Constantan

Constantan
A spool of Constantan wire
Material typeCopper-nickel alloy
Physical properties
Density (ρ)8885 kg/m3
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
Thermal conductivity (k)21.2 W/(m·K)
Specific heat capacity (c)390 J/(kg·K)
Electrical properties
Surface resistivity0.56 μΩ·m

Constantan is a proprietary name[unreliable source?] for a coppernickel alloy also known as Eureka, Advance, and Ferry.[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%] ).

  1. ^ M. A. Laughton; D. F. Warne (2003). Electrical Engineers Reference Book (16th ed.). Elsevier. p. 10/43. ISBN 0-7506-4637-3.
  2. ^ J. R. Davis (2001). Copper and Copper Alloys. ASM International. p. 158. ISBN 0-87170-726-8.