sino Published in 2011-08-02
NiCr-NiSi (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 Cr≈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
TYPE | Chemical Composition% | ||||
| Ni | Cr | Mn | Si | Al | |
| KP | 90 | 10 | / | / | / |
| KN | 97 | / | / | 3 | / |
Standard: IEC60584-1
| TYPE | EMF Versus Pt.67(mV) | |||||
| 100℃ | 200℃ | 400℃ | 600℃ | 800℃ | ||
| KP | 2.826~2.886 | 5.937~6.017 | 12.729~12.821 | 19.532~19.676 | 26.064~26.246 | |
| KN | 1.224~1.256 | 2.140~2.180 | 3.600~3.644 | 5.271~5.331 | 7.080~7.160 | |
| KP-KN | 4.050~4.187 | 8.077~8.197 | 16.329~16.465 | 24.803~25.007 | 33.144~33.46 | |
PhysicalProperties:
| Type | Density 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) |
| KP | 8.6 | 1427 | ≥490 | ≥10 | 0.71 |
| KN | 8.6 | 1360 | ≥390 | ≥15 | 0.30 |
