The copper coulometer is a one of the common application of the Copper-Copper sulfate electrode. Such a coulometer consists of two identical copper eletrodes immersed into the slightly acidic pH-buffered solution of the copper(II) sulfate. Passing of the current through the element leads to the anodic dissolution of the metal on anode and simultaneous deposition of the copper-ions on the cathode. These reactions have 100% efficiency over a wide range of the current densities. Amount of the quantity of electricity passed through the cell can be easily calculated by mass changes of any of the electrodes:
,
where Q-quantity of electricity (coulombs); 
-mass changes (gr); F-Faraday constant (96485);