standard atmosphere
atmosphere ***
atm
standard pressure

Pressure was already back up to half a standard atmosphere.

Unlike the weapon-filled chamber, it had been pressurised up to one standard atmosphere.

Air pressure in the room, one tenth of a standard atmosphere - and falling.

The air was thin, less than two-thirds of a standard atmosphere, but it still carried plenty of heat and moisture.

This pressure is known as one standard atmosphere.

But maintaining a standard two-gas atmosphere in the proper proportions through the vast complex was even more complicated.

If we use pure oxygen at one-thirtieth of a standard atmosphere, that will do nicely.

Even with terraforming we don't have a standard atmosphere on Mars.

With a standard atmosphere, electromagnetic waves are generally bent or refracted downward.

In the standard atmosphere, the Tropopause is the height at which the temperature stops decreasing.