Constantan
| Constantan | |
|---|---|
A spool of Constantan wire | |
| Material type | Copper-nickel alloy |
| Physical properties | |
| Density (ρ) | 8.885 g/cm3 |
| Mechanical properties | |
| Young's modulus (E) | 162 GPa |
| Tensile strength (σt) | ~450 MPa |
| Elongation (ε) at break | ~0.25% |
| Thermal properties | |
| Melting temperature (Tm) | 1210 °C |
| Electrical properties | |
| Surface resistivity | 0.56 μΩ·m |
Constantan, also known in various contexts as Eureka, Advance, and Ferry, refers to a copper-nickel alloy commonly used for its stable electrical resistance across a wide range of temperatures. It usually consists of 55% copper and 45% nickel. Its main feature is the low thermal variation of its resistivity, which is constant over a wide range of temperatures. Other alloys with similarly low temperature coefficients are known, such as manganin (Cu [86%] / Mn [12%] / Ni [2%] ).