Absolute Pressure is defined as the sum of gauge pressure and atmospheric pressure.

• A. Atmospheric Pressure
• B. Gauge Pressure
• C. Absolute Pressure
• D. Pressure Differential

Answer: (C)

Absolute pressure represents the total pressure in a system, measured from a vacuum. It is obtained by adding the pressure in the air around us (atmospheric pressure) to the pressure above atmospheric (gauge pressure). So the relationship is P_abs = P_atm + P_gauge. This is why the statement is true: it defines absolute pressure as the sum of gauge pressure and atmospheric pressure. Atmospheric pressure alone is just the ambient baseline, not the total; gauge pressure alone is the pressure above atmosphere and doesn’t include the atmospheric baseline; and a pressure differential is simply the difference between two pressures, not the total pressure itself. For example, with 14.7 psi atmospheric pressure and a gauge reading of 5 psi, the absolute pressure is 19.7 psi.