Comparative analysis of physical models of two-electrode conductivity cells with end and lateral liquid supplies

This article presents a physical model of a two-electrode conductivity cell with holes for filling located in the electrodes. The study investigates the non-uniformity of the current density distribution within the cell, caused by the presence of these holes. Using the finite element method (FEM), the electrical resistance bias of the cell is calculated and compared to an idealized model - a liquid column with specific geometric dimensions and a uniform field inside. A comparison of the resistance bias values between two models - one with end holes (located in the electrodes) and one with lateral liquid supply - is conducted. The results demonstrate that the resistance bias is highly dependent on the diameter of the holes and is mostly unaffected by their position. In most cases, the resistance bias of the model with holes in the electrodes is 3–6 % lower in absolute value compared to the model with side holes, assuming identical geometric parameters for the cell; meanwhile, the bias signs are opposite for these models.