Measurement of high temperatures, higher than 1000 C, using ceramic based thermocouples is actually a well established process. To do this successfully the resistance wires inside the thermocouple should be insulated and protected.
The usage of Ceramic materials to guard the platinum based wire is a method which has been used for several years, due to exceptional heat resistant properties of the materials. The thermocoupler is considered the most widely used heat measurement implement which is useful for measuring the temperature inside of a furnace, typically used for that melting or heat management of metal or indeed for manufacturing ceramic products.
The ceramic components within a typical thermocouple device would be the outer protection tube that may be in contact with the furnace. In some instances multiple tubes are employed inside each other to supply the amount of insulation and protection required.
Ceramic insulators (Tubes with 2 or higher core holes through them) can also be employed to isolate the several wires that proceed to the bi-metallic joint on the head the point from which sens0rs temperature is measured.
The typical materials for that tube is actually a 99.7% alumina material, impervious tube, which happens to be attached typically to some metal thermacouple head, containing a terminal block that is utilized for connecting to some standard wire to the instrumentation. Within a less demanding heat atmosphere a mullite tube can be utilized like a cheaper alternative, which can work sufficiently up to 1600 ‘oc. The mullite tube is also an impervious tube and contains 60% alumina content.