The Atmosphere and its Effects on Vacuum Technology

Illustration of ambient pressure at altitude

The air pressure (ambient pressure) depends on the elevation of the location as well as the temperature at that site. As shown in the diagram, the air pressure at sea level is 1,013 mbar. At an elevation of 600 m (location of the J. Schmalz GmbH in Glatten,Germany) air pressure is reduced to 938 mbar. At a height of 2,000 m, the air pressure is only 763 mbar.
This pressure loss also has an effect on working with a vacuum. The pressure drop with increasing height also reduces the maximum pressure difference that can be attained and therefore the maximum holding force. Per 100 m increase in elevation, the air pressure drops by about 12.5 mbar.
A vacuum generator that generates an 80% vacuum, achieves a vacuum value of -810 mbar at sea level (ambient pressure = 1,013 mbar); at 2,000 m (ambient pressure = 763 mbar) a vacuum generator only achieves -610 mbar. The possible holding force of a vacuum suction pad drops proportionally to the vacuum value that can be attained. This means the application at sea level presents the best case scenario.

All data on this website refer to an ambient pressure of 1,013 mbar and an ambient temperature of 20 °C.