1. What is the Porosity Formula?

Definition: This calculator determines the porosity of a material based on its bulk density and particle density.

Purpose: It helps geologists, soil scientists, and material engineers quantify the void space in porous materials.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \phi \) — Porosity (unitless, between 0 and 1)
• \( \rho_{bulk} \) — Bulk density (kg/m³)
• \( \rho_{particle} \) — Particle density (kg/m³)

Explanation: The ratio of bulk to particle density gives the solid fraction, and subtracting from 1 gives the void fraction (porosity).

3. Importance of Porosity Calculation

Details: Porosity affects material properties like permeability, strength, and fluid storage capacity. It's crucial in geology, construction, and material science.

4. Using the Calculator

Tips: Enter bulk density and particle density in kg/m³. Bulk density must be ≤ particle density. Results are unitless (0-1 scale).

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between bulk and particle density?
A: Bulk density includes voids between particles, while particle density is the solid material density excluding voids.

Q2: What are typical porosity values?
A: Common ranges: 0.25-0.5 for soils, 0.1-0.4 for rocks, and up to 0.9 for foams.

Q3: Why can't bulk density exceed particle density?
A: Particle density represents the solid material without voids, so bulk density (with voids) must be lower.

Q4: How do I measure bulk density?
A: Measure mass of a known volume of material including its natural void spaces.

Q5: How is porosity different from void ratio?
A: Porosity is void volume/total volume, while void ratio is void volume/solid volume.