Concept for a novel grain level measurement method in silos

The grain level in a silo is commercially important. In this work, a novel method is presented to detect the grain level in a silo. Existing methods are generally based on approximations, due to grain dust in the silo. The method proposed here eliminates the effect of grain dust and gives the accurate reading of the grain level. The method is based on the measurements of capacitances of parallel plate capacitive structures, which are designated as level, reference and dust sensors. It is mathematically proved that the method eliminates different factors, which affect the readings. The result of a computer simulation, which demonstrates the performance and limitations of the proposed structure, is also provided. The level is read exactly inside the reference sensor. However, comparing with the total amount of grain in the silo, there is an error of around 7 percent. The amount of this error is dependent on silo parameters and the flatness of the grain accumulation. Indeed, this error is intrinsic to any silo level measuring system due to non-flat grain accumulation.