The current I (in amperes) flowing in a conductor is directly proportional to the applied electromotive force (in volts) and inversely proportional to the resistance R (in ohms) of the conductor.
I = E/R
The conductivity of a solution (K) is the reciprocal of resistivity (p) which is defined as the quotient of the electric field and the density of the current (flowing the conductivity solution).
The resistance R (in Ὠ) of a conductor of cross-section S (in cm²) and length L (in cm) is given by expression R = p x L/S or 1/R x L/S; thus K = 1/R x L/S where , L/S cprresponds to the ideal cell constant.
The unit of conductivity in the international system in the Siemens per meter . generally used in expressing the electrical conductivity of a solution in Siemens per centimeter or mocrosiemens per centimeter. The resistivity of a solution is expressed in ohm-centimetres (Ὠ cm).
Unless otherwise stated, the reference temperature for the expression of conductivity or resistivity is 25º.