Project Description

NiCr-NiSi/NiAl thermocouple wire (Type K)

NiCr-NiSi/NiAl (Type K) thermocouple finds the widest use in all basemetal 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 Si≈3%. The operating temperature range is – 200~1300℃(for short term) and 0~1100℃( for long term).

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
TypeChemical Composition, %
NiCrMnSiAl
KP(Chromel)9010///
KN(Alumel)97//3Or 5

* Standard: IEC60584-1

TYPEEMF Versus Pt.67(mV)
100℃200℃400℃600℃800℃
KP2.826~2.8865.937~6.01712.729~12.82119.532~19.67626.064~26.246
KN1.224~1.2562.140~2.1803.600~3.6445.271~5.3317.080~7.160
KP-KN4.050~4.1878.077~8.19716.329~16.46524.803~25.00733.144~33.46

* Physical Properties:

TypeDensity at 20℃ (g/cm³)Melting point (℃)Tensile Strength(Soft annealed condition in 20℃)(Mpa)Elongation(Soft annealed condition in 20℃)(%)Resistivity at 20℃ (μΩ.m)
KP8.61427≥490≥100.71
KN8.61360≥390≥150.3