Conductivity definitions and equations

Electrolytic conductivity is the ability of an electrolytic solution to conduct electricity between two electrodes across which an electric field is appHed. Ohm s law, 

V = I R, is obeyed, and the magnitude of the current depends, in part, on the magnitude of the applied potential. The conductance, G, of a solution is expressed in terms of the solution electrolytic resistance. It is measured in reciprocal ohms (mhos) or in the SI unit siemens (S). 

Specific conductance (k) takes into account the area of the electrodes (A) in cm and the distance (1) between electrodes, in cm. Conductance increases with the area of the electrodes but decreases as the distance between the electrodes is 

Equivalent conductance takes into account the concentration of the chemical solution and is defined by the following equation  

Combining Eqs. (4.4) and (4.5) gives the following equation, which relates equivalent conductance to measured conductance, G  

Specific conductance ( ) takes into account the area of the electrodes (A) in cm  

A conductivity detector consists of a detection cell, a readout meter, and the electronics required to measure the conductance and vary the sensitivity setting. The readout for conductance C is given in Siemens (S), or, actually, microSiemens (pS) for solutions that are comparatively dilute. 

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