# Microsecond

Microsecond

A microsecond is an SI unit of time equal to one millionth (10−6) of a second. Its symbol is µs.

A microsecond is equal to 1000 nanoseconds or 1/1000 millisecond. Because the next SI unit 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 μs) – cycle time for frequency 1 x 106 hertz (1 MHz), the inverse unit. This corresponds to radio wavelength 300 m (AM mediumwave band), as can be calculated by multiplying 1 µs by the speed of light (approximately 3×108 m/s) to determine the distance travelled.
• 1 microsecond – the length of time of a high-speed, commercial strobe light flash.
• 1.8 microseconds - the amount of time subtracted from the Earth's day as a result of the 2011 Japanese earthquake.
• 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.[1]
• 3.33564095 microseconds – the time taken by light to travel one kilometer in a vacuum
• 4.63 microseconds – a fifth (a 60th of a 60th of a 60th of a second)
• 5.4 microseconds – the time taken by light to travel one mile in a vacuum
• 10 microseconds (μs) – cycle time for frequency 100 kHz, radio wavelength 3 km
• 17 microseconds: net amount per year that the length of the day lengthens, largely due to tidal acceleration.[citation needed]
• 20.8 microseconds – sampling interval for digital audio with 48000 samples/s
• 22.7 microseconds – sampling interval for CD audio (44100 samples/s)
• 38 microseconds – discrepancy in GPS satellite time per day (compensated by clock speed) due to relativity[2]
• 50 microseconds – cycle time for highest human-audible tone (20 kHz)
• 100 microseconds (0.1 ms) – cycle time for frequency 10 kHz
• 125 microseconds – sampling interval for telephone audio (8000 samples/s)
• 240 microseconds – half-life of copernicium-277
• 250 microseconds – cycle time for highest tone in telephone audio (4 kHz)[citation needed]
• 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.[3][4]

### For reference

• The average human eye blink takes 350,000 microseconds.
• A camera flash illuminates for 1,000 microseconds.
• Standard camera shutter speed opens the shutter for 4,000 microseconds or 4 milliseconds.

## References

1. ^ Buis, Alan (January 10, 2005). "NASA Details Earthquake Effects on the Earth". NASA. Retrieved June 29, 2011.
2. ^ Richard Pogge. "GPS and Relativity". Retrieved 2011-10-01.
3. ^
4. ^ R Bacon (2000) [1928]. The Opus Majus of Roger Bacon. University of Pennsylvania Press. table facing page 231. ISBN 9781855068568.

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### Look at other dictionaries:

• microsecond — (n.) 1906, from MICRO (Cf. micro ) + SECOND (Cf. second) (n.) …   Etymology dictionary

• microsecond — ► NOUN ▪ one millionth of a second …   English terms dictionary

• microsecond — [mī′krō sek΄ənd] n. [ MICRO + SECOND3] one millionth of a second: symbol, μs …   English World dictionary

• microsecond — UK [ˈmaɪkrəʊˌsekənd] / US [ˈmaɪkroʊˌsekənd] noun [countable] Word forms microsecond : singular microsecond plural microseconds a unit for measuring time. There are one million microseconds in a second …   English dictionary

• microsecond — [[t]ma͟ɪkroʊsekənd[/t]] microseconds N COUNT A microsecond is one millionth of a second …   English dictionary

• microsecond — mikrosekundė statusas T sritis Standartizacija ir metrologija apibrėžtis Dalinis trukmės matavimo vienetas, lygus milijonajai sekundės daliai, t. y. 1 μs =10⁻⁶ s. atitikmenys: angl. microsecond vok. Mikrosekunde, f rus. микросекунда, f pranc.… …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

• microsecond — mikrosekundė statusas T sritis fizika atitikmenys: angl. microsecond vok. Mikrosekunde, f rus. микросекунда, f pranc. microseconde, f …   Fizikos terminų žodynas

• microsecond — mikrosekundė statusas T sritis informatika apibrėžtis Tarptautinės matavimo vienetų sistemos (SI) laiko matavimo vienetas, lygus vienai milijonajai (10⁻⁶ ) sekundės daliai. Santrumpa µs. santrumpa( os) µs atitikmenys: angl. microsecond …   Enciklopedinis kompiuterijos žodynas

• microsecond — n. one millionth of a second. * * * microsecond, section see micro 5 a, 2 c …   Useful english dictionary

• microsecond — noun Etymology: International Scientific Vocabulary Date: 1906 one millionth of a second …   New Collegiate Dictionary