The SAS generates the exact same Fisher number as the FSSS so in that sense is a direct replacement of the original instrument, which reportedly is no longer manufactured by Fisher. The SAS works with a touch-screen computer interface and digital electronics to automatically generate data.

HEL says the SAS enables test procedures that can differ from the formal ASTM method. More tests can be performed in a day and calibration of the SAS is now only necessary every few days.