Copper and Steel Thermocouple

A thermocouple made from ordinary copper and steel wire can generate enough current to deflect a compass needle. Compensating for the earth’s magnetic field can make the compass sensitive enough to deflect when the thermocouple is heated with my fingers. I noticed a peculiarity in the copper and steel thermocouple while applying heat to a single junction connected to a voltmeter. For this experiment, I used a welded junction instead of a soldered one as used in the video. As I raised the temperatur