The physical behavior of components manufactured from polycrystalline materials is in many cases directly dependent on the porosity fraction (volume fraction of pores). As examples concerning key properties of technologically-important materials, porosity fraction has been shown to affect (1) the strength, toughness and modulus of structural and refractory materials such as Steel [1], Tungsten [2], SiC [3], Si3N4 [3], and Al2O3 [3], (2) the strength of nuclear fuel materials such as UO2 [4–5]. (3) the thermal shock behavior and strength of porcelain-based ceramics [6–7], (4) the dielectric and elastic properties of piezoelectric materials such as PZT [8], and (5) the critical current density, diamagnetic response, and modulus of superconducting ceramics such as YBa2Cu3O7−x [9–11]. In such cases where physical properties are directly dependent on porosity fraction, the measurement of porosity fraction becomes important in the quality assurance process for the material.