Measurement of high temperatures, greater than 1000 C, using ceramic based thermocouples is really a well-established process. To do this successfully the resistance wires throughout the thermocouple have to be insulated and protected.
The application of Ceramic materials to guard the platinum based wire is a method that has been used for quite some time, as a result of exceptional heat resistant properties of these materials. The thermocouple sensor is considered the most frequently used heat measurement implement and is employed for measuring the temperature inside of a furnace, typically being utilized for your melting or heat treatment of metal or indeed for manufacturing ceramic products.
The ceramic components in a typical thermocouple device are definitely the outer protection tube which is exposed to the furnace. Sometimes multiple tubes are used inside one another to supply the amount of insulation and protection required.
Ceramic insulators (Tubes with 2 or maybe more core holes through them) are also used to isolate the two or more wires that check out the bi-metallic joint on the head which is the point that sens0rs temperature is measured.
The typical materials used to the tube is actually a 99.7% alumina material, impervious tube, that is attached typically to a metal thermacouple head, containing a terminal block that is utilized in order to connect to a standard wire to the instrumentation. In a less demanding heat atmosphere a mullite tube can be utilized as being a cheaper alternative, that will work sufficiently up to 1600 ‘oc. The mullite tube is also an impervious tube and possesses 60% alumina content.