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La Crosse Technology introduced the radio-controlled clock, commonly (but incorrectly) called an "atomic clock" after the extremely accurate timepiece behind the radio signal it uses as a reference, into the United States commercial market in 1991. [3] [4] In 2004, the company was awarded a license to sell The Weather Channel branded weather ...
E. Howard & Co. was a clock and watch company formed by Edward Howard and Charles Rice in 1858, after the demise of the Boston Watch Company.The pair acquired some of the material and watches in progress, based upon a lien against the defunct company held by Rice, but they were unable to buy the existing factory or machinery, so they moved to Roxbury.
Download as PDF; Printable version; In other projects ... 18 cesium atomic clocks and 4 hydrogen maser clocks ... La Cañada Flintridge, California ...
The development of atomic clocks has led to many scientific and technological advances such as precise global and regional navigation satellite systems, and applications in the Internet, which depend critically on frequency and time standards. Atomic clocks are installed at sites of time signal radio transmitters. [113]
The following is a list of American companies that produced, or currently produce clocks. Where known, the location of the company and the dates of clock manufacture follow the name. Samuel Abbott; Montpelier, Vermont (1830–1861) Ansonia Clock Company; Ansonia, Connecticut and Brooklyn, New York (1851–1929)
The expected performance of a single-ion nuclear clock was further investigated in 2012 by Corey Campbell et al. with the result that a systematic frequency uncertainty (accuracy) of the clock of 1.5 × 10 −19 could be achieved, which would be by about an order of magnitude better than the accuracy achieved by the best optical atomic clocks ...
Commercial rubidium clocks are less accurate than caesium atomic clocks, which serve as primary frequency standards, so a rubidium clock is usually used as a secondary frequency standard. Commercial rubidium frequency standards operate by disciplining a crystal oscillator to the rubidium hyperfine transition of 6.8 GHz ( 6 834 682 610 .904 Hz ).
The first caesium clock was built by Louis Essen in 1955 at the National Physical Laboratory in the UK [1] and promoted worldwide by Gernot M. R. Winkler of the United States Naval Observatory. Caesium atomic clocks are one of the most accurate time and frequency standards, and serve as the primary standard for the definition of the second in ...