????? THANK YOU

 

Pounds per Square Inch. Measure of Pressure.

 

Pounds per Square Inch, ie pressure.

 

not Pressure pound per Square Inch ???

 

No. Pounds.

 

so is " pounds per square inch " ???

 

Yes. Ambient air pressure at sea level is 15 psia (pounds per square inch absolute) or 0 psig (g is for gauge pressure). The 15 pounds is the weight of a column of air 1 inch by 1 inch (or 1 inch square) that extends from sea level to space. As you increase altitude, the psi is reduced because that column height of air is reduced and so is the volume. and mass of air within that column.

 

Moving to Newbie Forum.