As potash material proceeds through the cleaning and grinding process, it is collected in production bins at various points. In the sizing process, material that is over- or undersized is recirculated for additional processing. Oversized material may be reground, while undersized material may be sent to the compaction area to become granular potash. Very fine powder is sent to the crystallization area to be made into a liquid or a finer powdered fertilizer. In production and sizing bins, the level may change quickly as the silos empty and refill, making a responsive level measurement critical to determine adequate supplies for production. In addition, the material is very dusty, making measurements difficult.