Apparent Porosity Calculator

What is Apparent Porosity?

Apparent porosity is a measure of the open pore volume in a material as a percentage of the total volume. It is an important property in materials science and engineering, particularly for ceramics, rocks, and building materials. Apparent porosity indicates the volume of open pores that can be filled with a fluid, which affects properties such as permeability, strength, and thermal conductivity.

Formula

The formula for apparent porosity is:

\[ \text{Apparent Porosity} = \frac{\text{Open Pore Volume}}{\text{Total Volume}} \times 100\% \]

Where:

• Open Pore Volume = Saturated Weight - Dry Weight
• Total Volume = Saturated Weight - Suspended Weight
• Saturated Weight: Weight of the sample after all open pores are filled with liquid
• Dry Weight: Weight of the sample before saturation
• Suspended Weight: Weight of the saturated sample when suspended in the liquid

Calculation Steps

Let's calculate the apparent porosity for a ceramic sample:

1. Given:
   • Dry Weight = 100 g
   • Saturated Weight = 120 g
   • Suspended Weight = 70 g
2. Calculate Open Pore Volume: \[ \text{Open Pore Volume} = \text{Saturated Weight} - \text{Dry Weight} \] \[ \text{Open Pore Volume} = 120 \text{ g} - 100 \text{ g} = 20 \text{ g} \]
3. Calculate Total Volume: \[ \text{Total Volume} = \text{Saturated Weight} - \text{Suspended Weight} \] \[ \text{Total Volume} = 120 \text{ g} - 70 \text{ g} = 50 \text{ g} \]
4. Apply the apparent porosity formula: \[ \text{Apparent Porosity} = \frac{\text{Open Pore Volume}}{\text{Total Volume}} \times 100\% \] \[ \text{Apparent Porosity} = \frac{20 \text{ g}}{50 \text{ g}} \times 100\% = 40\% \]

Example and Visual Representation

Let's visualize the concept of apparent porosity:

This diagram illustrates:

• The material sample (gray rectangle)
• Open pores (blue circles) that can be filled with liquid
• The apparent porosity is the ratio of the volume of these open pores to the total volume of the sample