What is a chronograph watch

What exactly is a chronograph watch?

One of the various complexities that our watches can add to is the chronograph. This function, which makes it possible to measure relatively short time intervals, is one of the most complex watchmaking movements that exist. But what exactly is a chronograph watch and how does the mechanism work? Allow us to explain.

The history of the chronograph watch

Etymologically, the term chronograph comes from the Greek khrónoswhat "time" means, and gráphôwhat "write" means: A chronograph is used to "write the time".

While the first watches that could be used to measure the duration of an event appeared as early as the 18th century, the real chronograph only became available at the beginning of the 19th century. In 1821 the French watchmaker Nicolas Mathieu Rieussec registered a patent for his new invention: an instrument that could measure the time of the Parisian horse races.

Photo Dominique Cohas - Fondation de la Haute Horlogerie à Genève

He called it the "chronograph with seconds display", later also known as the "ink chronograph". This device basically worked through a rotating dial and a pointer that was equipped with a small reservoir of ink. When the push-button was pressed, the pointer deposited a dot of ink on the dial, recording the end of the interval.

How does a chronograph watch work?

Nowadays the chronograph is a sought-after complexity for wristwatches, which itself did not appear until the beginning of the 20th century. In case you forget, the term "complication" refers to any additional function that serves a purpose other than showing the current time.

Whether manual, automatic or quartz, a chronograph watch has two timing systems: one to display the time, the other to measure the time that elapses from a certain moment. This can be done in seconds, minutes, or even hours.

The timing mechanism is triggered and stopped with a button located on the right side of the case. The count can be reset to zero with a second button.

In this case the central hand, or second hand, is linked to the chronograph function. It enables the user to measure the elapsed seconds, while the regular seconds display is achieved by a so-called "small seconds counter" on the dial. Most chronograph watches also have one or two additional counters: the first for minutes and the second for hours (or tenths of a second on certain models).

Curve-controlled or column wheel chronograph?

For mechanical watches, there is the chronograph with two different control systems: the column wheel system and the cam-driven system.

With column wheels: This system consists of a gear wheel at the top of vertically arranged columns. This starts to turn in one direction when the button is pressed and thus controls the various levers (clutch lever, hammer and brake) when initiating, stopping and resetting the mechanism.

Cam or shuttle drive: Here the levers are controlled by a cam, also known as a shuttle. In contrast to the column wheel, this part does not turn, but rocks. These regular back and forth movements (similar to a shuttle) actuate the levers, which in turn are responsible for various tasks over time.

From a technical point of view, both configurations are equally efficient, although the column wheel is the more common of the two in precision watchmaking.

The different types of chronograph watches

In addition to the traditional chronograph described above, there are three other variants of this movement:

  • The flyback chronograph: originally developed to allow military fighter pilots to save time, the flyback mechanism allows the timepiece to be triggered and immediately restarted with a single push of the reset button.
  • The "Foudroyante" chronograph: The Foudroyante or "jumping second" is a pointer that can stop at fractions of a second (quarter, fifth, eighth and tenths of a second), thus enabling extremely precise time measurement.
  • The split second or double chronograph: This elaborate complication is used to measure intermediate times using a second second hand, the "rattrapante", which rotates in time with the first second hand. If the pusher is pressed, the additional hand stops while the main second hand continues to run. After the time has been noted, the stopped hand can automatically "catch up" with the second hand by pressing the button again.

Chronograph watch or chronometer watch: what's the difference?

The term chronograph watch is often confused with that of the chronometer; however, the difference is in size. While the chronograph is a horological complication, the chronometer is a high-precision time measuring device that has received a test certificate from the COSC (Official Swiss Chronometer Testing Center).

With this certification, the organization certifies that the device meets a series of very strict standards established by a series of 7 technical tests in a laboratory. In particular, these tests evaluate the degree of precision of the chronometer at a temperature of 8 °, 23 ° and 38 ° and in 5 different positions.

Compared to the classic models, a chronograph watch is a multifunctional object that can be very practical in certain situations. Not to mention its unique design, which generally appeals to lovers of watchmaking and complex and sophisticated mechanisms.