Many people confuse definitions of chronograph and chronometer. Therefore, a chronometer is a watch that is certified by COSC to be exceptionally precise; a chronograph is a watch that has a stopwatch built into the movement that can be started and stopped independently from the watch`s basic timekeeping. It is used for measuring intervals of elapsed time, for example, sport event times (it also may be called timer).
Louis Moinet invented the first modern chronograph in 1816, as a tool for working with astronomical equipment. First chronographs had only one button, which was coaxial to the winding crown itself. Pushing the button in succession started, stopped and reset the chronograph. But in 1915, Gaston Breitling invented the separate pusher chronograph, and then a few years later the two-button chronograph.
Chronographs were very popular with aviators as they allowed them to make rapid calculations and conduct precise timing. The demand for chronographs grew along with the aviation industry in the early part of the 20th century. As the US exploration of outer space initially involved only test pilots, by order of President Eisenhower, chronographs were on the wrists of many early astronauts. They were able to use the chronograph function to time a critical engine burn despite all onboard computers having failed. Able to recalculate their reentry to earth, they successfully aligned the capsule that resulted in a safe splashdown.
Originally, all chronographs were “monopoussoirs” until Breitling introduced the two-button chronograph in 1923. The difference between a one and two button chronograph is that the one button model cannot measure interrupted time spans.Retour-En-Vol (Flyback Chronograph)
The Flyback chronograph is specially engineered so that when a second button is pushed while the chronograph is running, all the counters reset and immediately start again from zero. This feature was originally designed for pilots where split second accuracy is necessary for precise navigation. Flybacks are the exception, not the rule.Rattrapante (Split-seconds Chronograph)
It’s easy to tell if a chronograph is a rattrapante; it will have three pushers on the case. It also has two second hands on the chronograph, one right on top of the other.