Measurement of high temperatures, higher than 1000 C, using ceramic based thermocouples is really a well known process. To do this successfully the resistance wires inside the thermocouple should be insulated and protected.
The application of Ceramic materials to shield the platinum based wire is a method which has been used for many years, because of the exceptional heat resistant properties of those materials. The thermocouplers is considered the most widely used heat measurement implement which is employed for measuring the temperature inside of a furnace, typically getting used for that melting or heat treatments for metal or indeed for manufacturing ceramic products.
The ceramic components inside a typical thermocouple device will be the outer protection tube that may be exposed to the furnace. In some instances multiple tubes are utilized inside the other person to offer the level of insulation and protection required.
Ceramic insulators (Tubes with 2 or even more core holes through them) may also be used to isolate the two or more wires that go to the bi-metallic joint at the head which is the point from which sens0rs temperature is measured.
The common materials to the tube can be a 99.7% alumina material, impervious tube, which is attached typically to some metal thermacouple head, containing a terminal block which is often used to get in touch to some standard wire to the instrumentation. In the less demanding heat atmosphere a mullite tube may be used like a cheaper alternative, that can work sufficiently approximately 1600 ‘oc. The mullite tube is additionally an impervious tube and contains 60% alumina content.