Silo-Weigh Technology

AVT have brought a fresh approach to high capacity silo weighing, emanating from our extensive experience in stress analysis and structural monitoring. Unlike traditional weighing companies, we have a detailed understanding of the behaviour of structures, based on over 20 years’ experience.

While most current retrofit sensors are based on electrical resistance strain gauges, which struggle to provide sufficient stability and accuracy, the Silo-Weigh system uses specially developed ‘low strain’ sensors. These devices are insensitive to moisture, long cable runs and low signal levels. The Silo-weigh system, which is totally non-intrusive, can be fitted without having to stop the process or empty the silo, and has proved to be effective on both steel and concrete silos.

The main error sources in retrofit systems are temperature, differential support deflection and structure interaction (cross talk). Temperature changes in different parts of the structure will affect the sensors to different extents and the magnitude of these errors is usually significantly greater than the required system accuracy.

The accurate measurement of these extremely small and often irregular strains is not as straightforward as it might seem, and many early attempts at strain gauge based weighing systems have given the technique a bad reputation. However we believe our practical and logical approach is effective in minimizing inherent system anomalies, and it is in the handling and post-processing of data where we have been so successful.

After some ten years of ongoing trials and development work, we have developed compensation techniques which are effective in reducing these errors to acceptable levels. Rather than try to utilise standard weighing instrumentation, we utilize a robust multi - channel Control Unit to handle the data. This provides multi-functional capabilities for introducing non-linear calibration factors, combined with individual calibration factors for each silo support if necessary. In parallel, temperature data is used to provide real time thermal compensation. The system can also carry out intelligent data validation and signal conditioning together with data storage for weight trending. A single Control Unit can be expanded to accommodate any number of silos, thereby providing a very cost effective solution for multiple silo applications.