Business News: Switzerland’s COSC Unveils ‘Excellence Chronometer’ Level Of Certification

This new higher tier will demand three elements for watch brands hoping to achieve the top standard: tightened precision, anti-magnetic resistance, and confirmed power reserve. Under the new process, which will begin pilot testing in March with full implementation expected in October this year, watch movements will first need to pass the ISO 3159 “Certified Chronometer” standard testing regime over 15 days, including accuracy within -4 to +6 seconds per day.  

They will then return to the manufacturer to be cased and journey back to COSC to be subjected to an additional five days of testing. This will include robotic simulation of daily wrist wear for 24 hours, followed by testing where the average daily rate must fall between -2 and +4 seconds per day. The watch is then exposed to a 200 Gauss magnetic field and must maintain its performance. Finally, its power reserve is checked to confirm the manufacturer’s stated specifications.

While the accuracy, anti-magnetic, and power reserve elements are major, it’s also worth underlining the part about the movement being cased for this higher level of certification. The standard COSC certification is done to the movement before it’s installed in a case. With this new Excellence standard, COSC pushes closer to METAS (which Omega uses), Rolex’s Superlative Chronometer spec, and Grand Seiko’s own GS Standard, all of which test an assembled watch (also of note, Rolex does this after the watch returns from COSC as a Certified Chronometer).