The Contrôle Officiel Suisse des Chronomètres (COSC) has been a staple of the watch industry for over half a century now, established in 1973. Their independent and neutral testing of watch calibres has been a vital step forward in consumer confidence and horological rigour in a post observatory certification era. While they are by no means the only group to offer this type of service They are the most widely known. They are now introducing a new chronometric standard in their testing, the Excellence Chronometer.
To be clear, this is not a replacement to the standard chronometer certification. It’s instead an expansion of the certification process for movements that attain an even higher standard of performance. The decision to introduce it comes from the fact that as technology improves it’s easier to produce higher quality movements and having a single blanket term ‘chronometer’ doesn’t account for that fact two chronometers might be very different from each other in terms of performance.
Additionally, the original standard was introduced many years ago and the requirements of the modern collector have changed. With a hugely increased number of electronic goods in our lives, magnetic field resistance is more important than ever, so that is accounted for in the new certification. Plus, in this internet age, clarity and accuracy of information are more important than ever so they are adding tests to verify power reserve length (hopefully reducing the number of tech specs where the power reserve states “Approximately”). They also aim to improve their water resistance tests to simulate actual underwater conditions instead of only pressure, although this is a generic aim rather than specific to the Excellence Chronometer standard, it’s just being implemented at the same time.
So, what are the actual requirements of an Excellence Chronometer? Starting with accuracy, watches must now achieve a daily rate of -2/+4 seconds per day, in comparison to the standard -4/+6 seconds per day – reducing the overall variance from 10 to 6. They must achieve an anti-magnetic field resistance of at least 200 Gauss. The power reserve must match the stated value from the brand. These are the three core metrics of an Excellence Chronometer in addition to already passing the tests of a standard chronometer.
In terms of implementation, COSC are currently integrating the new technologies that will be required to their laboratories. Then, in March they will begin pilot testing to validate the procedures. In April they will showcase the new standard as part of discovery events in Geneva coinciding with Watches & Wonders. Then, in October full deployment will begin and you’ll start to see the Excellence Chronometer label hit the boutiques.
More details at COSC.
