Measurement of the low-frequency dielectric properties of colloidal suspensions: Comparison between different methods

A careful analysis of the main factors that affect the low-frequency dielec tric measurements of conducting liquid samples is carried out. The influenc e of the type of the measurement cell, the calibration method, and the type of the instrument used, on the spectra obtained using the variable electro de spacing technique, is investigated. Permittivity and conductivity measur ements in the 10 Hz to 10 MHz range are reported for low (sigma approximate to 0.01 S/m) and high (sigma approximate to 0.7 S/m) conductivity samples, both electrolyte solutions and polystyrene particle suspensions. Two measu rement cells are evaluated: one made of glass currently used at Granada and the other made of acrylic currently used at Tucuman. Two calibration metho ds, the classical Short/Open correction and the quadrupolar technique (simi lar to the Short/Open/Load correction), are contrasted, and two impedance a nalyzers, the HP 4284 A and the HP 4192 A, are compared, (C) 2000 Academic Press.