1. What is a PSI to PSIG Calculator?

Definition: This calculator converts absolute pressure (PSI) to gauge pressure (PSIG) by subtracting atmospheric pressure.

Purpose: It helps engineers, technicians, and mechanics work with pressure measurements in various systems.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

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

Explanation: Gauge pressure represents pressure relative to atmospheric pressure, while absolute pressure includes atmospheric pressure.

3. Importance of PSI/PSIG Conversion

Details: Proper pressure measurement is critical in HVAC systems, pneumatic tools, industrial processes, and many engineering applications.

4. Using the Calculator

Tips: Enter the absolute pressure in PSI. The calculator will automatically subtract standard atmospheric pressure (14.7 psi).

5. Frequently Asked Questions (FAQ)

Q1: Why subtract 14.7 psi?
A: This accounts for standard atmospheric pressure at sea level that's always present but not typically measured by gauges.

Q2: What if I'm at high altitude?
A: Atmospheric pressure decreases with altitude. For precise measurements, use local atmospheric pressure instead of 14.7 psi.

Q3: Can PSIG be negative?
A: Yes, when absolute pressure is less than atmospheric pressure (vacuum conditions).

Q4: What's the difference between PSI and PSIG?
A: PSI is absolute pressure, PSIG is gauge pressure (relative to atmosphere). PSIG = PSI - atmospheric pressure.

Q5: When would I need this conversion?
A: When working with specifications that use different pressure references or when calibrating pressure measurement devices.