I was asked this today by a friend, thought I would post it for all.

what makes a watch - pocketwatch - a chronometer?



Manufacturers who pay to submit their movements to the COSC for testing do so because they're confident they will pass, and this confidence comes from knowing the movements are high grade enough in terms of isochronism, (essentially regularity), to easily surpass the testing criteria. They go through this rigmarole to earn the coveted COSC certificate, and the 'Chronometre' caveat on the dial; which in turn, for many, still imparts an extra sense of kudos to the manufacturer and their watches... both within the industry, and out in the watch buying world. I'm certainly very fond of my two Chronometres, and it seems most WIS are also quite taken with this particular 'badge' of honour.

Q: What’s the difference between a chronograph and a chronometer?

A: A chronograph is a name given to a multifunction sport watch with a stopwatch function. Most have two or three sub-dials, or mini-dials, for measuring minutes and hours.

A chronometer, on the other hand, is a precision watch that has been rigorously tested by the Control Officile Suisse de Chronometers (COSC), an official watch testing laboratory in Switzerland, to keep accurate time in various temperatures and positions over a 15-day period. The watch must lose no more than five seconds per day in order to be designated a chronometer.

Hi Andy, As a Hampden collector I am the happy owner of several Hampden chronometers. To my knowledge they were never submitted for COSC certification but I seem to see the chronometer label on many watches from Europe that never were certified and many are not particularly high grade watches. I also notice that in some parts of the world chronometer seems to mean watch.Not all that surprising since chronos means time and meter means measure (roughly). The same does not seem to apply to the term chronograph. I find it interesting to note how the meaning of words changes over the years and why that did not happen to the word chronograph I do not know.