Yield monitoring apparatus, systems, and methods

A method of calibrating a yield sensor of a harvesting machine, the harvesting machine having a clean grain elevator with spaced elevator flights, each of the elevator flights carrying a clean grain pile toward a sensor surface of the yield sensor, as each of the spaced elevator flights passes around an upper sprocket, the clean grain pile carried by each of the elevator flights is thrown toward the sensor surface, the method comprising:

• with a grain height sensor disposed in the clean grain elevator, generating a grain height signal corresponding to a detected height of the clean grain pile on each passing elevator flight;
• recording each generated grain height signal for each of the passing elevator flights;
• generating a grain force signal corresponding to a force exerted against the sensor surface by the clean grain pile thrown by each elevator flight against the sensor surface;
• recording each generated grain force signal;
• associating each recorded grain height signal with the recorded grain force signal to which it corresponds by applying a time shift to account for a time delay between a time the grain height signal is generated and a time at which the grain force signal is generated for each one of the respective clean grain piles of each elevator flight;
• summing each of the recorded grain height signals over the predetermine period;
• summing each of the recorded grain force signals over a predetermined period;
• determining a correction factor by dividing the sum of the grain height signals by the sum of the grain force signals over the predetermined period;
• multiplying each recorded grain force signal by the correction factor to generate a corrected grain force signal.