Atomichron

{{Short description|First commercial atomic clock}}

The Atomichron was the world's first commercial atomic clock, built by the National Company, Inc. of Malden, Massachusetts. It was also the first self-contained portable atomic clock and was a caesium standard clock. More than 50 clocks with the trademarked Atomichron name were produced.{{cite journal |last= Forman |first= P |date= July 1985 |title= Atomichron: The atomic clock from concept to commercial product |journal= Proceedings of the IEEE |volume= 73 |issue=7 |pages= 1181–1204 |issn= 0018-9219 |url= http://ieee-uffc.org/freqcontrol/atomichron/automichron.htm |doi= 10.1109/PROC.1985.13266 |s2cid= 19716223 |archiveurl= https://web.archive.org/web/20071021044529/http://ieee-uffc.org/freqcontrol/atomichron/automichron.htm |archivedate= 2007-10-21|url-access= subscription }}{{cite web |title= The Global Positioning System |url= http://www.beyonddiscovery.org/includes/DBFile.asp?ID=84 |format= pdf |accessdate= 2008-04-23 |url-status=dead |archiveurl= https://web.archive.org/web/20100520121212/http://www.beyonddiscovery.org/includes/DBFile.asp?ID=84 |archivedate= 2010-05-20 }}{{cite news |title= Science Update |work= The Dallas Morning News |date= 1989-10-02}}{{cite book |title= The Global Positioning System: The Path from Research to Human Benefit |publisher= National Academy of Sciences |date= 1996 |pages=7 |url= http://books.nap.edu/openbook.php?record_id=9479&page=7 }}