How to Calculate Gauge Pressure

Gauge Pressure Formula:

\[ P_{gauge} = P_{abs} - P_{atm} \]

Gauge Pressure (P_gauge):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Gauge Pressure?

Gauge pressure is the pressure relative to atmospheric pressure. It represents the difference between absolute pressure and atmospheric pressure, commonly used in pressure measurement devices.

2. How Does the Calculator Work?

The calculator uses the gauge pressure formula:

\[ P_{gauge} = P_{abs} - P_{atm} \]

Where:

\( P_{gauge} \) — Gauge pressure (Pa)
\( P_{abs} \) — Absolute pressure (Pa)
\( P_{atm} \) — Atmospheric pressure (Pa)

Explanation: Gauge pressure measures pressure above atmospheric pressure. When gauge pressure is positive, it indicates pressure higher than atmospheric; when negative, it indicates vacuum or pressure lower than atmospheric.

3. Importance of Gauge Pressure Calculation

Details: Accurate gauge pressure calculation is essential for various applications including industrial processes, HVAC systems, pneumatic controls, tire pressure monitoring, and medical equipment calibration.

4. Using the Calculator

Tips: Enter absolute pressure and atmospheric pressure in Pascals (Pa). Standard atmospheric pressure is approximately 101,325 Pa at sea level. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between gauge pressure and absolute pressure?
A: Absolute pressure is measured relative to perfect vacuum (zero pressure), while gauge pressure is measured relative to atmospheric pressure.

Q2: Can gauge pressure be negative?
A: Yes, negative gauge pressure indicates vacuum or pressure below atmospheric pressure.

Q3: What is standard atmospheric pressure?
A: Standard atmospheric pressure at sea level is 101,325 Pa, 101.325 kPa, or 14.696 psi.

Q4: How do pressure gauges work?
A: Most pressure gauges measure gauge pressure by comparing the measured pressure to atmospheric pressure using mechanical elements like Bourdon tubes or diaphragms.

Q5: When should I use gauge pressure vs absolute pressure?
A: Use gauge pressure for most industrial and everyday applications. Use absolute pressure for scientific calculations, vacuum systems, and when working with ideal gas laws.