Abstract: The present disclosure relates to a conductivity measuring system of a fluid including a solvent and an ionic solute, comprising: —a holder comprising an isolated holder wall defining a fluid channel for holding fluid, wherein the holder is shaped to allow an electrical current induced in the fluid to form a current loop; —an excitation device configured to excite an electric field inside a first part of the fluid channel, the excitation device comprising an electrical signal generator configured to generate an alternating current signal and a conducting slab; —a sensing device arranged at a position remote from the first part of the fluid channel and configured to sense a voltage signal (V) resulting from the changing magnetic field resulting from the current generated inside the fluid by the excitation device.

Abstract: The present disclosure provides a high-power unipolar water electrolysis plant including a rectifier, a first U-bank, and a second U-bank electrically connected in series to the rectifier and to the first U-bank. Each U-bank is formed by a pair of adjacent, longitudinal cell arrays electrically connected to each other. The cell arrays are arranged in a spaced apart, side-by-side arrangement with a service corridor defined therebetween to allow sectional maintenance to be performed on each cell array. Each cell array has a plurality of unipolar water electrolyser cells. Each U-bank has input conduits for delivering water and cooling water to each cell array, output conduits for carrying hydrogen gas, oxygen gas and cooling water away from each cell array. The high-power unipolar water electrolysis plant includes a first jumper and a second jumper to isolate the U-bank, an electrical bypass busbar extension and a third jumper to bypass the U-bank.

Abstract: An electrochemical substrate holder assembly, including: a first housing and a second housing; wherein the first housing and the second housing collectively define an interior space; a first gasket coupled to the first housing and adapted to contact a first side of a substrate; and a second gasket coupled to the second housing and adapted to contact a second side of the substrate; wherein the first gasket and the second gasket are collectively adapted to hold the substrate within the interior space. The first housing defines a first port adapted to receive a first electrical lead to electrically contact the first side of the substrate. The second housing defines a second port adapted to allow a fluid to pass there through to fluidly contact at least the second side of the substrate. The second housing is adapted to receive one or more of a second and third electrical lead.

Abstract: The present disclosure discloses a conductivity sensor including a basic body of sintered ceramic having at least two cavities disposed on a frontal face and a metal electrodes disposed in each cavity. Each electrode is about one fifth the length of the basic body. Electrical cables extend from a rear face of the basic body into holes in each cavity and contact the electrodes. A solder paste or an electrically conductive adhesive disposed in each hole connects each cable with the respective metal electrode electrically and mechanically.

Abstract: There is provided an electrical measuring container of a biological sample in a liquid phase, including at least a biological sample holding section configured to accommodate a biological sample in a liquid phase and made of a resin, and an electrical conductive section fixed to the biological sample holding section. In a state in which a portion of the electrical conductive section is buried in the biological sample holding section, the biological sample holding section and the electrical conductive section are integrally formed with each other.

Abstract: A stressroll assembly may comprise a first bracket comprising a first load cell. The first load cell may form a first half of a Wheatstone bridge. A first stressroll wheel may be mounted to a first axle extending between a first arm of the first bracket and a second arm of the first bracket. A second bracket may comprise a second load cell. The second load cell may form a second half of the Wheatstone bridge. A second stressroll wheel may be mounted to a second axle extending between a first arm of the second bracket and a second arm of the second bracket.

Abstract: A measurement assembly for determining an electrical resistance of a fluid in a wellbore is provided. The measurement assembly can include a non-conductive frame, comprising an excitation electrode and a monitoring electrode coupled to the non-conductive frame. The measurement assembly can also include a central electrode in a flow path for the fluid, wherein the flow path is defined by the non-conductive frame. The central electrode can be positioned for conductively coupling the excitation electrode and the monitoring electrode through a conductive path defined by the fluid. Further, the measurement assembly can include a power source for transmitting power to the excitation electrode for determining the electrical resistance of the fluid. The electrical resistance of the fluid can be used to determine whether the fluid includes oil, water, or gas.

Abstract: Device for measuring electrical conductivity of a liquid medium comprising constant voltage means, connected to a first electrode arrangement for injecting an alternating signal into the liquid medium, detection means, connected to a second electrode arrangement coupled via the liquid medium, for generating a measurement signal influenced by the electrical conductivity with a clock frequency (CLK) of the alternating signal, and evaluation means which from a current-proportional injection signal of the current injected by the first electrode arrangement into the liquid medium and from the measurement signal generate a conductivity signal of the liquid medium. The constant voltage means are made in an individual circuit branch which has commutator means for the first electrode arrangement and ohmic resistance means in a series connection, the current-proportional injection signal being tapped as a voltage drop over the resistance means.

Abstract: A system for driving a first signal onto a wireline includes a driver and feedback circuitry. The driver drives a deterministic signal onto the wireline with an unknown impedance load. The feedback circuitry measures a quality of the output signal from the wireline and modifies a gain of the first signal based on the quality of the output signal. The driver then drives the first signal onto the wireline with the modified gain.

Abstract: A heat exchanger that is useful for analyzing samples, such as condensate, and methods of cooling a sample for analysis are provided as embodiments of the present invention. The heat exchanger includes an inner tube for containing cooling water and an annulus for containing steam so that heat exchange occurs between the cooling water and the steam so that condensate forms in the annulus. An external shield is attached to the heat exchanger to provide additional natural cooling and to prevent users from contacting the steam contained within the annulus.

Abstract: Disclosed is a circuit arrangement for determining a temporal change of an output voltage of a half-bridge circuit during a dead time. In one embodiment, the circuit arrangement includes a first input for applying the output voltage. A capacitive network includes a first and a second circuit node capacitively coupled to the input, and having a terminal for a reference potential. A recharging circuit during the switched-on phase of one of a first and second switching elements, adjusts electrical potentials of the first and second nodes, the electrical potentials each being different from the reference potential. A comparator arrangement, during the dead time, determines a time difference between such times at which the electrical potentials at the first and second node each assume a given potential value, the time difference being a measure for the change with time of the output voltage.

Abstract: A circuit arrangement for determining a temporal change of an output voltage of a half-bridge circuit during a dead time. In one embodiment, the circuit arrangement includes a first input for applying the output voltage. A capacitive network is provided having a first and a second circuit node capacitively coupled to the input, and having a terminal for a reference potential. A recharging circuit is configured, during the switched-on phase of one of a first and second switching elements, to adjust electrical potentials of the first and second nodes, the electrical potentials each being different from the reference potential. A comparator arrangement is provided that is configured during the dead time to determine a time difference between such times at which the electrical potentials at the first and second node each assume a given potential value, the time difference being a measure for the change with time of the output voltage.

Abstract: Disposable, pre-sterilized, and pre-calibrated, pre-validated conductivity sensors are provided. These sensors are designed to store sensor-specific information, such as calibration and production information, in a non-volatile memory chip on the sensor on in a barcode printed on the sensor. The sensors are calibrated using 0.100 molar potassium chloride (KCl) solutions at 25 degrees Celsius. These sensors may be utilize with in-line systems, closed fluid circuits, bioprocessing systems, or systems which require an aseptic environment while avoiding or reducing cleaning procedures and quality assurance variances.

Abstract: A gas detection sensor system including active and reference elements (Rsense, Rref) are arranged in a modified bridge circuit (12, 14, 22, 24) which allows power (Vbat) to be supplied seperately to the active and reference element (Rsense, Rref). A digal processor (30) monitors the resistances of the elements (Rsense, Rref) to control a pulse-width modulator supplying power to the elements, thereby maintaining nearly constant temperatures in the sensor elements (Rsense, Rref) and to translate the decrease in power needed to maintain constant temperature on the catalytic element into an output proportional to the concentration of combutible gas in air. The system periodically measures the resistance of the elements (Rref, Rsense) and enables dual operating modes of catalytic-bead detector. One active or reference element (Rsense, Rref) can alternately measure low concentrations of combustible gases up to the lower explosive limit (LEL) or measure high concentrations, up to 100% by volume.

Abstract: A stabilized fluid conductivity measurement system includes a threaded metal housing with an inner portion having two probes for contacting the fluid to be measured and having an outer portion in which electrical circuitry is mounted. The circuitry includes a balanced square wave generator providing excitation to a modified Wheatstone bridge, including first and second input excitation terminals, and first and second output terminals. Fixed resistances may be located in 3 arms of the Wheatstone bridge, and the fourth arm may have two resistances with an intermediate tap; and one of the two probes is connected to this tap while the other probe is connected to one of the input excitation points.

Abstract: A gas detector for sensing the presence of at least one predetermined gas is operative in conjunction with a electrical power source and includes a detection circuit, a temperature controller, and a electrical current controller, wherein the detection circuit includes a sensing device having first and second electrodes, the first electrode being connected to the power source for heating the first electrode, the temperature controller is operatively connectable to the detection circuit for maintaining a temperature of the first electrode at a predetermined magnitude, and the current controller is operatively connectable to the detection circuit for maintaining a current in the second electrode at a predetermined magnitude.

Abstract: A miniaturized ion analysis system with a contactless conductivity detection means is described for use in liquid phase sample analysis and detection. The device is formed by microfabrication of microstructures in novel support substrates. The detection means can be fabricated directly in the support body at the point of detection or other locations on the device or, alternatively, may be formed as part of a modular structure that is insertable into the device at the point of detection. In addition, a method is provided for analyzing ionic species present in a sample using the miniaturized ion analysis device. The invention herein is used for the analysis of ionic solutes in the liquid phase.

Abstract: A strain gage system for determining state of charge in a battery having a pressure vessel includes a strain gage bridge system mounted on a first cylindrical portion of the pressure vessel. The bridge system has a plurality of active strain gages and no inactive or dummy gages. An electrical output of the strain gage bridge is correlated to a state of charge of the battery.

Abstract: A water conductivity monitor that is controlled by a microcontroller which provides a pair of probe driving signals that are 180° out of phase. The monitor is connected to a feed water probe that is located within the unfiltered water of a water purification system and a filter water probe that is located within the filtered water of the system. The driving signals are provided to the probes to create a probe test signal. The filtered water test signal is a ratio of the voltage across the feed water probe and the voltage across the filter water probe. The driving signals are also provided to a resistor circuit which provides a threshold test signal. The test signals are integrated by an integrator circuit which is controlled by the microcontroller. The integrated test signals are compared by a comparator. The comparator provides an output signal to the microcontroller if the voltage level of the probe test signal is below the threshold test signal.

Abstract: The invention pertains to a solid-state chemical sensor with a substrate support. On one side of the support is mounted a heating element with branch circuit connections. On the other side interdigital electrodes are arranged and thereon a carbon dioxide-sensitive material, which comprises CuO and TiO.sub.3, as well as additional metal oxides, in the form of a thick film of approximately 20-200 .mu.m.

Abstract: A water softening system is provided in which a determination is made whether the slow rinse cycle of a regeneration has been completed or is abnormal. A reference cell and a spaced sensing cell are provided in a water tank. The impedance difference of the solution between the reference cell and the sensor cell is sensed. If the impedance difference is a first state, then after a predetermined period of time a determination is made if the impedance difference is a second state. If the impedance difference is a second state, then after a predetermined period of time a determination is made if the impedance difference is a third state. If the impedance difference is a third state, this indicates that the sodium ion concentration is uniformly reduced in the zone between the reference cell and the sensing cell and that the slow rinse cycle has been completed.

Abstract: Detector and method for detecting the presence of a liquid, such as water dew or of ice, or for detecting a change of phase in liquid, based on a change in an electrical resistance. The detector comprises a substrate onto whose face one or several resistor patterns are applied. For detecting the presence of a liquid or ice or equivalent by a change in the detector resistance, a low-mass detector resistor pattern is applied onto a substrate out of such a metal or equivalent as has a considerable dependence on temperature. On the substrate, there are contact patterns that feed a short pulse of electric current to heat the detector resistor as a short pulse, the presence of a liquid or ice and or a change of phase being detected by the change in resistance taking place during the short pulse. The thickness of the metal film in the resistor pattern (15) of the detector resistor (R.sub.det) is, as a rule, chosen as s<1 .mu.m.

Abstract: A control system for a water softener, control device therefor and methods of making the same are provided, the system comprising a microcontroller operatively interconnected to an output of a comparator to effect a subsequent operation of a recycling unit for the water softener when the output signal is at a certain condition thereof, the system causing the output signal to have a phase shift relative to the phase of an A.C. power supply of the system when a sensing electrode unit in the ion exchange bed of the water softener is at a certain resistance value relative to the resistance value of a reference electrode unit that is also disposed in the ion exchange bed, the phase shift comprising the certain condition of the output signal, the microcontroller determining the certain condition by comparing the phase of the output signal to the certain phase.

Abstract: A self-contained autonulling bridge circuit based on phase-sensitive deteon of an impedance to be measured is described. The system utilizes a feedback structure to control a variable impedance in order to establish the null of the bridge. The system utilizes a voltage-variable impedance having both resistance and capacitance and provides the phase sensitive relationship in the control means in order to provide highly accurate measurement of an unknown test impedance. The ability to measure small changes in impedance provides particularly useful application to the area of biological sensor impedance measurement or electrochemical impedance measurement using silicon-based devices.

Abstract: A device for detecting relative differences in conductivity between filtered and unfiltered states of fluid comprises a differential comparator for measuring the voltage difference of its input ports, a differential bridge connected to the input sorts of the differential comparator for measuring the conductivity of the fluid, the differential bridge having electrodes for contacting the fluid in each of its filtered and unfiltered states and bridge adjustment circuitry for compensating for voltage offsets of the comparator and the bridge, and an indicator connected to the output of the comparator for generating an output indicative of the differential conductivity of the fluid in its filtered and unfiltered states.

Abstract: The invention provides an apparatus for controlling both the supersaturation of the mother liquor and the crystal content of massecuite by measuring di-electric constant and electrical conductivity at radio frequencies by means of a probe which is included in a circuit which may be tuned to a fixed setting or may be variably tuned, the combined impedance is measured as a function of the tuning and the measurements are compared with predetermined desired values. By suitable combination of the two signals, measurement of crystal content and mother liquor supersaturation can be controlled.

Abstract: An electrochemical differential resistance measurement arrangement usable for detecting low concentration ionic impurities such as chemical warfare agents in liquids such as water. The disclosure includes details of electrochemical cells used in the liquid resistance measurement arrangement including one cell with fixed electrode positions and a selective ion transmitting membrane one cell with adjustable electrode position, and a combination cell. A differential bridge electrical circuit, together with a preferred form of alternating current energization therefor, an effluent circuit therefor and a balancing method sequence of steps for the bridge, are also included.

Abstract: A circuit for measuring the conductivity of a solution by applying a known ac current source across a pair of electrodes in the solution and utilizing an analog-to-digital dual slope converter, such as those of the integrated circuit type which include capacitor sampling of the signal input, for conversion of the ac voltage drop across the electrodes. The circuit includes means for synchronizing the ac current to the clock to time the sampling so that the same polarity of signal input is always obtained. Where the known ac current source consists of switching the sense of the electrode connections to a combination of a dc source in series with a known resistor, used for supplying the reference input to the converter, a dc signal input, instead of ac, obtained by including the voltage drop of the switch with the drop across the electrodes in the signal sampled. With this arrangement, higher cell constants can be used to minimize the effect of the voltage drop across the switch.

Abstract: A high sensitivity conductivity detector for ion chromatography includes an isolated fluid cell and a measuring circuit including an operational amplifier having its input connected to the center tap of a transformer. Feedback from the operational amplifier maintains the center tap at virtual ground potential. The excitation voltage for the transformer is supplied by two operational amplifiers. A thermoelectric semiconductor device maintains the temperature of the sample cell at a constant, ambient temperature.

Abstract: A liquid conductivity measuring circuit with power-save features is described for use with a four electrode conductivity cell having two potential electrodes and two current electrodes positioned in the cell in spaced relation in a particular sequence with a first operational amplifier having its output connected and its inputs connected via an isolating capacitor and a buffer amplifier and a voltage setting resistance to a source of square-wave voltage, a second operational amplifier having its inputs connected to ground and via an isolating capacitor and its output connected to a reference resistance such as to control the current through the reference resistor to maintain one electrode at a constant potential, readout means being adapted to measure, on initiation of a single or small number of square-wave voltage cycles in a period short enough that no significant change of polarization of the potential electrodes can occur, the voltage between the positive and the negative half cycles or the change from z

Abstract: An induction voidmeter for detecting voids in a conductive fluid may comprise: a four arm bridge circuit having two adjustable circuit elements connected as opposite arms of said bridge circuit, an input branch, and an output branch; two induction coils, bifilarly wound together, connected as the remaining two opposing arms of said bridge circuit and positioned such that the conductive fluid passes through said coils; applying an AC excitation signal to said input branch; and detecting the output signal generated in response to said excitation signal across said output branch. The induction coils may be located outside or inside a non-magnetic pipe containing the conductive fluid.

Abstract: A compensator device for providing direct and automatic correction of electrolytic gas sensor performance anomalies caused by exposure of the sensor to high levels of ionizing radiation. The compensator device, which compensates for changes in sensor performance while operating in a radiation field, provides an electromotive force which directly cancels that portion of the electromotive force developed by the active electrolytic gas sensor produced by the radiation rather than by presence of the gas. The compensating device is constructed in the same configuration as the active electrolytic sensor with the exception that the sensing electrode of the compensating device is not exposed to the sample gas environment. The sensor and compensator device are connected in a circuit such that their electromotive forces oppose one another, thereby determining the difference between the signals so that the radiation induced component is removed, and only the signal representing the partial pressure of gas remains.

Abstract: A method of and apparatus for determining very accurately the position of a device inside biological tissue comprising a detecting instrument with a probe, which probe generates a small magnetic field which can be disturbed by a magnetically permeable metal in the device inside the tissue when a narrow end of the probe is positioned immediately adjacent to tissue containing the metal, whereby after the metal-carrying device is inserted in the tissue, the end of the probe is used to precisely locate the device by scanning the tissue until the magnetic field is disturbed which causes the instrument to emit a signal.

Abstract: An electrochemical detector cell (10) and apparatus incorporating the cell (10) includes a first capillary (12) having an entrance (14) connected to an electrolyte source (30) and an exit (16). A second capillary (18) is connected to reactive gas source (32) and intersects the first capillary (12) at (22) to define a reaction zone (20) in the first capillary (12). A sensor electrode (24) is positioned in the first capillary (12) in the reaction zone (20). A third capillary (26) intersects the first capillary (12) within the reaction zone (20). A reference electrode (28) is positioned in the third capillary (26). The third capillary (26) is connected to a solution source (34). The electrodes (24) and (28) may be used for potentiometric measurements. A fourth capillary (38) intersects the first capillary between entrance (14) and intersection (22) of the first capillary (12) and the second capillary (18).

Abstract: A measuring circuit for use with an active polarized electrode, a reference electrode and a diaphragm which separates the solution to be examined from the electrolyte in which the electrodes are immersed. The output signals from the polarized electrode and from the reference electrode are processed as follows. The respective electrode is connected to one of the inputs of a respective operational amplifier (OA1, OA2) which serve as current voltage converters. The outputs of these amplifiers are then connected to a third operational amplifier (OA3) which detects the prevailing current difference in the electrode currents and initiates a necessary correction.

Abstract: An electronic apparatus and method for detecting a quantity of a predetermined substance disposed in a fluid medium. The apparatus includes a probe for contacting the fluid medium and for sensing an electrical condition, such as solution resistance, of the fluid medium caused at least in part by the substance to be detected. There is also included electronic control devices connected to the probe means for generating a signal which is proportional to the quantity of the substance to be detected. The signal is fed to some utilization means, such as a meter, for indicating the amount of substance in solution.