A stopwatch is a timepiece designed to measure the amount of time elapsed from a particular time when activated and when the piece is deactivated. A clock (from the Latin cloca, bell) is an instrument for measuring time. ...

A typical mechanical analog stopwatch.

A typical digital electronic stopwatch with LCD.

The stopwatch is typically designed to start at the press of the top button and stop by pressing the button a second time to display the elapsed time. A press of the second button then resets the stopwatch to zero. The second button is also used to record split times or lap times. When the split time button is pressed while the watch is running, the display freezes, but the watch mechanism continues running to record total elapsed time. Pressing the split button a second time allows the watch to resume display of total time. Image File history File links Stopwatch2. ... Image File history File links Stopwatch2. ... Image File history File links Stopwatch3. ... Image File history File links Stopwatch3. ... LCD redirects here. ...

Mechanical stopwatches are powered by a mainspring, which must be periodically wound up by turning the knurled knob at the top of the watch. Mainspring (U.S.A. motor spring): In a watch, long strip of hardened and blued steel or of a specially alloyed steel, between 2oo & 3oo millimeters in length and 0. ...

Digital electronic stopwatches are available which, due to their crystal oscillator timing element, are much more accurate than mechanical timepieces. Because they contain a microchip, they often include date and time-of-day functions as well. Some may have a connector for external sensors, allowing the stopwatch to be triggered by external events, thus measuring elapsed time far more accurately than is possible by pressing the buttons with one's finger. A crystal oscillator (sometimes abbreviated to XTAL on schematic diagrams) is an electronic circuit that uses the mechanical resonance of a physical crystal of piezoelectric material along with an amplifier and feedback to create an electrical signal with a very precise frequency. ... A microchip is, properly, an integrated circuit (IC). ...

The device is used when time periods must be measured precisely and with a minimum of complications. Laboratory experiments and sporting events like sprints are good examples. A sport consists of a normal physical activity or skill carried out under a publicly agreed set of rules, and with a recreational purpose: for competition, for self-enjoyment, to attain excellence, for the development of skill, or some combination of these. ... Sprints are races in athletics. ...

A large digital version of a stopwatch designed for viewing at a distance, as in a sports stadium, is called a stopclock.

The stopwatch function is also present as an additional function of many digital wristwatches. If an analog wristwatch has a stopwatch function, it is called a chronograph. This page is about timekeeping devices. ... An analog or analogue signal is any continuously variable signal. ... A stopwatch is a timepiece designed to measure the amount of time elapsed from a particular time when activated and when the piece is deactivated. ...

See also

• Time clock
• Timekeeper