**EXAMPLE 1**

Problem: If a pressure instrument has a reading of 30 psig, find the absolute pressure if the local barometric reading is 14.6 psi.

Solution: Since Pg > Patm, use Equation 1-A to find the absolute pressure:

Pa = Pg + Patm

Pa = 30 psi + 14.6 psi

Pa = 44.6 psia

**EXAMPLE 2**

Problem: Find the absolute pressure if a vacuum gauge reads 11.5 psig and

the atmospheric pressure is 14.6 psia.

Solution: When dealing with pressure below atmospheric pressure, you must

use Equation 5-B:

Pa = Pg – Patm

Pa = 11.5 psi – 14.6 psi

Pa = – 3.1 psia