Letter symbols to be used in electrical technology - Part 3: Logarithmic and related quantities, and their units

Applies to logarithmic quantities and units. Quantities that can be expressed as the logarithm of a dimensionless quantity, such as the ratio of two physical quantities of the same kind, can be regarded and treated in different ways. In many cases, differences do not affect practical treatment.

Formelzeichen für die Elektrotechnik - Teil 3: Logarithmische und verwandte Größen und ihre Einheiten

Symboles littéraux à utiliser en électrotechnique - Partie 3: Grandeurs logarithmiques et connexes, et leurs unités

La présente norme s'applique aux grandeurs et unités logarithmiques. Les grandeurs exprimables au moyen du logarithme d'une grandeur sans dimension, qui peut être, par exemple, un rapport de deux grandeurs physiques de même nature, peuvent être interprétées et traitées de différentes manières. Mais, dans beaucoup de cas, ces différences dans les principes n'affectent pas l'utilisation pratique.

Črkovni simboli za uporabo v elektrotehnologiji - 3. del: Logaritmične in z njimi povezane veličine in njihove enote (IEC 60027-3:2002)

General Information

Status
Published
Publication Date
04-Jan-2007
Current Stage
6060 - Document made available
Due Date
05-Jan-2007
Completion Date
05-Jan-2007

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SLOVENSKI STANDARD
SIST EN 60027-3:2008
01-januar-2008
1DGRPHãþD
SIST HD 60027-3:2004

ýUNRYQLVLPEROL]DXSRUDERYHOHNWURWHKQRORJLMLGHO/RJDULWPLþQHLQ]QMLPL

SRYH]DQHYHOLþLQHLQQMLKRYHHQRWH ,(&

Letter symbols to be used in electrical technology - Part 3: Logarithmic and related

quantities, and their units (IEC 60027-3:2002)

Formelzeichen für die Elektrotechnik - Teil 3: Logarithmische und verwandte Größen und

ihre Einheiten (IEC 60027-3:2002)

Symboles littéraux a utiliser en électrotechnique - Partie 3: Grandeurs logarithmiques et

connexes, et leurs unités (IEC 60027-3:2002)
Ta slovenski standard je istoveten z: EN 60027-3:2007
ICS:
01.060 9HOLþLQHLQHQRWH Quantities and units
01.075 Simboli za znake Character symbols
29.020 Elektrotehnika na splošno Electrical engineering in
general
SIST EN 60027-3:2008 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
EUROPEAN STANDARD
EN 60027-3
NORME EUROPÉENNE
January 2007
EUROPÄISCHE NORM
ICS 01.075; 01.060 Supersedes HD 60027-3:2004
English version
Letter symbols to be used in electrical technology
Part 3: Logarithmic and related quantities, and their units
(IEC 60027-3:2002)
Symboles littéraux à utiliser Formelzeichen für die Elektrotechnik
en électrotechnique Teil 3: Logarithmische und verwandte
Partie 3: Grandeurs logarithmiques Größen und ihre Einheiten
et connexes, et leurs unités (IEC 60027-3:2002)
(CEI 60027-3:2002)

This European Standard was approved by CENELEC on 2006-12-01. 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-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 official 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 committees 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 Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2007 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 60027-3:2007 E
---------------------- Page: 2 ----------------------
EN 60027-3:2007 – 2 –
Foreword

The text of the International Standard IEC 60027-3:2002, prepared by IEC TC 25, Quantities and

units, and their letter symbols, was approved by CENELEC as HD 60027-3:2004 on 2003-12-01.

This Harmonization Document was submitted to the formal vote for conversion into a European

Standard and was approved by CENELEC as EN 60027-3 on 2006-12-01.
This European Standard supersedes HD 60027-3:2004.
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) 2007-12-01
Annex ZA has been added by CENELEC.
__________
Endorsement notice

The text of the International Standard IEC 60027-3:2002 was approved by CENELEC as a European

Standard without any modification.
__________
---------------------- Page: 3 ----------------------
– 3 – EN 60027-3:2007
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following referenced documents 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.

NOTE Where an International Publication has been modified by common modifications, indicated by (mod), the relevant

EN/HD applies.
Publication Year Title EN/HD Year
IEC 60027-2 2000 Letter symbols to be used in electrical HD 60027-2 2003
technology
Part 2: Telecommunications and electronics
ISO 31-0 1992 Quantities and units - -
Part 0: General principles
ISO 31-2 1992 Quantities and units - -
Part 2: Periodic and related phenomena
ISO 31-7 1992 Quantities and units - -
Part 7: Acoustics
ISO 31-11 1992 Quantities and units - -
Part 11: Mathematical signs and symbols for
use in the physical sciences and technology
ISO/IEC 2382-16 1996 Information technology – Vocabulary - -
Part 16: Information theory
---------------------- Page: 4 ----------------------
NORME CEI
INTERNATIONALE IEC
60027-3
INTERNATIONAL
Troisième édition
STANDARD
Third edition
2002-07
Symboles littéraux à utiliser
en électrotechnique –
Partie 3:
Grandeurs logarithmiques et connexes,
et leurs unités
Letter symbols to be used
in electrical technology –
Part 3:
Logarithmic and related quantities,
and their units
 IEC 2002 Droits de reproduction réservés  Copyright - all rights reserved

Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in any

utilisée sous quelque forme que ce soit et par aucun procédé, form or by any means, electronic or mechanical, including

électronique ou mécanique, y compris la photocopie et les photocopying and microfilm, without permission in writing from

microfilms, sans l'accord écrit de l'éditeur. the publisher.

International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland

Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch Web: www.iec.ch

CODE PRIX
Commission Electrotechnique Internationale PRICE CODE
International Electrotechnical Commission
Международная Электротехническая Комиссия
Pour prix, voir catalogue en vigueur
For price, see current catalogue
---------------------- Page: 5 ----------------------
60027-3  IEC:2002 – 3 –
CONTENTS

FOREWORD .......................................................................................................................... 5

1 Scope .............................................................................................................................. 7

2 Normative references....................................................................................................... 7

3 Logarithmic quantities...................................................................................................... 7

4 Logarithmic ratios of field quantities and power quantities................................................ 9

4.1 Logarithmic ratios of field quantities........................................................................ 9

4.2 Logarithmic ratios of power quantities....................................................................13

4.3 Levels....................................................................................................................17

4.4 Additional information on logarithmic ratios of field quantities and power

quantities...............................................................................................................19

5 Logarithmic information-theory quantities........................................................................21

6 Other logarithmic quantities ............................................................................................23

6.1 General .................................................................................................................23

6.2 Logarithmic frequency interval ...............................................................................23

7 Names, symbols, and definitions.....................................................................................25

---------------------- Page: 6 ----------------------
60027-3  IEC:2002 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LETTER SYMBOLS TO BE USED IN ELECTRICAL TECHNOLOGY –
Part 3: Logarithmic and related quantities, and their units
FOREWORD

1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising

all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote

international co-operation on all questions concerning standardization in the electrical and electronic fields. To

this end and in addition to other activities, the IEC publishes International Standards. Their preparation is

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. The IEC collaborates closely with the International

Organization for Standardization (ISO) in accordance with conditions determined by agreement between the

two organizations.

2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an

international consensus of opinion on the relevant subjects since each technical committee has representation

from all interested National Committees.

3) The documents produced have the form of recommendations for international use and are published in the form

of standards, technical specifications, technical reports or guides and they are accepted by the National

Committees in that sense.

4) In order to promote international unification, IEC National Committees undertake to apply IEC International

Standards transparently to the maximum extent possible in their national and regional standards. Any

divergence between the IEC Standard and the corresponding national or regional standard shall be clearly

indicated in the latter.

5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any

equipment declared to be in conformity with one of its standards.

6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject

of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.

International Standard IEC 60027-3 has been prepared by IEC technical committee 25:

Quantities and units, and their letter symbols.

This third edition of IEC 60027-3 cancels and replaces the second edition published in 1989,

its amendment 1 (2000) and constitutes a technical revision.
The text of this standard is based on the following documents:
FDIS Report on voting
25/251/FDIS 25/253/RVD

Full information on the voting for the approval of this standard can be found in the report on

voting indicated in the above table.

This publication has been drafted in accordance with the ISO/IEC Directives, Part 3.

The committee has decided that the contents of this publication will remain unchanged until

2007. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
---------------------- Page: 7 ----------------------
60027-3  IEC:2002 – 7 –
LETTER SYMBOLS TO BE USED IN ELECTRICAL TECHNOLOGY –
Part 3: Logarithmic and related quantities, and their units
1 Scope

This part of IEC 60027 gives general information about logarithmic and related quantities, and

their units. Names and symbols for logarithmic quantities are given in other parts of

IEC 60027, mainly in part 2, in the context where they belong.
2 Normative references

The following referenced documents 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 60027-2:2000, Letter symbols to be used in electrical technology – Part 2: Telecom-

munications and electronics
ISO 31-0:1992, Quantities and units – Part 0: General principles
ISO 31-2:1992, Quantities and units – Part 2: Periodic and related phenomena
ISO 31-7:1992, Quantities and units – Part 7: Acoustics

ISO 31-11:1992, Quantities and units – Part 11: Mathematical signs and symbols for use in

the physical sciences and technology

ISO/IEC 2382-16:1996, Information technology – Vocabulary – Part 16: Information theory

3 Logarithmic quantities

Logarithmic quantities are quantities defined by means of logarithmic functions. For a

definition of a logarithmic quantity to be complete, the base of the logarithm must be

specified.

Depending on the source of the argument of the logarithm, logarithmic quantities may be

classified as follows:

a) logarithmic ratios which are defined by the logarithm of the ratio of two field quantities

of the same kind or of two power quantities of the same kind, for example attenuations

and gains in telecommunication, where the argument may be the ratio of two electric

currents or powers, and levels in acoustics, where the argument may be the ratio of a

sound pressure or a sound power to a reference quantity of the same kind;
---------------------- Page: 8 ----------------------
60027-3  IEC:2002 – 9 –

b) logarithmic quantities, in which the argument is given explicitly as a number, for

example logarithmic information-theory quantities, such as decision content, where the

argument is a number of mutually exclusive events, and information content, where the

argument is the reciprocal of a probability;
c) other logarithmic quantities.

In the set of logarithmic and related quantities there are also included quantities which are a

linear combination of logarithmic quantities, or a derivative of a logarithmic quantity, or a

quotient of a logarithmic quantity and another quantity, for example attenuation coefficient.

The logarithm to any specified base of an argument gives the same information about the

situation under consideration, as does the argument itself. Quantities defined with logarithms

of different bases are proportional to each other, but have different values and thus are

different quantities. In a given field of application, only logarithms of one base shall be used

to define logarithmic quantities. Because of the proportionality between the logarithms it is

possible to express the numerical values using different bases of the logarithm together with

different units. To avoid ambiguities in applications the unit shall be written out explicitly after

the numerical value in a logarithmic quantity.
NOTE 1 In this part of IEC 60027, complex quantities are deno
...

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