PSI Full Form is Pounds per Square Inch. To be more specific, it is ‘pound-force per square inch.’ It is the common unit to measure pressure. It indicates the amount or measure of force, which is exerted in one sq. inch area. The atmospheric pressure at the seal level is said to be 14.7 PSI. Based on the atmospheric pressure at the sea level, any pressure over the sea level or in the air is calculated by adding 14.7 PSI.
PSI is pronounced as individual letters P S I. Kilo pound per sq. inch is equal to thousand PSI and this is widely used in the field of material science. This is because; a material’s tensile strength is represented as a large number. Similarly, a mega pound per sq. inch or MPSI is equal to a million PSI and is normally used in the field of mechanics.