1、Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 16/06/2009 04:14, Uncontrolled Copy, (c) BSIg49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58P
2、art 1: General ICS 01.060; 01.075; 29.020Letter symbols to be used in electrical technology BRITISH STANDARDBS EN 60027-1:2006 +A2:2007BS EN 60027-1:2006+A2:2007Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 16/06/2009 04:14, Uncontrolled Copy, (c) BSIThis British Standard was published unde
3、r the authority of the Standards Policy and Strategy Committee on 28 February 2009 BSI 2009ISBN 978 0 580 60194 1Amendments/corrigenda issued since publicationDate CommentsThe UK participation in its preparation was entrusted to Technical Committee SS/7, General metrology, quantities, units and symb
4、ols.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity f
5、rom legal obligations.National forewordThis British Standard is the UK implementation of EN 60027-1:2006+A2:2007. 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 i
6、ndicating changes to IEC text carry the number of the IEC amendment. For example, text altered by IEC amendment 1 is indicated by !“.EUROPEAN STANDARD EN 60027-1:2006+A2 NORME EUROPENNE EUROPISCHE NORM April 2007CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normali
7、sation 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 means reserved worldwide for CENELEC members. Ref. No. EN 60027-1:2006 E ICS 01.060 Supersedes HD 60027
8、-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 60027-1:1995 (Reprint) + A1:1997) Formelzeichen fr die Elektrotechnik Teil 1: Allgemeines (IEC 60027-
9、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 for giving this European Standard the status of a national standard without any alteration. Up-to-dat
10、e 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 official versions (English, French, German). A version in any other language made by translation under
11、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 committees of Austria, Belgium, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany,
12、 Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 16/06/2009 04:14, Uncontrolled Copy, (c)
13、BSIForeword 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 the f
14、ormal 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 _ Endorsem
15、ent 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, prepared
16、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 implement
17、ed 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 IE
18、C 60027-1:1992 was approved by CENELEC as an amendment to the European Standard without any modification. _ Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 16/06/2009 04:14, Uncontrolled Copy, (c) BSIBS EN 60027-1:2006+A2:2007Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 16/06/2009 0
19、4:14, Uncontrolled Copy, (c) BSIBS EN 60027-1:2006+A2:2007Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 16/06/2009 04:14, Uncontrolled Copy, (c) BSI27-1 Qc IEC 9LETTER SYMBOLS TO BE USED IN ELECTRICAL TECHNOLOGYPart 1: GeneralSECTION 0: SCOPEThis part 1 of the International Standard, IEC 27
20、, 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 quantities
21、.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 other modi
22、fying 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 expression of t
23、heir 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 physic
24、al 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 Stand
25、ardized 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 or when
26、, 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.Other
27、 subscripts are printed in roman (upright) type.1) See annex E concerning names for quantities and units. 5 BS EN 60027-1:2006+A2:2007Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 16/06/2009 04:14, Uncontrolled Copy, (c) BSI27-1 IEC 11 Examples:Roman (upright) subscripts Italic (sloping) su
28、bscriptsCg (g: gas) Cp (p: pressure)gn (n: normal) Enan 9,z (n: running number)r (r: relative) 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 (uprigh
29、t) type. However, letter symbols representing numbers areprinted in italic (sloping) type.2 For 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
30、used as distinguishing means but in some cases other distinctionssuch as typographical signs 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
31、in different conductors la, Ib, Ic, etc.minimum value of frequencyfmin.Type variants:instantaneous 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
32、.1 Order of preferenceSubscripts and other distinguishing means that are independent of language (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 oth
33、er distinguishing means which are independent of languagea) SubscriptsSubscripts that are independent 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 rep
34、resent for instance: order, degree of importance, and reference. The subscript 0(zero) is used not only as a number, but also for basic, initial, or reference conditions. 6 BS EN 60027-1:2006+A2:2007Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 16/06/2009 04:14, Uncontrolled Copy, (c) BSI27
35、-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 fundamental and the second and third harmonic components of a current; or current in conductors 1, 2 and 3, orcurrent
36、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 signsEXAMPLE:ico current at infinite time.d) Sequence of lettersThere are occasions when samples of the same physica
37、l 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 are preferred.EXAMPLES:Qa Qb Qc three different electric charges.e) Reference lettersThe subscript indicates
38、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-ticular processes, to particular substances, to particular fields (electrical, mechanical, etc.). Thefollowing few
39、 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, L and Mcould denote current in phase u.f) Quantity or unit symbols used as subscriptsA letter symbol for a
40、 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 loss angle of capacitor of capacitance CW3 h energy capacity of a battery at three hours (3 h) discharge.g)
41、 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 for chemical elements are given in ISO 31-8, Quantities and units Part 8: Physical chemistry and molecularp
42、hysics.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 lower-case letters and some signs ( V “ )should be used as recommended in 2.1. Other recommendations are gi
43、ven for vector quantities andfor complex representation of quantities (1.6).EBSEFA KLMI 7 BS EN 60027-1:2006+A2:2007Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 16/06/2009 04:14, Uncontrolled Copy, (c) BSI27-1 IEC 15 EXAMPLES:i instantaneous value of currentI root-mean-square value of curr
44、entQ 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 the samein
45、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 suchword
46、s 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 words not d
47、erived 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 subscriptsIf
48、 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 the next
49、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 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. Sometime
