During the construction of major highway and railway projects, particularly in tunnel construction, huge quantities of excavation occur. When the mining takes years, it is worth to use giant conveyor belt systems. Such installations may be several kilometers long and have a capacity of more than 1000 tons/hour. These belts are of course fully automated. This creates the risk that the excavation blocks the hopper at the transfer points from one band to another.For permanent monitoring of the transfer stations robust ultrasonic sensors are used. They look down into the hopper and report if the level exceeds a certain value. The plant will then be slowed or stopped accordingly. Suitable ultrasonic sensors from Waycon Positionsmesstechnik are those of the UN series. The outstanding feature of the UN series is its high acoustic power combined with small sensor size. This is achieved with new optimized SONARANGE transducers, working at high electrical voltages. Thus also small, moving and poorly reflecting objects can be safely detected. Moreover the sensors work also under high contamination. With a length of <40mm the UN sensors are the most compact ultrasonic sensors for such high measuring ranges.
