What does gauge pressure take into account?

Gauge pressure specifically refers to the pressure measured relative to atmospheric pressure. It is the pressure in a system that does not include the ambient atmospheric pressure acting on the surface of that system. Therefore, gauge pressure is calculated by taking the absolute pressure and subtracting the atmospheric pressure from it.

This measurement is critical in various applications, especially in systems where the actual pressure affects performance but does not need to account for the atmospheric pressure acting on it, such as tire pressure or pressure in boilers.

Thus, when considering gauge pressure, it is accurate to say that it focuses on the pressure within a system minus the pressure exerted by the atmosphere, making the understanding of how gauge pressure functions essential in practical applications in fields like millwrighting.