Abstract: A miniaturized, portable sensor is provided for selectively sensing the presence of halogenated gases, particularly HFC's, within an atmosphere. The apparatus includes a ceramic element containing either a mixture of potassium silicate and either aluminum oxide or silicon dioxide which react with ions of the halogenated gas when the two are brought together forming a depletion layer on and within the ceramic. The sensor is formed with two electrodes on opposite sides of the ceramic having terminals connected into a circuit for detecting a potential difference across the depletion layer. Means are provided for detecting the potential differences and for producing a discernable signal in response thereto.

Abstract: A sensor for selectively sensing the presence of halogenated gases, particularly HFC's, within an atmosphere. The apparatus includes a ceramic element containing either a mixture of alkali metal silicates and aluminum oxide or aluminosilicate which react with ions of the halogenated gas when the two are brought together forming a depletion layer on and within the ceramic. A preferred ceramic composition is a mixture of potassium slicate and either one of silicon dioxide or aluminum oxide. The sensor is formed with two electrodes on opposite sides of the ceramic having terminals connected into a circuit for detecting a potential difference across the depletion layer. Means are provided for detecting the potential differences and for producing a discernable signal in response thereto.

Abstract: The invention relates to a novel process of etching a metal clad substrate which comprises contacting said substrate with one or more reactive gases, as for example ozone, to form one or more reaction products on the surface of the said metal which are more friable than said metal, and striking said reaction products with a plurality of abrasive particles.

Abstract: Novel catalytic electrode in which the oxidation catalyst is protected from unfavorable redox potentials by an insulation/rectification matrix composed of a polymeric matrix containing an insulating and rectifying effective amount of a dispersed redox conductor.