What standard is used to measure pressure in most refrigeration systems?

Pounds per square inch gauge (PSIG) is the standard commonly used to measure pressure in most refrigeration systems. This measurement indicates the pressure in relation to atmospheric pressure. In refrigeration applications, knowing the pressure relative to the ambient atmosphere is crucial for assessing the system's operation and efficiency. PSIG is particularly useful because it helps technicians determine whether the system is operating within the expected pressure ranges for various refrigerants and can indicate issues like leaks or charge problems.

This comparative measure is preferred over absolute pressure measurements (like pounds per square inch absolute) because it provides a clearer picture of the operating conditions relevant to the system's performance and safety standards. It simplifies troubleshooting and communication among technicians, as it reflects the actual working pressure in the system without needing to account for the atmospheric pressure.