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.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

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

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
The thermal properties for Constantan were used in equation (3) to calculate the heat flux.
Constantan. Constantan is a variation of cupronickel with 55% copper and 45% nickel and a resistivity of 19.63495 [micro] [ohm] -inch.
Key words: bismuth telluride; consensus mean curve; Constantan; functional data analysis; Ridge regression modeling; round-robin; Seebeck coefficient; Standard Reference Material; thermoelectric.
Here, about 80% of the 27-km ring is pumped by a linear NEG pump consisting of the St-101 alloy bonded as a powder to a constantan ribbon by cold pressing.
Typical gages are made from constantan (A alloy) or Karma (K alloy) foil.
Two opposite gold electrodes, diameter 0.005 m, were attached to the underside of the cylinder, 0.005 m from the center and close to the copper constantan thermocouple wire, optimizing the cell performance.
The temperature measurements were made at different locations of the setup and the test section by means of type T (copper constantan) thermocouples (24), while the pressure of the refrigerant was measured by pressure gauges (26) and pressure transducers (27) through pressure headers (25).
As the thermocouple contacts the target surface, the change in the electrical potential of the junction between the iron and constantan wires is measured by a voltmeter, and can be converted to a thermal value electronically.
The surface temperature of evaporator section (3 locations), adiabatic section (6 locations) and condenser section (3 locations) are measured using 10 evenly spaced copper constantan (T-type) thermocouples.
A sonda instalada do presente experimento foi o modelo TDP 30 mm (Dynamax, Huston, TX), confeccionada com fio de constantan de diametro de 0,5 mm.