Measurement of high temperatures, in excess of 1000 C, using ceramic based thermocouples is a well established process. In order 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 technique that has been used for quite some time, due to the exceptional heat resistant properties of these materials. The thermocouplers is the most commonly used heat measurement implement and it is employed for measuring the temperature inside of a furnace, typically getting used for the melting or heat treatments for metal or indeed for manufacturing ceramic products.
The ceramic components in a typical thermocouple device would be the outer protection tube that is open to the furnace. Occasionally multiple tubes are used inside one another to supply the amount of insulation and protection required.
Ceramic insulators (Tubes with 2 or higher core holes through them) may also be employed to isolate the two or more wires that go to the bi-metallic joint on the head the point that sens0rs temperature is measured.
The standard materials used for the tube can be a 99.7% alumina material, impervious tube, which can be attached typically to a metal thermacouple head, containing a terminal block which is often used to get in touch into a standard wire for the instrumentation. In the less demanding heat atmosphere a mullite tube can be utilized as being a cheaper alternative, that can work sufficiently approximately 1600 ‘oc. The mullite tube is also an impervious tube and possesses 60% alumina content.