Abstract: An air fuel ratio detecting device which is improved in accuracy as compared to similar prior art devices comprises a sensor cell for developing an electrical signal in response to the difference between the concentration of oxygen in the exhaust gas and the concentration of oxygen in a reference gas, a controlling means for developing an electrical control signal having a polarity determined from the output of the sensor cell, a pump cell for moving oxygen ions in response to the electrical control signal received from the controlling means, a control current detecting means for detecting control current flow between the controlling means and the pump cell, an air fuel ratio detecting means for detecting the air fuel ratio from the control current flow, a stoichiometric air fuel ratio detecting means for detecting the direction of the control current flow so as to determine the stoichiometric air fuel ratio, a storage means for storing therein a linear air fuel ratio value which is determined in a predetermi

Abstract: A miniaturized reference electrode includes a dielectric thermoplastic cup having a cavity to hold a reference liquid solution and having a sample contacting orifice at one end. A membrane comprising cellulose acetate and a solvent capable of exerting a solvent action on the sidewalls of the cup orifice is drop deposited in the orifice and cured in situ. The resulting membrane extends across the orifice and is interdigitatedly anchored to the orifice sidewalls. The reference electrode further includes an Ag/AgCl screw-in electrode machined from silver rod extending into and hermetically sealing the cup cavity. A reference liquid fill solution having a chloride ion and potassium ion concentration similar to that found in the samples to be tested and the storage soak solution is provided to minimize drift of reference potential.

Abstract: The invention provides an electroplating bath for forming a zinc-nickel alloy coating consisting essentially of water, about 1 to 70 grams/liter of zinc, about 0.6 to 118 grams per liter of nickel, at least one compound from the group consisting of (i) aliphatic amines in an amount not more than 16 grams/liter, (ii) polymers of aliphatic amines in an amount not more than about 20 grams per liter and (iii) a compound selected from the group consisting of hydroxyaliphatic carboxylic acids and salts thereof in an amount from 0 to 2 mols/liter, said bath having a pH of more than 11. The invention also provides an electroplating method for forming a chromate coating on a zinc-nickel alloy coating electrolytically deposited from the electroplating bath defined in the preceding sentence on electrically conductive metalics matrix material, and forming a chromate coating on the zinc-nickel alloy coating by means of a chromate treatment.

Abstract: An analysis system including an ion selective electrode assembly, a sample container and a transport mechanism. The electrode assembly includes a reference electrode within a reference gel-filled well and ion selective electrodes disposed on an elongated portion of the electrode assembly. The sample container includes a body defining a plurality of reservoirs and a slot retaining an absorbant wiping and/or blotting material. The electrode assembly may be removably fixed relative to the transport mechanism. The transport mechanism includes a support table adapted to receive the sample container. The support table moves relative to the electrode assembly under the control of a cam to sequentially position the elongated portion of the electrode assembly within the reservoirs and the slot of the sample container.

Abstract: A reference electrode device is provided for a high temperature electrolytic cell used to electrolytically recover uranium from spent reactor fuel dissolved in an anode pool, the device having a glass tube to enclose the electrode and electrolyte and serve as a conductive membrane with the cell electrolyte, and an outer metal tube about the glass tube to serve as a shield and basket for any glass sections broken by handling of the tube to prevent their contact with the anode pool, the metal tube having perforations to provide access between the bulk of the cell electrolyte and glass membrane.

Abstract: Ionic concentration in a solution is measured using a multiple membrane electrode potential amplification device. The apparatus includes a plurality of potential sensing membranes and reference elements. Preferably at least four of the membranes and associated elements are all connected in electrical series relationship and joined to the terminals of a potential measuring meter such that the potential read out by the meter is equal to the sum of all of the individual membrane potentials. Amplification of the electrode potential is obtained by virtue of the fact that the individual membranes function as capacitors in a series circuit with the potential measuring meter. The membranes may be placed in separate sample containing vessels, or a unitary test device may be provided having individual compartments for the test solution.

Abstract: A method for simultaneously removing and monitoring the removal of a metallic contaminant from the surface of a metallic workpiece is disclosed. The workpiece and a reference electrode are immersed in an electrically conductive cleaning solution. The potential difference between the workpiece and the reference electrode is periodically measured to generate a series of potential difference values. Differences between successive potential difference values of the series are quantified to generate a noise parameter value. The noise parameter value is compared to a reference value, wherein the reference value is indicative of a maximum allowable amount of contaminant, to determine if an amount of contaminant greater than the maximum allowable amount of contaminant is present on the surface of the workpiece.

Abstract: It now has been found that a smooth, level, matte and/or bright deposit of tin, lead or tin-lead alloy can be deposited on a substrate from an aqueous plating bath which comprises(A) at least one bath-soluble metal salt selected from the group consisting of a stannous salt, a lead salt, or a mixture of stannous and lead salts; and(B) at least one alpha-acetylenic alcohol or glycol of the formulaR.sub.1 R.sub.2 C(OH)C.tbd.CR.sub.3 (I)whereinR.sub.1 and R.sub.2 are each independently H, an alkyl group, a cycloalkyl group or R.sub.1 and R.sub.2 together with the carbon atom form a cyclic group, provided that at least one of R.sub.1 and R.sub.2 is an alkyl group containing at least three carbon atoms, andR.sub.3 is H, an alkyl group or --C(OH)R.sub.1 R.sub.2.Preferably the plating baths do not contain fluoride or fluoborate ions, and the baths are also free of strong inorganic acids such as sulfuric acid.

Abstract: A porous composite membrane comprises a base membrane of high mechanical strength and a coating of a hydrophilic polymer on the surface of the membrane and on the walls of the pores. The invention includes a method to prepare the membrane and a biosensor including the membrane.

Abstract: A simple inspection device is constituted for inspection of an analyzer for measuring ionic activity by using an ionic activity measuring device provided with at least one ion selective electrode pair for generating potential corresponding to ionic activity fo a predetermined ion, and a porous bridge for associating the electrodes of the ion selective electrode pair with each other, and by contacting potential difference measuring probes respectively with the electrodes of the ion selective electrode pair, thereby to measure a difference in potential between the electrodes. The simple inspection device comprises a supporting member having outer dimensions approximately equal to ther outer dimensions of the ionic activity measuring device, and an electrically conductive member supported on the supporting member for short-circuiting across the potential difference measuring probes when the potential difference measuring probes are contacted with the electrically conductive member.

Abstract: An electrolyte, system and process for depositing tin, lead or tin/lead alloys upon a substrate by high speed electroplating, which includes a basis solution of an alkyl or alkylol sulfonic acid; and at least one of a solution soluble tin compound or a solution soluble lead compound; and an alkylene oxide condensation compound of (1) an aliphatic hydrocarbon having seven, preferably six or less carbon atoms and at least one hydroxy group, or (2) an aromatic organic compound having at least one hydroxyl group and no more than two independent or joined rings optionally substituted with an alkyl moiety of a total of twenty carbon atoms in one or six carbon atoms or less.

Abstract: An electrochemical sensor for hydrogen has, as its reference, a metal having a choice of oxidation states, the metal redox reaction comprising the reference.The sensor preferably comprises(i) a platinum-black electrode 6 which is electronically conductive and in which the hydrogen to be sensed is mobile,(ii) a solid-state conductor 5 for protons, and(iii) a mixture 4 of FeSO.sub.4 and Fe.sub.2 (SO.sub.4).sub.3 powders, with the Fe(II)/Fe(III) redox reaction in this mixture providing the hydrogen reference.

Abstract: An oxygen concentration-sensing device includes an oxygen concentration-sensing element formed by an oxygen-pumping element and a cell element, each composed of an oxygen ion-conductive electrolytic member and a pair of electrodes having the member interposed therebetween. The two elements define a gas diffusion-limiting zone therebetween. A current-to-voltage converter circuit has an input terminal connected to the junction between mutually connected ones of the electrodes. A first amplifier generates an output having a level variable in response to the difference between a potential at a conversion output terminal of the current-to-voltage converter circuit and a potential at the other electrode of the cell element, and applies the output to the other electrode of the oxygen-pumping element. A second amplifier has an input thereof connected to the above junction and generates an output proportional to current flowing in the oxygen-pumping element.

Abstract: A process for the electrolytic coloring of anodized surfaces of aluminum or aluminum alloys using alternating current or direct current superimposed on alternating current, the electrolytic coloring being carried out with an electrolyte which contains cationic organic dyes and, optionally, conducting salts.

Abstract: An acidic aqueous electro-galvanizing solution consisting essentially of:Zinc chloride: from 100 to 400 g/l, at least one substance selected from the group consisting of ammonium chloride and potassium chloride: from 100 to 400 g/l, andat least one substance selected from the group consisting of saturated carboxylic acid,sodium salt thereof and potassium salt thereof: from 1 to 70 g/l.The above-mentioned electro-galvanizing solution permits manufacture of an electro-galvanized steel sheet having a satisfactory quality by largely inhibiting production of an anode sludge.

Abstract: A zinc-nickel alloy plating solution in an aqueous solution comprising, as represented in terms of ions, 4-30 g/liter of zinc and 0.05-4 g/liter of nickel, together with 50-220 g/liter of an alkali hydroxide, 4-110 g/liter of a complexing agent, 0.1-10 g/liter of a primary brightener, 0.01-0.2 g/liter of a booster brightener and preferably, further, 0.01-0.05 g/liter of a tertiary brightener. The primary brightener is at least one selected from the reaction products of amines such as ethylenediamine or its methyl-substituted derivatives, propylenediamine or its methyl-substituted derivatives, diethylenetriamine or its methyl-substituted derivatives, and the like with epihalohydrin. The booster brightener is at least one selected from aromatic aldehydes such as anisaldehyde, vanillin, heliotropin, veratraldehyde, and the like. The tertiary brightener is at least one selected from tellurium oxide, tellurous acid or its salts, or telluric acid or its salt.

Abstract: An oxygen analyzing method for determining a positive or negative oxygen concentration of a measurement gas which changes between oxidizing and reducing atmospheres. The method uses a sensing element having an oxygen sensing cell wherein an electromotive force is induced between its measuring and reference electrodes according to the principle of an oxygen concentration cell. The atmosphere adjacent to the measuring electrode is controlled by controlling a pumping current to be applied to an oxygen pumping cell such that the electromotive force induced in the sensing cell is maintained at a predetermined level. A heater is provided to heat the sensing and pumping cells, to maintain their operating temperature within a range of 700.degree.-960.degree. C. The pumping current, or a signal to control the pumping current, is converted into an oxygen concentration signal whose level is held within one of a positive range and a negative range.

Abstract: An electrochemical measuring electrode device (10) for polarographically measuring the partial pressure of oxygen in an electrolytic medium comprises a cathode (14) which is capable of reducing oxygen and defines an exposed oxygen-reducing cathode surface (20), an anode (18), which defines an exposed anode surface which is arranged relative to the exposed oxygen-reducing cathode surface so as to communicate electrolytically therewith through the electrolytic medium, and a membrane (24), which covers the exposed oxygen-reducing cathode surface and further defines an electrolyte chamber (22) in which the electrolytic medium is confined. In order to effectively promote the decomposition of H.sub.2 O.sub.2 generated in the electrolytic medium as an oxygen reduction intermediate and thereby reduce the response time of the electrode, a stable, non-biological catalytic means is provided catalytically communicating with the H.sub.2 O.sub.2.

Abstract: The invention relates to a microelectrochemical electrode structure comprising a monolithic substrate having a front surface and a back surface facing generally away from one another, a first well extending into the substrate from the surface towards the back surface and ending in a first well bottom, and a first passage extending into the substrate from the back surface to the first well bottom. A first electrode is located wholly within the first well. A first conductor in the first passage serves for electrically communicating the first electrode to adjacent the back surface. A plurality of such electrode structures can be provided on a single substrate. The use of semiconductor processing technology allows the entire sensor to be extremely small. If desired, an integrated circuit can be provided on the back surface of the substrate for amplifying or otherwise processing signals from the first electrode. Analysis can be carried out for vapors or dissolved species (ionic or non-ionic).

Abstract: A redox battery electrolyte is prepared from a chromium and/or iron base raw material containing nickel as impurities by dissolving the raw material in a hydrochloric acid-containing aqueous liquid to form a solution containing chromium ions and/or iron ions and nickel ions, the resulting solution being subjected to a cathodic reduction in the presence of lead ions until the electric potential thereof becomes lower than -0.6 V vs. saturated calomel electrode, thereby to remove the nickel ions therefrom.