a nickel-copper alloy containing approximately 43 per-cent Ni and 0.5 percent Mn. Copel resembles constantan in chemical composition and physical and mechanical properties. It has a melting point of approximately 1290°C. In combination with Chromel, it exhibits the highest thermoelectromotive force of all the nickel-copper alloys (about 6.95 mV at 100°C; 49.0 mV at 600°C). It is primarily used in pyrometry as a negative thermal electrode in thermocouples during measurement of temperatures up to 600°C. Copel is also used for the production of compensatory lead. The copel brand MNMts 43–0.5 is manufactured in the USSR.