The Double chronograph, also known as a split-seconds chronograph, is a
watch
A watch is a timepiece carried or worn by a person. It is designed to maintain a consistent movement despite the motions caused by the person's activities. A wristwatch is worn around the wrist, attached by a watch strap or another type of ...
that includes two distinct
stopwatch
A stopwatch is a timepiece designed to measure the amount of time that elapses between its activation and deactivation.
A large digital version of a stopwatch designed for viewing at a distance, as in a sports stadium, is called a stop clock ...
mechanisms in order to measure two separate events concurrently and/or comparatively. It is often confused with the
flyback chronograph.
Other names
* Rattrapante chronograph ()
* Split-second chronograph
* Split chronograph
Functioning
A watch with a double
chronograph
A chronograph is a specific type of watch that is used as a stopwatch combined with a display watch. A basic chronograph has hour and minute hands on the main dial to tell the time, a small seconds hand to tell that the watch is running, and ...
has two seconds hands. One hand is superimposed over the other. While one hand moves continuously, the other one can be either stopped, started or reset to zero.
The first push releases both hands. While one continues registering the time, the other hand can be repeatedly stopped. In order to stop and bring both hands to zero a watch has a return pusher. The position of the pusher, controlling the split-seconds function is usually at either 10 or 8 o'clock.
Brief history
The double chronograph was previously called
Fly-back second, but nowadays 'Fly-back second' relates to a chronograph where the timer resets instantaneously without the need to be stopped beforehand, and is to be distinguished from the double chronograph. It was invented in the 19th century by
Adolphe Nicole. During the 1930s, due to a smaller size, the mechanism was able to fit the case of a
wristwatch
A watch is a timepiece carried or worn by a person. It is designed to maintain a consistent movement despite the motions caused by the person's activities. A wristwatch is worn around the wrist, attached by a watch strap or another type of ...
.
In 1923,
Patek Philippe launched into the market its first double chronograph. Today, double chronographs (or rattrapante chronographs) can be divided into two subgroups. One comprises chronographs based on in-house movements of different
watchmaking
A watchmaker is an artisan who makes and repairs watches. Since a majority of watches are now factory-made, most modern watchmakers only repair watches. However, originally they were master craftsmen who built watches, including all their par ...
companies, and the other group contains timepieces based on movements like the
Valjoux
Valjoux (for ''Vallée de Joux'', "Joux Valley") is a Swiss manufacturer of mechanical watch movements, based in L'Abbaye, in the canton of Vaud, Switzerland, located in the Jura-Nord Vaudois district in the Vallée de Joux. It is known prima ...
7750 from ETA.
The group of the in-house movements began with the Venus series of calibers: 179, 185, 189 and 190. These calibers had a rattrapante pusher on the crown, but since 1952 they are no longer in production.
The first split-seconds mechanism based on the ETA-Valjoux 7750 was presented in 1992 at
BaselWorld. Today, this caliber is the main one used in watches with a split-seconds mechanism.
In 2010,
Gallet introduced the first self-winding double chronograph movement, powered by two separate mainsprings.
The Swiss company's in-house manufactured calibre G330 solved the decades old issue of decreased accuracy while utilizing the dual recording feature, a characteristic problem with double chronographs. Besides the longer duration (72 hours) between winds, this increase in available power enabled the G330 to maintain certified chronometer-level accuracy across the full range of functions.
Bibliography
*.
References
{{DEFAULTSORT:Double Chronograph
Watches
Timekeeping components