Conductivity is measured by determining the amount of current that can be carried between two electrodes by a known amount of liquid. To determine the amount of current that will flow through a “known amount of liquid”, the volume between the two electrodes must be exact. This precise volume is known as the Cell Constant. The cell constant is a multiplier constant specific to a conductivity sensor. The measured current is multiplied by the cell constant to determine the electrical conductivity of the solution.  The cell constant, known as K, refers to a theoretical electrode consisting of two 1 cm square plates 1 cm apart. A cell constant has units of 1/cm (per centimeter), where the number refers to the ratio of the distance between the electrode plates to the surface area of the plate.