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Therefore, many materials that produce acceptable values of include materials that have been alloyed or possess variable negative temperature coefficient (NTC), which occurs when a physical property (such as thermal conductivity or electrical resistivity) of a material lowers with increasing temperature, typically in a defined temperature range ...
The effective temperature coefficient varies with temperature and purity level of the material. The 20 °C value is only an approximation when used at other temperatures. For example, the coefficient becomes lower at higher temperatures for copper, and the value 0.00427 is commonly specified at 0 °C. [53]
1 Electrical resistivity. 2 References. Toggle References subsection. ... (room temperature) (alpha, polycrystalline) calculated 562 nΩm ... 29 Cu copper; use 2.15 ...
Constantan (Cu 55 Ni 45) has a low temperature coefficient of resistivity; and as a copper alloy, it is easily soldered. Other constant-resistance alloys include manganin (Cu 86 Mn 12 Ni 2), Cupron (Cu 53 Ni 44 Mn 3) [2] and Evanohm. Melts at about 1,220 °C (2,230 °F).
International Annealed Copper Standard (IACS) pure =1.7×10 −8 Ω•m =58.82×10 6 Ω −1 •m −1. For main article, see: Copper in heat exchangers. The TPRC recommended values are for well annealed 99.999% pure copper with residual electrical resistivity of ρ 0 =0.000851 μΩ⋅cm. TPRC Data Series volume 1 page 81. [8]
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%] ).
Electrical resistivity: 16.78 nΩ⋅m (at 20 °C) ... Copper is a chemical element ... and constantan used in strain gauges and thermocouples for temperature ...
Manganin is a trademarked name for an alloy of typically 84.2% copper, 12.1% manganese, and 3.7% nickel. It was first developed by Edward Weston in 1892, improving upon his Constantan (1887). Manganin foil and wire is used in the manufacture of resistors , particularly ammeter shunts , because of its virtually zero temperature coefficient of ...