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”.
The guardian of time
In a mechanical watch, the oscillator is the guardian of time. Comprising a hairspring and a balance wheel, this regulating organ determines the precision of the watch by the regularity of its oscillations. Rolex deploys exceptional know-how and resources to master the design and production of this inseparable and strategic couple. Conventional oscillator hairsprings are made of ferromagnetic alloys, leaving them vulnerable to magnetic fields and shocks.
After five years of research, Rolex created the blue Parachrom hairspring. Crafted from a paramagnetic alloy, it is unaffected by magnetic fields and up to 10 times more resistant to shocks. Historically, the unique blue colour of the hairspring has been a sign of prestige reserved for only the most accurate timepieces. Today, it guarantees the accuracy of your Rolex.
Enhanced robustness and reliability
To increase the resistance of its movements to shocks - especially if the watch is dropped - Rolex developed and patented an exclusive and highly efficient shock absorber: Paraflex. First invented in the 1930s, anti-shock devices protect the delicate workings of a watch movement. But although perfected over the years, these tiny shock absorbers have their limits.
In an effort to optimise protection, Rolex engineers, working hand in hand with its watchmakers, developed a system that would increase the shock absorber’s resistance by 50 per cent while preserving the chronometric properties of the balance wheel. Following extensive shock testing and laboratory measurements, the Paraflex was introduced in 2005, and the new geometry of the shock absorber springs is now an exclusive signature of Rolex movements.
The key to time
Have you ever wondered why a mechanical watch goes “tick-tock”? The ticking is produced by the escapement, a strategic part that plays a key role in
the movement’s measurement of time. “Tick”: a tooth of the escape wheel locks against one of the pallets. Then, released by the sweep of the oscillator, the pallet fork lets the wheel “escape”. The wheel continues to rotate and locks against the second pallet: “tock”.
The pallet fork is synchronised by the alternating movement of the oscillator. It continues its infinite pendular beat against the oblique teeth of the escape wheel precisely 28,800 times every hour – 14,400 “ticks” and 14,400 “tocks”. That's 250 million times
a year. We are at the very heart of the Rolex Perpetual movement, where its pace is distilled with chronometric precision.
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.