An instrument which measures accurate divisions in time, the most basic of which is commonly referred to as a stopwatch.
A chronograph provides a facility to start and stop a time recording process within a timepiece. This then provides the user with a visual display of the exact amount of time elapsed between the start and stop functions being executed.
An additional function is also provided in order to reset the Chronograph to the zero position.
A watch movement with a chronograph complication will allow the user to perform these functions independently of the running of the watch. This allows the watch to continue recording real time without being affected by the stopwatch process.
A most basic chronograph mechanism may record seconds and minutes. Others may record tenths of seconds, whilst others may record hours. And, of course any combination of the above.
Some Chronographs may additionally have a movable bezel to provide a tachymeter function allowing the user to calculate speed and distance as well as time elapsed.
A chronograph can usually be identified as having one or more smaller dials, or sub-dials, set within the main dial with their own independent indicators, or hands for hour and minute recording. Seconds recording will usually be represented by the center seconds hand, and in this case, the real time continuously running seconds hand may be found within it’s own sub dial.
A chronograph is a specific type of watch that is used as a stopwatch combined with a display watch. A basic chronograph has an independent sweep second hand; it can be started, stopped, and returned to zero by successive pressure on the stem. More complex chronographs use additional complications and can have multiple independent hands to measure seconds, minutes, hours and even tenths of a second. In addition, many modern chronographs use moveable bezels as tachymeters for rapid calculations of speed or distance. Louis Moinet invented the chronograph in 1816 for use in tracking astronomical objects. Chronographs were also used heavily in artillery fire in the mid to late 1800s. More modern uses of chronographs involve piloting airplanes, car racing, diving and submarine maneuvering.