A bar is a unit of pressure, nearly identical to the atmosphere. One bar is equal to 100 kilopascals.
Starfleet space suits measure oxygen pressure in millibars. (VOY: "Day of Honor")
This unit is used by meteorologists who find it easier to refer to atmospheric pressures without using decimals.
Comparative list of pressures
- 1,000 millibars = 1 bar
- While Paris and Torres shared their oxygen, the level dropped from 104 millibars, to 87 millibars, and finally to 71 millibars, before they were rescued by USS Voyager. (VOY: "Day of Honor")