What is the approximate gauge pressure (PSIG) equivalent to an absolute pressure of 25 psia?

To determine the gauge pressure from the absolute pressure, it's essential to understand the relationship between these two types of pressure. Absolute pressure (psia) is the total pressure measured from a complete vacuum, while gauge pressure (psig) measures pressure above atmospheric pressure.

To convert absolute pressure to gauge pressure, you typically subtract atmospheric pressure, which is approximately 14.7 psi at sea level. In this case, you start with an absolute pressure of 25 psia. The calculation would look like this:

1. Start with absolute pressure: 25 psia

2. Subtract atmospheric pressure: 25 psia - 14.7 psi = 10.3 psig

Given this result, the answer would be approximately 10 psig.

This method clearly illustrates how gauge pressure is derived from absolute pressure by removing the atmospheric pressure component. The choice reflecting this conversion properly is the one indicating approximately 10 psig. This understanding is foundational in fields such as plumbing and fluid dynamics, where accurate pressure measurements are crucial for system performance and safety.