3B Scientific Pascal’s Pressure Sphere User Manual

3B SCIENTIFIC® PHYSICS

U14325 Pressure propagation device for liquids

Operating instructions

1/03 ALF

®

The pressure propagation device for liquids is used to
demonstrate the equal distribution of pressure in all
directions in a liquid.

1. Safety instructions

• Handle the glass vessel carefully to avoid breakage
and resulting injury.

• Exercise particular caution when taking out the pis­ton in order to avoid breakage.

• Be careful when using coloured water not to let it
splash on your clothes, for example.

2. Description, technical data

The pressure propagation device consists of a piston in
a long glass cylinder which merges at one end into a
glass sphere to which 7 spray nozzles have been fused.

Total length: Approximately 450 mm
Glass sphere: Approximately 80 mm Ø
Glass cylinder: Approximately 35 mm Ø

3. Procedure

• Immerse the pressure propagation device fully in a

bucket of water. Push the piston forward to expel
any air bubbles from the glass sphere. If necessary,
turn the device to get rid of the air.

• Pull the piston back slowly to fill the glass sphere
with water.

• Hold the pressure propagation device about 1 m
above a large surface (for instance, the floor)

• Ensure that the nozzles are in a horizontal position.

• Push the piston forward to exert pressure on the

liquid.

• Mark the points at which the water impinges on
the surface.

• These points form a semicircle whose center is lo­cated beneath the middle of the glass sphere, pro­viding evidence that the pressure inside a liquid is
propagated equally in all directions.

For a more precise demonstration:

• Fill the glass sphere with coloured water (see above).

• Cover the experimentation table with paper or cel-

lulose.

• Clamp the pressure propagation device carefully on
a tripod.

• Exert a light and uniform pressure on the piston.

• Measure the coloured straight lines drawn by the

emitted water.

3B Scientific GmbH • Rudorffweg 8 • 21031 Hamburg • Germany • www.3bscientific.com • Technical amendments are possible

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