Video: Watch this demo

Description: This demo shows how a manometer works using water. When the balloon releases air, it adds pressure to the left side and pushes the water up on the right.


  • Manometer tube
  • Balloon and hose ring

Setup Procedures:

  1. Fill the tube no more than 3/4 full of water.
  2. Blow air into the balloon and hold onto the opening so no air can escape.
  3. Attach the balloon to the left side of the tube by placing the neck of the balloon around the connecting piece. You should still keep your hand higher up on the balloon so that no air escapes.

Demonstration Procedures:

  1. Release air from the balloon a few seconds at a time.
  2. The water will quickly raise. Be careful not to let so much out that water spills out the other end.
  3. After you stop the flow of air from the balloon, the water will remain at the different levels for a brief moment before returning to equilibrium and the levels even out.