Ceramic protection sheath: What are ceramic protection sheaths?

Ceramic protection sheaths are a ceramic tube covering, often made from technical ceramics such as aluminous porcelain and recrystallised alumina, used to shield a temperature sensor from attack. They are generally used in temperature sensors at very high temperatures from between 1000 to 1750°C. Some ceramic protection sheaths provide a very high electrical resistance so may be suitable for high voltage applications.

For applications where ceramic protection isn’t suitable, metal protection sheaths are used instead.