A Yield Monitor for Combines Based on Volume and Density Measurements

For monitoring the grain yield in a combine harvester a new system was developed and tested. The new monitor determines the volume flow and the density of the grain. The volume flow measurements are carried out with a belt conveyor. The density determination is achieved with a container which is installed on a load cell. This measurement is carried out for a longer period of time and an average is calculated over this measurement period. With it shocks and vibrations which are occurring on a combine are compensated. In most cases the density of the grain could be determined with errors of less than 1 %. When the monitoring system was on a slope (max. 13.1°), there was a major impact of up to almost 10 % error, but due to strong relationships between slopes and deviations (R2 > 97 %) it can be compensated.