What is the difference between a chronograph and a watch

Although these two words are related, they are not the same thing. A chronograph is a watch that has a built-in stopwatch feature , which allows it to measure elapsed time. This feature is referred to as a complication. Chronograph watches typically have two or three subdials that display the hours, minutes, and seconds.

If a watch has a chronograph, it will usually feature a return to zero button, or pusher, on the side of the watchcase. The top pusher will start the chronograph, while the bottom pusher will stop the chronograph.

If a watch is referred to as a chronometer , it has passed intense precision tests over a day period and has obtained an official rate certificate from the COSC , which is the Official Swiss Chronometer Testing Institute. These tests measure the movement of the watch towards a set of accuracy.

If a watch is referred to as a chronometer, it is a superior timekeeper and is very accurate. A watch can be both a chronometer and have a chronograph function. However, they can also be separate. In , Chang Hsiin redesigned the mechanism, recreating the design with mercury instead of water — solving the issue of time being frozen during winter. A German locksmith, Peter Henlein, is widely regarded as the creator of modern timepieces, as he was the first to create pocket-sized timepieces.

From this, he became renowned across the world as nobility and the privileged in society contacted him to commission smaller and more elegantly designed timepieces — which we now know as pocket watches.

Louis Moinet created the first chronograph timepiece in , though this was largely undiscovered until very recently. Until this discovery, it had been assumed that the first chronograph was created by Nicolas Mathieu Rieussec in to accurately time horse races. So, once again, fame and importance take the stand in horology history. This opened the industries in which chronograph watches were used, from horse racing and aviation to automobiles, naval navigation and, eventually, deep-sea diving.

A mechanical watch, and more precisely its movement is a piece of micro-mechanics. Like every mechanical engine relying on moving parts, it is affected by internal and external factors.

On one hand, it is subject to friction, to the use of oils to reduce the friction and to general wear and tear.

Just like the engine of a car, its performance will, necessarily, decline over time. Friction will increase, oils will degrade and the moving parts will be subject to wear. But what prompted the invention of chronometry testing? What is a watch? A device mechanical in this case that displays the time. What is time? A fixed norm, an agreed and averaged measurement of the length of our days, seasons or lives — all based on precise calculations.

Thus, you have two antagonistic concepts fighting here: the ultimate precision of time and the innate imperfection of a man-made mechanical device.

Mechanical watches are and always will be inaccurate. A chronometer, in its modern definition, is a watch that has been tested and certified to meet certain precision standards. What does the COSC do to certify watches as chronometers? Firstly, movements are sent to the COSC by brands which want their watches to be certified. Then, for 15 days wristwatches and pocket watches , the movements undergo daily tests.

Every day, including weekends, the instruments are measured and reassembled. On the basis of the measurements, 7 elimination criteria are calculated. The criteria are:. Below are the minimum requirements for a watch to be certified chronometer:. The most familiar of the requirements and the simplest to understand is the average daily rate. On the contrary of a chronometer, a chronograph has nothing to do with the precision of the movement. A chronograph is an additional function — a complication — added to the basic display hours, minutes, seconds.