Manometer Calculator

Calculate fluid pressure using manometer readings with Pascal's principle and hydrostatic pressure

Calculate Manometer Pressure

Select the type of manometer configuration

m/s²

Standard Earth gravity: 9.806 m/s²

Pa

Standard atmospheric pressure: 101,325 Pa

Height of liquid column in manometer

Pressure Results

0.00
Gauge Pressure (Pa)
101325.00
Absolute Pressure (Pa)
0.00
Equivalent Height (cm)
13600
Fluid Density (kg/m³)

Formula: P = ρgh

Configuration: Single Column

Pressure Analysis

Example: Mercury Manometer

Industrial Pressure Measurement

Application: U-tube mercury manometer for pipe pressure

Mercury height: 8.0 cm

Water height: 5.0 cm

Mercury density: 13,600 kg/m³

Water density: 1,000 kg/m³

Calculation Steps

1. Mercury pressure: P₁ = ρ₁gh₁ = 13,600 × 9.806 × 0.08 = 10,669 Pa

2. Water pressure: P₂ = ρ₂gh₂ = 1,000 × 9.806 × 0.05 = 490 Pa

3. Net pressure: P = P₁ - P₂ = 10,669 - 490 = 10,179 Pa

4. Result: 10.18 kPa gauge pressure

Manometer Types

1

Single Column

Simple tube attached to tank or vessel

U

U-Tube Open

U-shaped tube open to atmosphere

P

U-Tube Pipe

Connected to pressurized system

Δ

Differential

Measures pressure difference

Key Formulas

P = ρgh

Basic hydrostatic pressure

Pabs = Pgauge + Patm

Absolute pressure

ΔP = (ρ₁ - ρ₂)gh

Differential pressure

h = P/(ρg)

Height calculation

Understanding Manometer Physics

What is a Manometer?

A manometer is a scientific instrument used to measure fluid pressure in gases and liquids. It consists of a uniform diameter glass tube that can be attached to a reservoir, pipe, or used independently to measure atmospheric pressure and pressure differences.

Pascal's Principle

  • Pressure applied to any part of an enclosed incompressible liquid is transmitted equally in all directions
  • Forms the basis for manometer operation
  • Enables pressure measurement through liquid column height
  • Essential for hydraulic system design

Hydrostatic Pressure Equation

P = ρgh

Fundamental manometer equation

  • P: Gauge pressure (Pa)
  • ρ: Fluid density (kg/m³)
  • g: Gravitational acceleration (9.806 m/s²)
  • h: Liquid column height (m)

Note: For differential manometers with two fluids, the net pressure is calculated as the difference between the pressure contributions of each fluid column.

Applications and Design Considerations

Industrial Applications

  • • Pipeline pressure monitoring
  • • HVAC system measurements
  • • Boiler and furnace draft
  • • Tank level indication

Fluid Selection

  • • Mercury: High density, high pressures
  • • Water: Common, safe, moderate pressures
  • • Oil: Special applications
  • • Alcohol: Low-temperature applications

Design Factors

  • • Tube diameter uniformity
  • • Fluid compatibility
  • • Temperature effects
  • • Measurement accuracy