Contrôle officiel suisse des chronomètres (COSC)

Founded in 1973 and still operating from the same facilities, the COSC is a non-profit association acting in the public interest under the Swiss Civil Code. It was created by five Swiss watchmaking cantons (Bern, Geneva, Neuch‚tel, Soleure and Vaud) and by the Federation of the Swiss Watch Industry. It is an amalgamation of laboratories that were established independently of one another in the late 19th century.The COSC awards the title of "chronometer" to each watch whose accuracy and consistency of rate has been demonstrated in 5 positions and at different temperatures over fifteen days of testing at one of the COSC's testing offices. The COSC has testing offices at Le Locle, La Chaux-de-Fonds, Biel, Geneva and Le Sentier.