R.F. Admittance Level Limit Switch

SLA...M series is an admittance based level switch series with RF signal transmission between probe and evaluation unit via a co-axial cable with drain wire having driven shield arrangement to eliminate cable capacitance and drift due to change of cable capacitance with temperature. You can install the evaluation unit even far from the probe. The calibration controls are available in the evaluation unit. A special ten LED dot display/bar display simplifies calibration and indicates material trend in vicinity of the point level.

The SLA...M Series admittance based level switch can be efficiently used to reduce the inventory as the same evaluation unit can be field configured either for High or Low level fail-safe detection. The SLA...M series Ignores build-up of service material between probe, the vessel walls and the coating. The level limit switch uses 3-Electrode technique with driven shield arrangement to achieve high degree of immunity.

The measuring system for this level limit detection tool consists of an evaluation unit and an immune-coat probe that could be mounted either from the top or side of the vessel. The probe comprises sense and shield electrodes electrically isolated from the metallic tank by means of suitable insulators. The sense electrode of the switch and the vessel wall serve as the two electrodes of a capacitor with the service material as the dielectric. A change in material level causes a change in dielectric, which in turn causes a change in admittance of this tank capacitor.