Lever arm with sliding weight and spirit level measures force at the base of the vessel
Three alternative glass vessels supplied: Parallel sided, Conical and Tapering
Flexible diaphragm retained by ‘O’ ring for ease of replacement
Height adjustable pointer allows all vessels to be filled to a common depth
This apparatus, designed to demonstrate Pascal’s principle, consists of a machined body incorporating a horizontal flexible diaphragm to which one of three alternative glass vessels can be fitted. The diameter at the base of each vessel is common but the shape of each vessel varies; one parallel sided, one conical and one tapering inwards.
The diaphragm, located at the base of the vessel, conveys the force from the water inside the vessel to a lever arm with a sliding counterweight. A spirit level indicates when the lever arm is horizontal and therefore balancing the force / pressure at the base of the vessel. The force on the diaphragm depends on the depth of water above the diaphragm and the area of the diaphragm that is constant for all three vessels.
A height adjustable pointer allows each of the vessels to be filled to the same depth so that the force / pressure can be shown to be common for all three vessels, independent of shape.