Abstract: An apparatus for the detection and measurement of an object gas is disclosed. Such an apparatus comprises a sensing electrode having a catalytic surface, a counter electrode having a catalytic surface, an electrolyte in electrical contact with the sensing electrode and the counter electrode, a reference electrode in contact with the electrolyte and the sensing electrode, a means for supplying an electrical potential between the sensing electrode and the reference electrode and a means for measuring the current flow resulting from the reaction of the object gas with the sensing electrode by way of the sensing electrode substrate to the counter electrode substrate. The substrate, which supports the catalytic sensing electrode and counter electrode materials being electrically conductive carbon or graphite, which allows the electrons generated at the sensing electrode catalytic surface to be removed through the substrate instead of from the surface.

Abstract: The present invention discloses the use of gold oxide as a catalyst for use in a hydrogen sulfide gas detector. The gold oxide catalytic surface being supported on an electrically conductive substrate; thereby allowing the flow of electrons between the anode and the cathode to occur between the substrates of the electrodes instead of the catalytic surfaces. This will reduce the amount of catalytic material required to form the electrode, and will not require that the catalytic surface be an electrical continuum.

Abstract: This oxygen concentration detector employs an oxygen concentration sensor provided with a plate produced of a material which exhibits ionic conduction for oxygen (An oxygen ionic conductor), a cathode placed on the one surface of the oxygen ionic conductor plate, an anode placed on the other surface of the oxygen ionic conductor plate, and a porous material layer which functions to regulate the flow of oxygen which passes through the porous material layer to reach the cathode and the oxygen ionic conductor plate. The improvement realized in this oxygen concentration detector is to remove a drawback in which the output of this sensor makes an error depending on the temperature of a gas of which the oxygen concentration is measured.

Abstract: There is disclosed a composite membrane and an air electrode for use in hydrogen-oxygen fuel cells, metal-air cells and oxygen sensors. The composite membrane includes a porous membrane having micropores with a thin layer affixed thereto. The thin layer having metallic oxide in a carbon matrix, so that oxygen gas is able to permeate therethrough, but water vapor in air is not allowed to permeate therethrough.

Abstract: A method and instrument including an electrochemical cell for the detection and measurement of methane in a gas by the oxidation of methane electrochemically at a working electrode in a nonaqueous electrolyte at a voltage about about 1.4 volts versus R.H.E. (the reversible hydrogen electrode potential in the same electrolyte), and the measurement of the electrical signal resulting from the electrochemical oxidation.

Abstract: An electro-chemical cell has porous sensing and counter electrodes S, C mounted on porous PTFE tapes 4, 5 and contacting the electrolyte of the cell which is drawn from a reservoir by a wick 12. Gas passes directly to the electrode S at 14 and any gas which does not react passes through the electrode S to the electrode C, passing across the electrolyte space by way of a porous insulating separator 10 which is partly hydrophilic and partly hydrophobic, thus providing a path for gas while preserving the electrolyte path between the electrodes. The current flowing between the electrodes is measured in the usual way. The electrode C will not see any particular gas which reacts fully at the electrode S since it will be removed by this electrode first. The electrode C will, however, see any other gas which only partially reacts at the electrode S, thus achieving partial or even complete elimination of the effect of an interfering gas.

Abstract: An electrochemical gas detection cell, particularly suitable for detecting H.sub.2 S, includes an electrochemical gas sensor which has a reference electrode, a sensing electrode and a counter electrode. The counter electrode is composed of carbon. The sensing electrode is composed of either gold or platinum and the reference electrode is composed of platinum. Circuitry is provided to supply voltage to the electrodes, the sensing electrode bias can be held below 300 mv., with respect to the reference electrode. The agent H.sub.2 S can be readily detected when the bias is about 250 mv. The cell is associated with signal processing circuitry which produce audible and visual outputs. A nonaqueous electrolyte is provided. The electrolyte may be composed of either propylene carbonate or n-methyl-2-pyrrolidone and one of conductive compatible salts, such as tetrabutyl ammonium tetrafluoroborate.

Abstract: A method of making an electrochemical sensor is disclosed in which a liquid electrolyte such as sulfuric acid is blended with fumed silica in an amount sufficient to powderize the mixture. The resultant mixture is compacted under pressure between electrodes to form an electrochemical gas sensor.

Abstract: The measuring apparatus is based on an electrochemical sensor with a hollow chamber connected upstream through which the gas to be measured diffuses to the sensor surface. A pump for introducing a rinsing gas is connected to the hollow chamber. Moreover, the rinsing gas connection is connected to a test gas source which produces a known concentration of the component to be measured. The function of the sensor may be controlled by connecting the test gas source. The accuracy of the measured values and thus the reliability of the measuring apparatus may be substantially improved by these measures.

Abstract: A gas sensor cell assembly has planar electrodes separated by a planar hydrophilic wick which extends through the electrode into an electrolyte expansion chamber where it contacts an electrolyte. The cell is extremely compact and operates in all orientations.

Abstract: A device for sensing the oxygen concentration in an exhaust gas has a cup-like oxygen-ion permeable cylindrical member made of solid electrolyte consisting of oxygen-ion conducting metal oxide. The cylindrical member has an inner circumferential surface communicating with the atmosphere and an outer circumferential surface communicating with the exhaust gas for producing an electromotive force corresponding to a difference between the oxygen concentrations on the inner circumferential surface and on the outer circumferential surface and has a negative-resistance temperature characteristic. A pair of first electrodes serving as a lean sensor each comprise a thin film made of porous metal material and are provided on the inner circumferential surface and outer circumferential surface of the cylindrical member, respectively, in opposed relationship to each other. An oxygen-gas diffusion limiting layer covers the lean sensing electrode on the outer circumferential surface of the cylindrical member.

Abstract: Electroplating in an acidic zinc-nickel alloy plating bath containing vanadium ions as a third component provides a plating having a surprisingly high level of corrosion resistance equal to about 10 times that of pure zinc.

Abstract: The present invention relates to a method of treatment on the surface of copperfoil mainly used for printed circuits. More particularly, it relates to a method of electrodeposition of a binary alloy consisting of zinc and tin as a barrier layer against copper migration into an adhesive substrate during subsequent heat press lamination, while a binary alloy on copperfoil is converted to ternary alloy defusing into copper by heat press lamination resulting in a layer of Cu-Zn-Sn, ternary alloy. This layer prevents spottings on the etched surfaces and provides high resistance to hydrochloric acid, and better adhesion than hitherto used alloys.

Abstract: An electrochemical cell comprising an anode, a cathode and a reference electrode operating in an aqueous electrolyte is utilized for detection of noxious gases in air. The gas is oxidized at the anode and detection thereof occurs as a result of the current generated by the reaction. A fixed potential difference is maintained between the anode and the reference electrode to avoid generation of undesired current from reactions involving an oxygen-water redox couple within the cell which would invalidate anode-cathode current for gas detection purposes. The fixed potential is chosen from within the range of about 0.9 to 1.5 volts.

Abstract: A device for the detection of and quantitative measurement of a gas in a given environment, such as alcohol in the breath or carbon monoxide in the atmosphere, is described. The device comprises intake and flow control means for the gas sample, and an electrochemical cell having an anode which provides a site for electrochemical reaction of the gas being detected, a cathode, a reference electrode, and an electrolyte in contact with the anode, cathode, and reference electrode. The anode, to ensure that the current production is a result of the gas being detected and not other gases, including oxygen, is maintained at a fixed potential in relation to the potential of the reference electrode. The device provides an accurate and inexpensive means of detecting and quantitatively measuring a gas contained in a given environment, i.e., alcohol in the breath of the subject being tested or carbon monoxide in the atmosphere.

Abstract: An electrochemical cell comprising an anode, a cathode and a reference electrode operating in an aqueous electrolyte is utilized for detection of noxious gases in air. The gas is oxidized at the anode and detection thereof occurs as a result of the current generated by the reaction. A fixed potential difference is maintained between the anode and the reference electrode to avoid generation of undesired current from reactions involving an oxygen-water redox couple within the cell which would invalidate anode-cathode current for gas detection purposes. The fixed potential is chosen from within the range of about 0.9 to 1.5 volts.