Role of stopwatch in industry

As a result of industrialization developed from the mid-19th Century in various centers, mass production of watches. In Germany, especially the watch production in the Black Forest was significant in France, like the development of Morbier-stopwatch clock serve as an example. In the United States, especially the pocket of industrial production became popular. After initially very high quality production, the pocket watch walked there quickly to successful mass-produced. The so-called U.S. dollar watch, a simple type of watch for everyone was, 20 from different manufacturers to the Century sold millions of times.
Precision stopwatch clocks of Sigmund Riefler

At the end of the 19th Strasser & Rhode century and developed in Germany Sigmund Riefler precision stopwatch clocks, which were for many years the most precise stopwatch clocks, and were used primarily for business purposes and to astronomical observations.

Advances in precision engineering and later the electronics also allow for very sophisticated manufacturing of pocket watches with a Grande Complication.

With the advent of widespread power quickly led to the wish to use electricity for stopwatch. A first step was the drawing up of movements by a mains electric motor. Tower stopwatch clocks with heavy weights and precision watches that should run as undisturbed as possible, was equipped with it. Electrically reared balance watches were used eg in timers.

The regulator (pendulum or balance) of mechanical watches can also be driven electromagnetically and a ratchet rotate the wheels. Such watches were there as a wall stopwatch clock with a permanent magnet bearing "balance", which was driven by fixed coils. Many electric stopwatch clocks have traded today but only a mock pendulum, the stopwatch clock itself is powered by a quartz movement.

For the rapid spread of the national railways, it was a necessity, time signals to be transmitted over long distances. Master stopwatch clocks in public stopwatch clocks plants was time for adjustment from electrical impulses to remove standing daughter watches, which were driven by a simple sequencer. It also heralded the end of the regional and local times led to social change.
Railway stopwatch clock: → Main article

A historically short but major Intermezzo represent the synchronous stopwatch clocks that used the line frequency of the AC mains as normal time. They were inexpensive to produce and disseminate a large watches in the industry and in public institutions.

At the beginning of the 19th Century were isolated miniature stopwatch clocks built into decorative ribbons and worn on the arm. They must be seen as a forerunner of modern wristwatches, which were first produced in 1880 for the German navy in series. After the turn of the century, the watches put first as a handsome watch against the much larger pocket watches. Especially in the grave battles of World War I showed the watch their practical advantages over the pocket and learned first major improvements, such as luminescent hands and screw-down case against moisture. However, athletes and pilots set early on the benefits of the wristwatch .

The final breakthrough helped the invention of the automatic wristwatch by John Harwood (1923) and the introduction of the waterproof stopwatch clock by Hans Wilsdorf (Rolex Oyster, 1926). The development of shock protection was another step towards practicality. Around 1930, the watch had already reached the sales of pocket watches, 1934, it ruled two thirds of the market.
Watch: → Main article
Digital stopwatch clock
One of the cesium atomic stopwatch clocks of the PTB in Braunschweig

The first quartz watch in 1921, developed by HM Dadourian based with on short implemented after World War I by Paul Langevin ultrasonic experiments quartz crystals. The timing of a quartz watch is not a pendulum or balance, but an electronic crystal oscillator whose frequency is maintained using a quartz crystal to accurately.

First, such watches were not available as a consumer product, but sat by the early 1970s because of the high accuracy at a moderate price and very low maintenance on the market and took the watchmaking industry in the quartz crisis. The classic mechanical stopwatch clock was displaced by the quartz watch in almost all areas of life completely. For several years she lived as a wristwatch a remarkable revival.
Watch: → Main article
Kitchen stopwatch clock with timer (1956)

A final step to the highest present accuracy of timekeeping was the development of the atomic stopwatch clock, which was used in 1949 for the first time. Atomic stopwatch clocks use the radiative transitions of free atoms or ions as a timer and see the science of navigation in space and time as a normal application.
Atomic stopwatch clock: → Main article

stopwatch clocks whose time display is controlled by a radio signal, called radio stopwatch clocks one. Since the 1960s, all available wireless stopwatch clocks are synchronized by central European time services. They are matched in 1966 by the first European transmitter HBG time with atomic stopwatch clocks of the Federal Office of Metrology and since 1967 by the DCF77 with an atomic stopwatch clock, the Physikalisch-Technische Bundesanstalt. From the measured values ​​of more than 260 atomic stopwatch clocks in over 60 institutions worldwide distributed the International Bureau of Weights and Measures in Paris lays down the International Atomic Time (TAI) [16] as a reference time. In recent years, a whole host of additional electronic distribution mechanisms for time signal has been established, which are accessible via the RDS service the FM car radio, teletext and the Electronic Program Guide (EPG) of the television and via the NTP protocol of the Internet .