The Contrôle Officiel Suisse des Chronomètres (COSC) has announced their intention to introduce a new testing standard for the industry this year that will live alongside the original ISO 3159 Certified Chronometer standard that was established in 1976. The new standard will be called ‘Excellency Chronometer’ and not only will it tighten accuracy tolerances, it will also incorporate magnetic field resistance tests and seek to confirm power reserve claims made by the manufacturer. While steps to implement the new standard are already underway, COSC is aiming to deploy it fully by October of 2026.
A new standard will mean new testing procedures, and in the case of the new Excellency Chronometer standard being introduced. In Certified Chronometer testing, uncased movements are subjected to 15 days of testing according to the seven criteria of the ISO 3159 standard, and this will remain a part of the process. To meet the new Excellency Chronometer standard, the movements will return to the manufacturer for casing, and then face an additional five days of testing and evaluation.
In those five days, the cased movement’s precision will be tested under “semi-dynamic” conditions for 24 hours, which apparently entail the use of a robot to simulate average wrist wear. Once tested, the movement must be accurate to within -2/+4 seconds per day, a tighter standard than the -4/+6 currently required by the Certified Chronometer standard. Additionally, the watch will be exposed to a 200 Gauss magnetic field, after which it must maintain its performance. Finally, the manufacture stated power reserve will be checked and confirmed for accuracy.
In total, this is a welcome set of regulations being added to the COSC standard, and one that should bring some value to brands who choose to subject themselves to it. The benefits are also easy to understand and pass along to the consumer, with the only real question being how much of a premium the Excellency Chronometer will bring to pricing structures.
COSC aren’t the only independent testing body in the game anymore, with METAS getting increased visibility thanks to partnerships with the likes of Tudor and Omega. This new standard will close some of that gap, and look to increase visibility of the organization, not just by way of the new standard itself, but also with the new certificates that will be issued along with it. This will aim to give consumers access to the testing data of their watch, and establish a greater level of accountability as a result.
The Excellency Chronometer standard will be undergoing validation to its procedures throughout the first part of this year, and the new certificates will be introduced at Watches & Wonders in April (as a part of the show’s LAB series). Full rollout of the standard is set to commence by October of this year. COSC