The design of a vibrating level switch for solids must be fundamentally different to the design described for liquids. If two large parallel blades were used on powders or solids it would be too easy for product to build-up and become lodged between the blades causing the oscillations of the switch to stop regardless of product level. For solids applications on products ranging from cornflakes to coal, it is preferable to have only one blade in contact
with the product. This eliminates the potential for bridging between the forks and ensures that the switch does not give false alarms.