Pounds per Square Inch

Often abbreviated as psi. This is a British imperial unit of pressure. 1.0 psi = 6894.757 Pa

There are a number of other abbreviations appended to psi:

psia = pounds-force per square inch absolute = gauge pressure plus local atmospheric pressure.

psid = psi difference = difference between two pressures.

psig = psi gauge = difference between the measuring point and the local pressure.

psivg = psi vented gauge = difference between the measuring point and the local pressure.

psisg = psi sealed gauge = difference between a chamber of air sealed at atmospheric pressure and the pressure at the measuring point.

See also: Pressure.