The Rosemount Model 222 is a flow-through toroidal conductivity sensor engineered for viscous or fibrous liquids where solids accumulation is a concern. Its non-invasive design features a Teflon-lined carbon steel pipe carrying the sample through the toroid opening—no sensor components protrude into the flow path, preventing obstructions and plugging.

The sensor operates by completing an electrical circuit through carbon steel contact rings on either side of the toroids, coupling ionic current in the sample to an electronic current. Available with 1-inch or 2-inch 150 lb or 300 lb raised face ANSI flanges. Conductivity range 500 µS/cm to 2 S/cm with nominal cell constants of 6/cm (1" diameter) or 4/cm (2" diameter). Temperature rating 360°F (182°C) with pressure ratings 125 psig (150 lb flange) or 250 psig (300 lb flange). Wetted materials are Teflon-lined carbon steel with optional 316 stainless steel outer flanges. Insensitive to flow rate and direction. Applications include chemical processing, pulp and paper, mining, and any process with high suspended solids or fibrous content.