Sand's electrical parameters vary with frequency

this paper presents the results of two types of test in one kind of sand to obtain resistivity and permittivity values for frequency ranging from hz to mhz. one test involved wave generation at specific frequencies and the other an impulse generator (continuous frequency spectrum). tests were made for three humidity values. the results of both test revealed non-linear performance on test electrode surface. such non-linearity was modelled and eliminated to give the permittivity and resistivity values in frequency domain.