Cuprothal® CL is an austenitic copper-nickel (CuNi alloy) with the highest EMF value against Pt67 among the different types of Cuprothal alloys. The high EMF value is a result of low contents of additional elements in the grade's chemical composition. However, some additions are necessary to meet the EMF values requested by the norms.
Due to this characteristic of having a high thermoelectric output, Cuprothal® CL is typically used in the manufacture of thermocouples to detect the presence of flame in gas burners, connected to safety devices
Chemical composition
|
Cu % |
Ni % |
| Nominal composition |
Bal. |
45 |
Mechanical properties
| Wire size |
Yield strength |
Tensile strength |
Elongation |
| Ø |
Rp0.2 |
Rm |
A |
| mm |
MPa |
MPa |
% |
| 1.5 |
- |
650 |
3 |
in half hard condition
Physical properties
| Density g/cm3 |
8.9 |
|---|
| Electrical resistivity at 20°C Ω mm2/m |
0.49 |
|---|
Temperature factor of resistivity
| Temperature °C | 100 | 200 | 300 | 400 | 500 | 600 |
|---|
| Ct |
1.002 |
1.002 |
1.001 |
1.005 |
1.017 |
1.037 |
|---|
Coefficient of thermal expansion
| Temperature °C | Thermal Expansion x 10-6/K |
|---|
| 20 - 100 |
14 |
|---|
Thermal conductivity
| Temperature °C | 20 |
|---|
| W m-1 K-1 |
21.2 |
|---|
Specific heat capacity
| Temperature °C | 20 |
|---|
| kJ kg-1 K-1 |
0.410 |
|---|
| Melting point °C |
1210 |
|---|
| Magnetic properties |
The material is non-magnetic |
|---|
Thermoelectric properties
Minimal emf values vs Pt67
| Temperature °C |
0 |
100 |
200 |
800 |
| mV |
0 |
4.00 |
8.62 |
38.68 |
ITS 90 - Reference junction 0°C
