CEODD Dive Physics Practice Exam 2025 – The Complete All-in-One Guide for Exam Success!

To convert psig (pounds per square inch gauge) to ata (atmospheres absolute), it is important to understand the concepts of gauge pressure and absolute pressure. Psig measures pressure relative to atmospheric pressure, while ata is a measurement of absolute pressure, which includes the atmospheric pressure in its value.

When converting from psig to ata, the atmospheric pressure at sea level is approximately 14.7 psi. Therefore, the absolute pressure (in psia - pounds per square inch absolute) is equal to the gauge pressure plus atmospheric pressure.

In this case, to convert psig to ata, you add the atmospheric pressure (14.7 psi) to the psig value and then divide by the equivalent atmospheric pressure in psi (14.7 psi) because you need the result in atmospheres. This works out to the formula: (psig + 14.7) / 14.7.

This method correctly translates the gauge pressure into absolute terms, allowing for accurate measurements and calculations related to depth and pressure in diving, which is crucial for safety and planning.