Constantan - Thermally stable alloy of copper (Cu) (about 59%) with the addition of nickel (Ni) (39-41%) and manganese (Mn) (1-2%).
The alloy has a high electrical resistivity (about 0.5 micromhos/m), the minimum value of the thermal coefficient of electrical resistance, thermoelectric force in conjunction with copper, iron, chromium-nickel alloy.
Constantan copper-nickel alloy, characterized by a weak dependence of the electrical resistance of the temperature. Produced in Russia Constantan contains 39-41% nickel, 1.2% manganese, and the rest - copper. The electrical resistance of Constantan at 20 ° C - mO × 0.48 m, the temperature coefficient of electrical resistance after special heat treatment (stabilizing annealing) is about 2 × 10-6 1 / K. melting point of 1260 ° C. Constantan is used for the manufacture of electrical rheostats, items, instrumentation, etc. The lack of Constantan-large thermoelectric power (about 39 mV/K) in contact with the copper. Constantan so rarely used in high precision instruments - random heating terminals contact leads to an electrical circuit, distorting readings. Usually in the most critical cases, a manganin. With copper or iron Constantan thermocouple forms, suitable for temperatures up to 500 °C.
Temperature coefficient of linear expansion of 14,4 · 10-6 ° C-1. 8800-8900 kg/m3 density, melting point of about 1260 ° C. Responds well to treatment. Is used to make thermocouples, load cells of the active element, rheostats and electric heating elements with operating temperatures up to 400-500 ° C, a high-end instrumentation accuracy.
|39 - 41||≤ 0.5||≤ 0.1||≤ 0.1||1 - 2||56.1 - 60||≤ 0.9|
LLC Renal-d supplies thermocouple wire from Ukraine: