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To understand the difference between PSIG (pounds per square inch gauge) and PSIA (pounds per square inch absolute), it's important to consider what each measurement represents.

PSIG measures pressure relative to atmospheric pressure, meaning that it measures the pressure above the atmospheric baseline. Therefore, when you see 10 PSIG, it indicates that the pressure is 10 psi above the surrounding atmospheric pressure. Since atmospheric pressure at sea level is approximately 14.7 psi, the absolute pressure in this case is actually 10 PSI (gauge) + 14.7 PSI (atmospheric) = 24.7 PSIA.

On the other hand, PSIA represents absolute pressure, which includes the pressure exerted by the atmosphere. Therefore, 10 PSIA indicates that the pressure is simply 10 psi above a complete vacuum.

Thus, 10 PSIG is indeed greater than 10 PSIA by 14.7 psi, as it accounts for the additional pressure exerted by the atmosphere. This understanding leads to the conclusion that when you compare the two values, the gauge pressure (10 PSIG) exceeds the absolute pressure (10 PSIA) by a significant margin due to the atmospheric contribution.