How do I convert PSI to PSIA and PSIG?

Field Instrumentation Pressure Measurement
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How do I convert PSI to PSIA and PSIG? image

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Converting PSI to PSIA and PSIG is straightforward once you understand the relationship between them.

How to Convert PSI to PSIA and PSIG

Pressure measurements can sometimes be confusing because there are different units used to describe them, such as PSI, PSIA, and PSIG. Here’s a quick guide to help you convert between these units.

1. PSI (Pounds per Square Inch): This is the standard unit of pressure. However, PSI alone doesn’t specify if it’s relative to atmospheric pressure or absolute pressure.

2. PSIA (Pounds per Square Inch Absolute): This measures pressure relative to a perfect vacuum (0 PSIA). It includes atmospheric pressure in its measurement. At sea level, atmospheric pressure is about 14.7 PSI.

3. PSIG (Pounds per Square Inch Gauge): This measures pressure relative to atmospheric pressure. At sea level, 0 PSIG equals 14.7 PSIA. Conversions:

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Key Takeaway:

  • PSIA includes atmospheric pressure in its measurement.
  • PSIG excludes atmospheric pressure and measures just the pressure exerted by the substance in question.

I hope this clears things up! Feel free to ask if you have more questions.