A corrosion monitoring system includes at least one corrosion sensor. The corrosion sensor includes a metallic plug having at least one opening, at least one ceramic sheath in the opening of the metallic plug, and a plurality of probes. Each probe has a central portion with a predetermined cross sectional area extending from the metallic plug. The ceramic sheath electrically isolates each first end and each second end of the probes from the metallic plug and the other first ends and second ends. The probes are sized to provide a distribution of predetermined cross sectional areas of the central portions. The corrosion monitoring system also includes a resistance meter measuring an ohmic resistance for at least one of the probes and a computer determining a corrosion rate by correlating a rate of change of the ohmic resistance to the corrosion rate of the probe.