1. What is a PSI to PSIG Calculator?

Definition: This calculator converts absolute pressure (PSI) to gauge pressure (PSIG) by subtracting atmospheric pressure (14.7 psi).

Purpose: It helps engineers, technicians, and DIYers convert between absolute and gauge pressure measurements commonly used in various applications.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

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

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

3. Importance of PSI to PSIG Conversion

Details: Proper pressure conversion ensures accurate measurements in systems like pneumatic tools, HVAC systems, and industrial processes where gauge pressure is typically used.

4. Using the Calculator

Tips: Enter the absolute pressure (PSI) value. The calculator will automatically subtract 14.7 psi to give you the gauge pressure (PSIG).

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between PSI and PSIG?
A: PSI (absolute) includes atmospheric pressure, while PSIG (gauge) measures pressure relative to atmospheric pressure.

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

Q3: Can PSIG be negative?
A: Yes, when absolute pressure is less than atmospheric pressure (14.7 psi), resulting in vacuum conditions.

Q4: When would I need this conversion?
A: When working with equipment that displays absolute pressure but you need gauge pressure readings, or vice versa.

Q5: How does altitude affect this calculation?
A: At higher altitudes, atmospheric pressure decreases, so you would subtract less than 14.7 psi for accurate gauge pressure.