In the desalination process, seawater is first filtered to remove solids and then combined with acid. The treated seawater is then heated in an evaporator, which can create a scale formation on the hot surfaces of the evaporation equipment if pH levels are too high. Careful monitoring and control of the pH levels with an acid addition can minimize some of the scaling problems that occur in the evaporator. Chlorine is often added as a biocide, but excess chlorine must be removed. ORP measurements can be used to monitor chlorine and control additions of de-chlorination agents. The Rosemount™ 3900 pH/ORP Sensor is ideal for this application due to its rugged design and extended sensor life.