Abstract: A sensor element includes: an element base including: a ceramic body made of an oxygen-ion conductive solid electrolyte, and having an inlet at one end portion thereof; at least one internal chamber located inside the ceramic body, and communicating with the gas inlet; and an electrochemical pump cell including an outer electrode, an inner electrode facing the chamber, and a solid electrolyte therebetween, and a porous leading-end protective layer covering a leading end surface and four side surfaces in a predetermined range of the element base on the one end portion, wherein the protective layer has an extension extending into the gas inlet and fixed to an inner wall surface of the ceramic body demarcating the gas inlet, and a gap communicating with the gas inlet is located in the protective layer, with demarcated by a portion of the protective layer continuous with the extension.

Abstract: A sensor element includes: an element base including: a ceramic body made of an oxygen-ion conductive solid electrolyte, and having a gas inlet at one end portion thereof; at least one internal chamber located inside the ceramic body, and communicating with the gas inlet under predetermined diffusion resistance; an electrochemical pump cell including an electrode located on an outer surface of the ceramic body, an electrode facing the chamber, and a solid electrolyte located therebetween; and a heater buried in the ceramic body, and an leading-end protective layer being porous, and covering a leading end surface and four side surfaces in a predetermined range of the element base on the one end portion. The leading-end protective layer has an extension extending into the gas inlet, and fixed to an inner wall surface of the ceramic body demarcating the gas inlet.

Abstract: A sensor element includes: an element base including: a ceramic body made of an oxygen-ion conductive solid electrolyte, and having a gas inlet at one end portion thereof; at least one internal chamber located inside the ceramic body, and communicating with the gas inlet under predetermined diffusion resistance; an electrochemical pump cell including an electrode located on an outer surface of the ceramic body, an electrode facing the internal chamber, and a solid electrolyte located therebetween; and a heater buried in the ceramic body, and a leading-end protective layer being porous, and covering a leading end surface and four side surfaces in a predetermined range of the element base on the one end portion. The leading-end protective layer has an extension extending into a widened portion included in the gas inlet, and fixed to an inner wall surface of the widened portion.

Abstract: A method for producing an electromigration-resistant crystalline transition-metal silicide layer of a layer sequence, for example, to provide a micro heater includes, supplying a semiconductor substrate including an electrically insulating layer; physically depositing a transition metal on the electrically insulating layer; carrying out a plasma-enhanced chemical vapor deposition while forming an inert gas plasma; conveying monosilane to the inert gas plasma, with the monosilane decomposing into silicon and hydrogen and the silicon in the gaseous phase entering into a chemical reaction with the transition metal in order to form the electromigration-resistant crystalline transition-metal silicide layer.

Abstract: Disclosed herein are embodiments of a method and system for producing a halogen gas. The method may comprise contacting a solid oxidizing agent with a vapor comprising a halide compound, to produce a gas stream comprising a halogen corresponding to the halide in the halide compound. The halide compound may be an acyl halide, such as an acetyl halide or an oxalyl halide. The oxidizing agent may be any suitable oxidizing agent, and in certain examples, potassium permanganate is used. The method may be performed under a reduced pressure. Also disclosed herein is a system suitable to perform the disclosed method. The system may comprise a reservoir, an oxidizing agent support and a gas stream outlet.

Abstract: A pipe structure includes a pipe disposed in a state of contact with the air, a fluid with a temperature of at least 100° C. flowing inside the pipe; and a coating material containing nickel oxide and coated onto an outer periphery portion of the pipe.

Abstract: A gas sensor (100) includes a sensor element (120), a metallic shell (110), a powder filler member (133), a first ceramic holder (135) in contact with the rear end of the powder filler member and from which the sensor element protrudes, and a second ceramic holder (131) in contact with the forward end of the powder filler member and from which the sensor element protrudes. The powder filler member has a higher thermal expansion coefficient than that of the first and second ceramic holders. The first ceramic holder, powder filler member, and second ceramic holder are pressed by force application means (118). A relation 0.40<(L?M)/L<0.58 holds, where L is the axial distance between the rearward-facing surface of the first ceramic holder and the forward end of the second ceramic holder, and M is the axial length of the powder filler member.

Abstract: A hydrogen detection method using a gas sensor, in which the gas sensor includes a first conductive layer; a second conductive layer including a first region having a first thickness and a second region having a second thickness larger than the first thickness; a metal oxide layer disposed between the first conductive layer and the second conductive layer; and an insulation layer covering the first conductive layer, the second region of the second conductive layer, and the metal oxide layer and not covering the first region of the second conductive layer. The hydrogen detection method includes allowing a gas to come into contact with the first region of the second conductive layer; and detecting a hydrogen gas contained in the gas by detecting a decrease in resistance between the first conductive layer and the second conductive layer.

Abstract: A sensor for determining an air ratio of a fuel gas/air mixture, wherein a housing is formed, which delimitates a measuring space. The housing has on one side a diffusion passage for coupling with a fuel gas/air mixture flow, wherein the diffusion passage is formed by a gas-permeable separating agent. An electrically operated excitation element is arranged for energy supply into the measuring space in order to induce a chemical reaction of a fuel gas/air mixture in the measuring space. At least one optical detection device is directed into the measuring space with its detection area, wherein the at least one optical detection device detects the intensity of radiation from the reaction position in at least a first wavelength range and produces a signal being allocated to the detected intensity, from which the air ratio is inferable.

Abstract: A measured value of a sensor element is obtained during repeatedly executed measuring periods for performing different measurements and for setting different operating states, the sensor element being electrically connected in a periodically alternating manner, in consecutive switching positions, in a predefined order, where at least one measurement for determining the measured value is performed repeatedly within a measuring period for determining individual values at predefined switching positions, the measured value being determined from the individual values. Using the switching position within the measuring period, the operating state of the sensor element preceding the individual measurement, and therefore, the influence of the preceding circuit configuration on the individual measured value, is known, and the individual values are correspondingly corrected. By correcting the individual values, the measured value determined from the individual values is also corrected.

Abstract: A method for fastening a metallic bushing (3) to a metallic component (2) includes forming a ring-shaped contact surface (5) on the bushing, forming an opening (6) in the component and providing a collar (7) extending circumferentially along the opening in the component and projecting on a mounting side (8) of the component. The mounting side is brought into contact and pressed in the area of the opening in the component such that the contact surface touches the collar. The bushing (3) is pressed on the mounting side (8) of the component in the area of the opening (6), so that the contact surface is in contact with the collar under prestress. With the contact surface (5) in contact with the collar under prestress, the bushing (3) and the component (2) are resistance welded together in the area of the contact between the contact surface (5) and the collar (7).

Abstract: An air-fuel ratio sensor control unit connected with an air-fuel ratio sensor including a common terminal, a first terminal and a second terminal includes a common connection terminal connected with the common terminal, a first connection terminal connected with the first terminal, a second connection terminal connected with the second terminal, a voltage control circuit controlling a voltage of the first connection terminal, a resistor connected with the common connection terminal, a voltage sensing circuit sensing a two-end voltage of the resistor, a current applying circuit applying a constant current to the second connection terminal, and a determining unit sensing a change quantity of the two-end voltage by using the voltage sensing circuit and determining whether a disconnection failure of the first connection terminal occurs based on a sensing result of the change quantity.

Abstract: A gas concentration measuring apparatus is provided which works to calculate the concentration of a given gas component with enhanced accuracy. The gas concentration measuring apparatus 1 includes, a gas sensor 10 and a calculating portion 11. The gas sensor 10 is equipped with a pump cell 3, a monitor cell 4, and a sensor cell 5. The calculating portion 11 subtracts a monitor cell current Im that is a current flowing through the monitor cell 4 from a sensor cell current Is that is a current flowing through the sensor cell 5 to calculate the concentration of the given gas component in gas g. When calculating the concentration of the given gas component, the calculating portion 11 performs a correction operation to bring a value of the monitor cell current Im close to a value of an oxygen dependent current Iso that is a component of the sensor cell current Is which arises from the concentration of oxygen.

Abstract: A gas concentration measuring apparatus is provided which works to calculate the concentration of a given gas component with enhanced accuracy. The gas concentration measuring apparatus 1 includes, a gas sensor 10 and a calculating portion 11. The gas sensor 10 is equipped with a pump cell 3, a monitor cell 4, and a sensor cell 5. The calculating portion 11 subtracts a monitor cell current Im that is a current flowing through the monitor cell 4 from a sensor cell current Is that is a current flowing through the sensor cell 5 to calculate the concentration of the given gas component in gas g. When calculating the concentration of the given gas component, the calculating portion 11 performs a correction operation to bring a value of the monitor cell current Im close to a value of an oxygen dependent current Iso that is a component of the sensor cell current Is which arises from the concentration of oxygen.

Abstract: Methods for monitoring the performance of an oxidizing catalyst device are provided. Methods can include treating an exhaust gas stream with the oxidizing catalyst device, determining a reference liberated oxygen (LO) species measurement of the exhaust gas stream, measuring a downstream LO species measurement of the exhaust gas stream using a NOx sensor in a catalyst inactive mode, and determining a LO species differential. The downstream NOx sensor can comprise an amperometric sensor and include a NO2 selective reduction catalyst. Methods for using an amperometric NOx sensor utilizing an NO2 selective reduction catalyst are also provided, and include operating the NOx sensor in a catalyst active mode to generate a first LO species measurement, operating the NOx sensor in a catalyst inactive mode to generate a second LO species measurement, and comparing the first LO species measurement to the second LO species measurement to determine a LO species differential.

Abstract: The invention relates to a sensor structure and a method. The sensor structure includes a first sensor having a sensing element sensitive to humidity of the environment. In accordance with the invention the sensor structure also includes s second sensor having a sensing element sensitive to humidity, the second sensor comprising a catalytic permeable layer positioned on the second sensor such that it is between the sensing element of the second sensor and the environment.

Abstract: When an air-fuel ratio detection performed by detecting an output of a downstream sensor, which is a limiting-current type air-fuel ratio sensor arranged at a downstream side of a catalyst in an exhaust passage of an internal combustion engine, and calculating an air-fuel ratio at the downstream side of the catalyst in accordance with the output, if the output is within a predetermined range including an output corresponding to a theoretical air-fuel ratio, a relationship between the output and an air-fuel ratio that is calculated by calculation means is shifted more to a rich side relative to a correspondence relationship between an output of an upstream sensor, which is a similar sensor to the downstream sensor arranged at an upstream side of the catalyst in the exhaust passage of the engine, and an air-fuel ratio.

Abstract: A sensor system (36) determines the Stoichiometric Air to Fuel Ratio (SAFR) of fuel mixtures. The system includes a first electrode (12) and a second electrode (14), with the first electrode surrounding the second electrode so that a fuel mixture can flow between the first electrode and the second electrode. The electrodes are constructed and arranged to provide data for determining a conductivity and permittivity of the fuel mixture. A temperature sensor (18) is constructed and arranged to measure a temperature of the fuel mixture. A processor (19) is constructed and arranged to determine the SAFR of the fuel mixture based on the measured temperature and permittivity of the fuel mixture.

Abstract: Provided herein is technology relating to detecting gaseous analytes and particularly, but not exclusively, to devices and methods related to detecting gaseous analytes by monitoring changes in liquid crystals upon exposure to the gaseous analytes.

Abstract: Methods for detecting the type of lambda probes having at least two electrodes disposed on and/or in a solid electrolyte, of which at least one electrode is separated from a gas mixture by a diffusion barrier, and a pump current Ip being applied to at least one of the electrodes. Either the internal resistance of the lambda probe between the electrodes is determined and the type of probe is inferred on the basis of this resistance, or currents are impressed between the electrodes and the type of probe is inferred based on the voltages or resistance ratios thereby resulting.

Abstract: A volatile matter sharing system includes a first stamp-charged coke oven, a second stamp-charged coke oven, a tunnel fluidly connecting the first stamp-charged coke oven to the second stamp-charged coke oven, and a control valve positioned in the tunnel for controlling fluid flow between the first stamp-charged coke oven and the second stamp-charged coke oven.

Abstract: A device for operating a gas sensor having both at least one pump cell and a measuring cell is provided. A constant current source is provided that makes available a pump current which acts upon an outer electrode of the pump cell. The constant current source provides at least two different amounts of the pump current and/or allows for an alternating operation having ON phases and OFF phases, the duration of the ON phases/OFF phases being specifiable. The device may be largely implemented in digital circuitry and adapted to different requirements.

Abstract: The invention relates to a sensor assembly. The assembly includes a sensor body 2 of appropriate construction (preferably substantially ceramic) with a radial flange 8. A housing 20 is of two-part integral construction and includes an annular groove or recess in which the radial flange 8 of the sensor body 2 is received when the sensor assembly is in its assembled form. The annular groove is defined by a pair of facing shoulders 28, 36 each having an annular surface 30, 38 and a substantially cylindrical surface 32, 40. The annular surfaces 30, 38 are in sliding contact with the flange 8 and apply a compressive load to the flange to form a hermetic seal between the housing 20 and the sensor body 2. The hermetic seal is maintained even if the sensor assembly is used at high operating temperatures.

Abstract: Provided is a gas sensor capable of accurately obtaining a hydrocarbon gas concentration even if a measurement gas contains water vapor. A main pumping cell adjusts an oxygen partial pressure of a first internal space such that a hydrocarbon gas in a measurement gas is not substantially burned in the first internal space. An auxiliary pumping cell adjusts an oxygen partial pressure of a second internal space such that inflammable gas components except for hydrocarbon are selectively burned. Then, a measuring pumping cell supplies oxygen to a surface of a measuring electrode. As a result, hydrocarbon existing in the measurement gas being in contact with the measuring electrode is all burned on the surface of the measuring electrode and, based on the magnitude of a current flowing between the measuring electrode and a main pumping electrode at that time, identifies a concentration of a hydrocarbon gas component existing in the measurement gas.

Abstract: Provided is a gas sensor capable of accurately obtaining a hydrocarbon gas concentration even if a measurement gas contains water vapor. A main pumping cell adjusts an oxygen partial pressure of a first internal space such that a hydrocarbon gas in a measurement gas is not substantially burned in the first internal space. An auxiliary pumping cell adjusts an oxygen partial pressure of a second internal space such that inflammable gas components except for hydrocarbon are selectively burned. Then, the measurement gas is introduced into a third internal space through a third diffusion control part. With oxygen concentration equilibrium kept in the third internal space, hydrocarbon existing in the measurement gas that has reached the third internal space is all burned. Then, the concentration of the hydrocarbon gas component existing in the measurement gas is identified based on the magnitude of a current flowing between the measuring electrode and the main pumping electrode at that time.

Abstract: Disclosed is a control device, which controls an air-fuel ratio sensor that is mounted in an exhaust path of an internal-combustion engine. The air-fuel ratio sensor is capable of pumping oxygen in a gas. Normally (time t0-t1, time t3 or later), a positive voltage Vp1 is applied to a sensor element (FIG. 7A), and the air-fuel ratio is calculated (FIG. 7C) in accordance with a sensor current (FIG. 7B). A heater is driven after internal-combustion engine startup to heat the sensor element. In a process in which the sensor element temperature rises, a negative voltage Vm, which is oriented in a direction different from that of the positive voltage Vp1, is applied to the sensor element.

Abstract: A gas sensor control apparatus is provided which controls an operation of a gas sensor made up of a solid electrolyte body and a pair of electrodes to output a signal indicating the concentration of a given gas component contained in gas. The gas sensor control apparatus includes a constant current circuit that is connected electrically to one of the electrodes of the gas sensor and supplies a constant current thereto and a controller. The controller supplies a constant current to the gas sensor so that it flows from one of the electrodes to the other in a selected direction, thereby changing a response time the gas sensor takes to react to a change in concentration of the gas component. This results in an increased accuracy, for example, in controlling an air-fuel ratio of a mixture to an internal combustion engine in an engine control system.

Abstract: A gas sensor element includes a base member comprising a plurality of laminated solid electrolyte layers, and having a space that communicates with the outside of the gas sensor element and allows introduction of the gas to be measured into the gas sensor element, and a porous measurement electrode that is formed on a surface of the space inside the base member, and is covered with a porous measurement electrode protective layer, wherein an average pore size A of the measurement electrode and an average pore size B of the measurement electrode protective layer satisfy the relationship “0.05?B/A?0.9”, the measurement electrode has an average pore size of 0.5 to 15 ?m, and the measurement electrode protective layer has an average pore size of 0.05 to 9 ?m, a porosity of 5 to 50%, and a thickness of 10 to 200 ?m.

Abstract: A sensor control apparatus (3) includes a full-range gas sensor composed of an oxygen concentration detection cell having a pair of electrodes (21, 22) and an oxygen pump cell having a pair of electrodes (19, 20). In an electric circuit section (30), an Ip current flowing between the electrodes (19, 20) is controlled such that an electromotive force Vs produced between the electrodes (21, 22) becomes equal to a reference voltage. The reference voltage is usually set to a first reference voltage. However, when the subject gas is air, the reference voltage is set to a second reference voltage. Humidity of the subject gas is detected on the basis of an error ?Ip between an Ip current detected when the reference voltage is set to the first reference voltage, and an Ip current detected when the reference voltage is set to the second reference voltage.

Abstract: A gas sensor element with a bottom part is composed of at least a solid electrolyte body of oxygen ion conductivity, a reference electrode, a detection electrode, an electrode protection layer which supports noble metal catalyst, and a heater. The electrode protection layer is composed of a covering layer, a catalyst layer and a poisoning layer. A quantity of the noble metal catalyst supported in the electrode protection layer at the bottom part of the gas sensor element is larger than that in the electrode protection layer at a leg part of the gas sensor. The bottom part of the gas sensor element has a high temperature rising speed more than the leg part when the heater generates heat energy.

Abstract: A method of manufacturing an exhaust gas sensor that includes positioning at least a portion of a subassembly of the exhaust gas sensor in a mold fixture, overmolding at least a portion of the subassembly with a ceramic material, and removing the overmolded subassembly from the mold fixture.

Abstract: A sealing portion is formed of a calcined body that is made by calcining a powder compact of a spherically-shaped granulated powder that is selected from the group consisting of alumina, aluminum titanate and cordierite. Anisotropy in physical properties is less likely to occur in the powder compact, because these ceramics are not only good in terms of thermal stability but also their spherically-shaped granulated powders are less likely to be oriented at the time of powder compacting. Therefore, the sealing portion comes to have a long longevity, because slippages between the particles are less likely to occur even when thermal histories are applied thereto, and because it can maintain the gas sealing property stably for a long period of time.

Abstract: A gas sensor contains a sensor element for detecting the concentration of a particular gas component in a measurement gas and a housing for supporting the sensor element inside, and the sensor element has a rectangular solid structure of a solid electrolyte body containing a ceramic material. In the gas sensor, four edges of the solid electrolyte body are beveled over the entire length thereof to form eleventh to fourteenth chamfered portions corresponding to the four edges.

Abstract: A gas sensor includes a gas sensor element. The gas sensor element includes a first detection chamber; a first oxygen pumping cell including a first solid electrolyte body and a pair of first electrodes; a second detection chamber; a second oxygen pumping cell including a second solid electrolyte body and a pair of second electrodes; and an oxygen-concentration sensing cell including a third solid electrolyte body and a pair of third electrodes. A sensing electrode of the third electrodes is disposed downstream beyond a first inner electrode of the first electrodes relative to a gas flow direction. A cross-sectional area of a space of the first detection chamber which faces the first inner electrode falls within a range from 0.03 mm2 to 0.22 mm2.

Abstract: A gas sensor element is composed of a sensor section, a heater section, and a porous protective layer. The sensor section is composed of a solid electrolyte layer and a pair of electrodes. The heater section heats the sensor section to activate it. The porous protective layer covers surfaces of the sensor section and the heater section of the gas sensor element in a gas sensor which is exposed to a target detection gas to be detected. The porous protective layer is made of a mixture of hydrophobic heat resisting particles having a contact angle of not less than 75° to a drop of water, and the hydrophilic heat resisting particles having a contact angle not more than 30° to a drop of water. A gas sensor equipped with the above gas sensor element is also disclosed.

Abstract: There is provided a gas sensor, which includes a sensor element extending axially of the gas sensor and having a gas sensing portion at a front end thereof and an electrode portion at a rear end thereof, a cylindrical metal shell retaining therein the sensor element with the gas sensing portion and the electrode portion protruding from front and rear ends of the metal shell, respectively, and having a flange portion and a rear end portion located on a rear side of the flange portion, a cylindrical protection cover having a front end fitted onto the rear end portion of the metal shell so as to cover the electrode portion and a weld joint through which the entire circumference of the front end of the protection cover is joined through the metal shell. The weld joint extends from an end face of the protection cover to the metal shell.

Abstract: A gas sensor control apparatus is provided which controls an operation of a gas sensor made up of a solid electrolyte body and a pair of electrodes to output a signal indicating the concentration of a given gas component contained in gas. The gas sensor control apparatus includes a constant current circuit that is connected electrically to one of the electrodes of the gas sensor and supplies a constant current thereto and a controller. The controller supplies a constant current to the gas sensor so that it flows from one of the electrodes to the other in a selected direction, thereby changing a response time the gas sensor takes to react to a change in concentration of the gas component. This results in an increased accuracy, for example, in controlling an air-fuel ratio of a mixture to an internal combustion engine in an engine control system.

Abstract: The present invention provides oxygen partial pressure control apparatuses that can control the partial pressure of oxygen in atmospheric gases in processing apparatuses or the like to within the range of 0.2 to 10?30 atm, while maintaining low material and operational cost conditions.

Abstract: Electrodes comprising ruthenium oxide nanoparticles are disclosed. The ruthenium oxide nanoparticles are located within the electrode or as a coating thereon. The electrode is especially suited for measuring the presence and/or concentration of nitric oxide in a sample.

Abstract: A method and apparatus for controlling a multi-gas sensor, including an NOX sensor section and an ammonia sensor section. The NOX sensor section includes a first pumping cell adapted to pump oxygen into or out of a gas under measurement introduced into a first measurement chamber, and a second pumping cell communicating with the first measurement chamber and configured such that a second pumping current Ip2 corresponds to an NOX concentration of the gas under measurement. Oxygen concentration is calculated on the basis of a first pumping current flowing through the first pumping cell, and a corrected ammonia concentration is calculated on the basis of the oxygen concentration and the ammonia concentration output of the ammonia sensor section.

Abstract: An organic contaminant molecule sensor is described for use in a low oxygen concentration monitored environment. The sensor comprises an electrochemical cell, which is formed from a measurement electrode coated with (or formed from) a catalyst having the ability to catalyse the dissociative adsorption of the organic contaminant molecule, the electrode being positioned for exposure to the monitored environment, a reference electrode coated with (or comprised from) a catalyst selected for its ability to catalyse the dissociation of oxygen to oxygen anions, the reference electrode being positioned within a reference environment, and a solid state oxygen anion conductor disposed between and bridging the measurement and reference electrodes, wherein oxygen anion conduction occurs at or above a critical temperature, Tc. Sealing means are provided for separating the reference environment from the monitored environment.

Abstract: An electrochemical test strip, an electrochemical test system, and a measurement method using the same are provided. The electrochemical test strip includes an insulating substrate, an electrode system formed on the insulating substrate, and an insulating layer formed on the electrode system. The electrode system includes a set of measurement electrodes, a set of identifying electrodes, and a resistive path having a predetermined resistance value. The set of identifying electrodes is made of metal material, and the resistive path is made of non-metal material. The set of measurement electrodes includes a reference electrode and a working electrode insulated from each other, and the set of identifying electrodes includes a first identifying electrode and a second identifying electrode connected with each other through the resistive path.

Abstract: A vibrator has a large strength of a standing wave even with a low driving voltage, thereby improving the accuracy of component separation. A device according to the present invention includes a substrate having a channel groove provided in an upper surface of the substrate, a seal provided above the substrate so as to cover an upper opening of the channel groove, a projection provided on an outer side wall opposite to the channel groove, and a vibrator causing the projection to warp and vibrate in a depth direction of the channel groove. The warping vibration of the projection is amplified due to effect of leverage, and generates a large stress on the outer wall of the channel groove having the projection provided thereon. Consequently, the strength of a standing wave in the channel groove increases even for a low driving voltage, thereby improving the accuracy of component separation.

Abstract: The invention relates to an electrochemical gas sensor having improved response time and sensitivity. The electrochemical gas sensor includes a substrate for providing a surface upon which a film of conductive material may be deposited, a pair of electrodes deposited on the substrate for permitting a measurement of current, and an electrolytic material for providing an electrical connection between the electrodes. The electrochemical gas sensor further includes a passage in the surface for holding or transporting gas received from a gas source, whereby sensing occurs at a three way interface where the gas, electrolytic material, and electrodes come in direct contact with one another.

Abstract: Electrically charged molecules need to be transported in order to create a DNA sensor. The following measures are undertaken: base metals are introduced into a solution as a positive ion; negatively charged molecules are transported in an opposite direction and are enriched in the vicinity of the measuring electrodes. Binding-specific separation of the charged molecules can be achieved by forming metal layers on the measuring electrodes by depositing metal ions from the solution when a suitable potential is selected. Target DNA can more particularly be introduced into the vicinity of the catcher molecules on the measuring electrodes and non-specifically bound DNA can be removed. According to the associated device, the electrode arrangement may be associated with a sacrificial electrode made of more base metal than the material of the measuring electrodes. The measuring electrodes in particular may be made of noble metal, preferably gold, and the sacrificial electrode may be made of copper.

Abstract: A gas concentration measuring apparatus for use in air-fuel ratio control of motor vehicle engines is provided which is designed to determine the concentrations of oxygen at different resolutions within a wide and a narrow range using a first and a second sensor signal which are amplified by first and second operational amplifiers at different amplification factors. The apparatus samples values of the first sensor signal at different concentrations of oxygen to find an output characteristic error of the first operational amplifier and determines an actual concentration of oxygen to calculate an output characteristic error of the second operational amplifier using the one of the first operational amplifier and the actual concentration of oxygen. This permits values of the first and second sensor signals to be corrected so as to compensate for the output characteristics of the first and second operational amplifiers.

Abstract: Novel systems for combinatorially screening an array of electrochemical cells are disclosed. The screening aparatus may comprise a system of electrodes and electrolytes common to each of the members of an electrochemical cell array. An electrochemical probe is used to supply a reactive fluid (or reactive species) to only one of the cells in the array at a time. The probe is configured to address each of the cells of the array individually, and to be chemically isolated from all of the other cells of the array. Thus, the cells of the array that are not being addressed by the probe are in a non-active condition. Such a system is capable of combinatorially screening a library of materials, including catalyst, electrode, and electrolyte materials, wherein each of the members of the library defines one of the cells of the array.

Abstract: The invention relates to a method and apparatus for determining a total concentration of a component in a sample, including a reactor for oxidizing or reducing the sample, a chromatographic column coupled to the reactor for separating the component in the sample, and an electrochemical gas sensor coupled to the chromatographic column for detecting the component. In further embodiments, a filter may be used instead of or in addition to the column. Moreover, multiple sensors may be used instead of or in addition to the column for simultaneously detecting multiple components.

Abstract: A semiconductor sensing device in which a sensing layer is exposed to a medium being tested in an area below and/or adjacent to a contact. In one embodiment, the device comprises a field effect transistor in which the sensing layer is disposed below a gate contact. The sensing layer is exposed to the medium by one or more perforations that are included in the gate contact and/or one or more layers disposed above the sensing layer. The sensing layer can comprise a dielectric layer, a semiconductor layer, or the like.

Abstract: A novel process and apparatus to combinatorially screen a large number of discrete compositions for electrocatalytic activity have been developed. The apparatus contains a cell body adjacent to a fluid permeable catalyst array support supporting multiple solids. A catalyst mask having holes that are in alignment with the multiple locations for supporting solids is placed over the catalyst array support, masking the solids. A cell cover is positioned adjacent to the catalyst array support, with the cell cover having a passage for monitoring the solids through the mask. A detector may be in alignment with the passage of the cell cover.