A bridge technique for measuring the permittivity of a biological solution between 1 and 100 MHz

Abstract

Two parallel plate cells have been designed for use with an RF admittance bridge to investigate the permittivity of aqueous solutions of biological interest in the frequency range 1-100 MHz. A simple substitutional technique is used to correct for inductance and any second order effects in the apparatus. The versatility of the apparatus is illustrated by the achievement of +or-0.2 in the permittivity for aqueous solutions of conductivity up to 2.5*10^-2 Omega ^-1 m^-1. The performance of the bridge is demonstrated with results taken on ethane diol and on solutions of human low density lipoproteins (LDL).