The Rosemount Model 228 is a submersion-insertion type toroidal sensor. Because it measures conductivity by inducing a current, the toroids do not need to touch the sample, but can be encased in plastic. Thus, unlike metal electrode sensors, the Model 228 sensor can be used in corrosive and dirty samples. It is also ideal for measuring high conductivity liquids.
The sensor is available in glass-filled PEEK and in filled and unfilled Tefzel®. The temperature limit is 248ºF (120ºC); although a high temperature (392ºF (200ºC)) PEEK version is available. The pressure limit for PEEK body sensors is 295 psig (2135 kPa abs) and for Tefzel body sensors is 200 psig (1480 kPa abs).
Mechanical and manual retraction assemblies that allows the sensor to be removed from the process piping without shutting down the process and draining the line is also available.
