Stopwatch – definition, types, purpose

A stopwatch is a device for measuring time intervals with an accuracy down to fractions of a second. Stopwatches typically measure with an accuracy of 1/10 and 1/100 of a second. Mechanical stopwatches usually provide an accuracy of 1/10 second. With the advent of modern technology, it became possible to measure time much more precisely – down to ten-thousandths of a second and beyond. Stopwatches with laser finish line detection have an accuracy of 1/1000 second and higher. Stopwatches allow starting and stopping time measurement, as well as recording intermediate time intervals (split timing).

The field of application is extensive – stopwatches are used in sports competitions, medical tasks, scientific research, and other areas requiring precise time measurement. In the military, a stopwatch is used to measure the speed of assembling and disassembling firearms, the flight duration of projectiles, or the time required to complete a standard exercise, etc.

Mechanical stopwatches

These are visual time measurement instruments with an accumulative type of action, which do not reset but add readings after stopping and restarting the measurement. They can be very useful, for example, in multi-stage sports competitions. Such models also differ in that they have a separate reset button located at the top of the case.

The presence of two dials allows a stopwatch to measure time intervals in fractions of a second, seconds, and minutes. The difference in accuracy classes also affects the energy autonomy: for class 2 devices, it is at least 18 hours on a single winding; for class 3 models – at least 17 hours with a 0.2 s tick of the second hand, and at least 8 hours with a 0.1 s tick.

High accuracy of mechanical stopwatches is ensured by an oscillating “balance-spring” system, also used in pocket watches.

Electronic stopwatches

These stopwatches can measure and display in digital form a large number of time periods, as well as store multiple intervals with subsequent sequential viewing and deletion. This function can be applied, for example, when judging sporting events. Multiple presses of the capture button record times corresponding to the athletes finishing first, second, third, and so on. Stopping and resetting the timing is conveniently done with separate buttons on the top of the case, minimizing the risk of accidental reset or start.

It is worth noting that in electronic form, a stopwatch is not always a handheld device. There are stationary stopwatches equipped with a laser. Such a device stops the timing when an object crosses the laser beam trajectory. This provides more precise time measurement compared to operator button presses and eliminates the human factor.

A quartz microprocessor ensures stable and accurate operation of the device both in standard timing mode and in digital clock mode.