Patent ID: 6861853

Claim:
A method of investigating corrosion at a location, the method comprising: providing a mounting unit for two or more electrical contacts, introducing the mounting unit to a replica location, the replica location being a non-corroded replica of the location being investigated, measuring the voltage between the two or more electrical contacts at one or more times, the two or more electrical contacts being in contact with the replica location, introducing the mounting unit to the location being investigated which may have corroded, measuring the voltage between and/or the variation in the voltage between two or more electrical contacts at a first time and at one or more other times, the two or more electrical contacts being in contact with the location being investigated, and passing a current through the replica location at the time of the voltage measurement and through the location being investigated at the time of the voltage measurements, the current being provided by a given source for the various voltage measurements, the voltage measurement for the replica location defining the characteristics for an uncorroded location, and the voltage measurements for the location being investigated indicating the extent of corrosion which has occurred by the time of the first voltage measurement for the location being investigated and/or indicating the progress of corrosion between the first time and one or more of the other times of voltage measurement for the location being investigated.