If atmospheric pressure is recorded at 101.3 kPa, what type of pressure is this considered?

Atmospheric pressure recorded at 101.3 kPa is considered absolute pressure. Absolute pressure is the total pressure exerted on a system, which includes both the atmospheric pressure and any gauge pressure (if applicable). By definition, absolute pressure is measured relative to a complete vacuum, meaning it represents the total pressure as opposed to a reference pressure.

In practical terms, absolute pressure is essential in various applications, including thermodynamic calculations, where the actual pressure conditions need to be taken into account without any deductions. For instance, in refrigeration systems, understanding absolute pressure is critical because it affects boiling points, pressure ratios, and performance of refrigeration cycles.

In contrast, gauge pressure measures pressure relative to atmospheric pressure and does not account for the atmospheric component itself. Relative pressure typically refers to pressures measured against some reference point, often atmospheric pressure as well. Vacuum pressure is defined as the pressure below atmospheric pressure but expressed in relation to a vacuum. Since the question specifies atmospheric pressure directly, it aligns with the definition of absolute pressure.