Absolute pressure is the sum of which two types of pressures?

Absolute pressure is defined as the total pressure exerted by a fluid, considering the pressure from the atmosphere as well as any additional pressure applied by the fluid itself. To understand why the chosen answer is correct, it’s important to differentiate between gauge pressure and atmospheric pressure.

Gauge pressure measures the pressure relative to the ambient atmospheric pressure. It does not account for atmospheric pressure; instead, it only measures pressure that exceeds the local atmospheric pressure. On the other hand, atmospheric pressure is the pressure exerted by the weight of the atmosphere at a given location and can vary based on altitude and weather conditions.

By summing the gauge pressure and the atmospheric pressure, you arrive at absolute pressure. This is crucial in various engineering applications where accurate pressure readings are necessary, as absolute pressure provides a true representation of the system's pressure regardless of atmospheric conditions. Understanding this concept is essential for correctly sizing and operating pressure systems in power engineering.