Dear Anirudh,

As is known, the true porosity is the ratio of the volume of all the voids inside the sample to the volume of the sample itself, and the effective porosity is the ratio of the volume of all interconnected voids to the volume of the sample. Therefore, the true porosity can significantly exceed the effective porosity.

Maybe of some interest for your query: https://www.researchgate.net/post/How_to_measure_the_apparent_porosity_and_bulk_density_of_the_graphite_sample

Dear Anirudh Pai

This is an interesting question. The solid porosity value depends on the instrument used in the measurement. It can be more inaccurately calculated by volumetric or imaging measurements or more precisely by employing mercury intrusion porosimetry. In this last technique, the mercury under high pressure is able to interpenetrate pores up to 0.01 micrometers. But even this technique cannot measure blind pores (not connected to the surface).

Thus, different methods can generate results with a variation of more than 5%, depending on the average size of the pores and their distribution.

Regards,