Thermocouples are temperature sensors which can be embedded into ceramic elements or ceramic heaters (or inserted into cassette type quartz heating elements) for the purpose of controlling or monitoring heater temperature. The thermocouple consists of 2 specific dissimilar metals welded at 1 end to form a ‘hot’ junction. As the temperature at the hot junction increases, an emf or voltage is generated which is proportional to the change in temperature. The generated voltage is both predictable and repeatable for a given thermocouple type making them a good solution for many temperature measurement applications where low cost and a wide temperature range are important factors.
Ceramicx infrared heat consultants use type K thermocouples as standard. Type K uses Nickel-Chromium (NiCr) as the positive leg (+) and Nickel Aluminium (NiAl) as the negative leg (-). Type J thermocouples are also available on special request. In order to use a ceramic element with a standard built in thermocouple, a suitable temperature controller or temperature monitor must be used which is capable of accepting an input from a type K thermocouple. The thermocouple should be connected to the controller using suitable type K extension/compensating cable with no interconnections using dissimilar metals ( metals not of the same materials or not exhibiting the same electro thermal characteristics). Under IEC 60584.3, type K extension/compensating cables should have a green outer sheath with green insulated conductor for the (+) core and white for (-).