Due to the fact that copper nickel resistance wire is a complete solid solution, its features continuously change.
As shown in Graph 1, volume resistivity rises with the addition of Ni and reaches its maximum value when the proportion of Ni is 50% ~ 60%, and electromotive force against copper is maximum with Ni in the range of 40% ~ 50%. On the other hand, resistance temperature coefficient is at its minimum with Ni in the range of 40% ~ 50%.

Features of Copper Nickel Resistance Wire CN49W (Advance, Constantan, and Yurika)

1. Because Copper Nickel Resistance Wire contains more Ni than Manganin, its corrosion resistance and acid resistance are excellent.
2. Copper Nickel Resistance Wire cannot be used for direct current precision resistors due to its large thermal electromotive force against copper, - 40 ~ - 44 μV/K (0 ~ 100 ˚C).
3. Due to its small secondary temperature coefficient β= - 0.1X10^-6/K², the resistance/temperature curve is a straight line within the temperature range of 23 ~ 53 ˚C. Therefore, we calculated the mean temperature coefficient where the changing temperature remains between 23 ˚C and 53 ˚C.
4. Copper nickel resistance materials have been widely used in general resistance measurement devices within the wide resistance range from CN05 to CN49.



Table 3  Features of copper nickel resistance wire, ribbon, and bar
(CN49W, CN30W, CN15W, CN10W, CN05W)

Symbol	Chemical Composition %	Volume resistivity  μΩ · m	Mean temperature coefficient α X10-6/K 23 ~ 53 ˚C	Mechanical property
				Tensile strength	Elongation
				MPa	%
CN49W CN49R CN49B	Ni 42.0 ~ 48.0 Mn 0.5 ~ 2.5 Cu+Ni+Mn 99.0 <	0.490 0.030	Class AA 10 Class A 20 Class B	410 ~ 540	25 <
CN30W CN30R CN30B	Ni 20.0 ~ 25.0 Mn 1.5 > Cu+Ni+Mn 99.0 <	0.300 0.024	200	270 ~ 540	20 <
CN15W CN15R CN15B	Ni 8.0 ~ 12.0 Mn 1.0 > Cu+Ni+Mn 99.0 <	0.150 0.015	500	250 ~ 490	20 <
CN10W CN10R CN10B	Ni 4.0 ~ 7.0 Mn 1.0 > Cu+Ni+Mn 99.0 <	0.100 0.012	700	250 ~ 440	20 <
CN05W CN05R CN05B	Ni 0.5 ~ 3.0 Mn 1.0 > Cu+Ni+Mn 99.0 <	0.050 0.0075	1500	200 ~ 390	20 <




Explanation of each symbol





 Kind of insulation
 Insulation tolerance



List of resistance levels
List of insulation types




Features of copper nickel resistance wire   JIS C 2521-1999 (CN05W, CN10W, CN15W, CN30W, CN49W) Ni (%) Graph 1