NiCr-NiSi /NiAl (Type K) thermocouple wire finds the widest use in all basemetal thermocouple, at temperature above 500 °C.
Type K thermocouple wire 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.