New from Rosemount Analytical is the Model 242 âflow-throughâ? inductive sensor for the measurement of process liquid conductivity. Totally obstructionless, the Model 242 is supplied as a pipe-section sensor, particularly useful for monitoring viscous, fibrous or corrosive liquids or slurries. The sensor measures conductivity using toroidal coils wrapped externally around the flow tube, which induce and monitor the eddy currents circulating in the flowing liquid, but are completely isolated from it. Standard conductivity measurement electronics, such as the Rosemount 54eC or 1055 dual channel process analyser, or the 4081T or similar transmitter units with Foundation fieldbus, can be used to provide the external interface to this new sensor.
The Model 242 toroidal conductivity sensor is considerably lighter and more compact than competitive models, and has the distinct advantage of being a complete, pre-assembled unit.
There is no requirement to loosen the housing in order to install this sensor between process flanges, a procedure necessary with some competitive models. The wetted materials consist of a Teflon or glass-reinforced Peek liner, held between end-rings in 316 stainless steel, Hastelloy C, or Carpenter 20, and O-ring seals of EPDM, Viton or Chemraz. For really abrasive applications an alumina liner can be supplied.
