Analysis of the most common defects associated with the manufacture of ceramic tiles for floor and wall covering has shown that the said defects can be directly correlated to the porosity of the tiles before firing, to the fluctuaton of this porosity during the manufacturing process and to its nonhomogeneous distribution within the tiles. Various difficulties can be encountered in direct measurements of porosity, thus, for a rapid and reproducible check on the variable of condensation of ceramic tiles, it is more convenient to measure apparent density, which is directly linked to porosity.
New Experimental Method Measuring Apparent Density of Ceramic Tiles: Technical and Applicational Aspects / Amoros Albaro, J.; Blasco Fuentes, A.; Manfredini, T.; Pozzi, P.. - In: CERAMURGIA. - ISSN 0045-6152. - 17:1(1987), pp. 4-8.