A sensor to characterize particles for the control and monitoring of agricultural or mining processes

The authors introduce a model of a sensor system that can form the basis to measure particle characteristics by analyzing the vibrations caused by their elastic impact upon a thin plate. In this simple sensor model, the impacting particle generates a force pulse that has its shape influenced by the particle radius, density, impact velocity and modulus of elasticity. This force pulse can be estimated by analyzing the plate vibrations as measured by the transducer. A sensor based on this model could provide a number of particle characteristics in real time, and determine size distribution or perform particle discrimination by having a sample of the particle impact upon the sensor. The factors determining the generation of the force pulse and the thin plate´s response to this pulse are discussed. A system model and analysis is then reviewed. Finally some considerations in the design of a sensor are examined.