1、BRITISH STANDARDBS EN 60027-1:2006 +A2:2007Letter symbols to be used in electrical technology Part 1: General ICS 01.060; 01.075; 29.020g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g3
2、8g50g51g60g53g44g42g43g55g3g47g36g58BS EN 60027-1:2006+A2:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 28 February 2009 BSI 2009ISBN 978 0 580 60194 1National forewordThis British Standard is the UK implementation of EN 60027-1:2006+A2
3、:2007. It is identical with IEC 60027-1:1995, incorporating amendments 1:1997 and 2:2005.The start and finish of text introduced or altered by amendment is indicated in the text by tags. Tags indicating changes to IEC text carry the number of the IEC amendment. For example, text altered by IEC amend
4、ment 1 is indicated by !“.The UK participation in its preparation was entrusted to Technical Committee SS/7, General metrology, quantities, units and symbols.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include
5、 all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments/corrigenda issued since publicationDate CommentsEUROPEAN STANDARD EN 60027-1:2006+A2 NORME EUROPENNE EUROPISCHE N
6、ORM April 2007CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2006 CENELEC - All rights of exploitation in any form and by any m
7、eans reserved worldwide for CENELEC members. Ref. No. EN 60027-1:2006 E ICS 01.060 Supersedes HD 60027-1:2004English version Letter symbols to be used in electrical technology Part 1: General (IEC 60027-1:1995 (Reprint) + A1:1997) Symboles littraux utiliser en lectrotechnique Partie 1: Gnralits (CEI
8、 60027-1:1995 (Reprint) + A1:1997) Formelzeichen fr die Elektrotechnik Teil 1: Allgemeines (IEC 60027-1:1995 (Reprint) + A1:1997) This European Standard was approved by CENELEC on 2006-10-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions
9、 for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three o
10、fficial versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical c
11、ommittees of Austria, Belgium, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kin
12、gdom. Foreword The text of the International Standard IEC 60027-1:1995 (Reprint) + A1:1997, prepared by IEC TC 25, Quantities and units, and their letter symbols, was approved by CENELEC as HD 60027-1:2004 on 2003-12-01. Following BT Decision D125/089, this Harmonization Document was submitted to th
13、e formal vote for conversion into a European Standard and was approved by CENELEC as EN 60027-1 on 2006-10-01. The following date was fixed: latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2007-10-01 _ Endor
14、sement notice The text of the International Standard IEC 60027-1:1995 (Reprint) + A1:1997 was approved by CENELEC as a European Standard without any modification. _ 2 BS EN 60027-1:2006+A2:2007Foreword to amendment A2The text of amendment 2:2005 to the International Standard IEC 60027-1:1992, prepar
15、ed by IEC TC 25, Quantities and units, and their letter symbols, was submitted to the Unique Acceptance Procedure and was approved by CENELEC as amendment A2 to EN 60027-1:2006 on 2007-04-01 without any modification. The following dates were fixed: latest date by which the amendment has to be implem
16、ented at national level by publication of an identical national standard or by endorsement (dop) 2008-04-01 latest date by which the national standards conflicting with the amendment have to be withdrawn (dow) 2010-04-01 _ Endorsement notice The text of amendment 2:2005 to the International Standard
17、 IEC 60027-1:1992 was approved by CENELEC as an amendment to the European Standard without any modification. _ BS EN 60027-1:2006+A2:2007BS EN 60027-1:2006+A2:200727-1 Qc IEC 9LETTER SYMBOLS TO BE USED IN ELECTRICAL TECHNOLOGYPart 1: GeneralSECTION 0: SCOPEThis part 1 of the International Standard,
18、IEC 27, gives information about general quantities, unitsand their letter symbols and mathematical symbols that are to be used in electrical technology. It alsogives rules for writing and printing these symbols and for the use of additional marks (subscripts,superscripts, etc.) with symbols for quan
19、tities.There are no normative references quoted in this International Standard.SECTION 1: RECOMMENDATIONS FOR PRINTING SYMBOLS AND NUMBERS1.1 Symbols for quantities1.1.1 SymbolsThe symbols for quantities 1) are generally single letters of the Latin or Greek alphabet, sometimeswith subscripts or othe
20、r modifying signs. These symbols are printed in italic (sloping) type (irrespec-tive of the type used in the rest of the text).The symbol is not followed by a full stop except for normal punctuation, e.g., at the end of a sentence.NOTES1 Principles that apply to physical quantities and the expressio
21、n of their values in units of the International System of Units(SI) are described in ISO 31-0, Quantities and units Part 0: General principles.2 Notations for vectorial and other non-scalar quantities are given in ISO 31-11, Quantities and units Part 11: Mathematicalsigns and symbols for use in the
22、physical sciences and technology.3 Exceptionally, symbols made up of two letters are sometimes used for combinations of dimension one of quantities (e.g.,Reynolds number: Re). If such a two-letter symbol appears as a factor in a product, it is recommended that it be separatedfrom the other symbols.4
23、 Standardized symbols for quantities and constants generally used in electrical technology are given in section 3, tables 1, 2,3, 4, and 5.1.1.2 Rules for printing of subscripts and use of subscripts in electrical technologyWhen, in a given context, different quantities have the same letter symbol o
24、r when, for one quantity,different applications or different values are of interest, a distinction can be made by use of subscripts.The following principles for the printing of subscripts are recommended:A subscript that represents a symbol for a physical quantity is printed in italic (sloping) type
25、.Other subscripts are printed in roman (upright) type.1) See annex E concerning names for quantities and units. 5 BS EN 60027-1:2006+A2:200727-1 IEC 11 Examples:Roman (upright) subscripts Italic (sloping) subscriptsCg (g: gas) Cp (p: pressure)gn (n: normal) Enan 9,z (n: running number)r (r: relative
26、) Exaxbx (x: running number)Ek (k: kinetic) gik (i, k: running numbers)Xe (e: electric) Px (x: x coordinate)T112 (1/2: half) I2, (A.: wavelength)NOTES1 Numbers as subscripts shall be printed in roman (upright) type. However, letter symbols representing numbers areprinted in italic (sloping) type.2 F
27、or use of subscripts, see also special remarks to ISO 31-6 and ISO 31-10.3 Standardized subscripts for use in electrical technology are given in section 3, tables 6 and 7.In most cases, subscripts should be used as distinguishing means but in some cases other distinctionssuch as typographical signs
28、or variants in type are suitable.In a few cases, it is permissible to use different but related letter symbols.EXAMPLES:Subscripts:magnetic flux density in vacuum Bointrinsic magnetic flux density B,current in different conductors la, Ib, Ic, etc.minimum value of frequencyfmin.Type variants:instanta
29、neous value of current iroot-mean-square value of current Iforce vector F.Typographical signs:peak value of current , I.Different but related letter symbols:three different angles a, $ and y.1.1.3 Rules1.1.3.1 Order of preferenceSubscripts and other distinguishing means that are independent of langu
30、age (Sub-clause 1.1.3.2) andsubscripts of international character (Sub-clause 1.1.3.3) should, as far as possible, be chosen in prefer-ence to other subscripts (Sub-clause 1.1.3.4).1.1.3.2 Subscripts and other distinguishing means which are independent of languagea) SubscriptsSubscripts that are ind
31、ependent of language may be numbers, mathematical symbols and signs,sequences of letters, reference letters, letter symbols for quantities and units and symbols for chemicalelements.b) NumbersNumbers may represent for instance: order, degree of importance, and reference. The subscript 0(zero) is use
32、d not only as a number, but also for basic, initial, or reference conditions. 6 BS EN 60027-1:2006+A2:200727-1 IEC 13 Roman numerals as subscripts should be used sparingly.The letter “1“ and the numeral “1“ are often identical. Care should be taken to avoid ambiguity.EXAMPLES:i7 i2 i3 the fundamenta
33、l and the second and third harmonic components of a current; or current in conductors 1, 2 and 3, orcurrent in the same conductor at three different momentsR50 resistance at a temperature of 50 CR50 resistance at a frequency of 50 HzU99 sparkover voltage with 99% probability.c) Mathematical signsEXA
34、MPLE:ico current at infinite time.d) Sequence of lettersThere are occasions when samples of the same physical quantity that are classified in a sequence maybe distinguished by letter subscripts rather than by number subscripts. Both capital and lower-caseletters may be used, but lower-case letters a
35、re preferred.EXAMPLES:Qa Qb Qc three different electric charges.e) Reference lettersThe subscript indicates the applicability of a symbol in some way, for instance restrictions to particularlocation, to particular points of time, to particular pieces of apparatus or parts of apparatus, to par-ticula
36、r processes, to particular substances, to particular fields (electrical, mechanical, etc.). Thefollowing few examples illustrate the point.EXAMPLES:could denote electric field strength at point Bcould denote length of path from point E to point Fcould denote the area of a triangle with the corners K
37、, L and Mcould denote current in phase u.f) Quantity or unit symbols used as subscriptsA letter symbol for a quantity (or for a unit) when used as a subscript, shall be printed in the same styleas when used as a quantity symbol (or as a unit symbol).EXAMPLES:Cp heat capacity at constant pressure poc
38、 loss angle of capacitor of capacitance CW3 h energy capacity of a battery at three hours (3 h) discharge.g) Symbols for chemical elementsInternationally adopted symbols for chemical elements are independent of language and may be usedas subscripts.EXAMPLE:Qcu resistivity of copper (Cu).NOTE Symbols
39、 for chemical elements are given in ISO 31-8, Quantities and units Part 8: Physical chemistry and molecularphysics.h) Other distinguishing meansFor distinguishing between different types of values (e.g. instantaneous value, root-mean-squarevalue, peak value, minimum value, average value) capital and
40、 lower-case letters and some signs ( V “ )should be used as recommended in 2.1. Other recommendations are given for vector quantities andfor complex representation of quantities (1.6).EBSEFA KLMI 7 BS EN 60027-1:2006+A2:200727-1 IEC 15 EXAMPLES:i instantaneous value of currentI root-mean-square valu
41、e of currentQ average value of electric charged peak value of magnetic fluxH magnetic field strength as a vectore real part of complex permittivity.1.1.3.3 Subscripts of international charactera) Proper namesAbbreviations of proper names are, with extremely few exceptions, the same or practically th
42、e samein all languages. Such abbreviations are therefore of international character, and they may be usedas subscripts.EXAMPLES:Tc Curie temperatureR H Hall coefficient.b) Words derived from Latin and GreekLatin and Greek serve as a basis for most scientific and technical words, and abbreviations of
43、 suchwords are suitable as subscripts.EXAMPLES:Pei electrical powerPcr critical pressurevi initial velocityB; intrinsic magnetic flux densityText external thermodynamic temperatureReg equivalent resistancegn standard (normal) acceleration of free fallMy luminous (visual) exitance.c) International wo
44、rds not derived from Latin and GreekMany words which have been coined for scientific and industrial purposes have an internationalcharacter. Examples of such words are gas, radar, maser. Abbreviations of such words are suitable assubscripts.EXAMPLE:Cg heat capacity in the gas phase.1.1.3.4 Other sub
45、scriptsIf it is not possible in a specific case to find Latin, Greek, or other international words from which toderive an acceptable subscript, arbitrarily chosen letters or numbers are preferred. If such a choice isnot convenient, subscripts derived from words that are common to many languages are
46、the next bestchoice.1.1.3.5 Some observationsWhen a subscript is not self-explanatory, its meaning should be stated.Subscripts, whether they conform to these recommendations or not, may be ambiguous; thus i(roman, upright) may mean initial, induced or intrinsic. Ambiguity can often be avoided by the
47、 useof longer subscripts, as ini for initial, ind for induced, and intr for intrinsic.Subscripts which are abbreviations of words other than proper names are, as a rule written withlower-case letters. Sometimes it is practical to use both capital and lower-case letters for such 8 BS EN 60027-1:2006+
48、A2:2007Rm maxbv14(2)LmnZ12,13J3yJy327-1 IEC 17 making a difference in their significance which must be defined. Thus, in a certain context a capitalletter subscript may be used for the total value of a quantity and lower-case letter subscripts for itscomponents. In another context capital letter sub
49、scripts may be used for external quantities andlower-case letter subscripts for internal ones.1.1.3.6 Multiple subscriptsThe use of a subscript consisting of several parts, a multiple subscript, should be avoided if possible.When a multiple subscript is used the parts should be placed on the same level. The only exceptionmay be when a letter symbol consisting of a letter with a subscript is used as subscript, e.g. for the tem-perature coefficient (a) of reluctance (Rm), then the total s
