Sulphur hexafluoride was first synthesized in the laboratories of the Faculté de Pharmacie de Paris in 1900 by Moissan and Lebeau.
The dielectric strength of SF6 is about 2.5 times higher than that of air under the same conditions. This unique property of SF6 has led to its adoption for a number of industrial and scientific applications as an electrical insulation. Switchgear manufacturers use the unique dielectric or/and breaking properties to design their equipment.
Due to contact wear the contact resistance in SF6 GIS increase from the normal value of 5-7 μOhm up to 100 μOhm. The problem is to determine the local overheating.
The result is applicable to SF6 GIS up to 100 m of length. The current range is from 1 to 2 kA.