Home
Back
PSIA to PSIG Formula:
| From: | To: |
The PSIA to PSIG conversion calculates gauge pressure from absolute pressure by subtracting atmospheric pressure (14.696 psi at sea level). This conversion is essential in various engineering and industrial applications where pressure measurements are required.
The calculator uses the PSIA to PSIG formula:
Where:
Explanation: Gauge pressure represents pressure relative to atmospheric pressure, while absolute pressure includes atmospheric pressure. The conversion accounts for this fundamental difference.
Details: Accurate pressure conversion is crucial for engineering calculations, process control, safety systems, and equipment specifications where pressure measurements must be correctly interpreted.
Tips: Enter absolute pressure (PSIA) value in pounds per square inch absolute. The value must be greater than 0 and greater than atmospheric pressure for meaningful results.
Q1: What is the difference between PSIA and PSIG?
A: PSIA measures pressure relative to absolute vacuum, while PSIG measures pressure relative to atmospheric pressure. PSIG = PSIA - atmospheric pressure.
Q2: Why is 14.696 used in the conversion?
A: This represents standard atmospheric pressure at sea level (14.696 psi or 101.325 kPa), which is the reference point for gauge pressure measurements.
Q3: Does atmospheric pressure change with altitude?
A: Yes, atmospheric pressure decreases with increasing altitude. The 14.696 value is for sea level; adjustments may be needed for high-altitude applications.
Q4: When should I use PSIA vs PSIG?
A: Use PSIA for scientific calculations, vacuum systems, and absolute pressure references. Use PSIG for most industrial applications, pressure gauges, and process control.
Q5: Can PSIG be negative?
A: Yes, PSIG can be negative when measuring vacuum or pressures below atmospheric pressure, indicating suction or partial vacuum conditions.