Frequently, potential measurements of corroding or cathodically protected specimens are desired in environments and under conditions where inclusion of the IR drop from test currents flowing in the electrolyte causes a serious error in the measurements. This is particularly true when relating polarization potentials to current densities. Miniature probes placed very close to the specimen, where they may encounter (or even cause) conditions different from the average of the specimen, or reduction of electrolyte resistivity by additives, inevitably cast doubts over the validity of many investigations and discourage others which might well prove of exceptional value. Bridges which require auxiliary reference electrodes or a high test source potential have been described in the literature, but they have limitations.
This note describes a flexible bridge circuit with a minimum of limitations, which can be readily adapted to almost any kind of instrumentation from simple, manually balanced potentiometers to XY recorders and...
