a device used to keep a working electrode at desired potential with respect to a reference electrode

an electronic device for controlling the potential or voltage between a reference electrode and a working electrode, the reference electrode and the working electrode both being contained within an electrochemical cell

an electronic instrument capable of imposing electrical potential waveforms across a working electrode relative to a reference electrode

an electronic instrument that controls the electrical potential between the working and reference electrodes of a three-electrode (working, counter and reference electrodes) electrochemical cell at a preset value. It forces the necessary current to flow between the working and counter electrodes to maintain the desired potential, within the limits of the potentiostat.

An instrument for automatically maintaining an electrode in an electrolyte at a constant potential or controlled potentials with respect to a suitable reference electrode.

A potentiostat is a control and measuring device that, in an electrolytic cell, keeps the potential of the working electrode at a constant level respect to the reference electrode. It const of an electric circuit which controls the potential across the cell by sensing changes in its resistance, varying accordingly the current supplied to the system: a higher resistance will result in a decreased current, while a lower resistance will result in an increased current, in order to keep the voltage constant.