The Rosemount 397 pH Sensor / ORP Sensor offers high performance pH and ORP measurements in aqueous solutions with high suspended solids. The pH/ORP sensor features a large area, polypropylene reference junction for maximum resistance to process coatings generally found in harsh, dirty and high solid applications. In addition, the secondary helical reference pathway serves as added protection from poisoning ions. The Rosemount 397 pH/ORP Sensor is specifically designed for use with the Quik-Loc Kit and is only available without an integral preamplifier.