Interface Level Measurement by using Capacitance Probe

Interface level measurement by using capacitance probe


To know about capacitance probe u must know about the working of a capacitor

A capacitor consist of two parallel plates separated by a dielectric (insulator)

The capacitance of capacitor depends upon the height, distance of the plates and amount of dielectric between the plates

You can vary the capacitance of capacitor by varying dielectric between the plates
This method is used in level measurement

A probe is inserted into the tank containing dielectric liquid and the tank wall is referenced as the 2nd probe

As well as liquid level increase or decrease the capacitance (between probe and wall of the tank) will also increase or decrease

Interface level with the capacitance probe can be also measured

Two liquids having different specific gravity will also have a different dielectric constant therefore by using capacitance probe the probe will measure a interface between dielectric liquid’s level (capacitance) which can be denoted as interface level

NOTE: that capacitance probe must always be 100% submerged with either high, low density liquid or with the both liquids other wise it will measure two interface levels one between air and low density liquid and the other between low density and high density liquid

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