What reading corresponds to gauge pressure at sea level?

Gauge pressure is defined as the pressure relative to atmospheric pressure, which means it measures how much greater the pressure is compared to the surrounding atmospheric pressure prevailing at that time. At sea level, the atmospheric pressure is typically around 14.7 psi.

When gauge pressure is zero, it indicates that the measured pressure is equal to the atmospheric pressure, meaning there is no additional pressure above that of the atmosphere. Thus, at sea level, if a gauge reads zero, it signifies that the pressure being measured is simply the atmospheric pressure itself—14.7 psi in this case.

This understanding highlights that zero gauge pressure at sea level reflects that there is no difference between the pressure measured and the atmospheric pressure, making it the correct interpretation within the context of gauge pressure definitions. Hence, selecting zero as the gauge pressure reading at sea level is accurate and aligns with the standard reference point for gauge measurements.