Constantan | |
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![]() 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.[1] It usually consists of 55% copper and 45% nickel.[2] 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%] ).