Master Chronometer

Definition

Omega's certification since 2015, issued by METAS, the Swiss Federal Institute of Metrology, for the cased watch rather than the bare movement. A Master Chronometer must first be a COSC chronometer; the watch is then tested against eight criteria, including running correctly while exposed to a magnetic field of 15,000 gauss, a rate of 0 to +5 seconds a day measured over four days in six positions, and a power reserve and water resistance that match the claim. Every watch is tested, not a sample. The 8900 of the 2015 Globemaster was the first; the 8800, 8700, the 9900 chronograph and the Moonwatch's 3861 followed, and 694 watches in this library carry the certificate.