Chronograph or chronometer? The video guide

Chapters

1. 0:00Two words people mix up
2. 0:10The chronograph measures time
3. 0:25The chronometer is certified
4. 0:43A fifteen-day exam
5. 0:58From -4 to +6 seconds
6. 1:16Nearly 5% turned down
7. 1:29One, the other, or both
8. 1:52How to tell them apart

Transcript

Chronograph, chronometer. Almost everyone mixes them up. Yet the two words are not about the same thing at all. A chronograph is a function: it measures a length of time. One pusher starts and stops the hand, another sends it back to zero. The small subdials keep the minutes, sometimes the hours. A chronometer is a watch whose precision has been tested, then certified by an official body. In Switzerland, that body is the COSC, which applies the ISO standard three thousand one hundred and fifty-nine. The examination lasts fifteen days. The movement is checked every day, in five different positions, then at eight, twenty-three and thirty-eight degrees. To earn the title, a movement larger than twenty millimetres must not lose more than four seconds a day, nor gain more than six. Sounds like a lot? Six seconds over a day is like seven centimetres over a kilometre. It is no formality. In twenty twenty-five, the COSC issued just over two million certificates, and nearly five per cent of the pieces submitted were turned down. The two words do not rule each other out. A watch can be a chronograph without being a chronometer, a chronometer without a chronograph, both at once, or neither. And even when it is both, the title covers how the watch keeps time: no standard certifies the precision of the chronograph itself. How to tell them apart: pushers on the side and subdials on the dial mean a chronograph. The word chronometer written on the dial means a certified watch. The paper certificate is optional: the brand decides whether to supply it. Discover a whole selection of watches at Montres Outlet.