A chronograph is really just another word for “stop watch”. It is simply a multifunction sport watch with a stopwatch function. The word “chronograph” is a combination of the Greek words for “time” and “writing”. Most chronographs have two or three sub-dials, or mini-dials, for measuring minutes and hours. The stopwatch function operates independently of the timekeeping function. This means that while the user is timing an event or an activity, the watch will continue to keep track of the time of day.
Most Chronograph watches have 3 crowns/pushers on the side of the watch case and multiple sub-dials on their face. Though the exact configuration of sub-dials and operation vary slightly from watch to watch, here are a few basics that are common for all:
The top pusher generally starts and stops the stopwatch function. The bottom pusher resets the stopwatch to zero. The middle pusher is used to set or change the time.
The chronograph on an analog watch displays the elapsed time by means of “stopwatch” hands. The stopwatch second hand is usually mounted on the center of the dial, where the normal second hand would be. When the wearer starts the chronograph function by pushing the top pusher, this activates the normally stationary “second hand” which then starts keeping track of elapsed time. When the event is completed, the user stops the stopwatch function by pressing the same 2 o’clock pusher. Once the pusher has been pushed, the 4 o’clock pusher will return the stopwatch hands to their starting position.
NOTE: Please refer to the instruction manual that came with your watch as the operations of specific functions can vary from watch to watch.
Analog chronograph watches have mini dials called sub dials, also known as “totalizers”, “counters” or “registers” that register the amount of elapsed time in minutes, and on some watches, hours. Most chronographs also have a constantly running sub dial that displays the seconds because the “stopwatch” feature has assumed the position on the face of the watch that the normal second hand would occupy.
The sub dials are located in different positions on watches. Some chronograph watches have sub dials that measure seconds, some 1/10 of a second and some to 1/100 of a second. Most chronographs are able to keep track not only of the seconds, but also the minutes or even hours that have elapsed since the chronograph or stopwatch function was started.
Some watches only measure the first half hour of time that has elapsed. After that, the user will have to keep track of how much time has elapsed. Refer to the instruction manual that came with your chronograph to understand how much time it will measure.
Some analog chronometers also have a ‘tachymeter’ or ‘tachometer’ scale around the rim or bezel of the watch. Used in conjunction with the chronograph, it enables the wearer to determine his/her average speed traveling a pre-measured distance such as a measured mile, or lap around a racetrack.
Many chronographs are equipped with rotating bezels.
These can be uni-directional or bi-directional. A uni-directional bezel only turns in one direction, usually counter clockwise. It was first designed for diver’s watches to measure the amount of time left in the diver’s oxygen tank. It would tell the diver that he only had “X” amount of minutes left in his oxygen tank and that he would need to re-surface before that time before he was out of oxygen. Since most people do not dive, the bezel is usually used for such daily tasks as monitoring the number of minutes left on a parking meter.
How to use the Bezel:
Align the marker (triangle or dot) on the bezel with the current position on the minute hand.
As the minute hand advances around the dial, the engraved number to which it points on the bezel indicates how many minutes (from 1 to 59) have passed since the timing began.
When not in use, turn bezel counterclockwise until the marker is aligned at the 12:00 mark.
A true “divers watch” will not have a bi-directional bezel. They will have a uni-directional bezel instead. Reason: This prevents the overstatement of remaining time left in the event that the watch was accidentally bumped without the wearer’s knowledge and the bezel moved in the opposite direction giving the mis-reading that there was more time left than actually was.
NOTE: Not all watches that have this chronograph feature are chronometers. A chronometer is a watch that has been rigorously tested for accuracy 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. If the watch passes these strict tests, then it is awarded the designation of a chronometer.
Over 99% of the watches certified as chronometers are mechanical watches. Reason: The movements in Quartz watches, which use circuit boards and the extremely fast, consistent vibrations of the quartz crystal, are so precise that they do not need to be tested for their accuracy.