Thermocouple Type K

Thermocouple Type K

Thermocouple Type K is the most commonly used thermocouple for measuring high temperatures, providing the widest operating temperature range from – 200 ° to + 1260 °C. It usually works in most applications, which include industrial heat treatments, processing operations, precision laboratory and research work, and some of the most demanding applications from nuclear reactors and submarines, to jet aircraft engines. Type K is particularly appreciated due to its accuracy and reliability at high temperatures.

Maximum operating temperatures
Thermocouple operating conditions are very different from one to another. Precise instructions cannot be given on lifetime at various temperatures. The table shown below is to be used as a guideline to reach an acceptable lifetime. Reaction to temperature variation are faster with a smaller diameter, but to the detriment of the lifetime of the thermocouple. Please note that the data below are given as indicative values.

Recommendations for use
Our Thermocouple Type K has competitive advantages.  The type K thermocouple alloy manufactured by our company is melted with copper-nickel-silicon content instead of aluminium. One interesting advantage of this thermocouple is its very high stability in use at high temperature. On special request, we can supply a non aging material.

Environmental limitations
Thermocouple Type K has a better resistance to oxidation than other types of thermocouple (except type N) and is particularly recommended for oxidizing or inert atmospheres (see table of behaviours in part I). It should not be used without protection in sulphurous atmospheres, in reducing atmospheres or a long time in a vacuum. Embrittlement of the wire can be generated, which would change the metallurgical structure of the thermocouple, or spoil quality of the EMF couple by attacking the chromium. In reducing atmospheres, KP develops green oxide, also known as “green rot”, which decreases the chromium content. This phenomenon damages the metallurgical structure, resulting in reduction in EMF output. In addition, KP becomes magnetic due to lower chromium content. Pre-oxidized surface can be delivered in order to increase resistance to corrosion