Abstract: An electrode comprises a non-conductive substrate and a conductive layer comprising, in a bonded matrix, graphite particles coated with a noble metal, and carbon particles, wherein the graphite particles are up to 20 &mgr;m is size and have a surface area of 1-50 m2/g. This electrode is capable of measuring low levels of analyte, e.g. glucose in sweat when convined with a layer containing glucose oxidase.

Abstract: A sensor for measuring nitrogen oxide (NOx) in a gas by decomposing NOx in the gas and measuring an amount of oxygen generated by the decomposition includes: means for introducing the gas to a first inner space under a first diffusion resistance and connected with an external space, means for controlling an oxygen partial pressure in an atmosphere in the first inner space to be a predetermined low value at which NO is not decomposed substantially by a main pump means, means for introducing a controlled atmosphere of the first inner space into a second inner space which is connected with the first inner space and which is under a second diffusion resistance, and means for converting the atmosphere into an electric signal corresponding to the quantity of oxygen generated by decomposition or reduction of NOx contained in the atmosphere by an electric signal conversion means.

Abstract: An apparatus and a method for determining concentration of fluorine ions in aqueous solutions are provided. In the apparatus, a pH sensor is provided for sensing a pH value of an aqueous solution to be determined. A pH controller is then used to compare the pH value determined with stored pH data to determine whether the aqueous solution is acidic or alkalinic. An acid dispenser or a base dispenser is then used to dispense either an acid or a base into the pH adjustment tank for adjusting the pH value of the aqueous solution to within a desirable range. For instance, for the detection of fluorine ions, a suitable pH range is between about 4 and about 10. After the pH value is stabilized in the aqueous solution, a fluorine ion sensor may be used to sense the fluorine ion concentration in the aqueous solution. A common acid and base which may be used to bring the pH value within the desirable range may be H2SO4 and NaOH.

Abstract: A method of screening a water soluble gold complex for use as a sensitizer in a silver halide photographic element comprised of experimentally measuring the electrochemical potential of the gold complex and then determining if the electrochemical potential falls within a predetermined utility window.

Abstract: The gas sensor 1 has the following constituent features: (1) first processing space 9: a measurement gas is introduced thereinto via a first gas passage 11; (2) second processing space 10: a gas contained in the first processing space 9 is introduced thereinto via a second gas passage 13; (3) oxygen concentration detection element 4: adapted to measure the oxygen concentration of a gas contained in the first processing space 9; (4) oxygen pumping element 3: adapted to reduce the oxygen concentration of the measurement gas introduced into the first processing space 9 within a range such that water vapor contained in the measurement gas is not substantially decomposed; (5) oxidation catalyst section 16: adapted to accelerate combustion of a combustible gas component contained in a gas introduced into the second processing space 10; and (6) combustible gas component concentration detection element 5: a constant voltage is applied thereto, and element 5 has an output current which varies according to the amount o

Abstract: An apparatus is disclosed for electrolytic desilvering of photographic processing solutions, more particularly fixing solutions or bleach-fixing solutions, comprising an electrolysis unit equiped with a monitoring system comprising a cathode, an anode and a reference electrode, characterized in that said reference electrode is a pH sensitive electrode. The desilvering is preferably performed under potentiostatic conditions. Whe using a pH sensitive reference electrode the cathodic plating potential is automatically corrected for pH changes. A preferred pH sensitive electrode is a glass electrode.

Abstract: A gas sensor is provided which can efficiently flow air into a casing while having a sufficient on-axis sectional area in a ceramic separator for allowing lead wires to pass therethrough. The oxygen sensor has a ceramic separator main body portion axially formed with a plurality of separator-side lead wire insertion holes penetrating therethrough, whereby a first part thereof is arranged to extend to an inner side of a filter support portion. The first part has an on-axis sectional outer shape formed in a shape other than a circle, e.g. a polygonal shape, such as a square shape. By making the on-axis sectional outer shape of the ceramic separator main body part non-circular as above, it is possible to locally expand a gap defined between an outer peripheral surface of the ceramic separator and an inner surface of the filter support portion.

Abstract: A method of formulating a strong oxidizing solution comprising formulating a strong oxidizing solution having from about 2 to about 5 percent PDSA with concentrated sulfuric acid in the ratio of from about 1:8 to about 1:20 parts by volume and storing the strong oxidizing solution in a container having a space over the solution containing one of a vacuum or a non-oxidizing atmosphere inert to the oxidizing solution. The amount of PDSA is preferably about 4 percent by volume and the ratio is preferably about 1:10 parts by volume. The space over the strong oxidizing solution is preferably a vacuum or substantially all nitrogen.

Abstract: A method and device for detection and quantification of biologically significant analytes in a liquid sample is described. The method includes contacting a volume of a liquid sample with predetermined amounts of at least a first and second redox reversible species having redox potentials differing by at least 50 millivolts. At least one of the redox reversible species comprises a liquid sample diffusible conjugate of a ligand analog of an analyte in the liquid sample and a redox reversible label. A predetermined amount of at least one specific binding partner for each analyte to be measured is combined with the sample and current flow is measured at first and second anodic and cathodic potentials and correlated with current flows for known concentrations of the respective diffusible redox reversible species. Diagnostic devices and kits, including such devices and the specified specific binding partner(s) and redox reversible species are also described.

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: An apparatus and a method of characterising liquids employ liquid sensors of different types of technology, in order to generate characterisation data from the whole of the output signals originating from these sensors when they are soaked in a sample of the liquid. The set of sensors may comprise: lipid sensors, quartz microbalances, ion-selective electrodes, biosensors, chemical microelectrodes or even, in certain particular applications, fiber optic based-sensors. The output signals originating from the different sensors are normalized with respect to values which are determined in a prior standardization operation during which the sensors were soaked in at least one sample reference liquid.

Abstract: The invention relates to compositions and methods useful in the electrophoretic transport of target analytes to a detection electrode comprising a self-assembled monolayer (SAM). Detection proceeds through the use of an electron transfer moiety (ETM) that is associated with the target analyte, either directly or indirectly, to allow electronic detection of the ETM.

Abstract: A disposable electrode strip for testing a fluid sample including a laminated strip with a first and second end, a reference electrode embedded in the laminated strip proximate to the first end, at least two working electrodes embedded in the laminated strip proximate to the first end and the reference electrode, an open path for receiving a fluid sample beginning from the first end and being sufficiently long to expose the reference electrode and the working electrodes to the fluid sample, and conductive contacts located at the second end of the laminated strip. The laminated strip has a base layer with a conductive coating, a reagent holding layer, a channel forming layer and a cover. One of the working electrodes contains a reagent substantially similar to the reagent of the reference electrode and a second working electrode contains a reagent having an enzyme.

Abstract: The invention concerns a sampling system and a process for its production. Such systems can easily be employed throughout in chemical and biochemical analysis. The sampling system should be simply constructed and universally usable alone and in combination and fabricable with little effort. The sampling system constructed as per the invention for analytes which are fluid or are contained in fluids consists of a planar support with various holes in it through which the particular fluid can pass into a channel which it subsequently exits. The channel is at least partly covered by a cover over the side opposite the support. In addition, a membrane pervious to the analyte is inserted which at least partly covers the channel on its open upper side. The areas not covered by the cover can be used to extract the analyte or to make direct measurements.

Abstract: Disclosed is a gas sensor for measuring a NOx concentration comprising a main pumping cell and a detecting electrode, the main pumping cell including an electrode (an inner pumping electrode and an outer pumping electrode) having no decomposing/reducing ability for NOx or a low decomposing/reducing ability for NOx, to be used so that an oxygen concentration in a first chamber is controlled to have a predetermined value at which NO is not substantially decomposable, and the detecting electrode having a certain decomposing/reducing ability for NOx or a high decomposing/reducing ability for NOx, to be used so that NOx is decomposed to measure the NOx concentration by measuring an amount of oxygen produced during this process, wherein a buffering space is provided between a gas-introducing port and the first chamber. Accordingly, it is possible to avoid any influence of exhaust gas pressure pulsation generated in a measurement gas and improve the measurement accuracy on the detecting electrode.

Abstract: Disclosed is a NOx concentration-measuring apparatus for measuring a NOx concentration by using a main pumping cell including an electrode (inner pumping electrode and outer pumping electrode) having no or low decomposing/reducing ability with respect to NOx to control an oxygen concentration in a measurement gas to have a predetermined value which substantially does not affect measurement of NOx component, and using a detecting electrode having certain or high decomposing/reducing ability with respect to NOx to decompose NOx so that an amount of oxygen produced during this process is measured, wherein the detecting electrode is a cermet electrode composed of an alloy of Pt—Rh and a ceramic component, and Pt and Rh are contained in a weight ratio of Pt:Rh=20:80 to 1:99.

Abstract: An electrochemical sensor measures a gas concentration of a measured gas with an electrochemical element. The electrochemical sensor includes an electrochemical pump cell with a first solid electrolyte body, a first and a second electrode, and a gas chamber, which is connected to a measured gas chamber via a gas inlet opening and in which one of the two electrodes is located. The electrochemical sensor also includes a second solid electrolyte body with an electrochemical sensor cell (e.g., a Nernst cell), which has a third electrode and a reference gas chamber in which a fourth electrode is located, with the electrodes having a supply conductor for electrical contacting. A supply conductor of the fourth electrode is provided with an electrically insulating layer to insulate it against the second solid electrolyte body.

Abstract: An apparatus and method for the indirect determination of concentrations of additives in metal plating electrolyte solutions, particularly organic additives in Cu-metalization baths for semiconductor manufacturing. The apparatus features a reference electrode housed in an electrically isolated chamber and continuously immersed in the base metal plating solution (without the additive to be measured). An additive concentration determination method comprises electroplating a test electrode at a constant or known current in a mixing chamber wherein the base metal plating solution is mixed with small volumes of the sample and various calibration solutions containing the additive to be measured. Plating potentials between the electrodes are measured and plotted for each of the solution mixtures, and data are extrapolated to determine the concentration of the additive in the sample.

Abstract: On an insulating substrate 1 is formed an electrode 2 as a working electrode, on which is formed a binding layer 3 mainly consisting of &ggr;-aminopropyltriethoxysilane. On the binding layer are sequentially formed an immobilized enzyme layer 4 in which a catalytic enzyme is immobilized in an organic polymer and a permeation restricting layer 5.

Abstract: A solid state gas sensor generates an electrical potential between an equilibrium electrode and a second electrode indicative of a gas to be sensed. A solid electrolyte substrate has the second electrode mounted on a first portion of the electrolyte substrate and a composite equilibrium electrode including conterminous transition metal oxide and Pt components mounted on a second portion of the electrolyte substrate. The composite equilibrium electrode and the second electrode are electrically connected to generate an electrical potential indicative of the gas that is being sensed. In a particular embodiment of the present invention, the second electrode is a reference electrode that is exposed to a reference oxygen gas mixture so that the electrical potential is indicative of the oxygen in a gas stream.