Gas insulated switchgear and method for detecting arc damage in a gas insulated switchgear part

A method for detecting arc damage in a gas insulated switchgear part making up an arc-extinguishing chamber which is arranged in a container where an arc-extinguishing gas is sealed, and which has a pair of arc contacts capable of contacting with/separating from each other, a puffer chamber formed by a puffer piston and a puffer cylinder provided on the side of one of the arc contacts, or a nozzle integrally fixed with said puffer cylinder,

• Wherein said part includes, as a marking substance, a substance including an element different from an element originally used for securing resistance or insulation resistance in the part, and
• the method comprises the step of determining a wear limit of said part by detecting the concentration, in the gas within said container, of said marking substance released in gaseous form as said part wears down through thermal decomposition by heat from an arc formed between said pair of arc contacts as a result of a switching operation.