Electric potential turns out to be one of the most difficult concepts in
students’ learning: its role is not recognized either in electrokinetics or in electrostatics.
In this area the transfer of charge between conductors is explained according to
Coulomb’s law and looking at the same amount of an entity on them as a balancing
factor. Moreover, students’ ideas often imply a lack of awareness about the conservation
of charge. The inclusion of the idea of potential as a magnitude running the
transfer of charge was planned in a vertical path on electrostatics using a strategy
based on simple experiments. The need for repeated quantitative measurements,
with good sensitivity, makes the on-line measure a determining factor
