The Physics of 29 PSI
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The moment you "pop" a fresh can of tennis balls, you are witnessing a battle of physics. Inside that can, the balls were stored at 14 PSI of ambient pressure to match their internal 14 PSI (making a total of ~29 PSI absolute). Once the seal is broken, the battle is lost.
The Science of Permeability
A tennis ball isn't a sealed vault; it's a semi-permeable membrane. The rubber core is porous at a microscopic level. Because the air pressure inside the ball is higher than the atmospheric pressure outside, a "Pressure Gradient" is created.
Physics demands equilibrium. Nature wants the pressure inside and outside to be equal. Consequently, nitrogen and oxygen molecules are literally pushed through the rubber wall of the ball every second of every day. This is why a ball left in your bag for 48 hours feels "dead"—it hasn't been used, but it has been leaking.
The 48-Hour Cliff
Research shows that a standard tennis ball can lose up to 1-2% of its pressure every day just sitting on a shelf. By the third day, the rebound height has already changed enough to affect your timing and swing data on the STA 4.0 Analyzer.
Stopping the Leak: Artificial Equilibrium
The only way to stop this invisible leak is to remove the pressure gradient. By storing your balls in a pressurized environment—like our Volt-Pressure Smart Canister—you surround the ball with high-pressure air. When the pressure outside matches the pressure inside, the molecules have nowhere to go. The leak stops. The bounce stays.
Mastering the equipment is the first step to mastering the game. Don't let physics steal your bounce.