In most cases it is a good solution to use an oscillating fork sensor for the level control of solids as powders and granulates. The Soliphant is a rugged level limit switch for use in silos containing fine-grained and powdery solids, like washing powders, dyes, chalk, plastic granulates. It is famous for its quick and easy start-up, no wear and long operation. For hazardous areas versions for zone 10 are available.

Another older, but still effective method is the capacitive level measuring. The capacitive level measuring instruments are rugged and easy to use. Their function depends on the dielectric constant of the product and requires this value to be constant for precise measurements. They are available for hazardous area what is essential for polymer granulates because solvent escapes frequently.