For the open porosity the best method I can suggest is mercury porosimetry. For the closed porosity you can roughly say 100-96 %.

Dear Fatih,

Thank you for your suggestion. I have heard about using mercury porosimetry to measure the porosity, but unfortunately my laboratory does not have that device presently. Thats why I try to use BET to but I don't know whether BET will give me accurate porosity (especially closed porosity) of my sample.

I answered your question at the wrong place, as you had another similar question. Please have a look there.

Alain

Thank you, Sir! I have seen your answer :)

Archimedes technique is the most acurate technique but temperature (and corresponding water density) should be controlled. The technique is efficient up to 99%. At this level error can arises from the theoritical density. An accurate measurement of the unit-cell parameters and a picnometry control of the effective bulk density are welcome.

I agree with Prof. Philippe Colomban.

Also note that Archimedes method allow you to obtain open and close porosity...

If your sample have a perfect shape (cube, cylinder, etc) you can also obtain the porosity by geometrical measurements, but do not forget thar this method have more error than the Archimeds technique.

Because you have produced a relatively fully dense material, I think your sample has totally 4% closed pores, based on Archimedes technique.

Dear Son Thanh Nguyen,

I am working on full dense ceramic,too.I have problem with measuring saturated weight for density.I try to remove surface water with a wet tissue, but the number that the scale shows is changing continuously, the water is probably  evaporating.Could you please help me how can I measure saturated weight ?

Please share the accurate Archimedes method for density measurement.

Thank you.

Dear Umar Ali:

Answering to another question I gave a few experimental clues on determination of the density of bulk glass samples based on the Archimedes principle: https://www.researchgate.net/post/Use_of_Benzene_in_determining_the_density_of_glasses_by_archimedes_principle?exp_tc=tprc