What does PSIG stand for?

PSIG stands for "Pounds per Square Inch Gauge." This term is utilized to measure pressure in various systems, including refrigeration and pneumatic systems. The gauge pressure refers specifically to the pressure relative to the atmospheric pressure, which means that it accounts for the pressure reading above atmospheric pressure.

In many industrial applications, including ammonia refrigeration systems, it is important to distinguish between absolute pressure and gauge pressure. When PSIG is used, the reading will indicate how much pressure is exerted on a surface, excluding the atmospheric pressure. This is crucial in processes where accurate pressure readings are necessary to ensure safe and efficient operation. The other options, while they may sound plausible, do not accurately describe the standard terminology used in pressure measurement.