Chronograph vs. Chronometer Watches
A chronograph or a chronometer, what do they both mean? They both start with chrono, which means ‘time”, but they mean different things relating to a watch. One measures short periods of times while the other is a high-precision watch that is officially certified. You can also have a chronograph that is a chronometer. Continue reading to learn more about what each of these mean.
What Is A Chronograph?
A chronograph is one of the most common complications found on a watch. You can read more about the history of a chronograph on our blog, but here’s what you need to know about this watch complication. The watches have pushers to start, stop and reset the time tracker, and registers to read the elapsed time. There are different types of bezels that allow you to track different things, such as a tachymeter or pulsometer. There are also many types of chronograph watches, from a classic chronograph to a flyback chronograph or a split-second chronograph. Learn more about common types of chronographs in our video.
How a Split Second Chronograph Works
Going deeper into a more advanced chronograph, a split-seconds, or rattrapante chronograph has the ability to track two intervals that start at the same time. Imagine a race where runners all start together and want to track one racer with each lap. You would be able to start the chronograph when the race begins, and then stop one of the chronograph hands at the first lap, and the second at the next. You can watch our hands-on review of the Patek Philippe 5370P where Tim Mosso showcases the split-seconds function.
Popular Chronograph Watches
- A. Lange & Sohne 1815 Rattrapante Perpetual Calendar
- Zenith Defy El Primero 21
- Vacheron Constantin Overseas Chronograph
- Omega Speedmaster
- F.P. Journe Linesport Centigraphe
Chronometer: What It Means For Your Watch
A chronometer does not have to be a chronograph. While a chronograph measures time, a chronometer refers to an instrument (a watch) that accurately measures time. To be a chronometer, the watch must pass a variety of precision tests.
A watch is put to a number of internal and external factors once it leaves the manufacture. Gravity, humidity, water, magnetism, lubrication within the movement, and general wear and tear can all have an effect on the watch.
No watch is 100% accurate, but there are standards to which chronometer certified watches adhere to: +6/-4 seconds per day. The COSC Certification is the official Swiss chronometer testing, and it stands for Contrôle Officiel Suisse des Chronomètres.
COSC Certification: Official Swiss Testing Agency
Only watches that have gone through the COSC testing are able to have the word chronometer printed. The testing measures the movement across 15 days and multiple environments to ensure the +6/-4 seconds accuracy. The movements are put to extreme temperatures from around 46 degrees Fahrenheit to 100 degrees and set at different positions.
The COSC tests around 1.8 million watches per year, a small portion of the Swiss watch industry. Every watch that passes through the testing gets a chronometer engraving on the movement.
Does Patek Philippe Have A Chronometer?
Patek Philippe does not submit their watches to COSC certification. Instead, the brand had used the Geneva Seal for their watches, up until 2009. The Geneva Seal still rigorously tests watches, putting them through 12 stages or conditions, and produces a certification at the end. The movements are then stamped with the Geneva Seal. Cartier, Chopard, and Vacheron Constantin are among brands currently using the Geneva Seal.
Since 2009, Patek Philippe has used their own testing and seal, the Patek Philippe Seal. This can be spotted on the movement as the double P. The Patek Philippe Seal puts the watches through stricter tests than COSC. Their watches are set to a standard of -3/+2, a smaller deviance than the COSC certification.
Omega METAS Certification: In-House Chronometer Testing
Omega is a brand that takes COSC certification to the next level and performs its own in-house certification, METAS, giving the movement a dual certification. These secondary tests are performed after the movement has already been COSC certified and allow the watch to be called a Master Chronometer. There are 8 METAS tests and Omega has a digital record allowing owners to look up the testing results.
Popular Chronometer Watches
- Rolex Daytona
- Omega Seamaster Diver
- Rolex Submariner
- Breitling Aviator 8
- Tudor Black Bay Bronze
Looking for a chronograph or chronometer watch of your own? Explore our current selection of chronograph watches or browse all pre-owned watches and keep an eye out for the Chronometer phrasing found on COSC certified watches.