Part I. Design and construction of a potentiostat for a chemical metal-walled reactor

A non-isolated potentiostat suitable for the determination of electroactive species in electrically grounded metal-walled reactors is described. In th ese reactors, due to the large area of the container, the rest potential of the solution is virtually constant and cannot be controlled by immersing a relatively small counter electrode connected to a conventional potentiosta t. Electroanalytical methods, therefore, can be performed in reactors only with an electrically well isolated potentiostat connected to a floating exc itation signal generator and data processor. The non-isolated 'grounded cou nter electrode' potentiostat offers a better solution; the metallic contain er serves as a counter electrode and the potential of the working electrode is adjusted to the sum of the excitation signal and the potential of the r eference electrode located near the working electrode. This approach is als o very useful in systems containing shielded electrodes whose potentials ca nnot be controlled by conventional multi-electrode potentiostats. (C) 2000 Elsevier Science B.V. All rights reserved.