LINEAR AND NON-LINEAR PROPERTIES OF PLATINUM-ELECTRODE POLARIZATION .1. FREQUENCY-DEPENDENCE AT VERY LOW-FREQUENCIES

The polarization impedance of the platinum electrode was measured in physiological saline (0. 9% NaCl) over six decades of frequencies down to 1 MHz. The applicability of H. Fricke's phase angle rule was verified down 10 MHz. The resistive shunt which emerges at lower frequencies as shown to be equivalent to the direct current (dc) impedance of the interface. A K. S. Cole-R. H. Cole (1941) type of relaxation model is proposed to describe the interface behavior over all frequency ranges. Nonlinear polarization measurements have demonstrated the validity of H. P. Schwan's limit law of linearity at very low frequencies.