most of the problem is we read low in higher yields and high in lower yields, we can be 10% low and 10% high on loads out of same field, I'm sure it does not have A series sensor as there is 3/8" gap clear around sensor, the space above and behind does fill with dirt at times but it has a clean out cut out in the bottom to the bin. we have checked area when clean with same problems, not sure what grain recovery kit is. The strip on top off load bar, not sure if it is on, this could make some sense with grain setting up there, most of the time grain never comes off inspection plate. I feel that with elevator full that not all the grain contact sensor, and with elevator half full all grain hits sensor at a harder rate than it should be