Microsecond

Amicrosecondis a unit oftimein theInternational System of Units(SI) equal to onemillionth(0.000001 or 10⁻⁶or1⁄1,000,000) of asecond.Its symbol isμs,sometimes simplified touswhenUnicodeis not available.

A microsecond is equal to 1000nanosecondsor1⁄1,000of amillisecond.Because the nextSI prefixis 1000 times larger, measurements of 10⁻⁵and 10⁻⁴seconds are typically expressed as tens or hundreds of microseconds.

Examples

• 1 microsecond (1μs) – cycle time forfrequency1×10⁶hertz(1 MHz), the inverse unit. This corresponds to radio wavelength300m(AMmedium waveband), as can be calculated by multiplying 1 μs by thespeed of light(approximately3.00×10⁸m/s).
• 1 microsecond – the length of time of a high-speed, commercialstrobe lightflash (seeair-gap flash).
• 1 microsecond –protein foldingtakes place on the order of microseconds (thus this is the speed ofcarbon-based life).
• 1.8 microseconds – the amount of time subtracted from the Earth'sdayas a result of the2011 Japanese earthquake.
• 2 microseconds – the lifetime of amuoniumparticle.
• 2.68 microseconds – the amount of time subtracted from the Earth's day as a result of the2004 Indian Ocean earthquake.
• 3.33564095 microseconds – the time taken bylightto travel onekilometrein avacuum.
• 5.4 microseconds – the time taken by light to travel onemilein a vacuum (or radio waves point-to-point in a near vacuum).
• 8 microseconds – the time taken by light to travel one mile in typicalsingle-mode fiber optic cable.
• 10 microseconds (μs) – cycle time for frequency100 kHz,radio wavelength3km.
• 18 microseconds – net amount per year that the length of the day lengthens, largely due totidal acceleration.
• 20.8 microseconds –samplinginterval for digital audio with 48,000 samples/s.
• 22.7 microseconds – sampling interval forCDaudio (44,100 samples/s).
• 38 microseconds – discrepancy inGPSsatellitetime per day (compensated by clock speed) due torelativity .
• 50 microseconds – cycle time for highesthuman-audibletone (20 kHz).
• 50 microseconds – to read the access latency for a modern solid state drive which holds non-volatile computer data.
• 100 microseconds (0.1 ms) – cycle time for frequency 10 kHz.
• 125 microseconds – common sampling interval for telephone audio (8000 samples/s).
• 164 microseconds –half-lifeofpolonium-214.
• 240 microseconds – half-life ofcopernicium-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 byal-BiruniandRoger Baconin 1000 and 1267 AD, respectively.
• 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 itsindex of refraction).
• The average human eyeblinktakes 350,000 microseconds (just over1⁄3second).
• The average human fingersnaptakes 150,000 microseconds (just over1⁄7second).
• Acamera flashilluminates for 1,000 microseconds.
• Standard camerashutter speedopens 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)
• Picosecond
• Millisecond

External links

• The National Institute of Standards and Technology (NIST)