|Copper Nickel Electric resistance materials|
|Nickel Chromium Electric resistance materials|
|Precision resistance material Manganin|
|Precision resistance material Karmalloy|
|Enameled resistance wire|
JIS C2522-1999 describes this as "Copper Manganese Wire, Bar, and Plate for Electric Resistance". This widely used material is known as precision resistance wire CMW, "Manganin".
In order improve electromotive force against copper, resistance temperature coefficient, and corrosion resistance, we have developed a CMW Manganin alloy for use as precision resistance wire with additions of Ni and other elements to Cu-Mn alloy.
As the temperature dependence of resistance of Manganin wire is not linear, we describe it with a parabolic temperature/resistance curve within the temperature range of actual use, 5 ~ 45 ˚C, expressed by the following quadratic equation.
Resistance - temperature graph|
We apply heat treatment at the maximum resistance temperature in the above quadratic equation (temperature where resistance temperature coefficient α is 0) approach room temperature.
To use this material as precision resistance wire, it is critical that the surrounding temperature or temperature caused by self-heating be kept within the suitable usage range, from 5 to 45 ˚C.
μΩ · m
|Temperature coefficient α
α23 X 10-6/K
|Temperature coefficient β |
β X 10-6/K2
|CMW||Ni 1.0 ~ 4.0|
Mn 10.0 ~ 13.0
Cu+Mn+Ni 98.0 <
|0.44 0.03||AA||13 2||- 4 ~ + 8||- 0.7 ~ 0|
|A||23 2||- 10 ~ + 20||- 1.0 ~ 0|
|B||33 2||- 20 ~ + 40||- 1.0 ~ 0|
|CMW||340 ~ 590||10 <|
Explanation of each symbol