pound force per square inch
Pound force per square inch (psi) is a unit from the Imperial system defined as the pressure resulting from a force of one pound-force applied to an area of one square inch. It is used in various applications such as tire pressure and hydraulic systems.
mm of mercury
The millimeter of mercury (mmHg) is pressure unit traditionally used in meteorology. It is the pressure from a 1 mm column of mercury at 0°C under normal gravity.