calibrated for various fluids having a wide range of conductivities.

Abstract: For use in detecting micro-organisms in a sample of a substance, a container for holding the sample consists of a glass bottle and closure in the form of an elastomeric bung, the bung being provided with a pair of chambers each housing a respective electrode until the container is required for use, when the electrodes are urged upwardly, breaking through a membrane of the bung to bring the electrodes into contact with the test sample in the bottle.

Abstract: The invention relates to a capacitive measuring element intended for continuous measurements of conductance in streaming solutions. The essence of the measuring element is that in the measuring space the surfaces limiting it are covered by an electrically insulating material. A method for obtaining the dimensions of the measuring element has also been proposed. According to the measuring element of the invention the measurements of concentration from very low values with high accuracy and low noise level are possible. The life duration and the reliability of the measuring element are high, and it shows a high resistivity against corrosive media to be measured.

Abstract: A rapidly demountable structure for supporting electronic probes within a reactor vessel at the inner end of a dip tube element. The structure includes a fixed dip tube element which is permanently positioned in a recess at the inner end of the dip tube, and a probe supporting element selectively engaged with the dip tube element through a bayonet type interconnection. A damaged probe is replaced by first disconnecting the probe supporting element from the dip tube element, and disassembling the probe supporting element to permit removal and replacement of the probe. Means is provided to seal the opening to the reactor vessel during the period in which the probe supporting element is in disengaged condition thus affording safety to service personnel during replacement of the damaged probe.

Abstract: The new instrument for taking readings of the hematocrit value from a blood sample has two electrodes with which the conductivity of the sample may be measured. The sample contacting faces of the electrodes are placed in a horizontal plane with an accurately fixed spacing therebetween so that a blood column of a given size may be formed from the sample. The sample is acted upon by ac. From a reading representative of the change in impedance the hematocrit value may be read off from a calibration curve.

Abstract: Method and apparatus of determining the dynamic surface potential of a solution, wherein a steady stream of the solution is formed, and the surface potential at a free surface of the stream of solution is measured by means of a rotary electrode that rotates in close vicinity of, but separated from, the free surface of the solution, and is mounted within an electrically grounded chamber.

Abstract: An ultrasonic streaming current detector for developing on a continuous basis, electrical signal which is a function of the charge condition existing in the stream containing charged particles therein, for thereby facilitating the determination of the dosage of floculate to be added to a charge implacing species field stream, for thereby ultimately controlling floculation of such streams. The present invention employs a cross-shaped housing having cross-member and a longitudinal member, a piston receiving member, a reciprocating piston, a pair of electrodes, a meter recorder and a electrical mortar. The piston pumps, the simple stream within its interior and by means of this reciprocating shear force against the simple stream generating an electrical signal across electrodes dispositioned at either end of the pump stroke of the piston to thereby generate an electrical signal through lead wires connected to a meter recorder box.

Abstract: A conductivity probe having a cylindrical body with an annular open-sided groove in which the electrodes are disposed, and a sliding cover wall for the groove biased to a position covering the groove but easily operable with one hand to slide the cover so as to open the groove. Viscous or slurried material can easily enter the groove, be trapped and confined for the conductivity measurement and then readily washed from the groove and surrounding parts for the next operation.

Abstract: A cell potential measurement apparatus, which uses a planar electrode enabling a multi-point simultaneous measurement of potential change arising from cell activities, is provided which can conduct measurements accurately and efficiently as well as can improve convenience of arranging measurement results.

Abstract: A cell potential measurement apparatus, which uses a planar electrode enabling a multi-point simultaneous measurement of potential change arising from cell activities, is provided which can conduct measurements accurately and efficiently as well as can improve convenience of arranging measurement results.