Abstract: A miniaturized gas sensor including film type electrodes, and a solid ionomer electrolyte, for the detection of toxic gases, i.e., carbon monoxide, and other oxidizable or reducible gases and vapors is described. The all-solid planar sensor cell has two or more film type electrodes arranged on a non-conductive planar surface of a supportive material. The electrodes are discrete and in intimate contact with the same solid polymer ionomer membrane. The sensor cell contains no liquid electrolyte and is operated in a potentiostatic or potentiodynamic mode. The unique feature of the sensor cell is that high sensitivity to a select gas or vapor is achieved by a novel three-phase contact area design for a sensing electrode which is easily accessible to the gas sample via small diffusion openings or holes that penetrate through the solid polymer ionomer membrane layer above the sensing electrode.

Abstract: Disclosed herein is a method for producing a gas sensor, comprising disposing a reference electrode on a side of an electrolyte, disposing a measuring electrode on a side of the electrolyte opposite the reference electrode, disposing a first protective coating on a side of the measuring electrode opposite the electrolyte, treating the sensor with an aqueous salt solution comprising chloride and carbonate salts comprising elements selected from the group consisting of Group IA and IIA elements of the Periodic Table to form a treated sensor comprising the chloride and the carbonate salt mixture, drying the treated sensor, and disposing a second protective coating on a side of the first protective coating opposite the measuring electrode.

Abstract: A gas sensor is provided which comprises a sensor element for detecting a component of a gas and a cup-shaped protector for covering a detecting section of the sensor element. The protector is dual-walled and have cup-shaped inner and outer protector members. The inner and outer protector members are constructed and arranged so that g1>g2 where g1 is the distance between an inner surface of a circumferential wall of the outer protector member and an outer surface of a circumferential wall of the inner protector member and g2 is the distance between an inner surface of a bottom wall of the outer protector member and an outer surface of a bottom wall of the inner protector member. The outer protector member has at the circumferential wall thereof a plurality of first gas holes. The inner protector member has at the circumferential wall thereof a plurality of second gas holes.

Abstract: Method and apparatus for trace metal detection and analysis using bismuth-coated electrodes and electrochemical stripping analysis. Both anodic stripping voltammetry and adsorptive stripping analysis may be employed.

Abstract: An oxygen sensor is disposed downstream from a catalyst for purifying exhaust gas from an internal combustion engine and which can suppress an influence of unburnt hydrocarbon on an output voltage. After forming a platinum thin film on the outer periphery of a zirconia ceramic body, only a detection electrode of the ceramic body is dipped in a silver nitrate aqueous solution of 0.1 mol/l, and the silver nitrate is pyrolyzed through a heat treatment. Subsequently, a platinum reference electrode is formed on the inner periphery of the ceramic body. To protect the silver-doped detection electrode, a protective layer is formed on the surface of the detection electrode. By the exposure to combustion gas and through aging, a detection element is formed, and set into a metal case together with a cylindrical heater, to complete an oxygen sensor to be disposed downstream from a CNG engine catalyst.

Abstract: For the reduction of internal stresses and formation of cracks caused thereby, an exhaust gas probe includes two measuring electrodes separated by a solid electrolyte layer made substantially of ZrO2 and a circuit-board conductor layer for electrically heating the solid electrolyte layer. The circuit-board conductor layer is firmly connected to the solid electrolyte layer via a first sealingly sintered insulating layer made of an Al2O3-containing material. A pore-forming material is added to the Al2O3-containing material before. sintering.

Abstract: The present invention discloses a gas sensing device, an oxygen pumping cell, and a gas detection apparatus using the same for detecting lower ranges of gas concentration with high accuracy and stability. An under layer made of oxygen-ion-conductive solid electrolyte was formed between an electrolyte substrate and a sensing electrode, a conversion electrode or a gas treatment electrode. This allows the physical and chemical adhesion between these electrodes and the electrolyte substrate, thereby improving the sensing properties and stability.

Abstract: A method for concentrating and/or positioning and/or separating particles or cells comprises placing a liquid medium containing the particles and/or cells over a surface having an electrode array associated with the surface, applying an alternating voltage to the electrode array to create an electric field above the surface within the medium to repel the particles or cells from the electrode array and thereby levitate the particles or cells above the surface, within the medium, by negative dielectrophoresis, and heating the liquid medium so as to cause convection currents to circulate within the medium which concentrate or relocate the levitated cells within the medium. Apparatus for concentrating and/or positioning and/or separating particles or cells are also disclosed.

Abstract: A cathode cartridge (N) for an electroplating tester includes a cathode conductor (10) that conducts electricity to a surface (Wa) to be plated of a silicon wafer (W) as an object to be plated, a first insulator (20) that covers a front side of the silicon wafer (W) and holds the cathode conductor (10), and a second insulator (30) that covers a back side of the silicon wafer (W) and holds the silicon wafer (W). Negative portions other than the surface (Wa) to be plated of the silicon wafer (W) are insulated from plating solution with a first O-ring (22) fitted in the first insulator (20) and a second O-ring (32) fitted in the second insulator (30).

Abstract: An improved structure of a mechanical seal for keeping a gas chamber and a reference gas chamber airtight in a sensor body. A sensor element is disposed within an insulator. A gap between the sensor element and the insulator is sealed hermetically by a glass sealing member. The glass sealing member has a coefficient of thermal expansion whose differences between itself and the sensor element and the insulator is within a range of ±3×10−6/° C. This provides a mechanical seal required to keep the reference gas chamber and the gas chamber in the gas sensor airtight in an environment such as an automotive exhaust system subjected to a great temperature change.

Abstract: A compact, long-lived oxygen sensor having an aqueous electrolyte and three gas diffusion electrodes, a working electrode, a reference electrode and a counter electrode. A porous, hydrophobic means is employed in conjunction with the counter electrode to allow air pressure in the sensor to be balanced with atmospheric pressure. The working and reference electrodes are further protected from contact with flow of electrolyte from the reservoir by a separator, so that the current output is fairly independent of sensor movement.

Abstract: An electrochemical sensor element, in particular for determining the oxygen level in gas mixtures, includes at least one measuring electrode exposed to a measured gas, at least one reference electrode exposed to a reference gas, at least one heating device, and one reference gas channel, through which the reference gas can be supplied to the reference electrode. The reference electrode is connected to the reference gas via a volume provided with pores. The volume is formed in a layer between the reference gas channel and the reference electrode.

Abstract: Disclosed is a microchip-based differential-type potentiometric oxygen gas sensor, which comprises a working electrode and a reference electrode. The working electrode is composed of a cobalt-plated electrode, a buffered hydrogel, and an ion sensitive gas permeable membrane while the reference electrode is composed of an oxygen non-sensitive silver chloride electrode and the same ion-selective gas-permeable membrane of working electrode. By taking advantage of the corrosion potential, the microchip-based oxygen gas sensor can accurately and quickly detect the content of dissolved oxygen in a sample solution. With this structure, the oxygen gas sensor is applied to a microchip-based all potentiometric multi-sensor capable of detecting two or more ions and gas species on a single chip.

Abstract: A sensor structure having a metallic terminal member. The metallic terminal member 23 includes press portions 23d and 23e, which press the heating member 3 in a direction intersecting the center axis of a hollow portion 2a of an oxygen detection element 2. Holding means for holding the heating member 3 is formed separately from the metallic terminal member 23. Thus, without use of special heating-member holder means, the metallic terminal member 23 can bring at least a portion of the heating member 3 into contact with the inner wall surface of the hollow portion 2a of the oxygen detection element 2.

Abstract: The present invention relates to an electrochemical sensor for a liquid sample. The sensor comprises a substrate (1) along which a liquid may travel by capillary action, said substrate being associated with an electrochemical detection arrangement (3) and a power source therefor, wherein the power source comprises at least one pair of electrodes (7, 8) of dissimilar material provided on the substrate and arranged such that liquid travel between the electrodes causes a current to be generated for operating the electrochemical detection arrangement.

Abstract: An oxygen sensor element is provided which may be used in an oxygen sensor designed to measure the concentration of oxygen contained in exhaust gasses of an automotive internal combustion engine. The gas sensor element includes a solid electrolyte body, a target gas electrode, a reference gas electrode, and a catalytic layer formed over the target gas electrode. The catalytic layer is made of heat resisting ceramic grains which hold thereon catalytic metal grains whose average grain size is 0.3 to 2.0 &mgr;m, a weight of catalytic metal grains per unit area of the catalytic layer, as defined by projecting the target gas electrode on a plane, is 10 to 200 &mgr;g/cm2. This facilitates the reaction of exhaust gasses such as H2, NOx, and HC with O2 over the target gas electrode, thus resulting in improved accuracy of a sensor output over a wide temperature range.

Abstract: A nonfragile ad quickly activatable structure of a gas sensor element which may be built in a gas sensor employed in an air-fuel ratio control system for automotive vehicles for measuring the concentration of gas such O2, NOx, or CO. The gas sensor element is made of a lamination of a measurement gas electrode, a reference gas electrode, and a heater. The heater works to elevate the temperature of the gas sensor element up to a given value required to bring the gas sensor element into an activated condition. The heater includes a heater substrate, a heating element, and power supply leads. A minimum distance X between an edge of the heater substrate and an edge of the heating element meets a relation of 0.1 mm≦X≦0.6 mm, thereby minimizing a thermal expansion difference between the heater element and the heater substrate to avoid cracks in a portion of the heater substrate near the heater element.

Abstract: An electrochemical sensor has a sensor element, and is used to determine a gas concentration of a gas to be analyzed. The sensor element has a first solid electrolyte layer, an electrode that includes an electrode surface and an electrode lead, and a second solid electrolyte layer; a gas channel being introduced into the first solid electrolyte layer in such a manner, that the electrode is situated in a first, clamped region between the first and the second solid electrolyte layers, and in a second, open region between the second solid electrolyte layer and the gas compartment. In a transition region between the clamped region and the open region, the electrode borders on a layer pattern, which is constructed in such a manner, that the electrode is subjected to a lower pressure during a laminating procedure.

Abstract: A hydrocarbon sensor is formed with an electrolyte body having a first electrolyte surface with a reference electrode depending therefrom and a metal oxide electrode body contained within the electrolyte body and having a first electrode surface coplanar with the first electrolyte surface. The sensor was formed by forming a sintered metal-oxide electrode body and placing the metal-oxide electrode body within an electrolyte powder. The electrolyte powder with the metal-oxide electrode body was pressed to form a pressed electrolyte body containing the metal-oxide electrode body. The electrolyte was removed from an electrolyte surface above the metal-oxide electrode body to expose a metal-oxide electrode surface that is coplanar with the electrolyte surface. The electrolyte body and the metal-oxide electrode body were then sintered to form the hydrocarbon sensor.

Abstract: An apparatus for measuring partial hydrogen pressure in a gas stream is described. The apparatus includes a housing with micro-fuel cell sensor disposed therein. The sensor includes a sensing element having first and second gas diffusing electrodes spaced from one another with an acidic electrolyte disposed between the electrodes. A first gas permeable membrane separates the first electrode from an external gas stream. A second gas permeable membrane separates the second electrode from atmospheric air. Electrochemical charging of the first electrode occurs when hydrogen from a gas stream diffuses through the first membrane to react with the first electrode, while the potential of the second electrode remains unchanged. The potential difference between the first and second electrodes measured as current is identified to represent the sensor output.