Metrological Prerequisites for Determination of Silage Density Compacted in a Bunker silo using Gamma Rays


  • Sabine Geyer Leibniz-Institute for Agricultural Engeneering
  • Thomas Hoffmann Leibniz-Institute for Agricultural Engeneering


silage compaction, silage density, radiometric measuring device


In order to produce high quality silage feed it is particularly important to appropriately compact the chopped material upon storage. It was the objective of the research to understand the metrological prerequisites for online density measuring, using a radiometric probe.

Caesium 137 with an activity of 37 MBq was used as radiation source in the tests. Source and detector were hovered over the goods to be measured. The number of gamma photons reflected from the goods occurs to be proportional to the density of the silaged goods.

The probe was tested in a compaction test arrangement on chopped grass and maize, as well as on different bulk goods.

It could be shown that radiometric measuring devices are suitable to measure the density of agricultural goods, particularly ensiled goods, using back-scattering. The measuring built the basis for the development of a probe which shall be deployed on horizontal silos in the future.






VI-Postharvest Technology and Process Engineering