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.