On the reliability of impedance and admittance data measured with limited bandwidth at an object that varies with time, the dropping mercury electrode, also complicated by shielding effects, in particular

Abstract

The consequences of the presence of a sluggish tuned amplifier in an a.c. bridge used for measurements at a dropping mercury electrode are discussed. Also a digital simulation is made of the response of a network analyser with limited bandwidth. In order to explain the experimental results the drop size dependence of the shielding of the mercury drop is treated in a semi-quantitative way. These consequences appear to be minor under circumstances that apply to the way double layer capacitances are usually measured but in the study of electrode kinetics errors are likely to be introduced.