1. What is Gauge Pressure?

Gauge pressure is the pressure relative to atmospheric pressure. It represents the difference between absolute pressure and atmospheric pressure. The formula P_g = ρgh calculates the pressure at a certain depth in a fluid, where ρ is density, g is gravity, and h is height/depth.

2. How Does the Calculator Work?

The calculator uses the gauge pressure formula:

Where:

• \( P_g \) — Gauge pressure (Pa)
• \( \rho \) — Density of the fluid (kg/m³)
• \( g \) — Acceleration due to gravity (m/s²)
• \( h \) — Height or depth of the fluid (m)

Explanation: This formula calculates the pressure exerted by a fluid column due to its weight. The pressure increases linearly with depth and density.

3. Importance of Pressure Calculation

Details: Accurate pressure calculation is crucial for engineering applications, fluid dynamics, scuba diving, hydraulic systems, and understanding atmospheric and oceanic pressure variations.

4. Using the Calculator

Tips: Enter density in kg/m³ (water ≈ 1000 kg/m³), gravity in m/s² (Earth ≈ 9.81 m/s²), and height/depth in meters. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between gauge and absolute pressure?
A: Gauge pressure is measured relative to atmospheric pressure, while absolute pressure is measured relative to a perfect vacuum.

Q2: How does pressure change with depth in water?
A: Pressure increases by approximately 1 atmosphere (101.325 kPa) for every 10 meters of depth in water.

Q3: Does this formula work for all fluids?
A: Yes, but you need to use the correct density value for the specific fluid (water, oil, mercury, etc.).

Q4: Why is gravity included in the formula?
A: Gravity determines the weight of the fluid column, which directly affects the pressure at depth.

Q5: What are typical units for pressure measurement?
A: Pascals (Pa) in SI units, but also commonly measured in atmospheres (atm), bars, psi (pounds per square inch), or mmHg (millimeters of mercury).