search
Dial Instruments Pte Ltd
Level Measurement Solutions for Petrolchemical, Pharmaceutical,
Marine & General Industries
 
Subpage :: Masthead
Capacitive level sensors CL (with detector)

Capacitive level sensors CL (with detector)

CLSCL

Description

Applications

Continuous measurement of solids/liquids level and interface level
 

Features

  • Continuous measurement of level and interface of any material
    • Offers interface measurement of two materials with different dielectric constant as well as the level measurement of liquids and solids.
  • No affection from buildup on the pipe
    • The measurement electrode is sealed in a pipe, so buildup on the pipe or electric interference poses no issue.
  • No affection from pressure or chemicals
    • The electrode is sealed in a chemical resistant plastic pipe and isolated from the process. The sensor offers stable operation regardless of the environment in the tank.

Principle of Operation

Principle of Operation  
  • The electrode is suspended from the detector in the pipe using coaxial cable. The cable end is wound on the spool and then connected to an external device through the slip ring.
  • When inductance and the detected capacitance tune to the frequency of the voltage applied from the controller, the parallel resonance circuit resonates, causing the highest high frequency voltage to be applied to the electrode.
  • The high frequency voltage on the measurement electrode varies with the measured capacitance, and so does the output voltage.
  • The reference voltage is adjusted such that the centre of the electrode becomes the zero point, and the bridge circuit is made to output zero at this point.
  • When a voltage (+E or ?E) is applied to the electrode due to level change, the servo motor rotates normally or reversely so that the bridge is always balanced, causing the electrode to rise or fall with the material surface.