The official Swiss Chronometer Testing Institute that puts every chronometer watch through a rigorous, 15-day testing procedure to verify the watch's precision.

Controle Officiel Suisse des Chronometres [Official Swiss Chronometer Testing Institute].

is the Contrôle Officiel Suisse des Chronomètres (Swiss Chronometer Control Board). They are the official Swiss agency that certifies all watch movements that bear the internationally recognized and protected status of "Chronometer." Also see Chronometer and the section on Accuracy.

Abbreviation of "Contrôle Officiel Suisse des Chronomètres," the most important Swiss institution responsible for the functioning and precision tests of movements of chronometers (s.). Tests are performed on each individual watch at different temperatures and in different positions before a functioning bulletin and a chronometer certificate are issued, for which a maximum gap of -4/+4 seconds per day is tolerated.

The Swiss Official Chronometer Control - Consists of three independent control offices.

Contrôle Officiel Suisse des Chronomètres. Switzerland's official rating bureau for chronometers.