END POINT DETERMINATION FOR CHEMICAL CLEANING PROCESS

An on-line, real-time method of determining the end of a cleaning process for an equipment being cleaned by a cleaning solution and flowing through the equipment in a feed path, comprises the use of two electrodes having different electric potentials in the feed path of the cleaning solution. The voltage difference between the electrodes is measured and is plotted against time to produce a characteristic curve. When the voltage difference remains constant, this corresponds to the presence of a constant percentage of iron in the solution, which indicates the end of the cleaning process. platinum and iron electrode combination can be utilized in an acid cleaning solution to practice the invention.