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

Abstract

The article shows an idealized 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 highlighted in this article were used in the creation of 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.