What is the difference between type K and N thermocouple

K type & N type are normal for thermocouple, which are widely used in temperature measurement zone. The positive pole for K type is NI/CR alloy normally, the negative one is NI/SI(NI/AL). The positive pole for N type is NI/CR/SI alloy, the negative one is NI/SI/MGO alloy. Due to different composition of two poles wire materials, they have different thermoelectric characteristic , physical and chemical capability.

K type has better capability in base metal thermocouple, which has good linearity , large thermoelectric power, high sensitivity, better stability and uniformity, good anti-oxidation and low price. But it has less stability in high temperature lead to slow drift for thermopotential,which will affect the measurement accuracy.

N type is another normal type in base metal termocouple. For basic use, it has better anti-oxidation and sulfur resistance than K type.It’s generally used in wide range of temperature, which will have bigger non-linear deviation and slower hot response time. At temperature 300-500℃, it has better thermoelectric stability than K type.

Accuracy and reliability of thermocouple measurement mostly decided by thermoeletric uniformity and stability of thermocouple materials. You need choose suitable thermocouple type according to specific applied situation and measuring requirements. If you have any needs, please contact our professional engineers, we can offer professional advise and solutions.