It will help to write these values out separately. For example, if your question provides Vt{\displaystyle Vt} and Vs{\displaystyle Vs}, you would write: Vt{\displaystyle Vt} = 5. 00 cm^3 Vs{\displaystyle Vs} = 3. 00 cm^3
Using the same values as listed in previous steps, Vt{\displaystyle Vt} = 5. 00 cm^3 and Vs{\displaystyle Vs} = 3. 00 cm^3, we can solve Vt{\displaystyle Vt} - Vs{\displaystyle Vs} = Vp{\displaystyle Vp} to find that Vp{\displaystyle Vp} = 5. 00 cm^3 - 3. 00 cm^3 = 2. 00 cm^3.
It’s important to match the units because porosity is a unitless value that is usually expressed as a percentage. The units from the volume variables will cancel each other out by division. [3] X Research source
Since porosity is often expressed as a percent, once you have found the decimal value, it is common to multiply this value by 100%. Using the same values from the above examples, your equation will look similar to this: Pt{\displaystyle Pt} = 2. 00 cm^3 / 5. 00 cm^3 = 0. 400. If you would like to express that value as a percent, you would multiply it by 100% to yield Pt{\displaystyle Pt} = 40%.
This equation will give you a decimal value for porosity. To express porosity as a percent, simply multiply that decimal by 100%. For example, 0. 41 x 100% = 41%.
Note that transferring the sample from one container to another may affect the porosity by disrupting the material.
You can find pre-weighed steel rings in home improvement stores and online.
