A history of precision
The four simple words Superlative Chronometer Officially Certified engraved on the timepiece's dial mean that the movement of this watch
has endured 15 days and nights of testing by the COSC (Contrôle
Officiel Suisse des Chronomètres), an independent not-for-profit association. To receive COSC certification, a watch must demonstrate extreme precision in a variety of positions and temperatures –
the standard level of quality for every Rolex Chronometer.
Chronometer vs chronograph
A “chronometer” is a high-precision watch, tested for 15 days and 15 nights in different positions and at varying temperatures, and whose performance has been certified by an independent official entity such
A chronograph is a watch equipped with an additional mechanism that makes it possible to measure short periods of time with start, stop
and reset functions. And a chronograph can also be certified as a “chronometer”, which is the case of the Cosmograph Daytona.
The red seal
In 1951, the Federation of the Swiss Watch Industry (FH) decided to enhance the “chronometer” designation by reserving its use exclusively for timepieces having obtained (and no longer “having the capacity to obtain”) a certificate issued by one of the Swiss Official Watch Rating Centres. Abuse of the term was no longer possible. Rolex created a red seal to accompany each watch, with the inscription “Officially Certified Chronometer”.
OF THE PHRASE
Did you know?
"Superlative chronometer officially certified"
Historically, a chronometer could be certified by its own manufacturer,
a process which obviously carried a risk of fraudulent abuse.
To guarantee the quality of its chronometers, Rolex made the choice
to have them officially certified, in spite of the costs and extra time required.
Today, everyone knows that 100 per cent of Oyster Perpetual watches are chronometers. That is what the phrase “Superlative Chronometer Officially Certified" attests to first and foremost.
This inscription can even be considered the symbol of the brand’s tireless pursuit of chronometric excellence.