Patent ID: 7508223

Claim:
A method of using multihole corrosion sensor to measure the corrosion penetration rate, comprising: exposing the sensor to the corrosion medium of interest; wherein the sensor has a plurality of electrodes embedded in individual cavities that are formed by one or more pieces of metal of interest and have different values of known effective wall thickness, such that the external surface of the wall is exposed to the corrosion medium, and such that each electrode is electrically isolated from other electrodes and properly sealed, so that it contacts only with the corrosion medium leaking through the wall of the cavity in which the electrode resides after the wall of the cavity is perforated by corrosion; wherein each electrode is connected to a common electrode exposed to the same corrosion medium, such that an electrical path will be formed between the common electrode and the electrode that has contact with the corrosion medium; measuring the electrical signal, from an electrical readout device connected between each electrode and the common electrode, which responds to the perforation of the cavity wall surrounding the electrode; determining the time it takes for the electrical signal to change from the initial state; determining which electrode causes the signal change and the effective thickness of the wall surrounding the electrode; calculating the corrosion penetration rate of the metal, using the effective wall thickness and the time it takes for the electrical signal to change.