Centralized level monitoring for gravel silos and material handling processes

At Tiefensteiner Granitwerk GmbH in Görwihl, reliable level measurement in gravel silos was challenged by dust, uneven material surfaces and demanding operating conditions. In addition, the level indication of the previous setup was difficult for operators to interpret, limiting inventory transparency. By upgrading to Micropilot FMR20B 80 GHz radar level sensors and FlexView FMA90 control unit, the company achieved continuous, reliable level measurement and clear visualization across the entire measuring range, even under dusty conditions.

The implemented solution provides stable and continuous level measurement across the entire silo filling range and eliminates the former signal instability. Inventory transparency has improved significantly, as level measurement data is now clear and easy to understand for all operators. The project also demonstrates a straightforward modernization approach for existing setups: a one-to-one replacement using existing wiring, providing clear local visualization and requiring no major system modifications. Following the successful implementation in the silo application, the same measuring concept has already been extended to the crusher, showing that the approach can be scaled to additional process steps with even more demanding conditions such as vibration, dust and rapid material movement.

At Tiefensteiner Granitwerk GmbH in Görwihl, gravel silos are exposed to heavy dust during filling and discharge, as well as varying grain sizes that create uneven material surfaces with filling cones and discharge funnels. In combination with tall silo geometries and long measuring distances, these conditions resulted in unstable measurement performance. The previously installed sensors increasingly lost the echo at higher fill levels, leading to unreliable readings and fluctuating trends. As a result, inventory transparency and reliable process control were limited, particularly under demanding operating conditions. In addition, the unstable analog display made it difficult for operators to clearly interpret fill levels.

A simple start to smarter control was achieved at Tiefensteiner Granitwerk GmbH in Görwihl by implementing a modern radar-based level measurement solution. The control and visualization unit FlexView FMA90 combined with Micropilot FMR20B radar level sensors was selected as a robust and flexible setup for reliable silo level monitoring and transparent inventory visualization. The retrofit was designed as a one-to-one replacement of the previous measurement setup. Existing wiring could be used and the customer did not need to make major adaptations to the surrounding control infrastructure, which was a key factor for modernizing the plant step by step. The 80 GHz radar technology provides stable measurement performance independently of dust, grain size, surface structure or material properties. With focused signal transmission and available 40 mm and 80 mm antenna options, the sensors reliably detect the material surface even in tall silos with uneven filling cones and discharge funnels.

FlexView FMA90 enhances the level sensors and brings every insight into clear view by visualizing level values and trends in a simple and intuitive way. Instead of relying on a fluctuating analog display, operators now benefit from improved inventory transparency and accessibility in daily operation. Previously, personnel had to physically access the silo area by climbing along the conveyor belts. Although level information was also available at ground level via an analog display, it was difficult to interpret and required experience. With the updated setup and local visualization, relevant information is now clearly presented and easy to understand, enabling convenient and reliable monitoring from ground level.

Based on the consistently positive results in the silos, the same concept was also applied to the crusher, where the radar-based setup supports overfill protection through alarm generation. To protect the instrumentation in this harsh environment, the radar level sensor is installed outside the direct danger zone and can be moved aside when large stones need to be removed. This allows reliable monitoring while protecting the instrument from mechanical impact near the crusher.