Resistance bias estimation of a liquid column in a cylindrical conductivity cell with lateral liquid supply

Abstract

Abstract The article shows a physical model of a cylindrical two-electrode conductivity cell with inlet and outlet holes for filling located perpendicular to the cell axis. Based on the finite element method (FEM), the non-uniformity of the current density distribution inside the cell was determined. For a range of geometrical parameters of the cell, the resistance biases of the liquid column with respect to the idealized model—a cell with a uniform current density distribution (without holes) are calculated. A mathematical expression is given that describes calculating the electrolytic conductivity value using the geometrical parameters of a conductivity cell, taking into account the field distortion caused by holes for filling. It has also been found that at the ratio of the cell diameter to the hole diameter D/d ≥ 5, the entire field distortion inside the cell is provided by a liquid column in the holes with a length of only (h ≤ d) mm. Theoretical estimates and mathematical models covered in this article were used to create the primary differential conductivity cell. Structurally, such a cell consists of two tubes of the same diameter but of different lengths, at the edges of which platinized electrodes are placed.