The Milwaukee SMS510 ORP Monitor/Controller SMS510 will measure the ORP (oxidation-reduction potential, or REDOX) of your system. It is popular with those who use ozone gas or potassium permanganate as an artificial oxidation agent in fresh or saltwater. It is also popular for measurement of hydrogen rich water. The constant monitoring of the ORP is useful in keeping tabs on the overall health of a system, as a drop in ORP often precedes visual or other indications of trouble. The SMS510 ORP Monitor/Controller can be used to control an ozone generator, such as the Red Sea Aquazone Ozone Generator.