From en.wikipedia.org:
[Historical synonym for hertz, the unit of frequency] [the unit of frequency]
{{Infobox unit | bgcolor = | name = Cycle per second | image = Octal base
crystal.jpg | caption = A 1 MHz military-grade crystal resonator with an octal
base, marked "1000 KC" for 1000 kilocycles per second. | standard = |
quantity = Frequency, rotational frequency | symbol = cps | symbol2 = c/s |
namedafter = | extralabel = | extradata = | units1 = SI units | inunits1 = 1
Hz=1 s<sup>−1</sup> }}
The CYCLE PER SECOND is a once-common English name for the unit of frequency
now known as the _hertz_ (Hz). Cycles per second may be denoted by C.P.S.,
C/S, or, ambiguously, just "cycles" (Cyc., Cy., C, or c). The term comes from
repetitive phenomena such as sound waves having a frequency measurable as a
number of oscillations, or cycles, per second.[1]
With the organization of the International System of Units in 1960, the cycle
per second was officially replaced by the hertz, or reciprocal second,
"s<sup>−1</sup>" or "1/s". Symbolically, "cycle per second" units are
"cycle/second", while hertz is "Hz" or "s<sup>−1</sup>".[2] For higher
frequencies, _kilocycles_ (kc), as an abbreviation of _kilocycles per second_
were often used on components or devices. Other higher units like _megacycle_
(Mc) and less commonly _kilomegacycle_ (kMc) were used before 1960[3] and in
some later documents.[4] These have modern equivalents such as kilohertz
(kHz), megahertz (MHz), and gigahertz (GHz). Following the introduction of
the SI standard, use of these terms began to fall off in favor of the new
unit, with hertz becoming the dominant convention in both academic and
colloquial speech by the 1970s.[5]
Cycle can also be a unit for measuring usage of reciprocating machines,
especially presses, in which cases _cycle_ refers to one complete revolution
of the mechanism being measured (i.e. the shaft of a reciprocating engine).
Derived units include CYCLES PER DAY ( CPD) and CYCLES PER YEAR ( CPY).
** See also
- Cycles per instruction (CPI)
- Cycles per metre
- Heinrich Hertz
- Instructions per cycle (IPC)
- Instructions per second (IPS)
- MKS system of units a predecessor of the SI set of units
- Normalized frequency
- Radian per second
- Revolutions per minute (RPM)
- Turn (angle)
** References
[reflist]
Category:Units of frequency
Dansk: Cycles-per-second