1. What is PSIG?

PSIG (Pounds per Square Inch Gauge) is a unit of pressure relative to atmospheric pressure. It measures the difference between the system pressure and atmospheric pressure (14.7 psi at sea level).

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• \( PSIG \) — Gauge pressure (relative to atmospheric pressure)
• \( PSIA \) — Absolute pressure (relative to perfect vacuum)
• \( 14.7 \) — Standard atmospheric pressure at sea level (psi)

Explanation: The formula converts absolute pressure to gauge pressure by subtracting atmospheric pressure.

3. Importance of PSIG Calculation

Details: Most pressure gauges display PSIG, while many engineering calculations require absolute pressure (PSIA). Converting between these units is essential for accurate measurements and system design.

4. Using the Calculator

Tips: Enter the absolute pressure (PSIA) value. The calculator will automatically compute the gauge pressure (PSIG) by subtracting atmospheric pressure.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between PSIG and PSIA?
A: PSIG measures pressure relative to atmospheric pressure, while PSIA measures pressure relative to a perfect vacuum.

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

Q3: Can PSIG be negative?
A: Yes, negative PSIG indicates vacuum pressure (pressure below atmospheric).

Q4: How does altitude affect this calculation?
A: At higher altitudes, atmospheric pressure is less than 14.7 psi, so the conversion factor should be adjusted.

Q5: What units are used in this calculator?
A: The calculator uses psi (pounds per square inch) for both input and output.