The low maintenance Rosemount 397 pH/ORP sensor offers long life and high performance in pH and ORP measurements in aqueous solutions with high suspended solids. The sensors are housed in a highly chemical resistant polypropylene body and is completely sealed with EP (ethylene propylene) to eliminate process intrusion. Sensors feature 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 pathway² serves as added protection from poisoning ions. The Rosemount 397 sensor is specifically designed for use with the Quik-Loc Kit and is only available without an integral preamplifier.