Abstract: Methods of using multihole and multiwire sensors to measure general and localized corrosion penetration rates near real time are disclosed. The multihole penetration sensor is included of multiple electrodes embedded in individual cavities that are formed by a metal whose external surface is exposed to a corrosion environment. The distance between the inner surface and the external surface of the cavities (wall thickness) varies from one cavity to the other. The electrical resistance or current between each of the electrodes and a common electrode exposed to the same corrosion environment changes significantly when the wall of the cavity in which the electrode resides is perforated by corrosion and the corrosion medium is in contact with the electrode. The corrosion penetration rate is calculated by dividing the wall thickness of the different cavities by the time it takes to penetrate these cavities.

Abstract: An electronic system and software program for multielectrode electrochemical devices; a multielectrode sensor for application in environments containing electrochemically active species; and a multielectrode sensor with a built-in removable large electrode. The electronic system has a large electrode connected to the coupling joint through a resistor element to adjust the potential of the multielectrodes. The electronic system, along with the software program, automatically changes the values of the coupling resistors so that the potentials of a group of electrodes or all the electrodes of a sensor are similar, or automatically disconnects malfunctioning electrodes from the coupling joints to avoid the effect of such electrodes. A variation of the electronic system uses an ammeter or a zero-resistance-ammeter to measure the coupling currents and has resistors between the electrodes and the coupling joint to reduce the transient current produced during switching.

Abstract: A basic electronic unit, an integrated electronic system, and the associated software program for coupled multielectrode electrochemical devices or sensors. The basic electronic unit uses different values of resistors for coupling the multiple electrodes in an electrochemical device or a sensor, so that the effective value of the coupling resistance can be dynamically changed according to the magnitude of the measured coupling current during the measurement. This feature allows the electronic unit to measure a wide range of coupling currents without compromising the principle that the coupled multielectrode electrochemical device simulates the one-piece metal behavior. The integrated electronic system uses several basic electronic units, so that it can simultaneously measure several independent multielectrode electrochemical devices or sensors that have a small number of electrodes, or measure one or more multielectrode devices or sensors that have a large number of electrodes.