Manganin – precision alloy based on copper (about 85 %) with the addition of manganese (11,5-13,5 %) and Nickel (2,5-3,5 %).
Characterized by an extremely small change of electric resistance (TCR) in the range of room temperatures.
Manganin is widely used in electrical measurement technology high precision in the manufacture of high quality resistors, for the manufacture of a measure of electrical resistance (e.g., resistance boxes), etc.
– a density of 8.4·103 kg/m3,
– the strength of 300-600 HPa,
– melting point is 960 °C,
– the corrosion resistance of the medium,
– electrical resistivity 0,43 – 0,48·10-6 Ohm·m,
– coefficient of linear expansion 14-19·10-6 1/To
– the thermal conductivity of 22 W/(m·K),
– elongation at break < 50 %,
– young’s modulus 124-159 MPa,
– is similar to that of Constantan,
– has a very small thermoelectric power paired with copper (less than 1 µv/K),
– unstable if there is corrosion in the atmosphere containing acid vapors, ammonia,
– sensitive to changes in humidity of the air.