Waste measurements obtained on lint cotton using the Shirley Trash Separator (STS) were compared to those obtained using the standard Shirley Analyzer (SSA). The objective was to determine whether the STS can be used to measure fine trash not captured by the SSA and if the STS can be used to predict total waste content expected using the SSA. Two studies and preliminary tests for a third study were conducted to compare the two machines. Tests showed that visible waste contents were significantly lower with the STS and invisible and total waste contents were slightly lower in the first study but higher in the second study. Preliminary results of the third study indicate a significant temperature rise may have occurred in the STS lint box thereby reducing initial weights of cleaned lint. This would, in turn, inflate invisible and total waste values indicated in studies 1 and 2. Tests showed that weighing the lint after conditioning and using those weights instead of those obtained immediately after lint collection decreased calculated invisible waste quantities substantially. This is more in line with what is expected since the STS was designed to catch what previously went out as invisible waste in the SSA. These tests have shown that the STS can be used to measure fine trash not collected by the SSA.