BY HARLAN CHAPMAN-GREEN
A few days ago, an announcement was made that could impact the wider world of mechanical watchmaking. Since 1973, COSC, the Contrôle Officiel Suisse des Chronomètres (Official Swiss Chronometer Testing Institute), has been providing the watch industry with independent accuracy certification, giving consumers something tangible they can understand that speaks for the precision of their timepiece. On the 12th of February, COSC announced the launch of a new certification scheme, the “Excellence Chronometer”.
COSC’s requirements for chronometers have historically been quite stringent. Although there are a few factors the watches need to meet, the main focus is a movement’s average daily rate – that is, how many seconds it gains or loses over 24 hours. For the standard COSC chronometer, the tolerance is -4s to +6s per day. However, modern manufacturing techniques mean that many watches can meet that requirement quite easily. Should a brand want to, they can now submit their watch for the Excellence Chronometer certificate, which supplements the COSC chronometer certificate rather than replacing it.
For the standard chronometer, COSC examines mechanical movements for their accuracy before they are cased by the manufacturer. Because the new Excellence Chronometer enhances the standard one, watches destined to be tested as Excellence Chronometers will still undergo the standard 15 days of testing uncased, where the average daily rate must stay within -4s to +6s per day. They will then be returned to the manufacturer for casing, and a robot simulating daily wear will be used for five days. The average daily rate during this period must fall within -2s to +4s per day.
The watches are then submitted to a magnetic field of 200 Gauss to ensure resistance to the low-powered magnetic fields we might encounter in our daily lives. For context, that’s equal to 20,000 microtesla (µT), the unit most commonly used when discussing everyday magnetic fields. By contrast, the Earth’s static magnetic field, as measured in the UK, measures around 50µT, or 0.5 Gauss. Even an induction hob – widely cited as a strong domestic magnetic field source – emits only a few microtesla in normal use. At the other extreme, a “typical” MRI machine’s magnet is rated at 3 tesla, which is 3,000,000µT, or 30,000 Gauss.
The final step in the Excellence Chronometer testing is to ensure the manufacturer’s claimed power reserve is accurate; if a watch doesn’t meet it, it won’t get the certificate.
All of this sounds like good progress for the watch industry. There are clear intentions to further the reputation of the Swiss watch industry and the watch industry at large by making a new certification with tougher standards. Perhaps the biggest change of all of these is that the testing for the Excellence Chronometer occurs when the watch has been cased up, which is as close to simulating real-life wear as you can get. I expect it is also a pushback against in-house testing. Manufacturers like Rolex and Omega continue to offer their own certification, such as Rolex’s “Superlative Chronometer” and Omega’s METAS-certified “Master Chronometer”. Although the Excellence Chronometer doesn’t have the stringent requirements of +/-2 seconds deviation per day like the Superlative Chronometer or the Master Chronometer’s 15,000 Gauss resistance requirement, it does allow more manufacturers to prove their mettle in watchmaking. We should also remember that there are complex watches that are also COSC-certified chronometers, such as Chopard’s L.U.C Perpetual T tourbillon watch, which is more complex than most of Rolex’s and Omega’s offerings. I imagine then that the Excellence Chronometer is something Chopard and makers of complicated mechanical watches will be interested in.
Of course, the Excellence Chronometer is an optional extra, but I expect more manufacturers will take on the challenge. Will it impact in-house certification? I doubt it. The brands that do in-house certification will undoubtedly have spent hundreds of thousands at least, on restructuring their manufacturing processes to incorporate the testing phases, although we should bear in mind that we can only rely on the manufacturer itself to tell us that its watches are accurate. At least with COSC, it’s an independent testing body doing the examinations. The Excellence Chronometer could draw new brands that fancy a challenge. COSC says that it will continue ensuring it’s ready to deploy the new certification, and will officially unveil it at Watches & Wonders Geneva in April. Starting in October, brands will be able to send their watches for Excellence Chronometer testing, with the first Excellence Chronometer-certified watches coming as soon as possible after that.
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