Constantan

Constantan is a copper–nickel alloy, typically containing about 55% copper and 45% nickel. Its high electrical resistivity and low temperature coefficient make it useful in resistance wires and thermocouples.

Resistance wire: Wire made from a resistive material to produce heat or set electrical resistance. Constantan’s high resistivity lets compact lengths provide substantial resistance.
Electrical resistivity: A material property that quantifies how strongly a material opposes electric current. Constantan’s relatively high resistivity allows useful resistance in short, thin wires.
Manganin: A copper–manganese–nickel alloy with high resistivity and a very low temperature coefficient. Manganin is a close alternative for precision resistors, with different composition and thermoelectric behavior.
Nickel: A silvery metal used in alloys to alter strength, corrosion resistance, and electrical properties. Nickel is the other principal constituent in Constantan.
Thermocouple: A temperature sensor that generates a voltage from the junction of two dissimilar conductors. Constantan forms the negative leg of several common thermocouple types.
Temperature coefficient of resistance: A measure of how a material’s electrical resistance changes with temperature. Constantan’s low coefficient keeps its resistance comparatively stable as temperature changes.
Nichrome: A nickel–chromium alloy valued for electrical resistance and oxidation resistance at high temperatures. Nichrome suits hotter heating elements, while Constantan is often selected for low temperature sensitivity.
Alloy: A material containing a metal combined with one or more other elements. Constantan’s properties arise from combining copper and nickel rather than using either pure metal.
Strain gauge: A sensor that measures deformation through changes in electrical resistance. Constantan foil is widely used because its resistance changes predictably as it deforms.
Seebeck effect: The generation of voltage across a temperature difference in a conducting material or circuit. A Constantan junction develops thermoelectric voltage when paired with another conductor.

Linked from 1 page

List of copper alloysBroader topic: Its electrical behavior supports uses unlike the structural roles of many copper alloys.