Constantan


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Related to Constantan: Chromel, Manganin, Alumel

constantan

[kən′stan·tən]
(metallurgy)
An alloy containing 45% nickel and 55% copper, used to form iron-constantan and copper-constantan thermocouples.

Constantan

 

a cupronickel alloy characterized by low dependence of resistance on temperature. The constantan produced in the USSR contains 39–41 percent nickel, 1–2 percent manganese, and the balance copper. The specific resistance of constantan is about 0.48 microhm.m at 20°C, and the temperature coefficient of resistance after special heat treatment (stabilizing annealing) is about 2 × 10−6 1/0K; melting point, 1260°C.

Constantan is used in electrical engineering for the manufacture of rheostats and of elements in measuring devices. A short-coming of constantan is its high thermoelectromotive force (about 39 microvotts per degree Kelvin) in contact with copper. For this reason it is seldom used in high-precision instruments, since the random heating of any contact generates a current in the circuit that distorts the readings of the instrument. Manganin is usually used in the most critical cases. With copper or iron, constantan forms thermocouples that are suitable for measuring temperatures of up to 500°C.

L. L. ZHUKOV

References in periodicals archive ?
In comparison, Constantan is an alloy of the same elements, but in very different proportions, having between 40% and 60% nickel, a small amount of manganese, and the remainder copper.
Thermometric sensor selected was a thermocouple, by the manual interlacement of decoated copper and constantan wires, both 0.
The alloy legs used in the jack plug on the type T thermocouples are copper and constantan, resulting in a thermoelectric voltage of 4.
Temperature monitoring was done by placement of copper constantan T-type thermocouples at the pith of full-size poles (18 in.
constantan wire wrapped around the stem as described previously (Bruening and Egli, 1999).
Tenders are invited for Supply Of Soft Annealed Copper Constantan (T-Type) Thermocouple Wire
Logan, Utah), dois psicrometros ventilados com termopares do Tipo T de Cobre Constantan, ambos instalados em uma torre micrometeorologica de oito metros de altura e tres fluximetros situados em diferentes posicoes nas linhas de cultivo (HFT3-REBS, Campbell Scientific, Inc.
Tenders are invited for Purchase of Different Laboratory Equipments: Travelling Microscope,Telescope : 825 mm, air spaced doublet Achromatic, 9 Arc sec, fully multicoated, two speed crayford style, W/adjustable tension and lock,Coefficiant of Viscosity appartus,Viscous Liquid,Steel ball,Sono Meter: one meter long with brass fitting,Digital PN Junction Apparatus,Digital Diode Apparatus,Digital NPN/PNP transistor Apparatus,Thermometer,Rheostat: Mounted on metal feet, oxidized eureka/ constantan wire used.
Girdling was accomplished by wrapping a bare constantan wire (approximately 0.
Nine copper constantan thermocouples (Campbell Scientific, Logan, UT) attached to a datalogger (Campbell Scientific CR-10) were randomly placed inside the chamber, some on top of the Cone-tainers and a few at 5-cm depth inside a Cone-tainer to monitor the temperatures.