A system for measuring a solution pH includes a potentiostat with a working electrode made of an electro-conductive solid polymer transducer, an input to receive the potential to be applied between the working electrode and a reference electrode, and an output to transmit a signal representative of the current flowing between a counter electrode and the working electrode, the three electrodes being immerged into the solution. The system further includes a digital processor connected to a digital to analog converter for generating the potential to be applied between the working and the reference electrodes; and to an analog to digital converter for receiving a digital value representative of the current. The digital processor is adapted to modify the potential to maintain the current inside a predetermined range such that the potential is representative of the solution pH when the current is inside the predetermined range.