The Rosemount Models 225, 226, and 228 are toroidal (inductive) conductivity sensors consisting of two wire-wound metal toroids overmolded with corrosion-resistant PEEK or Tefzel. When immersed in conductive liquid, the transmitter coil induces a current in the solution, which induces another current in the receiver coil directly proportional to conductivity.

Toroidal sensors are ideal for highly conductive liquids up to 2 S/cm (2,000,000 µS/cm). Minimum conductivity ranges from 50 to 500 µS/cm depending on toroid size and windings. Measurement is insensitive to flow rate or direction. The center hole must remain open.

Model 225 is a sanitary sensor with 2" tri-clamp fitting for pharmaceutical and food/beverage applications, available in glass-filled/unfilled PEEK and unfilled Tefzel. Temperature limits: 230°F (110°C) for glass-filled PEEK and Tefzel, 266°F (130°C) for unfilled PEEK. Pressure: 200 psig (1480 kPa abs). Meets 3A sanitary and FDA/USP Class VI standards.

Model 226 features a large bore PEEK design resistant to plugging from high suspended solids, making it ideal for viscous or fibrous liquids. Temperature: 248°F (120°C) max, pressure: 295 psig (2135 kPa abs).

Model 228 is a submersion/insertion sensor for dirty, corrosive samples. Available in glass-filled PEEK and filled/unfilled Tefzel. PEEK versions: 248°F (120°C) standard or 392°F (200°C) high temp option, 295 psig. Tefzel: 248°F (120°C), 200 psig. Features ¾" MNPT or 5/8" UNC connection. Retraction assemblies allow removal without process shutdown.

All sensors include integral RTD for temperature compensation. Maximum cable length 200 ft (61 m). Compatible with most Rosemount analyzers.