Abstract: Molybdenum oxide is doped with vanadium, nobidium, tantalum or titanium to form a stable M5O14 theta phase crystal structure as a vapor sensitive material for detecting vapors of volatile organic compounds. That material is used between electrodes connected to a measuring device to measure a change in an electrical quality in the presence of a vapor of a volatile organic compound. Concentration of the vapor is measured to low part per million ranges.

Abstract: A sensor for detecting hydrogen or ammonia gas uses a gas sensitive material based on Cr2O3 with a small percentage of the chromium replaced by transition metal ions having a valency greater than four, but still having a corundum crystal structure. Electrodes in contact with the gas sensitive material are connected by conductors to electrical measuring means for measuring the resistance, conductance, capacitance, or impedance of the gas sensitive material. A temperature sensing means and heating means allow the temperature of the gas sensitive material to be regulated. The gas sensitive material is formed on an insulator substrate over one or both electrodes. One electrode can be on the non-substrate side of the gas sensitive material. The gas sensitive material can be formed by deposition from a suspension or colloidal dispersion and firing. The gas sensitive material is contacted with gas and changes in electrical properties of the material are observed.

Abstract: An air quality monitor having multiple sensors deployed in an electric circuit returns a single sign indication of atmospheric impurity regardless of whether the impurity gas is of the oxidizing or reducing type. Each sensor employs a gas sensitive material that exhibits a response in the form of a change in electrical resistance of the material in the presence of a gas and that exhibits a negligible response to changes in the moisture content of the atmosphere. A powder is dried and calcined and the result is ground into a fine powder and pressed into a desired shape to make the gas sensitive material. Adding a binder during the pressing and firing the shaped powder results in a gas sensitive material with porosity. Gas is flowed to the gas sensitive material and the resulting change in resistance is measured and returned as a single sign indication of atmospheric impurity.

Abstract: A sensor responds sensitively to low concentrations of carbon dioxide in an atmosphere of air. Carbonates formed at the surface of preferred oxides can be decomposed by raising the temperature, thus reforming the original oxide. A CO2 sensor operating according to this principle may be cycled between the temperature at which the surface carbonate is decomposed and the temperature at which the surface carbonate is formed from atmospheric carbon dioxide. The present invention relates to sensors and more particularly to sensors suitable for use in gaseous mixtures containing carbon dioxide.

Abstract: An air quality monitor having multiple sensors deployed in an electric circuit returns a single sign indication of atmospheric impurity regardless of whether the impurity gas is of the oxidizing or reducing type. Each sensor employs a gas sensitive material that exhibits a response in the form of a change in electrical resistance of the material in the presence of a gas and that exhibits a negligible response to changes in the moisture content of the atmosphere. A powder is dried and calcined and the result is ground into a fine powder and pressed into a desired shape to make the gas sensitive material. Adding a binder during the pressing and firing the shaped powder results in a gas sensitive material with porosity. Gas is flowed to the gas sensitive material and the resulting change in resistance is measured and returned as a single sign indication of atmospheric impurity.

Abstract: The mixed oxide WxMo1-xO3, where preferably x can be in the range 0.01 to 0.9, is very useful for the detection of oxidizing gases and in particular is superior for the detection of ozone. The preferred composition is in the range of 1% to 21% Mo (i.e. 99% to 79% W). The present example in which the composition of the sensing material is in the range WxMo1-xO3 with x varying from 0.01 to 0.9, is clearly distinct from the device claimed in applicant's earlier patent. Precipitation of the material as a mixed oxide from an aqueous solution of the ammonium metallates in concentrations of the appropriate stoichiometric proportions yields a powder that can be screen-printed to give an ideal microstructure. Resistivity of the material may be tailored to a desired value by adjusting the Mo/W ratio within the single phase field. Varying this ratio adjusts catalytic properties of the material.

Abstract: The mixed oxide WxMo1−xO3, where preferably x can be in the range 0.01 to 0.9, is very useful for the detection of oxidizing gases and in particular is superior for the detection of ozone. The preferred composition is in the range of 1% to 21 % Mo (i.e. 99% to 79% W). The present example in which the composition of the sensing material is in the range WxMo1−xO3 with x varying from 0.01 to 0.9, is clearly distinct from the device claimed in applicant's earlier patent. Precipitation of the material as a mixed oxide from an aqueous solution of the ammonium metallates in concentrations of the appropriate stoichiometric proportions yields a powder that can be screen-printed to give an ideal microstructure. Resistivity of the material may be tailored to a desired value by adjusting the Mo/W ratio within the single phase field. Varying this ratio adjusts catalytic properties of the material.

Abstract: A sensor and a sensing method for use in a gas or gaseous mixture is provided. The sensor includes a gas sensitive material, MO3-x, in which M is predominantly or exclusively MO and MO3-x, is a substoichiometric molybdenum trioxide which exhibits a response in the form of an increase or a decrease in an electrical property of the material in the presence of a gas. The gas sensitive material is in communication with two or more electrodes and is arranged for being contacted with a gas or gaseous mixture. The electrodes are in direct communication with the gas sensitive material by being in contact therewith. The sensor incorporates a temperature sensor. The sensor includes a heating element.

Abstract: There is disclosed a lead acid battery and battery separator, the separator comprising a porous ceramic body manufactured from ceramic fibers welded together at their respective contact points such that the resulting separator body is substantially rigid and non-compressible and wherein the separator has a porosity of at least about 90%. The electrodes of the battery may be comprised of a similar porous ceramic material impregnated, respectively, with Pb and PbO.sub.2. A lead-containing foil may be maintained in close contact with each of the electrodes as current collectors attached to the battery terminals.

Abstract: An electrochemical cell is provided with a molten sodium anode and a molten sodium aluminium halide salt electrolyte. The cathode comprises FeCl.sub.2, NiCl.sub.2, CoCl.sub.2 or CrCl.sub.2 as active cathode substance dispersed in an electronically conductive electrolyte-permeable matrix which is impregnated by the electrolyte. Between the anode and the electrolyte, and isolating them from each other, is a solid conductor of sodium ions or a micromolecular sieve which contains sodium sorbed therein. The proportions of sodium and aluminium ions in the electrolyte are selected so that the solubility of the active cathode substance in the electrolyte is at or near its minimum.

Abstract: A positive electrode for a lead acid electric storage cell is made by chemically preparing beta lead dioxide. The beta lead dioxide is then applied to a support structure with a binder, or poured into a permeable, tubular container located about a current collecting rod. The negative electrode can be made by compacting fine lead metal about a carrier, and the fine lead metal might comprise lead wool or particulate lead metal.

Abstract: The positive electrode for a lead acid electric storage cell is made by preparing by a chemical route particulate beta lead dioxide, mixing together the beta lead dioxide with a relatively low proportion of a binder, and applying the mixture to a perforated electrically conductive support structure.