Type K Thermocouple Wire Description
The NiCr-NiSi thermocouple (Type K) is the most frequently employed thermocouple made from non-precious metals at temperatures above 500 °C. It is cost-effective, accurate and reliable, providing an extensive operating temperature range. The Type K is utilised in nuclear applications given its relative radiative hardness. Its maximum continuous operating temperature is approximately 1 100 °C.

Type K Thermocouple Wire Specifications
Type
|
Chemical Composition (%)
|
Ni
|
Cr
|
Mn
|
Si
|
Al
|
NiCr (Anode)
|
90
|
10
|
/
|
/
|
/
|
NiSi (Cathode)
|
97
|
/
|
/
|
3
|
/
|
Type
|
EMF versus Pt.67 (mV)
|
100°C
|
200°C
|
400°C
|
600°C
|
800°C
|
NiCr (KP)
|
2.826-2.886
|
5.937-6.017
|
12.729-12.821
|
19.532-19.676
|
26.064-26.246
|
NiSi (KN)
|
1.224-1.256
|
2.140-2.180
|
3.600-3.644
|
5.271-5.331
|
7.080-7.160
|
NiCr-NiSi (KP-KN)
|
4.050-4.187
|
8.077-8.197
|
16.329-16.465
|
24.803-25.007
|
33.144-33.46
|
Type
|
Density at 20°C (g/m³)
|
Melting Point (°C)
|
Tensile Strength (annealed at 20°C) (MPa)
|
Elongation (annealed at 20°C) (%)
|
Specific Resistivity at 20°C (µΩ⋅m)
|
NiCr (KP)
|
8.6
|
1427
|
≥490
|
≥10
|
0.71
|
NiSi (KN)
|
8.6
|
1360
|
≥390
|
≥15
|
0.3
|
Type K Thermocouple Wire Applications
- Temperature measurements in process plants, for example in chemical production and petroleum refineries.
- Safety assessments of heating appliances.