Design of a Grain Sampling Device for Combines Equipped with a Differential Global Positioning System (dgps) and a Yield Meter

During the last decade much effort has been made on estimating the spatial variation of the grain quality in full-scale field trials exploring the potentials of real-time grain quality measuring systems. This has often been made by hand harvesting within a grid setup. However, when performing full-scale field trials it is preferable to collect the grain sample directly from the grain flow passing the yield meter of the combine. By doing so it will be possible to relate the yield registration directly from the yield monitor with the specific grain sample. A simple and inexpensive grain sampler was developed which required a minimal alteration of the combine itself. The paper describes the developed grain sampling system and how to calculated the positing of a collected grain sample taking combine delay time and the D-GPS receiver offsets into account enabling comparable sampling and yield registrations.