Device and method for determining internal pressure in a pressurized ball

摘要

A pressurized ball testing device for determining the relative pressure of tennis balls or other inflated balls whose internal pressure cannot be directly measured comprises a housing having two half shells, attached along a common axis so that the two half shells are movable along the central axis relative to each other. The interior of each half shell has a ball support centered on the central axis. The ball to be measured is placed between the two ball supports so that when the two half shells are pressed together, the ball is simultaneously compressed and held in place. The pressures are relative to a new ball or reference ball, allowing the balls to be sorted for suitability of play. Two methods of measurement are described, one using constant force and the other using constant displacement. In either case the ball to be tested is squeezed from opposite sides by finger-like protrusions to enhance the displacement of the side of the ball for a given force.