Compacted ceramic insulated thermocouple material consists of three parts as shown in Fig. 5.1. This type of thermocouple is in common use because it isolates the thermocouple wires from environments that may cause rapid deterioration and provides excellent high-temperature insulation for thermocouple wires. The sheath can be made of a metal compatible with the process in which it is being used and provides mechanical protection. The material is easy to use because it forms easily, retains the bent configuration, and is readily fabricated into finished thermocouple assemblies.