The most precision instrument for measurement of time created by the person are an atomic clock. Since the middle of the last century of their measurement are considered as reference. One atomic second is defined as duration of 9,192,631,770 periods of radiation of atom of caesium-133. In spite of the fact that usually atomic clock is the huge installations used in scientific laboratories it is possible to receive time measured to within atomic second and at home.
Instruction
1. In network there are many websites which allow to see time synchronized with the atomic clock. For example, exact time on hours established in U.S Naval Observatory at any time can see on the website http://www.anafor.ru/time/index.htm.
2. If desired it is possible to adjust synchronization of time on the computer and always to have its most exact indications. For this purpose in the Windows system it is necessary to come into ""Settings of date and time"" and on the Time on the Internet tab to press the Change Parameters button. In the appeared window it is necessary to replace the standard server of time with more suitable. For example, the State scientific metrological center provides the following servers for synchronization: ntp1.vniiftri.runtp2.vniiftri.runtp3.vniiftri.runtp21.vniiftri.ru
3. Instead of the last way it is possible to get the small Chronograph Atomic Time Clock utility (http://www.altrixsoft.com/en/chrono/). She will make everything for you. The program automatically and regularly updates time of your computer online. Time from servers of National Institute of standards and technologies of the USA is used. Besides the program has the pleasant interface and is capable to replace standard hours of Windows if you were bothered by their habitual shape.
4. Hypothetically there is one more way: to receive the most real atomic clock in the order. In spite of the fact that development of their "household" version is conducted long ago, the only ready-made product was created quite recently. The American company Symmetricom since 2011 is engaged in release of the SA.45s CSAC model in the size of all about a small chip.