Rf principle based level sensors have been designed based on the considerations discussed and various other aspects. Spectec's Rf level sensors are highly reliable for use with materials that are conductive or nonconductive, granular or slurries, fines to large particles and contaminated or pure liquids at varying temperatures and pressures
Spectec's Rf level switch series FLRF 20 models work on Rf principle. Independent but identical low power Rf signals equal in frequency, phases, amplitude and wave shape generated in the electronic controller are provided to active and shield sections of the sensing probe, whereas, the reference ground of electronics is connected to the vessel shell. The signal provided to the electronic controller while the signal applied to the active section varies with change of media between probe and the vessel shell/wall.
The suspended dust or material in-transit do not have cohesive inter-particle contact, and have no role in this Rf Principle of level sensing. The variation in active signal is compared with the constant shield signal. At a predetermined value of difference a relay is actuated to obtain potential free relay change-over contacts for further alarm and control.
