that seems implausible to me, for two major reasons:
1. you're suggesting that the machine has a zero percent false positive rate, which I believe given the circumstances is physically impossible. for this type of machine, there must necessarily be some increasing function relating false positive to true positive rate. perhaps doubling true positives from (making up some numbers) 0.0001% to 0.0002% only wastes 0.01% of the available grain, but either way, I refuse to believe that increasing the true positive rate is truly "free".
2. you're effectively stating that the grain processors take out most of the bad grain, then dump it back in. given that the allowable percentages of "bad material" are (as far as I know) quite low, I don't really see why they would bother reducing the amount thrown away from, say, 0.0001% to 0.00008% to save that tiny amount of money.
1. you're suggesting that the machine has a zero percent false positive rate, which I believe given the circumstances is physically impossible. for this type of machine, there must necessarily be some increasing function relating false positive to true positive rate. perhaps doubling true positives from (making up some numbers) 0.0001% to 0.0002% only wastes 0.01% of the available grain, but either way, I refuse to believe that increasing the true positive rate is truly "free".
2. you're effectively stating that the grain processors take out most of the bad grain, then dump it back in. given that the allowable percentages of "bad material" are (as far as I know) quite low, I don't really see why they would bother reducing the amount thrown away from, say, 0.0001% to 0.00008% to save that tiny amount of money.