ETA 2824
One workhorse of the ETA mechanical line is the ETA 2824-2, The 2824 is an automatic winding, twenty-five (25) jewel movement, available in four executions or grades: Standard, Elaborated (improved), Top and Chronometer[4]. The key components which differ at the line of demarcation between Elaborated and Top are the barrel spring, shock protection system, pallet stones, balance wheel & hairspring and the regulator mechanism. To illustrate the differences in accuracy garnered by the successive grades, consider the following specifications:
the Standard grade is adjusted in two positions with an average rate of +/-12 seconds/day, with a maximum daily variation of +/-30 seconds/day;
the Elaborated grade is adjusted in three positions with an average rate of +/-7 seconds/day, with a maximum daily variation of +/-30 seconds/day;
while the Top grade is adjusted in five positions with an average rate of +/-4 seconds/day, with a maximum daily variation of +/-10 seconds/day.