Standard Electrical Resistance (ER)
Electrical Resistance (ER) probes and instruments determine metal loss from corrosion or erosion by the electrical resistance method. This method may be used in virtually any environment except liquid metals or some conductive molten salts.
ER instruments directly measure the metal loss on ER probes. Plotting metal loss as a function of time permits corrosion rate to be determined. The slope of the curve represents the average corrosion rate over the selected interval. There are a wide variety of ER probes to match various applications.
In general the ER probes have sensing elements made of the metal or alloy for which corrosion data is required. The probe bodies may be of the same alloy, but thicker, or of a higher, less corrosive alloy.