1. What is a PSI to PSIA Calculator?

Definition: This calculator converts pressure readings from PSI (gauge pressure) to PSIA (absolute pressure).

Purpose: It helps engineers, technicians, and students convert between these common pressure measurement units.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• PSIA — Absolute pressure (pounds per square inch absolute)
• PSI — Gauge pressure (pounds per square inch gauge)
• 14.7 — Standard atmospheric pressure at sea level

Explanation: Absolute pressure includes atmospheric pressure while gauge pressure excludes it.

3. Importance of PSI/PSIA Conversion

Details: Proper conversion is essential for accurate pressure measurements in various applications including HVAC, engineering, and scientific research.

4. Using the Calculator

Tips: Simply enter the PSI (gauge pressure) value and the calculator will automatically compute the absolute pressure in PSIA.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between PSI and PSIA?
A: PSI is gauge pressure (relative to atmospheric pressure), while PSIA is absolute pressure (including atmospheric pressure).

Q2: Why is 14.7 psi used in the formula?
A: This represents standard atmospheric pressure at sea level. Actual atmospheric pressure varies with altitude and weather.

Q3: When would I need to use PSIA instead of PSI?
A: PSIA is used in scientific calculations, vacuum systems, and anywhere absolute pressure is required rather than relative pressure.

Q4: Can this calculator work in reverse (PSIA to PSI)?
A: Yes, simply subtract 14.7 from the PSIA value to get PSI.

Q5: Does this value change with altitude?
A: Yes, atmospheric pressure decreases with altitude, so the conversion factor would be less than 14.7 at higher elevations.