Pounds per square foot
Pounds per square foot (psf) is a unit used in the United States, United Kingdom and some other countries that use the Imperial system. It is the pressure of a one pound on an area of one square foot.
Inches of Mercury
Inches of Mercury (inHg) are used to measure pressure in the imperial system. Traditionally this unit is used in the United States for barometric pressure in weather reports. It is the pressure from a column of mercury exactly one inch high at standard gravity.