PROJECT TITLE :

Measurement System for Evaluating Dielectric Permittivity of Granular Materials in the 1.7–2.6-GHz Band

ABSTRACT:

The look and therefore the experimental characterization of a waveguide system for complicated permittivity measurements on both solid and granular materials are presented. The proposed system is meant for the dielectric characterization of asphalt concrete and of its elements at frequencies around 2.45 GHz. Therefore, the system provides measurements on granular materials, like mineral aggregates found within the asphalt concrete. A series of experimental tests on reference materials shows, via comparison with a normal measurement system, errors among one%. A theoretical analysis of uncertainty contributions confirms a predicted expanded uncertainty lower than two%. Furthermore, to test the proposed system for dielectric spectroscopy on materials typical of the asphalt trade, measurements were also performed on calcareous and basaltic materials, that are usually used for the production of asphalt. Finally, 3 different dielectric models (specifically, model, Ansoult’s model, and Topp’s equation) were comparatively assessed to spot the foremost appropriate ones in describing the water content and dielectric permittivity relationship for the considered materials.