An electrical resistance method, employing alternating current for measuring corrosion rates, has been developed. This method is based on the fact that when a low voltage, stable alternating current passes through the corrosion specimen, a small AC voltage drop is produced across the specimen. This small voltage drop is amplified and measured. Increases in voltages drop values so measured are directly proportional to the corrosion occurring.
It is shown that this method of corrosion measurement is applicable to systems containing distilled water at room temperature, closed recirculating tap water at temperatures above 170 F, flowing return line condensate, and possibly to tubular material in service. In all of the above applications, corrosion measurements may be made without interrupting the process or system. 2.3.5
