psi

name

1. Initialism of Policy Studies Institute, a British think tank.

noun

1. Initialism of pre-sentence investigation.
2. Initialism of protein structure initiative.
3. Initialism of pollutant safety/standard index (measurement of the air pollutant such as haze).

symbol

Etymology: Initialism of pounds per square inch.

1. Pound per square inch (an imperial unit of pressure)

   “Each turbogenerator consisted of a steam turbine, powered by 900 psi of superheated steam, that was coupled by a set of reduction gears to a General Electric marine alternating-current generator operating at 1,800 rpm. Each generator had a capacity of 2,000 kilowatts of three-phase power at 450 volts and 60 hertz. The main 450-volt switchboard was energized by the two turbogenerators. The emergency switchboard, in the emergency generator room, was fed from the main switchboard through an electrical tie.”

   “For M2, this is typically around 3250 MPa (471,000 psi) when tempered at 300°F (149°C).”