Enter the reflection coefficient and the density of the porous material into the calculator to determine the absorption coefficient. This calculator can also evaluate any of the variables given the others are known.

## Porous Absorber Formula

The following formula is used to calculate the absorption coefficient of a porous absorber.

α = 1 - (R + 1)^2 / (R + ρ^2)

Variables:

- α is the absorption coefficient R is the reflection coefficient ρ is the density of the porous material

To calculate the absorption coefficient of a porous absorber, add 1 to the reflection coefficient and square the result. Then, square the density of the porous material and add it to the reflection coefficient. Divide the first result by the second result, and subtract the quotient from 1.

## What is a Porous Absorber?

A porous absorber is a type of material that is capable of absorbing sound waves. It is characterized by its porous structure, which allows sound waves to penetrate into the material and get trapped, reducing the amount of sound that is reflected back. This makes porous absorbers effective for soundproofing and noise reduction applications. Common examples of porous absorbers include foam, fiberglass, and certain types of fabric.

## How to Calculate Porous Absorber?

The following steps outline how to calculate the absorption coefficient (α) for a Porous Absorber using the given formula:

- First, determine the reflection coefficient (R).
- Next, determine the density of the porous material (ρ).
- Next, substitute the values of R and ρ into the formula: α = 1 – (R + 1)^2 / (R + ρ^2).
- Finally, calculate the absorption coefficient (α).
- After inserting the variables and calculating the result, check your answer with the calculator above.

**Example Problem:**

Use the following variables as an example problem to test your knowledge:

Reflection coefficient (R) = 0.6

Density of the porous material (ρ) = 0.8