Nicrosil-Nisil thermocouple is the latest base metal thermocouple, developed to improve the drawbacks that type K thermocouple has. The main chemical composition of positive leg Nicrosil(NP) is Ni: Cr: Si≈84.4: 14.2: 1.4; negative leg Nisil (NN) is Ni: Si: Mg≈95.5: 4.4: 0.1. Type N thermocouple also be used in the similar atmospheres that type K works, and the operating temperature range is -200~1300℃.
Type N thermocouple improves the EMF drift and short term EMF change, compared to type K thermocouple, and has a longer life than type K thermocouple. Therefore, in the industries where temperature control and measurement are especially critical, type N thermocouple has more advantages than other thermocouple as it has long life and stable thermal EMF.
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TYPE |
Chemical Composition% |
||||
Ni |
Cr |
Mn |
Si |
Mg |
|
NP |
rest |
13.7~14.7 |
/ |
1.2~1.6 |
0.01 |
NN |
rest |
0.02 |
/ |
4.2~4.6 |
0.5~1.5 |
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TYPE |
EMF Versus Pt.67(mv) |
||||||
100℃ |
200℃ |
400℃ |
600℃ |
800℃ |
1000℃ |
||
NP |
1.755~1.813 |
3.910~3.976 |
8.880~8.959 |
14.307~14.433 |
20.012~20.180 |
32.313~32.525 |
|
NN |
0.975~1.005 |
1.954~1.988 |
4.035~4.075 |
6.212~6.274 |
8.318~8.402 |
8.807~8.907 |
|
NP-NN |
2.730~2.818 |
5.864~5.962 |
12.915~13.033 |
20.519~20.707 |
28.330~28.582 |
8.807~8.907 |
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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) |
NP |
8.5 |
1410 |
≥620 |
≥25 |
0.97 |
NN |
8.6 |
1340 |
≥550 |
≥30 |
0.33 |
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