Improved calibration of impedance analyzers for measurements on highly conductive liquids

An improved calibration method for low-frequency dielectric measurements of conducting liquids using an impedance analyzer is presented. It consists o f representing the instrument as an electric quadrupole and performing thre e calibrations over the whole frequency range. These calibrations consist o f short, open, and a reference load whose impedance is similar to that of t he unknown sample. The reference load consists of the sample cell filled wi th an electrolyte with known dielectric properties. This method allows a di fferential measurement of the dielectric properties of the unknown liquid w ith far higher precision than what is possible using the standard calibrati on method. It proved useful for measurements on suspensions of up to 0.8 S/ m conductivity at frequencies down to 10 kHz using the Hewlett Packard HP 4 192 A instrument.