stopwatch

from Wikipedia, the free encyclopedia
Mechanical stopwatch from Hanhart

The stopwatch (also called chronograph ) is a precise measuring device for the time difference between start and stop.

Every stopwatch timer is a precise oscillation. It is generated mechanically by a short- swinging balance wheel or electronically by resonant circuits ( oscillator ). The time system is mostly a relative , i.e. H. with any zero point.

scope of application

Stopwatches are used to measure time intervals ( timing ), for example in sport, celestial navigation, physics, chemistry, working and production processes, transport, chess and more. In contrast to a chronograph , a classic stopwatch does not display the time . A bracelet or pocket chronograph in addition to a normal watch a stop function with a similar trigger mechanism such as a stopwatch.

function

Start - stop - zero

The start-stop function measures the difference between two events. A single pusher starts the measurement with the first press and stops it with the second press. A third press resets the clock to zero. With mechanical stopwatches, the pusher is designed as a "crown stopper" with which the stopwatch is wound mechanically via a spring.

Break

There is another button to the left of the main push button so that the measurement can be interrupted for breaks. If it is pressed, the measurement process stops and is continued at the previous position with the second press. In this way, the pure transit time is measured from the sections. Intermediate breaks are not taken into account. Such clocks are called "addition stoppers".

Individual times

If there are several runners starting at the same time, it must be possible to read the times one after the other. The same applies if intermediate times are to be measured for a runner, for example for individual laps. The stopwatch has another button to the right of the main pusher, which can be used to display the intermediate time while the clock continues to run in the background. For this purpose, mechanical stopwatches have a “drag pointer” that is stopped to read the intermediate time while the main hand continues to run. After pressing the right button a second time, the drag pointer jumps back to the main pointer and runs parallel to it again.

design type

Electronic stop watch

Nowadays electronic stopwatches have become popular. They have a measuring accuracy of 1/100 to 1/1000 of a second, are cheaper than mechanical ones and also easier to use.

Mechanical stopwatch

The mechanical stopwatch is in the shape of a pocket watch. It is started and stopped at the push of a button. Hands for minute, second and 1/10 second show the measured time. Well-known manufacturers are Hanhart (Switzerland, Germany), Heuer (Switzerland), Junghans (Germany) and Agat (Russia).

Wristwatch with stopwatch

First mechanical wristwatches with stopwatch function ( bracelet stopwatches ), so-called " chronograph ", there was a pilot's watch and dive watch . Well-known manufacturers are Japanese companies Casio and Seiko as well as Hanhart in Germany.

A stopwatch function is usually integrated into today's electronic wristwatches.

Timing system

Automatic timing systems are standard in competitive sports and at major sporting events . Light barriers measure the start and finish passage, the automatic stopwatch calculates the time difference, data is transmitted by radio or cable and evaluated by specialized software. The results and rankings are shown on large displays and distributed in real time on the Internet and television.

history

Nicholas Rieussec invented the first stopwatch in 1821, which recorded the measured time using an ink pen. This is where the misleading term chronograph for watches with a stop function is commonly used today . In 1776, Jean Pouzait constructed a clock accurate to the second that could be stopped, but stopped the entire clock. In 1831 Joseph Thaddäus Winnerl built a pocket watch that is accurate to the second. Intermediate times could be read with two independently stopping second hands. He called it "Chronoscope". In 1862 Adolphe Nicole invented the first pocket watch in the world whose second hand could be stopped and which was reset to zero with the push of a button.

In 1936, at the Olympic Games, the times of skiers were measured for the first time with two stopwatches at the start and finish lines and then the driving time was calculated. The final race results were only available hours later. In 1962, lap times could be shown live on television for the first time in Helsinki. In 2012, special cameras filmed the finish line at the Summer Games in London at 2000 frames per second.

literature

  • Rudi Koch (Hrsg.): BI-Lexicon - clocks and time measurement. VEB Leipzig, 1986, ISBN 3-323-00100-1 , p. 204 f.
  • Günther Glaser (Ed.): Handbook of chronometry and clock technology. Volume II / 8: Mechanical watches. Stuttgart 1993, chap. 7.1 and 7.2: Stopwatches, sports time measurement, Chapters 7.3 to 7.7: Mechanical timers, control watches, time regulators.

Web links

Commons : Stopwatches  - collection of pictures, videos and audio files
Wiktionary: stopwatch  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. ↑ Lukas Stolberg: Lexicon of the pocket watch. Carinthia Verlag, Klagenfurt 1995, ISBN 3-85378-423-2 , p. 221.
  2. ↑ Fritz von Osterhausen: Callweys lexicon. Munich 1999, ISBN 3-7667-1353-1 , p. 319 f.
  3. ^ R. Haider, O. Jacobs, A. Zimmermann: Mechanical wrist stopwatches - Chronographs. Vienna 1988.