Absolute pressure Definition - College Physics I – Introduction Key Term

Definition

Absolute pressure is the total pressure exerted on a system, including atmospheric pressure. It is measured relative to a perfect vacuum.

Absolute pressure is calculated as the sum of gauge pressure and atmospheric pressure.
The standard unit of absolute pressure in the International System of Units (SI) is the pascal (Pa).
Absolute pressure can never be negative because it includes atmospheric pressure, which is always positive.
Common instruments used to measure absolute pressure include barometers and specific types of manometers.
In equations, absolute pressure is often denoted by $P_{abs}$.

The difference between absolute pressure and atmospheric pressure, often measured with a gauge that reads zero at atmospheric conditions.

The force per unit area exerted against a surface by the weight of the air above that surface in the Earth's atmosphere.

$\text{Pascal (Pa)}$: $\text{The SI unit for measuring pressure, equal to one newton per square meter (N/m}^2\text{).}$