Nicrosil NPX strip is an austenitic nickel-chromium-silicon alloy (NiCrSi alloy) used for the positive leg of thermocouple type N. It offers a better oxidation resistance in air than type E, J and K thermocouples.
Nicrosil NPX strip alloy cannot be exposed to reducing or alternatively oxidizing and reducing atmospheres or to vacuum. This thermocouple is the most recent one among the different types covered by the international standards.
Mechanical properties
| Yield strength | Tensile strength | Elongation |
|---|---|---|
| Rp0.2 | Rm | A |
| MPa | MPa | % |
| 310 | 800 | 35 |
Properties are measured on wire Ø 2 mm
Physical properties
| Density g/cm3 | 8.53 |
|---|---|
| Electrical resistivity at 20°C Ω mm2/m | 1.0 |
| Temperature °C | Thermal Expansion x 10-6/ K |
|---|---|
| 20 - 100 | 17 |
| Temperature °C | 20 |
|---|---|
| W m-1 K-1 | 13 |
| Temperature °C | mV |
|---|---|
| 100 | 2.774 |
| 200 | 5.913 |
Size range
Standard sizes for thermocouple strip range from thickness 0.10 to 3.0 mm (0.0039 to 0.181 inch) and width from 4 to 195 mm (0.157 to 7.68 inch).
| Melting point °C | 1420 |
|---|---|
| Magnetic properties | The material is non- magnetic. |