A chronograph is a watch with a stopwatch built into it. You press one pusher to start timing, press it again to stop, and press the second pusher to reset. Everything else about a chronograph, the extra hands, the subdials, the scale printed round the edge, exists to serve that one function.
How a chronograph works
A normal watch has hands that never stop. A chronograph adds a second set that only move when you tell them to.
The long, thin hand sweeping from the centre of the dial is usually the chronograph seconds hand. It sits still until you start it. The small subdials count the elapsed minutes, and on larger chronographs the elapsed hours. Running seconds, the ordinary ticking seconds of the watch itself, are often moved to their own small subdial to keep the centre free.
The pusher above the crown starts and stops. The pusher below resets to zero.
What is the scale printed around the dial?
Most often a tachymeter. It converts elapsed time into an average speed over a fixed distance. Start the chronograph as you pass a kilometre marker, stop it at the next one, and the number the hand points to is your average speed in kilometres per hour.
It is a genuinely useful tool that almost nobody uses any more. It survives because it looks right, and because a bezel or flange with numbers on it gives a dial depth and purpose.
Do you need one?
Almost certainly not, in the sense of needing to time things. Your phone does that better.
The honest reasons to buy a chronograph are that it is more interesting to look at, more interesting to operate, and mechanically more ambitious than a two-hand watch. A chronograph movement has more parts and more to go wrong, which is precisely why watchmakers find them satisfying. Pressing a well-made pusher is a small pleasure that repeats every time you wear the watch.
If you want a watch that disappears on the wrist and tells the time cleanly, a chronograph is the wrong choice. Look at Slim Line or Ora Vera instead.
Quartz or mechanical chronograph?
Quartz chronographs are more accurate, thinner and considerably less expensive, because a quartz movement counts intervals electronically. Mechanical chronographs do the same job with a column wheel or cam, a clutch and a set of levers, all of which must engage cleanly the moment you press.
Both are legitimate. The mechanical one is the object you buy because of how it is made. The quartz one is the object you buy because of what it does.
How to use one properly
Reset the chronograph to zero before you start a new measurement rather than stopping and restarting from wherever it sits. Do not leave a mechanical chronograph running for days on end, because the chronograph train is running and wearing the whole time. And do not operate the pushers underwater, even on a water-resistant watch, because that is exactly how water gets in.
Where Claude Bernard makes them
Chronographs appear across the range, most visibly in NEO 1973, where the nineteen-seventies case shapes and coloured subdials suit the layout, and in Dress Code. Every one is Swiss Made and hand-assembled in Les Genevez.
Common questions
What is the difference between a chronograph and a chronometer?
A chronograph is a function, a stopwatch. A chronometer is a certification of accuracy awarded to a movement that has passed independent testing. A watch can be one, both, or neither.
What are the small dials on a chronograph called?
Subdials, or registers. Typically one counts elapsed minutes, one counts elapsed hours, and one shows the watch's own running seconds.
Does using the chronograph damage the watch?
No. It is designed to be used. Leaving it running continuously for weeks adds unnecessary wear, but ordinary use is exactly what it is for.
Why do chronographs cost more?
More parts, more assembly, more adjustment. A mechanical chronograph movement can carry well over a hundred additional components compared with a simple time-only movement.