Cycle per second

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Crystal resonators, the 1940s-era center unit is marked in kc.

The cycle per second was a once-common English name for the unit of frequency now known as the hertz. The plural form was typically used, often written "cycles per second," "cycles/second", "c.p.s," "~" or just "cycles."

With the organization of the International System of Units (abbreviated SI from the French) in 1960, the cycle per second was officially replaced by the hertz, or reciprocal second—i.e. the cycle in 'cycle per second' was dropped. Symbolically, "cycle per second" units are "cycle/second", while hertz is "1/second" or \text{s}^{-1}.[1] This particular mandate has been so widely adopted as to render the old 'cycle per second' all but extinct.

For higher frequencies, the terms kilocycle (kc), megacycle (Mc) and (less commonly) kilomegacycle (kMc) were used before 1960[2] and in some later documents.[3] The modern equivalents are kilohertz (kHz), megahertz (MHz) and gigahertz (GHz), respectively.

See also[edit]

References[edit]

  1. ^ Taylor, B. N. (2008). International System of Units (SI) (rev. , 2008 Ed. ). DIANE Publishing. p. 27. ISBN 9781437915587. 
  2. ^ George Grammer (January 1933). "Rationalizing the Autodyne". QST. "The 7000- and 14,000-kc. grid coils are wound with No. 18 enameled wire..." 
  3. ^ Ronald E. Guentzler (April 1967). "The "Monode: Noise Generator". QST. "The Monode described here is usable at frequencies below 144 Mc. with slight modification."