PSI, PSIA, and PSIG: What’s the Difference?

Odds are that you ’ ve hear of the term PSI, which is one of the most common units of press measurement. PSI is used across industries and applications to describe and assess the measure of military unit being exerted by something. Take, for example, tire pressure PSI. When you pump vent into a tire, the molecules will bounce around within the tire, which exerts press against the inside ; this pressure is the breeze pressure of your tires. In terms of air travel compressor measurements, however, PSI has a slightly different mean .
Compressed Air Measurements: PSI
PSI indicates the utmost atmospheric pressure produced by an air out compressor, and in conjunction with CFM ( cubic feet per minute ), is one of the key measurements that indicates how a compressor will perform. Keep in mind that your elevation and geographic placement do affect air pressure measurements, so we recommend consulting with a local anesthetic compressed vent technical when specifying a compressor for your application and process. There are 3 unlike ways to look at PSI :

• PSI. PSI stands for pounds per square inch, and it’s the measure of air force delivered by the air compressors. For example, a compressor could be rated at 125 psi, which means that it delivers 125 pounds of pressure per square inch.
• PSIA.PSIA is pounds per square inch absolute. Sometimes referred to as total pressure, PSIA refers to pressure relative to zero, or a perfect vacuum.
• PSIG. PSIG is pounds per square gauge, which is a pressure measurement that is measured relative to ambient atmospheric pressure.

PSIG is constantly lower than PSIA. The formulas used to describe the relationship are : PSIA = PSIG + 1 cash machine and PSIG = PSIA – 1 standard atmosphere, where standard atmosphere is atmospheric pressure. Did you know that you can easily calculate PSIA, PSIG, or even convert between the two ? If you know the actual atmospheric atmospheric pressure value for your location, you can use that number in the convention ; alternatively, you can use 14.7 psi, the estimate atmospheric press at sea degree, as a standard value to convert PSIG to PSIA and vice-versa.

Have a wonder on any of the above ? Reach out to our compressed air experts at www.atlascopco.com/air-usa !