What is the purpose of the chronometer certification?

The purpose of the chronometer certification is to guarantee the accuracy of the watch movement. This certification, primarily awarded by the Contrôle Officiel Suisse des Chronomètres (COSC), involves rigorous testing to ensure that a watch keeps time within specific tolerances. A watch that receives this certification demonstrates a high level of precision, often achieving an accuracy of within -4 to +6 seconds per day.

Unlike water resistance ratings or validation of materials, which pertain to the durability and construction of the watch, chronometer certification specifically focuses on the temporal performance of the movement. This distinction highlights the importance of accuracy in performance for horological experts and enthusiasts, reflecting a commitment to quality and reliability in the watchmaking industry.