Bi-Metallic Compound Bar
by GSC International

Two metals with different heat coefficients have been laminated together and then mounted to a plastic handle. The bi-metal compound bar helps to demonstrate the unequal expansion of different metals, by bending one way or the other when heated. It is the same principle as a bi-metallic strip thermometer, which relies on the different expansion rates as the temperatures of metals changes.

By bonding two different metals together, a simple electric controller is made that is capable of withstanding fairly high temperatures. As the strip bends, it can make contact with a switch and turn on a refrigeration or heating system.