CORROSION SENSOR, CORROSION MONITORING SYSTEM, AND METHOD OF QUANTIFYING CORROSION

A corrosion monitoring system (110) includes at least one corrosion sensor (100). The corrosion sensor (100) includes a metallic plug (104) having at least one opening, at least one ceramic sheath (106) in the opening of the metallic plug (104), and a plurality of probes (102). Each probe (102) has a central portion with a predetermined cross sectional area extending from the metallic plug (104). The ceramic sheath (106) electrically isolates each first end and each second end of the probes (102) from the metallic plug (104) and the other first ends and second ends. The probes (102) are sized to provide a range of predetermined cross sectional areas of the central portions. Such arrangement permits to extend the lifespan of the system since when one probe has been completely corroded, measurement can be switched to another probe having a higher cross sectional area and which is still operational.The corrosion monitoring system (110) also includes a resistance meter (112) measuring an ohmic resistance for at least one of the probes (102) and a computer (116) determining a corrosion rate by correlating a rate of change of the ohmic resistance to the corrosion rate of the probe (102). The corrosion monitoring system (100) is particularly suitable for real-time corrosion monitoring of components in the hot gas path of turbines.