Method and apparatus for measuring grain loss in harvesting machines

Claim 1

In an apparatus including detector means associated with a grain handling mechanism in a crop harvesting machine for measuring grain loss from said machine, said grain handling mechanism including threshing means for threshing grain from crop material, separating means for removing threshed grain from said crop material, and cleaning means in flow communication with said separating means to receive separated grain therefrom and clean trash material from said separated grain to create cleaned grain, said grain moving through said grain handling mechanism along a crop flow path terminating at the discharge of said grain from said grain handling mechanism, said crop material defining operating condition parameters affecting the efficiency of said grain handling mechanism to harvest said crop material, the improvement comprising: at least two detector means associated with said grain handling mechanism, each of said detector means being provided at spaced apart locations along the length of the flow path of the crop material through said grain handling mechanism and being operable to measure grain separation in said grain handling mechanism at each said location within the machine and to produce electrical output signals representative thereof; processor means programmed with a plurality of grain loss algorithms against which the output signals are applied to derive therefrom a substantially absolute indication of grain loss at a given instant, said processor means being operable to select one of said algorithms for utilization in response to said operating condition parameters, each said algorithm calculating the absolute indication of grain loss using a ratio of selected said output signals; and a grain flow detector operable to produce signals indicative of the rate of grain flow through said grain handling mechanism, said processor means being programmed to divide the signals derived from said algorithm by the signals derived from the grain flow detector so that the substantially absolute grain loss indication is expressed in terms of percentage.