4B20.10-Convection Tube

4b2010convection_tubeVideo: Watch this demo

Instructor’s video

Description: This demonstration shows convection currents.


  • Convection Tube
  • Water
  • Food Coloring
  • (Optional) UV reactive dye and UV light
  • Bunsen burner
  • Matches
  • Table clamp
  • S clamp
  • long pole and short rod
  • 2 Finger clamps

Setup Procedure:

  1. Connect the rods as shown in the picture.
  2. Connect the two finger clamps onto the small rod.
  3. Fill up the convection tube with water.
  4. Hang the convection tube on the two finger clamps.
  5. Connect the Bunsen burner to the gas valve and place under one side of the convection tube.
  6. Test the Bunsen burner and set it to a small flame.
  7. When taking apart the apparatus, use caution as the parts might still be very hot.

Demonstration Procedure:

  1. Turn on the gas and light the Bunsen burner to make a small flame (too much heat and the water starts to boil).
  2. Add a drop or food coloring into the top. Note that the food coloring follows the convection current in the tube.
  3. (Optional) If using the UV dye, add a drop to the water, turn off the lights, and turn on the UV light. Hold the UV light up to the tube and watch the convection currents.
  4. When finished, turn off the flame.

Open Flame Open Flame
Keep away from flammable materials.

Note: If the water gets too hot, the water may bubble out of the top.