"Chronometer-certified” means that the movement of a watch is adjusted to within a tolerance of between -4 /+6 seconds per 24 hours, corresponding to 99.99 % precision. This supreme guarantee of reliability and precision is issued by the Swiss Official Chronometer Testing Institute (Contrôle Officiel Suisse des Chronomètres, COSC), an independent organisation certified by the Swiss Accreditation Service (SAS).
SEVEN STRINGENT CRITERIA
A certified chronometer is a high-precision movement capable of displaying the seconds and that has been tested over a period of 15 consecutive days and nights, in five positions and at three temperatures by an official neutral body (COSC). Each chronometer is unique, identified by a number engraved on its bridges and a certification number given by the COSC. Mechanical movements must satisfy seven extremely stringent criteria to earn the much sought-after distinction.
ONLY FIVE PERCENT QUALIFY
A PRIVILEGED CERTIFICATION
Only five percent of the watchmaking production of Switzerland qualifies for this exclusive certification. The level of reliability and quality reached by L.U.C calibres enables them all to earn chronometer certification from the Swiss Official Chronometer Testing Institute (COSC).