Level detection in case of bulk solids or powders in a bin/silo can be problematic due to following reasons:
- It is necessary to transform the level into volume and mass for measurement purpose.
- The characteristics of the material under measurement can also pose problem, for example, the material can be either too heavy or very light in weight.
- The solids being measured can be in the form of either minute size powders or outsized having pointed edges.
- Also some materials tend to generate huge quantities of dust while filling and expulsion.
- Sometimes, the materials used can be hygroscopic in nature means they have the tendency to easily absorb the moisture in the air. This moisture then mixes with solids due to which they get clustered inside the vessel resulting in material blockage.
- Unlike all virtual liquids, the bulk solids contained in a vessel do not possess a plane horizontal surface. They generally have an angular surface shape known as the angle of repose which can change according to the fill and discharge settings.
- Besides, the coarser the process material, the more is its probability to cluster, bridge, leave voids and stack up.