Absolute Pressure Scale in Psia (right scale - top part)

The term "absolute pressure" indicates the pressure reading which includes the atmospheric pressure.

This scale is shown on the right hand side. It extends from 0 psia to increasing numbers as we go upward. Notice the following:

a. 0 psia also indicates total vacuum.

b. Normal atmospheric condition is 14.7 psia

In the illustration shown here 5 psia and 10 psia are shown in approximate locations. For a student's learning purposes, there are reasonably accurate.