BS EN 80000-13-2008 Quantities and units –– nPart 13 Information science nand technology《量和单位 信息科学和技术》.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI British StandardsWB9423_BSI_StandardColCov_noK_AW:BSI FRONT COVERS 5/9/08 12:55 Page 1Quantities and units Part 13: Information scienceand technologyBS EN 80000-13:2008NO COPYING WITHOUT BSI PERMISSI

2、ON EXCEPT AS PERMITTED BY COPYRIGHT LALicensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 31/05/2009 04:19, Uncontrolled Copy, (c) BSINational forewordThis British Standard is the UK implementation of EN 80000-13:2008. It isidentical to IEC 80000-13:2008. It partially supersedes BS EN 60027-2:200

3、7, specifically Subclauses 3.8 and 3.9.The UK participation in its preparation was entrusted to TechnicalCommittee SS/7, General metrology, quantities, units and symbols.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport

4、 to include all the necessary provisionsof a contract. Users are responsible for its correct application. BSI 2008ISBN 978 0 580 59469 4ICS 01.060; 35.020Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of the Sta

5、ndardsPolicy and Strategy Committee on Amendments issued since publicationAmd. No. Date Text affectedBRITISH STANDARDBS EN 80000-13:200831 January 2009. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 31/05/2009 04:19, Uncontrolled Copy, (c) BSI 2 80000-13 IEC:2008 CONTENTS INTRODUCTION.5 0.1

6、 Arrangements of the tables .5 0.2 Tables of quantities .5 0.3 Tables of units.5 0.3.1 General .5 0.3.2 Remark on units for quantities of dimension one, or dimensionless quantities.6 0.4 Numerical statements in this International Standard 6 1 Scope.9 2 Normative references .9 3 Names, definitions an

7、d symbols .9 4 Prefixes for binary multiples .24 Bibliography25 BS EN 80000-13:2008Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 31/05/2009 04:19, Uncontrolled Copy, (c) BSI80000-13 IEC:2008 3 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ QUANTITIES AND UNITS Part 13: Information science and

8、technology FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-operation on all questions concerning standardiza

9、tion in the electrical and electronic fields. To this end and in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their preparation is

10、entrusted to technical committees; any IEC National Committee interested in the subject dealt with may participate in this preparatory work. International, governmental and non-governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely with the In

11、ternational Organization for Standardization (ISO) in accordance with conditions determined by agreement between the two organizations. 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international consensus of opinion on the relevant subjects sin

12、ce each technical committee has representation from all interested IEC National Committees. 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National Committees in that sense. While all reasonable efforts are made to ensure that the technical content

13、 of IEC Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any misinterpretation by any end user. 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications transparently to the maximum extent possible

14、in their national and regional publications. Any divergence between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter. 5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any equipment

15、declared to be in conformity with an IEC Publication. 6) All users should ensure that they have the latest edition of this publication. 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and members of its technical committees and IEC Nat

16、ional Committees for any personal injury, property damage or other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications. 8) Attention

17、is drawn to the Normative references cited in this publication. Use of the referenced publications is indispensable for the correct application of this publication. 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent rights. IEC sha

18、ll not be held responsible for identifying any or all such patent rights. International Standard IEC 80000-13 has been prepared by IEC technical committee 25: Quantities and units, and their letter symbols. This standard cancels and replaces subclauses 3.8 and 3.9 of IEC 60027-2:2005. The only signi

19、ficant change is the addition of explicit definitions for some quantities. The text of this standard is based on the following documents: FDIS Report on voting 25/371/FDIS 25/377/RVD Full information on the voting for the approval of this standard can be found in the report on voting indicated in th

20、e above table. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. BS EN 80000-13:2008Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 31/05/2009 04:19, Uncontrolled Copy, (c) BSI80000-13 IEC:2008 5 INTRODUCTION 0.1 Arrangements of the tables The tables of quan

21、tities and units in ISO/IEC 80000 are arranged so that the quantities are presented on the left-hand pages and the units on the corresponding right-hand pages. All units between two full lines on the right-hand pages belong to the quantities between the corresponding full lines on the left-hand page

22、s. Where the numbering of an item has been changed in the revision of a part of IEC 60027, the number in the preceding edition is shown in parenthesis on the left-hand page under the new number for the quantity; a dash is used to indicate that the item in question did not appear in the preceding edi

23、tion. 0.2 Tables of quantities The names in English and in French of the most important quantities within the field of this document are given together with their symbols and, in most cases, their definitions. These names and symbols are recommendations. The definitions are given for identification

24、of the quantities in the International System of Quantities (ISQ), listed on the left hand pages of Table 1; they are not intended to be complete. The scalar, vectorial or tensorial character of quantities is pointed out, especially when this is needed for the definitions. In most cases only one nam

25、e and only one symbol for the quantity are given; where two or more names or two or more symbols are given for one quantity and no special distinction is made, they are on an equal footing. When two types of italic letters exist (for example as with and ; and ; a and a; g and g) only one of these is

26、 given. This does not mean that the other is not equally acceptable. It is recommended that such variants should not be given different meanings. A symbol within parenthesis implies that it is a reserve symbol, to be used when, in a particular context, the main symbol is in use with a different mean

27、ing. In this English edition the quantity names in French are printed in an italic font, and are preceded by fr. The gender of the French name is indicated by (m) for masculine and (f) for feminine, immediately after the noun in the French name. 0.3 Tables of units 0.3.1 General The names of units f

28、or the corresponding quantities are given together with the international symbols and the definitions. These unit names are language-dependent, but the symbols are international and the same in all languages. For further information, see the SI Brochure (8thedition 2006) from BIPM and ISO 80000-1 (u

29、nder preparation). The units are arranged in the following way: a) The coherent SI units are given first. The SI units have been adopted by the General Conference on Weights and Measures (Confrence Gnrale des Poids et Mesures, CGPM). The use of coherent SI units, and their decimal multiples and subm

30、ultiples formed with the SI prefixes are recommended, although the decimal multiples and submultiples are not explicitly mentioned. b) Some non-SI units are then given, being those accepted by the International Committee for Weights and Measures (Comit International des Poids et Mesures, CIPM), or b

31、y the International Organization of Legal Metrology (Organisation Internationale de Mtrologie Lgale, OIML), or by ISO and IEC, for use with the SI. BS EN 80000-13:2008Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 31/05/2009 04:19, Uncontrolled Copy, (c) BSI 6 80000-13 IEC:2008 Such units ar

32、e separated from the SI units in the item by use of a broken line between the SI units and the other units. c) Non-SI units currently accepted by the CIPM for use with the SI are given in small print (smaller than the text size) in the “Conversion factors and remarks” column. d) Non-SI units that ar

33、e not recommended are given only in annexes in some parts of ISO/IEC 80000. These annexes are informative, in the first place for the conversion factors, and are not integral parts of the standard. These deprecated units are arranged in two groups: 1) units in the CGS system with special names; 2) u

34、nits based on the foot, pound, second, and some other related units. e) Other non-SI units given for information, especially regarding the conversion factors, are given in another informative annex. 0.3.2 Remark on units for quantities of dimension one, or dimensionless quantities The coherent unit

35、for any quantity of dimension one, also called a dimensionless quantity, is the number one, symbol 1. When the value of such a quantity is expressed, the unit symbol 1 is generally not written out explicitly. EXAMPLE Refractive index n = 1,53 1 = 1,53 Prefixes shall not be used to form multiples or

36、submultiples of this unit. Instead of prefixes, powers of 10 are recommended. EXAMPLE Reynolds number Re = 1,32 103Considering that plane angle is generally expressed as the ratio of two lengths and solid angle as the ratio of two areas, in 1995 the CGPM specified that, in the SI, the radian, symbol

37、 rad, and steradian, symbol sr, are dimensionless derived units. This implies that the quantities plane angle and solid angle are considered as derived quantities of dimension one. The units radian and steradian are thus equal to one; they may either be omitted, or they may be used in expressions fo

38、r derived units to facilitate distinction between quantities of different kinds but having the same dimension. 0.4 Numerical statements in this International Standard The sign = is used to denote “is exactly equal to”, the sign is used to denote “is approximately equal to”, and the sign := is used t

39、o denote “is by definition equal to”. Numerical values of physical quantities that have been experimentally determined always have an associated measurement uncertainty. This uncertainty should always be specified. In this standard, the magnitude of the uncertainty is represented as in the following

40、 example. EXAMPLE l = 2,347 82(32) m BS EN 80000-13:2008Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 31/05/2009 04:19, Uncontrolled Copy, (c) BSI80000-13 IEC:2008 7 In this example, l = a(b) m, the numerical value of the uncertainty b indicated in parentheses is assumed to apply to the las

41、t (and least significant) digits of the numerical value a of the length l. This notation is used when b represents one standard uncertainty (estimated standard deviation) in the last digits of a. The numerical example given above may be interpreted to mean that the best estimate of the numerical val

42、ue of the length l, when l is expressed in the unit metre, is 2,347 82, and that the unknown value of l is believed to lie between (2,347 82 0,000 32) m and (2,347 82 + 0,000 32) m with a probability determined by the standard uncertainty 0,000 32 m and the probability distribution of the values of

43、l. BS EN 80000-13:2008Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 31/05/2009 04:19, Uncontrolled Copy, (c) BSI 8 80000-13 IEC:2008 Blank page BS EN 80000-13:2008Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 31/05/2009 04:19, Uncontrolled Copy, (c) BSI80000-13 IEC:2008 9 QUANTITIE

44、S AND UNITS Part 13: Information science and technology 1 Scope In IEC 80000-13 names, symbols and definitions for quantities and units used in information science and technology are given. Where appropriate, conversion factors are also given. 2 Normative references The following referenced document

45、s are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60027-3:2002, Letter symbols to be used in electrical technology Part 3: Logar

46、ithmic and related quantities, and their units IEC 60050-704:1993, International electrotechnical vocabulary Part 704: Transmission IEC 60050-713:1998, International electrotechnical vocabulary Part 713: Radiocommuni-cations: transmitters, receivers, networks and operation IEC 60050-715:1996, Intern

47、ational electrotechnical vocabulary Part 715: Telecommuni-cation networks, teletraffic and operation IEC 60050-721:1991, International electrotechnical vocabulary Part 721: Telegraphy, fac-simile and data communication ISO/IEC 2382-16:1996, Information technology Vocabulary Part 16: Information theo

48、ry 3 Names, definitions and symbols The names, definitions and symbols for quantities and units of information science and technology are given in the tables on the following pages. Prefixes for binary multiples are also given. BS EN 80000-13:2008Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS

49、, 31/05/2009 04:19, Uncontrolled Copy, (c) BSI 10 80000-13 IEC:2008 INFORMATION SCIENCE AND TECHNOLOGY QUANTITIES Item No. Name Symbol Definition Remarks 13-1 (801) traffic intensity fr intensit (f) de trafic A number of simultaneously busy resources in a particular pool of resources See IEC 60050-715, item 715-05-02. 13-2 (802) traffic offered intensity fr intensit (f) de trafic offert oAtraffic intensity (item 13-1) of the traffic that would have been generated by the users