Absolute pressure

Definition

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

5 Must Know Facts For Your Next Test

1. Absolute pressure is calculated as the sum of gauge pressure and atmospheric pressure.
2. In fluid mechanics, absolute pressure is crucial for understanding fluid behavior under different conditions.
3. Atmospheric pressure at sea level is approximately 101.3 kPa, which must be added to gauge pressure to get absolute pressure.
4. Absolute pressure can never be negative because it is measured relative to a perfect vacuum.
5. Common applications of absolute pressure measurements include weather forecasting, aviation, and underwater diving.

Review Questions

• How do you calculate absolute pressure from gauge pressure?
• Why can absolute pressure never be negative?
• What is the standard atmospheric pressure at sea level in kPa?

Related terms

Gauge Pressure:

The difference between the absolute pressure and the atmospheric pressure. It can be positive or negative.

Atmospheric Pressure:

The force per unit area exerted against a surface by the weight of air above that surface in the atmosphere of Earth. Standard atmospheric pressure at sea level is approximately 101.3 kPa.

Vacuum Pressure: $Pressure$ $below$ $the$ $atmospheric$ $pressure$, $often$ $measured$ $in$ $negative$ values$ $relative$ $to$ $atmospheric$.