NiCr-NiSi(Type K) thermocouple finds the widest use in all basemetal thermocouple, at temperature above 500ã??The main chemical composition of positive leg NiCr (KP) are Ni~90% and Cr~10%; negative leg NiSi (KN) are NiÃ?97% and Cr~3%. The operating temperature range is -200~1300(for short term) and 0~1100( for long term)ã?? Type K thermocouple has strong resistance to oxidation than other base metal thermocouples. It has high EMF against Platinum 67, excellent temperature accuracy, sensitivity and stability, with a low cost. It is recommended for oxidizing or inert atmospheres, but cannot be used directly in the following cases: (1) Alternatively oxidizing and reducing atmosphere, (2) Atmosphere with sulphur gases (3) Long time in vacuum (4) Low oxidizing atmosphere such as hydrogen and carbon monoxide atmosphere