92.82.95.166: /* See also */See also time units fixed

2025-05-26T17:46:48Z

See also: See also time units fixed

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{{short description|One millionth of a second}}

{{Infobox unit
| name = microsecond
| image =
| caption =
| symbol = μs
| standard = [[SI]]
| quantity = [[time]]
| units1 = [[SI units]]
| inunits1 = {{val|e=-6|ul=s}}
}}
A '''microsecond''' is a unit of [[time]] in the [[International System of Units]] (SI) equal to one [[millionth]] (0.000001 or 10−6 or {{frac|1|1,000,000}}) of a [[second]]. Its symbol is '''μs''', sometimes simplified to '''us''' when [[Unicode]] is not available.

A microsecond is to one second, as one second is to approximately 11.57 days.

A microsecond is equal to 1000 [[nanosecond]]s or {{frac|1|1,000}} of a [[millisecond]]. Because the next [[Metric prefix|SI prefix]] is 1000 times larger, measurements of 10−5 and 10−4 seconds are typically expressed as tens or hundreds of microseconds.

==Examples==

* 1 microsecond (1 [[Mu (letter)|μ]]s) – cycle time for [[frequency]] {{val|1|e=6|ul=hertz}} (1 MHz), the inverse unit. This corresponds to radio wavelength [[1 E2 m|300]] [[metre|m]] (AM [[medium wave]] band), as can be calculated by multiplying 1 μs by the [[speed of light]] (approximately {{val|3.00|e=8|u=m/s}}).
* 1 microsecond – the length of time of a high-speed, commercial [[strobe light]] flash (see [[air-gap flash]]).
* 1 microsecond – [[protein folding]] takes place on the order of microseconds (thus this is the speed of [[carbon-based life]]).
* 1.8 microseconds – the amount of time subtracted from the Earth's [[day]] as a result of the [[2011 Tōhoku earthquake and tsunami|2011 Japanese earthquake]].<ref>{{cite news |last1=Gross |first1=R.S. |title=Japan quake may have shortened Earth days, moved axis |url=http://www.jpl.nasa.gov/news/news.php?release=2011-080 |access-date=23 August 2019 |agency=Jet Propulsion Laboratory |publisher=JPL News |date=14 March 2014}}</ref>
* 2 microseconds – the lifetime of a [[muonium]] particle.
* 2.68 microseconds – the amount of time subtracted from the Earth's day as a result of the [[2004 Indian Ocean earthquake and tsunami|2004 Indian Ocean earthquake]].<ref name="IndianOceanNASA">{{cite web | url=https://www.nasa.gov/home/hqnews/2005/jan/HQ_05011_earthquake.html | title=NASA Details Earthquake Effects on the Earth | publisher=NASA | date=January 10, 2005 | access-date=September 18, 2021 | last1=Cook-Anderson | first1=Gretchen | last2=Beasley | first2=Dolores}}</ref>
* 3.33564095 microseconds – the time taken by [[light]] to travel one [[kilometre]] in a [[vacuum]].
* 5.4 microseconds – the time taken by light to travel one [[mile]] in a vacuum (or radio waves point-to-point in a near vacuum).
* 8 microseconds – the time taken by light to travel one mile in typical [[Single-mode optical fiber|single-mode fiber optic cable]].
* 10 microseconds (μs) – cycle time for frequency [[Hertz|100 kHz]], radio wavelength [[Orders of magnitude (length)|3]] [[kilometre|km]].
* 18 microseconds – net amount per year that the length of the day lengthens, largely due to [[tidal acceleration]].<ref>{{Cite news|url=http://www.sciencealert.com/astronomers-find-a-day-on-earth-is-getting-longer-each-century|title=Earth's Days Are Getting 2 Milliseconds Longer Every 100 Years|last=MacDonald|first=Fiona|work=ScienceAlert|access-date=2017-03-08|language=en-gb}}</ref>
* 20.8 microseconds – [[Sampling (signal processing)|sampling]] interval for digital audio with 48,000 samples/s.
* 22.7 microseconds – sampling interval for [[Compact disc|CD]] audio (44,100 samples/s).
* 38 microseconds – discrepancy in [[GPS]] [[satellite]] time per day (compensated by clock speed) due to [[General relativity|relativity]]{{hsp}}.<ref>{{cite web | url=http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html | title= GPS and Relativity | access-date=2011-10-01 | author= Richard Pogge }}</ref>
* 50 microseconds – cycle time for highest [[Hearing (sense)|human-audible]] tone (20 kHz).
* 50 microseconds – to read the access latency for a modern solid state drive which holds non-volatile computer data.<ref>[http://www.intel.com/content/dam/www/public/us/en/documents/product-specifications/ssd-dc-s3500-spec.pdf Intel Solid State Drive Product Specification]</ref>
* 100 microseconds (0.1 ms) – cycle time for frequency 10 kHz.
* 125 microseconds – common sampling interval for telephone audio (8000 samples/s).<ref>{{Citation |last=Kumar |first=Anurag |title=Application Models and Performance Issues |date=2008 |url=https://linkinghub.elsevier.com/retrieve/pii/B9780123742544500041 |work=Wireless Networking |pages=53–79 |publisher=Elsevier |language=en |doi=10.1016/b978-012374254-4.50004-1 |isbn=978-0-12-374254-4 |access-date=2022-08-08 |last2=Manjunath |first2=D. |last3=Kuri |first3=Joy|url-access=subscription }}</ref>
* 164 microseconds – [[half-life]] of [[polonium]]-214.
* 240 microseconds – half-life of [[copernicium]]-277.
* 260 to 480 microseconds - return trip ICMP ping time, including operating system kernel TCP/IP processing and answer time, between two Gigabit Ethernet devices connected to the same local area network switch fabric.
* 277.8 microseconds – a fourth (a 60th of a 60th of a second), used in astronomical calculations by [[al-Biruni]] and [[Roger Bacon]] in 1000 and 1267 AD, respectively.<ref>{{cite book
|author=al-Biruni
|author-link=al-Biruni
|translator=Sachau C Edward
|year=1879
|title=The chronology of ancient nations: an English version of the Arabic text of the Athâr-ul-Bâkiya of Albîrûnî, or "Vestiges of the Past"
|url=https://books.google.com/books?id=pFIEAAAAIAAJ&q=thirds&pg=PA148|pages=147–149
|publisher=[[W. H. Allen & Co.|W. H. Allen]]
|oclc=9986841
}}</ref><ref>
{{cite book
|author=R Bacon
| author-link= Roger Bacon
|others=translator: BR Belle
|year=2000 |orig-year=1928
|title= [[Opus Majus|The Opus Majus of Roger Bacon]]
|publisher=[[University of Pennsylvania Press]]
|page=table facing page 231
|isbn=978-1-85506-856-8
|no-pp=true
}}</ref>
* 490 microseconds – time for light at a 1550 nm frequency to travel 100 km in a singlemode fiber optic cable (where speed of light is approximately 200 million metres per second due to its [[Refractive index|index of refraction]]).
* The average human eye [[blink]] takes 350,000 microseconds (just over {{frac|1|3}} second).
* The average human finger [[Finger snapping|snap]] takes 150,000 microseconds (just over {{frac|1|7}} second).
* A [[Flash (photography)|camera flash]] illuminates for 1,000 microseconds.
* Standard camera [[shutter speed]] opens the shutter for 4,000 microseconds or 4 milliseconds.
* 584542 years of microseconds fit in 64 bits: (2**64)/(1e6*60*60*24*365.25).

==See also==
* [[International System of Units]]
* [[Jiffy (time)]]
* [[Orders of magnitude (time)]]
* [[Millisecond]]
* [[Nanosecond]]
* [[Picosecond]]

==References==
{{Reflist}}

==External links==
* [https://www.nist.gov/pml/time-and-frequency-division The National Institute of Standards and Technology (NIST)]

{{Orders of magnitude seconds}}

{{DEFAULTSORT:1 E-6 S}}
[[Category:Orders of magnitude (time)]]

[[de:Sekunde#Abgeleitete Maßeinheiten]]

Microsecond - Revision history

92.82.95.166: /* See also */See also time units fixed