This tab is displayed when you select to show the Physical Units and tolerance Options Dialog and on this tab one can edit thresholds for values such as mass, flows and temperature, needed for precision in calculations.
The user for example, can set the Zero Flow Threshold limit for streams. Any component with flow below this threshold will be considered as ‘zero’ and will not be shown in the composition table of an intermediate or output stream’s i/o simulation dialog, see Viewing and Editing the Simulation Data of Bulk Streams.