Manganin


Manganin is a trademarked name for an alloy of typically 84% copper, 12% manganese, and 4% nickel. It was first developed by Edward Weston in 1892, improving upon his Constantan.
Manganin foil and wire is used in the manufacture of resistors, particularly ammeter shunts, because of its virtually zero temperature coefficient of resistance value and long term stability. Several Manganin resistors served as the legal standard for the ohm in the United States from 1901 to 1990. Manganin wire is also used as an electrical conductor in cryogenic systems, minimizing heat transfer between points which need electrical connections.
Manganin is also used in gauges for studies of high-pressure shock waves because it has low strain sensitivity but high hydrostatic pressure sensitivity.

History

In 1887 Edward Weston discovered that metals can have a negative temperature coefficient of resistance, inventing what he called his "Alloy No. 2."
It was produced in Germany where it was renamed "Constantan".
In 1892 Weston had finally completed his discovery of an alloy
of copper, nickel, and manganese prepared by a complicated series
of heat-treatments. In May, 1893, he received a basic patent on the
composition, manufacture, and use of the material for electrical
resistors. Production was carried out in Germany, and it
became known as "Manganin".
The availability of a practical conductive metal with an extremely
constant resistance over the range of ordinary temperatures
was a great advance in electrical technology and equipment design,
but Weston did not receive general recognition for this.

Properties

Cu86/Mn12/Ni2

Electrical Properties
Mechanical Properties
Temperature coefficient of resistivity
12+.000006
25.000000
100−.000042
250−.000052
475.000000
500+.00011

AWGohms per cmohms per ft
10.0008360.0255
12.001330.0405
14.002110.0644
16.003360.102
18.005350.163
20.008500.259
22.01350.412
24.02150.655
26.03421.04
27.04311.31
28.05431.66
30.08642.63
32.1374.19
34.2186.66
36.34710.6
40.87826.8