Sensor for decomposition prod. of insulating gas pref. sulphur hexa:fluoride - comprises indicator composed of composite material including a filler in matrix which is chemically inert and permeable to prods.

摘要

Sensor has indicator(s) (7) which can be placed inside (2) the capsule (1) so that at least point of its surface is in contact with (I) formed during operation. At least one measurable property varies according to the (I) partial pressure. The novel features are that (a) the indicator(s) consists of a composite material, comprising a filler (II) embedded in a matrix (III); (b) (III) consists of chemically inert material, which is permeable to at least one (I); and (c) (II) reacts chemically with at least one (I). Pref. the surface of the indicator exposed to (I) is covered by a selectively permeable membrane, permeable to at most one (I). The composite contains component(s) preventing at least one (I) activating (I) up to a given partial pressure. (III) consists of a thermosetting polymer pref. an epoxide or polyester; and (II) of material contg. SiO2, esp. glass or quartz. USE/ADVANTAGE - Used for decomposition prods. (I) of an insulating gas, pref. contg. SF6, encapsulated in electrical equipment. The sensor gives accurate results, even over long periods. It is easy to incorporate, robust and very economical and requires no maintenance.