Metal protection sheath: What are Metal protection sheaths?

Metal protection sheaths are a metal tube covering, often made from alloys such as 310 Stainless Steel and Alloy 600, used to shield a temperature sensor from attack. They are generally used in temperature sensors at temperatures from between 350 to 1200°C. Metal protection sheaths are often used in aggressive environments. Special alloys can provide adequate sensor life, and are more robust than a ceramic sheath.