Measurement of permittivity of some biological solutions at frequencies below 1 MHz

Two sets of bridge equipment which operate in the frequency ranges 1-17 kHz and 100 kHz-1 MHz, respectively, are described. The main emphasis is on the former for which a new detector was designed. The apparatus was used for measuring the capacitance and conductance of aqueous biological solutions. Several theoretical techniques for calculating the dielectric constant of the solution from these two parameters are discussed together with the relative merits of each method. The results obtained for glycine, diglycine, alanine and urea, none of which had been previously measured at these frequencies, are compared with the extrapolated values from previous work in the microwave region. In no case was an intermediate dispersion region indicated.