Table of Thermodynamics Demonstration

Thermodynamics Equipment List

Lecture Demonstrations

Bimetallic Strip with Stand, 4A30.10b

Topic and Concept:




A mounted bimetallic strip is heated or cooled and compared to its room temperature state.



ID Number

Mounted bimetallic strip

TD, Bay B1, Shelf #2 ??

Burner with attached air hose

TD, Bay B1, Shelf #2 ??

Red and white gas carts

Rooms 2103, 2241, (and 2223 upon request)

Liquid nitrogen

Safety glasses and gloves

Important Setup Notes:

Setup and Procedure:

  1. Set the red needled so that it marks the position of the end of the bimetallic strip.
  2. To light the burner, connect the attached gas hose to the gas out (red panel) on the red and white gas cart.

  3. Open the gas valve.
  4. Light a match and bring it near the top of the burner.
  5. The flame will ignite the gas. Adjust the flame height accordingly by adjusting the valve.
  6. Use the lit flame to heat the bimetallic strip by hand and notice which way the strip curls.
  7. Extinguish the flame by closing the gas valve.
  8. Pour liquid nitrogen on the strip to cool it and notice that the strip curls in the opposite direction.

Cautions, Warnings, or Safety Concerns:


The bimetallic strip consists of two different metals. Since one metal has a higher coefficient of thermal expansion than the other, it expands more for a given change in temperature than does the other. Thus, when heated, the strip bends toward the side with the lower coefficient of thermal expansion. On the other hand, when the strip is placed in liquid nitrogen (77K), the same side with a higher coefficient contracts more for a given change in temperature than does the other metal causing the strip to bend in the opposite direction.







fw: BimetalStripStand (last edited 2013-07-18 20:33:25 by srnarf)