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 chronometer is a high-precision movement certified by the COSC, capable of displaying the seconds, tested over a period of 15 consecutive days and nights, in 5 positions and at 3 temperatures by the COSC. Each chronometer is issued with an individual certificate by the COSC which states the serial number of the movement. Mechanical movements must satisfy seven extremely stringent criteria to earn the distinction.
AN EXCLUSIVE CERTIFICATION
Less than 30% 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).