Before diving into the world of vacuum chuck workholding there are some basic definitions that are helpful to know.
- Air Consumption – The volume of compressed air required to power a venturi style vacuum generator.
- Atmospheric Pressure – The atmosphere that surrounds the Earth can be considered a reservoir of low pressure air. Its weight exerts a pressure that varies with temperature, humidity and altitude.
- Barometer – A device usually filled with mercury that measures atmospheric pressure.
- Vacuum Flow – The volume of free air induced by a vacuum pump per unit of time, expressed as standard cubic feet per minute – SCFM or LPM (liters per minute).
- Vacuum Level – The magnitude of the suction created by the vacuum pump. The unit of measure is inches of Hg (“Hg).
- Vacuum Force – Equal to the vacuum level multiplied by the surface area of the vacuum surface, i.e. vacuum cup, vacuum chuck surface.
- Vacuum Fade – For each 1,000 of elevation, vacuum level decreases by 1″ of Hg.