NiCr-NiSi (Type K) thermocouple finds the widest use in all base metal thermocouple, at temperature above 500℃。The main chemical composition of  positive leg NiCr (KP) are Ni≈90% and Cr≈10%; negative leg NiSi (KN) are Ni≈97% and Cr≈3%. The operating temperature range is -200~1300℃(for short term) and 0~1100℃( for long term)