The Full Wiki

Si prefix: Wikis

Encyclopedia

Updated live from Wikipedia, last check: May 20, 2013 01:31 UTC (46 seconds ago)
(Redirected to SI prefix article)

From Wikipedia, the free encyclopedia

.The International System of Units (SI) specifies a set of unit prefixes known as SI prefixes or metric prefixes.^ The SI (International System of Units) [7] also promotes the use of this new binary prefixes.
  • Use of prefixes in wget 2 February 2010 17:16 UTC www.mail-archive.com [Source type: FILTERED WITH BAYES]

 ^ Known as the International System of Units (abbreviated SI), the system is the basis for worldwide standardization of measurement units.
  • IEEE Standards Description: si.10-2002 2 February 2010 17:16 UTC standards.ieee.org [Source type: Reference]

 ^ The conversion to a known system of units.
  • Units in MathML 2 February 2010 17:16 UTC www.w3.org [Source type: Reference]

 .An SI prefix is a name that precedes a basic unit of measure to indicate a decimal multiple or fraction of the unit.^ Describe the names and abbreviations of the SI base units and the SI decimal prefixes .
  • Units of measure 2 February 2010 17:16 UTC www.chem1.com [Source type: FILTERED WITH BAYES]

 ^ SI prefixes are used to form decimal multiples and submultiples of SI units.
  • SI Prefixes : Measurement Units : Reference : National Physical Laboratory 2 February 2010 17:16 UTC www.npl.co.uk [Source type: Academic]

 ^ Metric and SI unit prefixes .
  • Metric & SI units,metric prefix table 2 February 2010 17:16 UTC www.800mainstreet.com [Source type: Reference]

 .Each prefix has a unique symbol that is prepended to the unit symbol.^ Each prefix has a unique symbol that is prepended to the unit symbol.
  • Whats the differences between RDA ,EAR & SI ? - Yahoo! UK & Ireland Answers 2 February 2010 17:16 UTC uk.answers.yahoo.com [Source type: General]

 ^ SI Prefixes List SI Prefixes List An SI prefix (also known as a metric prefix) is a name or associated symbol that precedes a unit of measure (or its symbol) to form a decimal multiple or submultiple.
  • SI Prefixes List 2 February 2010 17:16 UTC www.unitarium.com [Source type: FILTERED WITH BAYES]

 ^ The size or quantity is indicated by the first letter or prefix symbol and the second letter or symbol identifies the base or derived unit .

 .The SI prefixes are standardized by the International Bureau of Weights and Measures in resolutions dating from 1960 to 1991.[1] Their usage is not limited to SI units and many of these date back to the introduction of the metric system in the 1790s.^ The SI system of units uses prefixes that indicate powers of ten.

 ^ The SI (International System of Units) [7] also promotes the use of this new binary prefixes.
  • Use of prefixes in wget 2 February 2010 17:16 UTC www.mail-archive.com [Source type: FILTERED WITH BAYES]

 ^ Known as the International System of Units (abbreviated SI), the system is the basis for worldwide standardization of measurement units.
  • IEEE Standards Description: si.10-2002 2 February 2010 17:16 UTC standards.ieee.org [Source type: Reference]
.SI prefixes are used to reduce the number of zeros shown in numerical quantities before or after a decimal point.^ SI prefixes quantity calculus .
  • Christian Hill's website - physical chemistry tutorial - units and some basics: non-SI units 2 February 2010 17:16 UTC physchem.ox.ac.uk [Source type: Academic]

 ^ Zeros at the end of a number and before a decimal point may or may not be significant.
  • Size and Scale - Made to Measure 2 February 2010 17:16 UTC invsee.asu.edu [Source type: FILTERED WITH BAYES]

 ^ SI prefixes are used to reduce the number of zeros shown in numerical quantities.
  • Convert centi to zetta - SI System Prefixes Conversion 2 February 2010 17:16 UTC www.convertcenter.com [Source type: Academic]
  • Convert kilo to zetta - SI System Prefixes Conversion 2 February 2010 17:16 UTC www.convertcenter.com [Source type: Academic]

 For example, an electrical current of 0.000000001ampere, or one-billionth (short scale) of an ampere, is written by using the SI-prefix nano as 1 nanoampere or 1 nA.

Contents

List of SI prefixes

The International System of Units specifies twenty SI prefixes:
SI prefixes
Prefix Symbol 1000m 10n Decimal Short scale Long scale Since[1]
yotta Y 10008 1024 1000000000000000000000000 Septillion Quadrillion 1991
zetta Z 10007 1021 1000000000000000000000 Sextillion Trilliard 1991
exa E 10006 1018 1000000000000000000 Quintillion Trillion 1975
peta P 10005 1015 1000000000000000 Quadrillion Billiard 1975
tera T 10004 1012 1000000000000 Trillion Billion 1960
giga G 10003 109 1000000000 Billion Milliard 1960
mega M 10002 106 1000000 Million 1960
kilo k 10001 103 1000 Thousand 1795
hecto h 10002⁄3 102 100 Hundred 1795
deca da 10001⁄3 101 10 Ten 1795
10000 100 1 One
deci d 1000−1⁄3 10−1 0.1 Tenth 1795
centi c 1000−2⁄3 10−2 0.01 Hundredth 1795
milli m 1000−1 10−3 0.001 Thousandth 1795
micro µ 1000−2 10−6 0.000001 Millionth 1960[2]
nano n 1000−3 10−9 0.000000001 Billionth Milliardth 1960
pico p 1000−4 10−12 0.000000000001 Trillionth Billionth 1960
femto f 1000−5 10−15 0.000000000000001 Quadrillionth Billiardth 1964
atto a 1000−6 10−18 0.000000000000000001 Quintillionth Trillionth 1964
zepto z 1000−7 10−21 0.000000000000000000001 Sextillionth Trilliardth 1991
yocto y 1000−8 10−24 0.000000000000000000000001 Septillionth Quadrillionth 1991
.
  1. The metric system was introduced in 1795 with six prefixes.^ Tags: object , stick , meter , measurement , significant , prefixes Help on the Metric System .
    • Tag: Prefixes - Explore content tagged Prefixes on eHow.com 2 February 2010 17:16 UTC www.ehow.com [Source type: FILTERED WITH BAYES]

     ^ The prefixes were taken from the metric system & assigned new meanings in the Binary system of measurement.
    • DailyTech - A Download for Your Troubles: Seagate Hard Drive Settlement Now Online 2 February 2010 17:16 UTC www.dailytech.com [Source type: FILTERED WITH BAYES]

     ^ Fr.: déca- Prefix meaning "ten" and "ten times" used in terms belonging to the metric system.
    • An Etymological Dictionary of Astronomy and Astrophysics - English-French-Persian 2 February 2010 17:16 UTC aramis2.obspm.fr [Source type: Academic]

     The other dates relate to recognition by a resolution of the CGPM.
  2. The 1948 recognition of the micron by the CGPM was abrogated in 1967.

Examples

  • 5 cm = 5×10^−2 m = 5×0.01 m = 0.05 m
  • 3 MW = 3×10^6 W = 3×1000000 W = 3000000 W

General use of prefix names and symbols

.Twenty SI prefixes are available to combine with units of measure.^ SI Units can have a multiple or sub-multiple prefix.
  • TCLLIB - Tcl Standard Library: units 2 February 2010 17:16 UTC tcllib.sourceforge.net [Source type: Academic]

 ^ Standard prefixes for the SI units of measure .
  • SI (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

 ^ Definitions of the SI units: The twenty SI prefixes.
  • International System of Units: Encyclopedia of chemistry, analytics & pharmaceutics with 64,557 entries. 2 February 2010 17:16 UTC www.chemie.de [Source type: Reference]

 .For example, the prefix kilo- denotes a multiple of one thousand, so 1 kilometre equals 1000 metres, 1 kilogram equals 1000 grams, 1 kilowatt equals 1000 watts, and so on.^ Remember, kilo equals one thousand, and mega equals one million.
  • Lesson 6 - Metric Prefixes 2 February 2010 17:16 UTC www.qsl.net [Source type: FILTERED WITH BAYES]

 ^ For example, the prefix kilo denotes a multiple of a thousand, so the kilo metre is 1 000 metres, the kilo gram 1 000 grams, and so on.

 ^ For example, the prefix kilo denotes a multiple of a thousand, so the kilo metre is 1000 metres, the kilo gram 1000 grams, and so on.

 .Each SI prefix name has an associated symbol which can be used in combination with the symbols for units of measure.^ Describe the names and abbreviations of the SI base units and the SI decimal prefixes .
  • Units of measure 2 February 2010 17:16 UTC www.chem1.com [Source type: FILTERED WITH BAYES]

 ^ Writing unit symbols and names • 133 .
  • The International System of Units (SI) 2 February 2010 17:16 UTC www.scribd.com [Source type: Reference]

 ^ SI units with compound names .
  • Bartlett's Guide to SI Units 2 February 2010 17:16 UTC www.abdn.ac.uk [Source type: Reference]

 .Thus, the "kilo-" symbol, k, can be used to produce km, kg, and kW, (kilometre, kilogram, and kilowatt).^ Thus the prefix kilo could be used both for weight ( kilogram ) or length ( kilometre ) both indicating a thousand times the base unit.
  • Metric system, SI - The metric system units and history 2 February 2010 17:16 UTC www.sciencemadesimple.com [Source type: Reference]

 ^ For technical documentation, the preferred way of writing SI prefixes and units is by their symbols; for example, 5 kg, not 5 kilogram, or five kilograms.
  • Metric HowTo 2 February 2010 17:16 UTC www.astm.org [Source type: FILTERED WITH BAYES]

 ^ In contrast to unit symbols, the spelling and grammar for unit names are specific to a given language and are not part of the SI (for example, the spellings kilogram and ampere are used in English, while kilogramme and ampère are used in French, but kg and A are the universal SI symbols).
  • Physics Today August 2004 Guide for Metric Practice 2 February 2010 17:16 UTC www.aip.org [Source type: Academic]

 .SI prefixes are internationally recognized and also exist outside the SI (many of them long pre-date SI, going back to the original introduction of the metric system); prefixes may also be used in combination with non-SI units; for example: milligauss (mG), kilofoot (kft) and microinch (µin).^ Internationally recognized conventions have been established for standard usage of SI units.
  • Physics Today August 2004 Guide for Metric Practice 2 February 2010 17:16 UTC www.aip.org [Source type: Academic]

 ^ A prefix may be added to a unit to produce a multiple of the original unit.
  • SI (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

 ^ Examples of SI derived units .
  • Physics Today August 2004 Guide for Metric Practice 2 February 2010 17:16 UTC www.aip.org [Source type: Academic]
.Prefixes may not be used in combination.^ String getShortName () The preferred short name (prefix) as indicated in the TLD. This may be used by authoring tools as the preferred prefix to use when creating an taglib directive for this library.
  • TagLibraryInfo (JavaServer Pages API Documentation) 2 February 2010 17:16 UTC www.access.si [Source type: General]

 ^ Note 1: Using prefix maps may not find the desired prefix as many maps only show primary prefixes.
  • Amateur Radio Prefixes 2 February 2010 17:16 UTC www.ac6v.com [Source type: Reference]

 ^ Some other nouns may be used as prefixes, especially in nouns or in single lexical items.
  • Old Skourene 2 February 2010 17:16 UTC zompist.com [Source type: FILTERED WITH BAYES]

 .This even applies for mass, for which the SI base unit (which is the kilogram, not the gram) already contains a prefix.^ Describe the names and abbreviations of the SI base units and the SI decimal prefixes .
  • Units of measure 2 February 2010 17:16 UTC www.chem1.com [Source type: FILTERED WITH BAYES]

 ^ Expression in terms of SI base units .
  • Int'l System of Units 2 February 2010 17:16 UTC www.sas.org [Source type: Reference]
  • PowerPedia:International System of Units - PESWiki 2 February 2010 17:16 UTC www.peswiki.com [Source type: Reference]

 ^ Note that the kilogram is the only base unit with a prefix .
  • PowerPedia:International System of Units - PESWiki 2 February 2010 17:16 UTC www.peswiki.com [Source type: Reference]

 .So milligram (mg) is used instead of microkilogram (µkg), for example.^ Also i want to extend my previous example because we must use ini_get('arg_separator.output') instead of '&' separator!
  • PHP: http_build_query - Manual 2 February 2010 17:16 UTC www.php.net [Source type: FILTERED WITH BAYES]

 ^ Maybe you could use EXTR_PREFIX_ALL instead of EXTR_OVERWRITE, for example.
  • PHP: extract - Manual 2 February 2010 17:16 UTC www.php.net [Source type: FILTERED WITH BAYES]
Prefixes corresponding to an exponent that is divisible by three are often recommended. .Hence "100 m" rather than "1 hm" (hectometre) or "10 dam" (decametres).^ The system used the multiplier 1024 (2 10 ), rather than 1000 (10 3 ) as in the SI system, to arrive at successively larger prefixes.
  • Binary prefixes (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

 ^ It has also been adopted by computer scientists in the kilobyte (kB); this, however, is often used to mean 2 10 , or 1,024 bytes 1 , rather than 1,000.
  • http://www.bbc.co.uk/dna/h2g2/A29779159 2 February 2010 17:16 UTC www.bbc.co.uk [Source type: FILTERED WITH BAYES]

 .The "non-three" prefixes (hecto-, deca-, deci-, and centi-) are however more commonly used for everyday purposes than in science.^ Many SI prefixes, and the very idea of using prefixes for this purpose, predate the introduction of the SI in 1960, so they are also quite properly used with many non-SI units.
  • Keiger Printing - Glossary of Terms 2 February 2010 17:16 UTC www.keiger.com [Source type: General]

 ^ However, these prefixes have decimal meanings in other contexts, e.g., when used with SI units .
  • Binary prefixes (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

 ^ To avoid possible misinterpretation when more than one unit appears in the denominator, the preferred practice is to use parentheses or negative exponents (for example, W/(m 2 ·K 4 ) or W·m −2 ·K −4 ).
  • Physics Today August 2004 Guide for Metric Practice 2 February 2010 17:16 UTC www.aip.org [Source type: Academic]

SI prefixes with symbols for time and angles

.Official policies about the use of these prefixes vary slightly between the Bureau International des Poids et Mesures (BIPM) and the American National Institute of Standards and Technology (NIST); and some of the policies of both bodies are at variance with everyday practice.^ The binary definition of the prefixes k, M, G etc is not permitted by the United States National Institute of Standards and Technology (NIST).
  • Binary prefixes (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

 ^ Bureau International des Poids et Mesures (2006).
  • SI (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]
  • International System of Units: Encyclopedia of chemistry, analytics & pharmaceutics with 64,557 entries. 2 February 2010 17:16 UTC www.chemie.de [Source type: Reference]

 ^ The Bureau International des Poids et Mesures (BIPM) was set up in 1875 with the principal aim of establishing and publishing standards of physical measurement.
  • Notes on Measures - Prefixes 2 February 2010 17:16 UTC www.cleavebooks.co.uk [Source type: FILTERED WITH BAYES]

 .For instance, the NIST advises that "…to avoid confusion, prefix symbols (and prefixes) are not used with the time-related unit symbols (names) min (minute), h (hour), d (day); nor with the angle-related symbols (names) ° (degree), ′ (minute), and ″ (second)."^ Describe the names and abbreviations of the SI base units and the SI decimal prefixes .
  • Units of measure 2 February 2010 17:16 UTC www.chem1.com [Source type: FILTERED WITH BAYES]

 ^ A controversy has developed concerning GSA publication conventions on the use of time units.
  • Geological Society of America - Policy 2 February 2010 17:16 UTC www.geosociety.org [Source type: FILTERED WITH BAYES]

 ^ The binary definition of the prefixes k, M, G etc is not permitted by the United States National Institute of Standards and Technology (NIST).
  • Binary prefixes (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

 [2] The BIPM’s position on the use of SI prefixes with units of time larger than the second is the same as that of the NIST but their position with regard to angles differs: they state "However astronomers use milliarcsecond, which they denote mas, and microarcsecond, µas, which they use as units for measuring very small angles." [3]

SI prefixes for temperature in °C

Official policy also varies from common practice for the degree Celsius (°C). NIST states; "Prefix symbols may be used with the unit symbol °C and prefixes may be used with the unit name 'degree Celsius'. For example, 12 m°C (12 millidegrees Celsius) is acceptable." However the use of prefixed forms of "°C" (such as "µ°C") has not been adopted in science and engineering; prefixed forms of the kelvin are usually used instead.

Exponentiation of symbols

.When units occur in exponentiation, for example, in square and cubic forms, any size prefix is considered part of the unit, and thus included in the exponentiation.^ Included are factors (usually 10 -3 to 10 3 ) of the meter, the liter, and the gram which cannot be formed simply by attaching prefixes to these 3 units.

 ^ Symbols for derived units formed from multiple units by multiplication are joined with a space or centre dot (·), for example "N m" or "N·m".
  • SI (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

 ^ Multiples and submultiples of metric units are related by powers of ten; the names for these are formed with prefixes.
  • Metric system, SI - The metric system units and history 2 February 2010 17:16 UTC www.sciencemadesimple.com [Source type: Reference]

Pronunciation

.There are two accepted pronunciations for the prefix giga-: /ˈɡɪɡə/ and /ˈdʒɪɡə/.^ "Giga" is an internationally and interdisciplinarily accepted standard prefix that means "multiplied by 10^9".
  • DailyTech - A Download for Your Troubles: Seagate Hard Drive Settlement Now Online 2 February 2010 17:16 UTC www.dailytech.com [Source type: FILTERED WITH BAYES]

 .According to the American writer Kevin Self, in the 1920s a German committee member of the International Electrotechnical Commission proposed giga- as a prefix for 109, drawing on a verse by the humorous poet Christian Morgenstern that appeared in the third (1908) edition of Galgenlieder (Gallows Songs).^ The IEEE (Institution of Electrical and Electronics Engineers), IEEE Computer Society, ISO (International Standards Organisation) and IEC (International Electrotechnical Commission) have begun work jointly on defining standards and conventions for prefixes that are multiples of 2 not 10.
  • A concise reference to the Metric System (SI) 2 February 2010 17:16 UTC www.pyxidium.u-net.com [Source type: Reference]

 ^ To eliminate this imprecision and confusion, a set of prefixes for binary multiples that closely parallel those for powers of 10 has been adopted as a standard by the International Electrotechnical Commission ( IEC ).
  • Prefixes for binary multiples 2 February 2010 17:16 UTC cnx.org [Source type: General]

 ^ Ned noted that one of the SI proposals is for the prefix "luma" , representing 10 63 .
  • Coding Horror: Gigabyte: Decimal vs. Binary 2 February 2010 17:16 UTC www.codinghorror.com [Source type: FILTERED WITH BAYES]

 This suggests a hard German g was originally intended as the pronunciation. Self was unable to ascertain at what point the /dʒ/ (soft g) pronunciation became accepted, but as of 1995 current practice had returned to /ɡ/ (hard g). [4] [5]
.When an SI prefix is affixed to a root word, the prefix carries the stress, while the root drops its stress but retains a full vowel in the syllable that is stressed when the root word stands alone.^ Spell with spelling rules and associations and by learning root words with prefixes and suffixes.
  • Tag: Prefixes - Explore content tagged Prefixes on eHow.com 2 February 2010 17:16 UTC www.ehow.com [Source type: FILTERED WITH BAYES]

 ^ Now, Seagate can claim that it's the HDD industry standard to use SI prefixes instead of IT (information technology) prefixes (even if the prefixes use the same word, they are different values!
  • DailyTech - A Download for Your Troubles: Seagate Hard Drive Settlement Now Online 2 February 2010 17:16 UTC www.dailytech.com [Source type: FILTERED WITH BAYES]

 ^ It uses the allomorph – ah of the causative prefix, which is the allomorph typically used for roots which begin with non-low vowels.
  • Reanalysis of Passive and Negative Prefixes in Seri 2 February 2010 17:16 UTC journals.dartmouth.edu [Source type: FILTERED WITH BAYES]

 .For example, gigabyte is pronounced /ˈɡɪɡəbaɪt/, with stress on the first syllable.^ The former seems to be more common in Britain (short stress on the first syllable) and may have the slight advantage of being consistent with the English pronunciation of kilogram and kilohertz.
  • Metric System FAQ 2 February 2010 17:16 UTC www.faqs.org [Source type: Reference]

 ^ It is suggested that in English, the first syllable of the name of the binary-multiple prefix should be pronounced in the same way as the first syllable of the name of the corresponding SI prefix, and that the second syllable should be pronounced as "bee."
  • Binary prefixes (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

 ^ (The sentence, "I live with her," for example, is stressed the same way as I pronounce "kilometer".
  • xkcd • View topic - Colloquial SI units 2 February 2010 17:16 UTC forums.xkcd.com [Source type: FILTERED WITH BAYES]

 .However, words in common use outside the scientific community may follow idiosyncratic stress rules.^ SI has nothing to do with anything; it's just using the same word but different definition which is a common phenomenon in language and science.
  • DailyTech - A Download for Your Troubles: Seagate Hard Drive Settlement Now Online 2 February 2010 17:16 UTC www.dailytech.com [Source type: FILTERED WITH BAYES]

 ^ May-2005 03:59 The following is a neat use for extract to store and manipulate large amounts of form data from.
  • PHP: extract - Manual 2 February 2010 17:16 UTC www.php.net [Source type: FILTERED WITH BAYES]

 ^ The word coherent is used here in the following sense: when coherent units are used, equations between the numerical values of quantities take exactly the same form as the equations between the quantities themselves.
  • The International System of Units (SI) 2 February 2010 17:16 UTC www.scribd.com [Source type: Reference]

 For example, kilometre is commonly pronounced /kɨˈlɒmɨtər/, with reduced vowels on both syllables of metre.

Other and obsolete prefixes

See also: Non-SI unit prefixes
.The prefix myria-, [6][7] denoting a factor of 10000, originated from the Greek μύριοι (mýrioi) for ten thousand, and the prefixes demi and double, denoting a factors of 1/2 and 2, respectively,[8] were parts of the original metric system adopted by France in 1795. These were not retained when the SI prefixes were internationally adopted by the 11th CGPM conference in 1960. They were dropped because they were not decimal, nor symmetrical.^ These principles still underpin the modern metric system (SI).
  • A concise reference to the Metric System (SI) 2 February 2010 17:16 UTC www.pyxidium.u-net.com [Source type: Reference]

 ^ They are the creators > and maintainers of the SI system.

 ^ Of course the CGPM "recognizes" SI as a system - they created the > SI system.
.Double prefixes such as those formerly used in micromicrofarads (picofarads), hectokilometres (100 kilometres), and millimicrons or micromillimetres (both nanometres) were disallowed with the introduction of the SI. The choice of commonly used prefixes with a given unit is usually dictated by convenience of use, unit prefixes that are much larger or smaller than encountered in practice, are seldom used, albeit valid combinations.^ But non-SI unit systems are in such disarray that using them for interchange is not practical.
  • Representation of numerical values and SI units in character strings for information interchanges 2 February 2010 17:16 UTC people.csail.mit.edu [Source type: Reference]

 ^ Non-SI units accepted for use with SI .

 ^ The most commonly used prefix is in color.
  • Amateur Radio Prefixes 2 February 2010 17:16 UTC www.ac6v.com [Source type: Reference]

 In most contexts only a few, the most common, standard combination are established:
  • Mass: hectogram, gram, milligram, microgram, and smaller are common. .However, megagram or larger are rarely used; tonnes (and kilotonnes etc) or scientific notation are used instead.^ However, for arrays whose elements are larger than four bytes, you can use the movs instruction to initialize the entire array to the content of the first element.
    • Art of Assembly: Chapter Fifteen-2 2 February 2010 17:16 UTC ipoint.vlsi.uiuc.edu [Source type: Reference]

     ^ A very useful reference not only on the correct use of SI units, but on international standard conventions for mathematical and scientific notation in general is: ISO Standards Handbook: Quantities and units.
    • Metric System FAQ 2 February 2010 17:16 UTC www.faqs.org [Source type: Reference]

     .Megagram is occasionally used to disambiguate the (metric) tonne from the various (non-metric) tons.
  • Volume in litres: litre, decilitre, centilitre, millilitre, microlitre, and smaller are common.^ During the history of the metric system a number of variations have evolved and their use spread around the world replacing many traditional measurement systems.

     ^ The history of the metric system has seen a number of variations, whose use has spread around the world, to replace many traditional measurement systems.
    • International System of Units: Encyclopedia of chemistry, analytics & pharmaceutics with 64,557 entries. 2 February 2010 17:16 UTC www.chemie.de [Source type: Reference]

     ^ Bar tenders in many countries use centilitres (cL) or decilitres (dL) and have measuring spoons for these.
    • Metric System FAQ 2 February 2010 17:16 UTC www.faqs.org [Source type: Reference]

     .Larger volumes are sometimes denoted in hectolitres; otherwise in cubic metres or cubic kilometres.^ For example, kilo- denotes a multiple of a thousand and milli- denotes a multiple of a thousandth hence there are one thousand millimetres to the metre and one thousand metres to the kilometre.
    • International System of Units: Encyclopedia of chemistry, analytics & pharmaceutics with 64,557 entries. 2 February 2010 17:16 UTC www.chemie.de [Source type: Reference]

     ^ The official unit of volume in the SI is the cubic metre.
    • A concise reference to the Metric System (SI) 2 February 2010 17:16 UTC www.pyxidium.u-net.com [Source type: Reference]

     .In Australia, large quantities of water are measured in kilolitres, megalitres and gigalitres.
  • Length: kilometre, metre, decimetre, centimetre, millimetre, and smaller are common.^ METRE The base unit for length quantities ( m ).
    • SI 2 February 2010 17:16 UTC jscience.org [Source type: Reference]

     ^ For example, kilo- denotes a multiple of a thousand and milli- denotes a multiple of a thousandth hence there are one thousand millimetres to the metre and one thousand metres to the kilometre.
    • International System of Units: Encyclopedia of chemistry, analytics & pharmaceutics with 64,557 entries. 2 February 2010 17:16 UTC www.chemie.de [Source type: Reference]

     ^ The yard or the metre shall be the unit of measurement of length and the pound or the kilogram shall be the unit of measurement of mass by reference to which any measurement involving a measurement of length or mass shall be made [...
    • DailyTech - A Download for Your Troubles: Seagate Hard Drive Settlement Now Online 2 February 2010 17:16 UTC www.dailytech.com [Source type: FILTERED WITH BAYES]

     .The micrometre is often referred to by the non-SI term micron.^ Since most non-SI units in common use, such as the US customary units, are nowadays defined in terms of SI units, any change in the definition of the SI units results in a change of the definition of the older units, as well.
    • International System of Units: Encyclopedia of chemistry, analytics & pharmaceutics with 64,557 entries. 2 February 2010 17:16 UTC www.chemie.de [Source type: Reference]

     ^ The micrometre, μm, is commonly used in precision engineering, and is sometimes referred to as a micron.
    • http://www.bbc.co.uk/dna/h2g2/A29779159 2 February 2010 17:16 UTC www.bbc.co.uk [Source type: FILTERED WITH BAYES]

     ^ The International System of Units, the SI, is a system of units, adopted by the CGPM, which provides the internationally agreed reference in terms of which all other units are now defined.
    • The International System of Units (SI) 2 February 2010 17:16 UTC www.scribd.com [Source type: Reference]

     .In some fields such as chemistry, the ångström (equal to 0.1 nm) competes with the nanometre.^ Currency may also be taken to be a base dimension in some fields such as economics.
    • Units in MathML 2 February 2010 17:16 UTC www.w3.org [Source type: Reference]

     ^ Atomic scale units used in physics and chemistry, such as the ångström, electronvolt, atomic mass unit , and barn.
    • International System of Units: Encyclopedia of chemistry, analytics & pharmaceutics with 64,557 entries. 2 February 2010 17:16 UTC www.chemie.de [Source type: Reference]

     .The femtometre, used mainly in particle physics, is usually called a fermi.^ Will: Modems always were wierd; mainly becaue they (usually) used 10 bit bytes.
    • Coding Horror: Gigabyte: Decimal vs. Binary 2 February 2010 17:16 UTC www.codinghorror.com [Source type: FILTERED WITH BAYES]

     .For large scales, megametre, gigametre, and larger are rarely used.^ Greek names were used for the integral (large-scale) multipliers, and Latin for the fractional (small-scale) ones.
    • http://www.bbc.co.uk/dna/h2g2/A29779159 2 February 2010 17:16 UTC www.bbc.co.uk [Source type: FILTERED WITH BAYES]

     ^ The Celsius temperature scale; kelvins are rarely employed in everyday use.
    • SI (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]
    • International System of Units: Encyclopedia of chemistry, analytics & pharmaceutics with 64,557 entries. 2 February 2010 17:16 UTC www.chemie.de [Source type: Reference]

     ^ At small scales the basic unit is the gram (or fractions thereof), but for larger orders fractions of ounces and pounds are used generally starting at ⅛ ounce, which is often defined in turn as 3.5 grams.
    • xkcd • View topic - Colloquial SI units 2 February 2010 17:16 UTC forums.xkcd.com [Source type: FILTERED WITH BAYES]

     .Often used are astronomical units, light years, and parsecs; the astronomical unit is mentioned in the SI standards as an accepted non-SI unit.
  • Time: second, millisecond, microsecond, and shorter are common.^ As of 2000, the units bit and byte have not been accepted for use with SI, but are in widespread use.
    • Representation of numerical values and SI units in character strings for information interchanges 2 February 2010 17:16 UTC people.csail.mit.edu [Source type: Reference]

     ^ Non-SI units accepted for use with SI .
    • Metric System of Measurement -- SI 2 February 2010 17:16 UTC www.edinformatics.com [Source type: Reference]

     ^ Units that are used with the SI .
    • A concise reference to the Metric System (SI) 2 February 2010 17:16 UTC www.pyxidium.u-net.com [Source type: Reference]

     The kilosecond and megasecond also have some use, though for these and longer times one usually uses either scientific notation or minutes, hours, and so on.
.† the United Kingdom, Ireland, Australia and New Zealand previously used the long scale number name conventions, but have now at least partly switched to the short scale usage.^ Formatting the value of a quantity The numerical value always precedes the unit, and a space is always used to separate the unit from the number.
  • The International System of Units (SI) 2 February 2010 17:16 UTC www.scribd.com [Source type: Reference]

 ^ Each cache always stores the drive and "parent" sector (the ;** first sector of the directory containing the entry) and the ;** short and long names.

 ^ The directory cache also stores the ;** first sector of the directory, whilst the name cache stores the ;** sector and offset of the directory entries (short & long).

 .In particular, above a million and below a millionth, the same name has different values in the two naming systems, so billion and trillion (for example) have unfortunately become potentially ambiguous terms internationally.^ Since the measurement of a meter is now defined in absolute physical terms that has nothing whatever to do with the absolute value of a "meter" then you can also standardize a foot as multiples of that same base measure.
  • DailyTech - A Download for Your Troubles: Seagate Hard Drive Settlement Now Online 2 February 2010 17:16 UTC www.dailytech.com [Source type: FILTERED WITH BAYES]

 ^ When writing dimensionless quantities, the terms 'ppb' (parts per billion) and 'ppt' (parts per trillion) are recognised as language-dependent terms since the value of billion and trillion can vary from language to language.
  • International System of Units: Encyclopedia of chemistry, analytics & pharmaceutics with 64,557 entries. 2 February 2010 17:16 UTC www.chemie.de [Source type: Reference]

 ^ The Russian example is interesting, but highlights the difference between the two languages more than anything.
  • xkcd • View topic - Colloquial SI units 2 February 2010 17:16 UTC forums.xkcd.com [Source type: FILTERED WITH BAYES]

 .Using the SI prefixes can circumvent this problem.^ SI prefix in binary use .
  • Binary prefixes (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

 ^ My point is that using SI prefixes to determine values that are not SI standards is where confusion arises.
  • DailyTech - Nanochip Promises 100GB-per-chip Alternative to Flash Memory 2 February 2010 17:16 UTC www.dailytech.com [Source type: General]

 ^ Blanka on March 25, 2008 3:50 PM "they intentionally use the official SI definitions of the Giga prefix so they can inflate the the sizes of their hard drives" .
  • Coding Horror: Gigabyte: Decimal vs. Binary 2 February 2010 17:16 UTC www.codinghorror.com [Source type: FILTERED WITH BAYES]

Non-SI units

  • The use of prefixes can be traced back to the introduction of the metric system in the 1790s, long before the SI was introduced in 1960. The prefixes, including those introduced after the introduction of the SI, are used with any metric units, whether officially included in the SI or not (e.g., millidynes).
  • SI prefixes rarely appear with imperial units or English units except in some special cases (e.g., microinches, kilofeet, kilopound or 'kip').
  • They are also used with other specialized units used in particular fields (e.g., megaelectronvolts, gigaparsecs).
  • They are also occasionally used with currency units (e.g., gigadollar), mainly by people who are familiar with the prefixes from scientific usage.

Similar prefixes as abbreviations

.The symbol K is often used informally to mean a multiple of thousand in many contexts.^ Derived units are the units which may be expressed in terms of base units and supplementary units by means of algebra (using the mathematical symbols of multiplication and division).
  • International System of Units (SI) - KEYENCE Corporation 2 February 2010 17:16 UTC www.sensorcentral.com [Source type: Reference]

 ^ Unit symbols formed from other unit symbols by multiplication are indicated by means of a dot (PERIOD, " .
  • Representation of numerical values and SI units in character strings for information interchanges 2 February 2010 17:16 UTC people.csail.mit.edu [Source type: Reference]

 ^ However, these prefixes have decimal meanings in other contexts, e.g., when used with SI units .
  • Binary prefixes (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

 .For example, one may talk of a 40K salary (40 000), or call the Year 2000 problem as Y2K problem.^ The qualifications would be that deque lacks some features that list has, and that the shift-by-one operation is actually a call to memmove () and may not apply to all implementations.
  • list.pop(0) vs. collections.dequeue - comp.lang.python | Google Gruppi 2 February 2010 17:16 UTC groups.google.it [Source type: FILTERED WITH BAYES]

 ^ The problem with reversing the lists is that it gets sliced and diced and passed around to other methods, one of which, html_block_tag, recursively calls back to the main method.
  • list.pop(0) vs. collections.dequeue - comp.lang.python | Google Gruppi 2 February 2010 17:16 UTC groups.google.it [Source type: FILTERED WITH BAYES]

 ^ Here's a nice example, conveniently titled 40 000 km .
  • xkcd • View topic - Colloquial SI units 2 February 2010 17:16 UTC forums.xkcd.com [Source type: FILTERED WITH BAYES]

 .In these cases an uppercase K is often used, although the uppercase K is the official symbol of the kelvin.^ Although these prefixes are not part of the SI, they should be used in the field of information technology to avoid the incorrect usage of the SI prefixes.
  • PHP Bugs: #46534: Incorrect usage of SI-prefixes by PHP 2 February 2010 17:16 UTC bonsai.php.net [Source type: Reference]

 ^ (I’ve used the durative 3s form for these to emphasize the commonality; but they must agree with their subject in case and person.
  • Old Skourene 2 February 2010 17:16 UTC zompist.com [Source type: FILTERED WITH BAYES]

 ^ Its symbol is the lowercase h-, but the uppercase H- was used before 1960.
  • http://www.bbc.co.uk/dna/h2g2/A29779159 2 February 2010 17:16 UTC www.bbc.co.uk [Source type: FILTERED WITH BAYES]
.In other financial and business contexts, the letter M is often used to denote multiplication by 1000, in recognition of the Latin term mille, also used in roman numerals.^ However, these prefixes have decimal meanings in other contexts, e.g., when used with SI units .
  • Binary prefixes (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

 ^ Donald Morrison proposed to use the Greek letter κ to denote 1024, κ² to denote 1024×1024, and so on.
  • Binary prefixes (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

 ^ Quantities that are multiples of the unit by a power of 2 are indicated using similarly-valued SI prefixes, such as using kilo (the SI prefix for 1000) to indicate 2 10 =1024.
  • Binary prefixes (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

 .In these situations one million is often written as 1 MM.^ By precalcuting one of these domain names and registering it, the gang behind Conficker could take over any or all of the millions of computers they had infected.
  • Black Hat ® Technical Security Conference: USA 2009 // Briefings 2 February 2010 17:16 UTC blackhat.com [Source type: FILTERED WITH BAYES]

 .In other financial situations, one M can mean million, such as £2M or £2m which is equal to £2 000 000. Similar usage of M occurs in the term CPM (Cost per mille) used in advertising.^ The term billion should be avoided since in most countries outside the USA (including the UK) it means a million-million (prefix tera), whereas in the USA it means a thousand million (prefix giga).
  • A concise reference to the Metric System (SI) 2 February 2010 17:16 UTC www.pyxidium.u-net.com [Source type: Reference]

 ^ I've often run applications with millions of lists > I bet even in your application, the amount of memory consumed by the > PyListObjects themselves is greatly dwarfed by other objects, notably > the list elements themselves Such lists often would just one element or even be empty.
  • list.pop(0) vs. collections.dequeue - comp.lang.python | Google Gruppi 2 February 2010 17:16 UTC groups.google.it [Source type: FILTERED WITH BAYES]

 ^ Regarding points #2 and #4, > the tutorial is at least not overly technical or specific; it just > explains the requirement to shift other elements one by one in simple > layman's terms.
  • list.pop(0) vs. collections.dequeue - comp.lang.python | Google Gruppi 2 February 2010 17:16 UTC groups.google.it [Source type: FILTERED WITH BAYES]

Units used in computing and telecommunications

.The International System of Units does not define units of information, such as the storage size units bit and byte.^ The allocated storage is File System defined.
  • DailyTech - A Download for Your Troubles: Seagate Hard Drive Settlement Now Online 2 February 2010 17:16 UTC www.dailytech.com [Source type: FILTERED WITH BAYES]

 ^ But Bytes and bits are not SI units.
  • DailyTech - Nanochip Promises 100GB-per-chip Alternative to Flash Memory 2 February 2010 17:16 UTC www.dailytech.com [Source type: General]

 ^ BIT The unit for binary information ( bit ).
  • SI 2 February 2010 17:16 UTC jscience.org [Source type: Reference]
  • SI (JSR-275 0.9.2-SNAPSHOT API) 2 February 2010 17:16 UTC jsr-275.kenai.com [Source type: Reference]

 .This has allowed ambiguities to emerge with respect to the symbols in use, as well as their usage and meaning in combination with the SI prefixes.^ SI prefixes and symbols for multiples and submultiples.
  • Recommendations concerning Units (SI Units) | IAU 2 February 2010 17:16 UTC www.iau.org [Source type: Reference]

 ^ SI prefix in binary use .
  • Binary prefixes (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

 ^ EVERYBODY IN THE WHOLE WORLD thinks that the SI prefixes mean powers of 2, and there is SO much history behind this usage -- literally DOZENS of years!
  • Coding Horror: Gigabyte: Decimal vs. Binary 2 February 2010 17:16 UTC www.codinghorror.com [Source type: FILTERED WITH BAYES]

 .The bit is often given the symbol bit or b, while byte is usually written as byte, B, and occasionally as b.^ What are the official short symbols for bit and byte?
  • Metric System FAQ 2 February 2010 17:16 UTC www.faqs.org [Source type: Reference]

 ^ In fact, in UNIX (as anywhere else in the IT world), the term "octet" by itself usually refers to bit octets, also known as 8-bit characters, or 8-bit bytes.
  • DailyTech - A Download for Your Troubles: Seagate Hard Drive Settlement Now Online 2 February 2010 17:16 UTC www.dailytech.com [Source type: FILTERED WITH BAYES]

 ^ It is generally accepted that a single binary measure of information, the bit, is described symbolically by a small "b", and the byte consisting of 8 bits as capital "B".
  • A concise reference to the Metric System (SI) 2 February 2010 17:16 UTC www.pyxidium.u-net.com [Source type: Reference]

 .Thus, kb/s often means kilobits per second, but may sometimes refer to kilobytes per second.^ As used in this document, the terms kilobyte (kB) means 2 10 or 1024 bytes, megabyte (MB) means 1024 kilobytes, and gigabyte (GB) means 1024 megabytes."
  • Binary prefixes (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

 ^ There are no SI units for computer storage capacity but the decimal prefix meanings of KB, MB, and GB are often referred to as SI prefixes.
  • Binary prefixes (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

 ^ Secs may sometimes be seen instead of s or seconds .
  • SI (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]
.The National Institute of Standards and Technology in the United States has suggested the use of bit for bits and B for bytes.^ The binary definition of the prefixes k, M, G etc is not permitted by the United States National Institute of Standards and Technology (NIST).
  • Binary prefixes (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

 ^ As of 2000, the units bit and byte have not been accepted for use with SI, but are in widespread use.
  • Representation of numerical values and SI units in character strings for information interchanges 2 February 2010 17:16 UTC people.csail.mit.edu [Source type: Reference]

 ^ But Bytes and bits are not SI units.
  • DailyTech - Nanochip Promises 100GB-per-chip Alternative to Flash Memory 2 February 2010 17:16 UTC www.dailytech.com [Source type: General]

 [9]
In non-standard use, K is often used as a symbol prefix to the units bit and byte to designate the binary prefix kibi = 210 = 1024.

Binary prefixes

Main article: Binary prefix
.The prefixes kilo, mega, giga and greater are often used in combination with the storage size units bit and byte.^ Prefix tera giga mega kilo hecto deca .
  • The International System of Units (SI) 2 February 2010 17:16 UTC www.scribd.com [Source type: Reference]

 ^ Kilo, Mega, Giga etc.
  • DailyTech - A Download for Your Troubles: Seagate Hard Drive Settlement Now Online 2 February 2010 17:16 UTC www.dailytech.com [Source type: FILTERED WITH BAYES]

 ^ As of 2000, the units bit and byte have not been accepted for use with SI, but are in widespread use.
  • Representation of numerical values and SI units in character strings for information interchanges 2 February 2010 17:16 UTC people.csail.mit.edu [Source type: Reference]
.The binary multiple 210 = 1024 is close to the value 1000 of the prefix kilo, therefore computer professionals have historically used the unit kilobyte to refer to 1024 bytes of computer memory, in non-conformance with the SI definition of the prefix kilo.^ The IEC introduced prefixes to represent binary multiples of units.
  • Units in MathML 2 February 2010 17:16 UTC www.w3.org [Source type: Reference]

 ^ As of 2000, the units bit and byte have not been accepted for use with SI, but are in widespread use.
  • Representation of numerical values and SI units in character strings for information interchanges 2 February 2010 17:16 UTC people.csail.mit.edu [Source type: Reference]

 ^ Does kilo mean 1024 in computing?
  • Metric System FAQ 2 February 2010 17:16 UTC www.faqs.org [Source type: Reference]

 .220 = 1048576, which is close to 1000000, has likewise been expressed with the mega prefix.^ As the binary multipliers 1024 (2 10 ), 1 048 576 (2 20 ), etc., are close in value to certain SI prefixes such as kilo (1000 = 10 3 ) and mega ( 1 000 000 = 10 6 ), respectively, it has been common practice amongst computer professionals to use these prefixes for the binary multiples – for example, to use the symbol "M" ("mega") to mean 1 048 576 instead of 1 000 000 .
  • Binary prefixes (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

 ^ M : mega - : megal - : [SI prefix; Gk] large; a million, 106, 1,000,000.
  • Numbers/Prefixes/Suffixes 2 February 2010 17:16 UTC www.arapacana.com [Source type: FILTERED WITH BAYES]

 .This has led to some confusion, because megabyte is commonly used to refer to 1000000bytes in the specifications of hard disk drive capacities and network transmission bit rates.^ Hard Disk Drives are computer memory.
  • DailyTech - A Download for Your Troubles: Seagate Hard Drive Settlement Now Online 2 February 2010 17:16 UTC www.dailytech.com [Source type: FILTERED WITH BAYES]

 ^ Hard drives from all manufacturers use 1 GB = 1 billion bytes.
  • DailyTech - A Download for Your Troubles: Seagate Hard Drive Settlement Now Online 2 February 2010 17:16 UTC www.dailytech.com [Source type: FILTERED WITH BAYES]

 ^ Yes, and the bytes in a 80,000,000 "80GB" hard drive are binary bytes.
  • DailyTech - A Download for Your Troubles: Seagate Hard Drive Settlement Now Online 2 February 2010 17:16 UTC www.dailytech.com [Source type: FILTERED WITH BAYES]
.To eliminate this ambiguity the International Electrotechnical Commission (IEC) adopted new binary prefixes in 1998 (IEC 80000-13:2008 formerly subclauses 3.8 and 3.9 of IEC 60027-2:2005).^ The harmonized ISO / IEC IEC 80000-13:2008 standard cancels and replaces subclauses 3.8 and 3.9 of IEC 60027-2:2005 (those defining Prefixes for binary multiples).
  • Binary prefixes (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

 ^ International Electrotechnical Commission (2005-08-15).
  • Binary prefixes (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

 ^ The IEC introduced binary prefixes in 1998 to correct the confusion resulting from this.
  • Units in MathML 2 February 2010 17:16 UTC www.w3.org [Source type: Reference]

 .Each binary prefix is formed from the first syllable of the decimal prefix with the similar value, and the syllable 'bi' (pronounced 'bee').^ Understand what a prefix is, it is to describe the suffix which is a binary not decimal value.
  • DailyTech - Nanochip Promises 100GB-per-chip Alternative to Flash Memory 2 February 2010 17:16 UTC www.dailytech.com [Source type: General]

 ^ It doesn't make any sense to arrange bytes in decimal values because they are themselves a binary representation, 2^3 bits.
  • Coding Horror: Gigabyte: Decimal vs. Binary 2 February 2010 17:16 UTC www.codinghorror.com [Source type: FILTERED WITH BAYES]

 ^ Only ignorant people who can't understand that there is more than one number system think that a prefix can only exist in the decimal system or has to have a decimal value, that it couldn't be a binary value.
  • DailyTech - Nanochip Promises 100GB-per-chip Alternative to Flash Memory 2 February 2010 17:16 UTC www.dailytech.com [Source type: General]

 The symbols are the decimal symbol, always capitalized, followed by the letter 'i'.
.According to this standard one kilobyte (1 kB) is 1000 bytes, whereas one kibibyte (1 KiB) is 1024 bytes.^ However, it's absolutely false that, according to SI, a kilobyte is 1000 bytes.
  • Coding Horror: Gigabyte: Decimal vs. Binary 2 February 2010 17:16 UTC www.codinghorror.com [Source type: FILTERED WITH BAYES]

 ^ Within the field of computer science, one kilobyte = 1024 bytes.
  • Coding Horror: Gigabyte: Decimal vs. Binary 2 February 2010 17:16 UTC www.codinghorror.com [Source type: FILTERED WITH BAYES]

 ^ Therefore it became convenient to have, e.g., KB = 1024 bytes instead of 1000 bytes.
  • DailyTech - A Download for Your Troubles: Seagate Hard Drive Settlement Now Online 2 February 2010 17:16 UTC www.dailytech.com [Source type: FILTERED WITH BAYES]

 .Likewise mebi (Mi; 220), gibi (Gi; 230), tebi (Ti; 240), pebi (Pi; 250), exbi (Ei; 260), zebi (Zi; 270) and yobi (Yi; 280).^ It now defines new unit prefixes for powers of two: 1024 = 2^10 = 1 024 kibi Ki 1024^2 = 2^20 = 1 048 576 mebi Mi 1024^3 = 2^30 = 1 073 741 824 gibi Gi 1024^4 = 2^40 = 1 099 511 627 776 tebi Ti 1024^5 = 2^50 = 1 125 899 906 842 624 pebi Pi 1024^6 = 2^60 = 1 152 921 504 606 846 976 exbi Ei This way, the 90 mm floppy disk has now unambiguously a capacity of 1400 kibibytes (KiB).
  • Metric System FAQ 2 February 2010 17:16 UTC www.faqs.org [Source type: Reference]

 ^ In the BINARY system of notation K=2^10, M=2^20, G=3^30, T=2^40, P=2^50.
  • DailyTech - A Download for Your Troubles: Seagate Hard Drive Settlement Now Online 2 February 2010 17:16 UTC www.dailytech.com [Source type: FILTERED WITH BAYES]

 ^ In electrical engineering, a jiffy used to be the period of the electrical power grid, namely: 20 ms in Europe (50 Hz) or about 16.6667 ms in the US (60 Hz).
  • Measurements, Units of Measurement, Weights and Measures - Numericana 2 February 2010 17:16 UTC home.att.net [Source type: FILTERED WITH BAYES]
.The use of these new binary prefixes is increasing,[citation needed] but is largely limited to technical literature and new computer software.^ Traditional prefixes in binary use .
  • Binary prefixes (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

 ^ SI prefix in binary use .
  • Binary prefixes (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

 ^ Standard dictionaries do recognize the binary use of these prefixes.
  • Binary prefixes (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

Proposed changes

There are proposals for further harmonisation of the capitalisation. .Therefore the symbols for kilo, hecto, and deca would be changed from ‘k’ to ‘K’, from ‘h’ to ‘H’, and from ‘da’ to ‘D’.^ Original Metric Prefixes (1793): kilo, hecto, deca, (unity), deci, centi, milli] .
  • Humor and Science - Numericana 2 February 2010 17:16 UTC home.att.net [Source type: FILTERED WITH BAYES]

 ^ For example, "kilo", "hecto" and "deca" are used in various countries for 1 kg, 100 g and 10 g when buying groceries.
  • Metric System FAQ 2 February 2010 17:16 UTC www.faqs.org [Source type: Reference]

 .Likewise, some lobby for the removal of prefixes that do not fit the 10±3n scheme, namely hecto, deca, deci, and centi.^ With the exception of da (deca), h (hecto), and k (kilo), all multiple prefix symbols are capital (upper case) letters, and all submultiple prefix symbols are lower case letters.
  • The International System of Units (SI) 2 February 2010 17:16 UTC www.scribd.com [Source type: Reference]

 ^ Because SI prefix symbols can neither be attached to the symbol 1 nor to the name “one”, powers of 10 are used to express the values of particularly large or small dimensionless quantities.
  • The International System of Units (SI) 2 February 2010 17:16 UTC www.scribd.com [Source type: Reference]

 ^ Prefix tera giga mega kilo hecto deca .
  • The International System of Units (SI) 2 February 2010 17:16 UTC www.scribd.com [Source type: Reference]

 The CGPM has postponed its decision on both matters for now.
.An unsolved (and maybe unsolvable) issue is the application of prefixes to units with exponents other than ±1. The prefix is always applied before the exponent.^ Further letters in a unit or prefix are always lowercase.
  • Metric System FAQ 2 February 2010 17:16 UTC www.faqs.org [Source type: Reference]

 ^ This also applies to other larger-scale prefixes such as gigabytes and terabytes.
  • http://www.bbc.co.uk/dna/h2g2/A29779159 2 February 2010 17:16 UTC www.bbc.co.uk [Source type: FILTERED WITH BAYES]

 ^ However, these prefixes have decimal meanings in other contexts, e.g., when used with SI units .
  • Binary prefixes (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

 This eventually led to the introduction of special units for area and volume without exponents in the original metric system:
  • 1 are (a) = 100 m2 (10 m × 10 m = 1 dam × 1 dam = 1 dam2)
    • ⇒ 1 ca = 1 m2 (1 m × 1 m)
    • ⇒ 1 ha = 10 000 m2 (100 m × 100 m = 1 hm × 1 hm = 1 hm2)
  • 1 stere (st) = 1 m3
  • 1 litre (l or L) = 1 dm3 = 1 mst = 0.001 m3
.Of these the litre and the hectare are the most common.^ It also contains the hectare, the litre, and the tonne, which are all in common everyday use throughout the world, and which differ from the corresponding coherent SI unit by an integer power of ten.
  • The International System of Units (SI) 2 February 2010 17:16 UTC www.scribd.com [Source type: Reference]

 .Litre designations are sometimes used to differentiate a volume of liquid (as opposed to a gas, or solid which are usually designated as cubic volumes).^ Symbols are written in upright Roman type (m for metres, l for litres), so as to differentiate from the italic type used for mathematical variables ( m for mass, l for length).
  • International System of Units: Encyclopedia of chemistry, analytics & pharmaceutics with 64,557 entries. 2 February 2010 17:16 UTC www.chemie.de [Source type: Reference]

 ^ Symbols are written in upright ( Roman ) type (m for metres, l for litres), so as to differentiate from the italic type used for variables ( m for mass, l for length).
  • SI (Linux Reviews) 2 February 2010 17:16 UTC linuxreviews.org [Source type: Reference]

 ^ Also back home liquids are usually done in decilitres and solids in decagrams, so we call them "deci" and "deka" respectively.
  • xkcd • View topic - Colloquial SI units 2 February 2010 17:16 UTC forums.xkcd.com [Source type: FILTERED WITH BAYES]

 .Hectares are widely used as a metric alternative to the acre (approximately 2.5 acres to the hectare).^ Although the introduction of the metric system is clearly slowest in the US, compared to any other developed country, it is widely used today in the US in selected areas.
  • Metric System FAQ 2 February 2010 17:16 UTC www.faqs.org [Source type: Reference]

 ^ What inch-based standards are widely used in metric countries?
  • Metric System FAQ 2 February 2010 17:16 UTC www.faqs.org [Source type: Reference]

 ^ Users of the metric system, on the other hand, have to use conversion factors only where there are significant physical reasons for using alternative units to express some situation.
  • Metric System FAQ 2 February 2010 17:16 UTC www.faqs.org [Source type: Reference]
.As of 2010 there is currently a petition to make "hella" the international prefix for 1027.^ There was a legitimate need to compare bandwidth with storage (the Internet), but it also did not make sense to use powers of 2 because bandwidth was actually provided in powers of 10 (bits).
  • Coding Horror: Gigabyte: Decimal vs. Binary 2 February 2010 17:16 UTC www.codinghorror.com [Source type: FILTERED WITH BAYES]

 ^ Or to make it so that kilo always, always, always means 10^3, and create the new prefix to always mean 2^10?
  • Coding Horror: Gigabyte: Decimal vs. Binary 2 February 2010 17:16 UTC www.codinghorror.com [Source type: FILTERED WITH BAYES]

 ^ Funny Prefixes There are no official metric prefixes above 10 24 or below 10 - 24 .
  • Humor and Science - Numericana 2 February 2010 17:16 UTC home.att.net [Source type: FILTERED WITH BAYES]

 .An example would be, the sun has a mass of nearly 2 million hellagrams [1].^ The average distance from the Earth to the Sun is actually a bit larger than that (by a relative amount very nearly equal to a third of the Earth-Sun mass ratio).
  • Measurements, Units of Measurement, Weights and Measures - Numericana 2 February 2010 17:16 UTC home.att.net [Source type: FILTERED WITH BAYES]

See also

References

This article was originally based on material from the Free On-line Dictionary of Computing, which is licensed under the GFDL.
  1. ^ Four Resolutions
  2. ^ http://physics.nist.gov/Pubs/SP811/sec06.html
  3. ^ http://www.bipm.fr/en/si/si_brochure/chapter3/prefixes.html
  4. ^ Self, Kevin (October 1994). "Technically speaking". Spectrum (IEEE): 18. 
  5. ^ Self, Kevin (April 1995). "Technically speaking". Spectrum (IEEE): 16. 
  6. ^ 29th Congress of the United States, Session 1 (1866-05-13). "H.R. 596, An Act to authorize the use of the metric system of weights and measures". http://lamar.colostate.edu/~hillger/laws/metric-act-bill.html. 
  7. ^ D. Brewster (1830). "The Edinburgh Encyclopaedia". p. 494. http://books.google.com/books?id=h6miHpDMjXEC&pg=PA494. 
  8. ^ histoire.du.metre.free.fr
  9. ^ Ambler Thompson, Barry N. Taylor. (2008). Guide for the Use of the International System of Units (SI). Gaithersburg, MD: National Institute of Standards and Technology p. 74. This source recommends B as a symbol for byte, but is silent concerning bits.

External links


Citable sentences

Up to date as of December 19, 2010

Here are sentences from other pages on SI prefix, which are similar to those in the above article.








Got something to say? Make a comment.
Your name
Your email address
Message