Process Instrumentation for the Measurement and Control of Level

The use of capacitance-type measuring methods is described for indicating and controlling the level of liquid, granular or powdery materials. The purpose of this paper is twofold. First, it summarizes commercially available devices for various requirements (on-off control, proportional indication, proportional control, or combinations of these). Second, it formulates a method of analysis enabling users to choose suitable probe designs for specific applications.