IEC/DIS 80000-6

Quantities and units

Grandeurs et unités

Standards Content (sample)

DRAFT INTERNATIONAL STANDARD
IEC/DIS 80000-6
ISO/TC 12 Secretariat: SIS
Voting begins on: Voting terminates on:
2020-01-07 2020-03-31
Quantities and units —
Part 6:
Electromagnetism
Grandeurs et unités —
Partie 6: Électromagnétisme
ICS: 01.060
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
This document is circulated as received from the committee secretariat.
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
This draft is submitted to a parallel vote in ISO and in IEC.
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
IEC/DIS 80000-6:2020(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. IEC, 2020
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25 INTERNATIONAL ELECTROTECHNICAL COMMISSION
26 ____________
28 QUANTITIES AND UNITS –
30 Part 6: Electromagnetism
33 FOREWORD

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

35 electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-operation on all questions

36 concerning standardization in the electrical and electronic fields. To this end and in addition to other activities, IEC publishes

37 International Standards, Technical Specifications, Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter

38 referred to as “IEC Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested in

39 the subject dealt with may participate in this preparatory work. International, governmental and non-governmental organizations

40 liaising with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for

41 Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.

42 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international consensus of opinion

43 on the relevant subjects since each technical committee has representation from all interested IEC National Committees.

44 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National Committees in that

45 sense. While all reasonable efforts are made to ensure that the technical content of IEC Publications is accurate, IEC cannot be held

46 responsible for the way in which they are used or for any misinterpretation by any end user.

47 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications transparently to the

48 maximum extent possible in their national and regional publications. Any divergence between any IEC Publication and the

49 corresponding national or regional publication shall be clearly indicated in the latter.

50 5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any equipment declared to be in

51 conformity with an IEC Publication.

52 6) All users should ensure that they have the latest edition of this publication.

53 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and members of its technical

54 committees and IEC National Committees for any personal injury, property damage or other damage of any nature whatsoever,

55 whether direct or indirect, or for costs (including legal fees) and expenses arising out of the publication, use of, or reliance upon, this

56 IEC Publication or any other IEC Publications.

57 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is indispensable for the

58 correct application of this publication.

59 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent rights. IEC shall not

60 be held responsible for identifying any or all such patent rights.

61 International Standard IEC 80000-6 has been prepared by IEC technical committee 25: Quantities

62 and units, and their letter symbols in close cooperation with ISO/TC 12, Quantities, units, symbols,

63 conversion factors.

64 This second edition of IEC 80000-6 cancels and replaces the first edition published in 2008.

65 The text of this standard is based on the following documents:
FDIS Report on voting
XX/XX/FDIS XX/XX/RVD

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

68 indicated in the above table.

69 This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

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

71 maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in the data

72 related to the specific publication. At this date, the publication will be
73 • reconfirmed,
74 • withdrawn,
75 • replaced by a revised edition, or
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25 INTERNATIONAL ELECTROTECHNICAL COMMISSION
26 ____________
28 QUANTITIES AND UNITS –
30 Part 6: Electromagnetism
33 FOREWORD

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

35 electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-operation on all questions

36 concerning standardization in the electrical and electronic fields. To this end and in addition to other activities, IEC publishes

37 International Standards, Technical Specifications, Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter

38 referred to as “IEC Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested in

39 the subject dealt with may participate in this preparatory work. International, governmental and non-governmental organizations

40 liaising with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for

41 Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.

42 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international consensus of opinion

43 on the relevant subjects since each technical committee has representation from all interested IEC National Committees.

44 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National Committees in that

45 sense. While all reasonable efforts are made to ensure that the technical content of IEC Publications is accurate, IEC cannot be held

46 responsible for the way in which they are used or for any misinterpretation by any end user.

47 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications transparently to the

48 maximum extent possible in their national and regional publications. Any divergence between any IEC Publication and the

49 corresponding national or regional publication shall be clearly indicated in the latter.

50 5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any equipment declared to be in

51 conformity with an IEC Publication.

52 6) All users should ensure that they have the latest edition of this publication.

53 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and members of its technical

54 committees and IEC National Committees for any personal injury, property damage or other damage of any nature whatsoever,

55 whether direct or indirect, or for costs (including legal fees) and expenses arising out of the publication, use of, or reliance upon, this

56 IEC Publication or any other IEC Publications.

57 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is indispensable for the

58 correct application of this publication.

59 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent rights. IEC shall not

60 be held responsible for identifying any or all such patent rights.

61 International Standard IEC 80000-6 has been prepared by IEC technical committee 25: Quantities

62 and units, and their letter symbols in close cooperation with ISO/TC 12, Quantities, units, symbols,

63 conversion factors.

64 This second edition of IEC 80000-6 cancels and replaces the first edition published in 2008.

65 The text of this standard is based on the following documents:
FDIS Report on voting
XX/XX/FDIS XX/XX/RVD

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

68 indicated in the above table.

69 This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

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

71 maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in the data

72 related to the specific publication. At this date, the publication will be
73 • reconfirmed,
74 • withdrawn,
75 • replaced by a revised edition, or
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76 • amended.

77 IEC 80000 consists of the following parts, under the general title Quantities and units:

78 – Part 6: Electromagnetism
79 – Part 13: Information science and technology
80 – Part 15: Logarithmic and related quantities, and their units
81 – Part 16: Printing and writing rules
82 – Part 17: Time dependency
83 The following parts are published by ISO:
84 – Part 1: General

85 – Part 2: Mathematical signs and symbols to be used in the natural sciences and technology

86 – Part 3: Space and time
87 – Part 4: Mechanics
88 – Part 5: Thermodynamics
89 – Part 7: Light
90 – Part 8: Acoustics
91 – Part 9: Physical chemistry and molecular physics
92 – Part 10: Atomic and nuclear physics
93 – Part 11: Characteristic numbers
94 – Part 12: Condensed matter physics
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97 0 Introduction
98 0.1 Arrangements of the tables

99 Where the numbering of an item has been changed in the revision of a part of IEC 80000 or

100 ISO 80000, the number in the preceding edition is shown in parenthesis on the left-hand page under

101 the new number for the quantity; a dash is used to indicate that the item in question did not appear in

102 the preceding edition.
103 0.2 Tables of quantities

104 The names in English of the most important quantities within the field of this document are given

105 together with their symbols and, in most cases, their definitions. The definitions are given for

106 identification of the quantities in the International System of Quantities (ISQ), listed in Table 1; they

107 are not intended to be complete.

108 The scalar, vectorial or tensorial character of quantities is pointed out, especially when this is

109 needed for the definitions.

110 In most cases only one name and only one symbol for the quantity are given; where two or more

111 names or two or more symbols are given for one quantity and no special distinction is made, they are

112 on an equal footing. When two types of italic letters exist (for example as with ϑ and θ; φ and φ; a

113 and a; g and g) only one of these is given. This does not mean that the other is not equally

114 acceptable. It is recommended that such variants should not be given different meanings. A symbol

115 within parenthesis implies that it is a reserve symbol, to be used when, in a particular context, the

116 main symbol is in use with a different meaning.
117 0.3 Units
118 0.3.1 General

119 The names of units for the corresponding quantities are given together with the international symbols

120 and the definitions. These unit names are language-dependent, but the symbols are international and

121 the same in all languages. For further information, see the SI Brochure (9 edition 2019) from BIPM

122 and ISO 80000-1.
123 The units are arranged in the following way:

124 a) The coherent SI units are given first. The SI units have been adopted by the General

125 Conference on Weights and Measures (Conférence Générale des Poids et Mesures, CGPM).

126 The use of coherent SI units, and their decimal multiples and submultiples formed with the SI

127 prefixes are recommended, although the decimal multiples and submultiples are not explicitly

128 mentioned. The order of the units is kg, m, s, A, K, mol, cd.

129 b) Some non-SI units are then given, being those accepted by the International Committee for

130 Weights and Measures (Comité International des Poids et Mesures, CIPM), or by the

131 International Organization of Legal Metrology (Organisation Internationale de Métrologie Légale,

132 OIML), or by ISO and IEC, for use with the SI.

133 c) Non-SI units that are not recommended are given only in annexes in some parts of ISO 80000

134 and IEC 80000. These annexes are informative, in the first place for the conversion factors, and

135 are not integral parts of the standard. These deprecated units are arranged in two groups:

136 1) units in the CGS system with special names;
137 2) units based on the foot, pound, and some other related units.

138 0.3.2 Remark on units for quantities of dimension one, or dimensionless quantities

139 The coherent unit for any quantity of dimension one, also called a dimensionless quantity, is the

140 number one, symbol 1. When the value of such a quantity is expressed, the unit symbol 1 is

141 generally not written out explicitly.
142 EXAMPLE
143 Refractive index n = 1,53 × 1 = 1,53
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144 Prefixes shall not be used to form multiples or submultiples of this unit. Instead of prefixes, powers of

145 10 are recommended.
146 EXAMPLE
147 Reynolds number Re = 1,32 × 10

148 Considering that plane angle is generally expressed as the ratio of two lengths and solid angle as the

149 ratio of two areas, in 1995 the CGPM specified that, in the SI, the radian, symbol rad, and steradian,

150 symbol sr, are dimensionless derived units. This implies that the quantities plane angle and solid

151 angle are considered as derived quantities of dimension one. The units radian and steradian are thus

152 equal to one; they may either be omitted, or they may be used in expressions for derived units to

153 facilitate distinction between quantities of different kinds but having the same dimension.

154 0.4 Numerical statements in this standard

155 The sign = is used to denote “is exactly equal to” and the sign ≈ is used to denote “is approximately

156 equal to”.

157 Numerical values of physical quantities that have been experimentally determined always have an

158 associated measurement uncertainty. This uncertainty should always be specified. In this standard,

159 the magnitude of the uncertainty is represented as in the following example.
160 EXAMPLE
161 l = 2,347 82(32) m

162 In this example, l = a(b) m, the numerical value of the uncertainty b indicated in parentheses is

163 assumed to apply to the last (and least significant) digits of the numerical value a of the length l. This

164 notation is used when b represents one standard uncertainty (estimated standard deviation) in the

165 last digits of a. The numerical example given above may be interpreted to mean that the best

166 estimate of the numerical value of the length l, when l is expressed in the unit metre, is 2,347 82 and

167 that the unknown value of l is believed to lie between (2,347 82 −0,000 32) m and (2,347 82

168 +0,000 32) m with a probability determined by the standard uncertainty 0,000 32 m and the

169 probability distribution of the values of l.
170 0.5 Special remarks

171 The items given in IEC 80000-6 are generally in conformity with the International Electrotechnical

172 Vocabulary (IEV), especially IEC 60050-121 and IEC 60050-131. For each quantity, the reference to

173 IEV is given in the form: “See IEC 60050-121, item 121-xx-xxx.”.
174 The font used for text is sans serif; that used for quantities is serif
175 0.5.1 System of quantities

176 For electromagnetism, several different systems of quantities have been developed and used

177 depending on the number and the choice of base quantities on which the system is based. However,

178 in electromagnetism and electrical engineering, only the International System of Quantities, ISQ, and

179 the associated International System of Units, SI, are acknowledged and are reflected in the

180 standards of ISO and IEC. The SI has seven base units, among them kilogram (kg), metre (m),

181 second (s), and ampere (A).
182 0.5.2 Sinusoidal quantities

183 For quantities that vary sinusoidally with time, and for their complex representations, the IEC has

184 standardized two ways to build symbols. Capital and lowercase letters are generally used for electric

185 current (item 6-1) and for voltage (item 6-11.3), and additional marks for other quantities. These are

186 given in IEC 60027-1.
187 EXAMPLE 1

188 The sinusoidal variation with time of an electric current (item 6-1) can be expressed in real

189 representation as
190
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191 and its complex representation (termed phasor) is expressed as
192

193 where is the instantaneous value of the current, I, is its root-mean-square (rms) value (subclause

194 0.5.2), (ωt – φ) is the phase, φ is the initial phase, and j is the imaginary unit (j = -1), in mathematics

195 often denoted by i..
196 EXAMPLE 2

197 The sinusoidal variation with time of a magnetic flux (item 6-22.1) can be expressed in real

198 representation as
199

200 where Φ is the instantaneous value of the flux, Φ is its peak value and Φ is its rms value.

eff
201
202 0.5.3 Root-mean-square value, rms value
203

204 For a time-depending quantity a, the positive square root of the mean value of the square of the

205 quantity taken over a given time interval is called root-mean-square value, i.e.

206

207 The root-mean-square value of a periodic quantity is usually taken over an integration interval the

208 range of which is the period multiplied by a natural number. For a sinusoidal quantity

209 a(t) = Â cos(ωt + φ), the root-mean-square value is Â/

210 The root-mean-square value of a quantity may be denoted by adding one of the subscripts eff or rms

211 to the symbol of the quantity. In electrical technology, the root-mean-square values of electric current

212 i(t) and voltage u(t) are usually denoted I and U, respectively.
213
214
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215
216 QUANTITIES AND UNITS –
217
218 Part 6: Electromagnetism
219 1 Scope

220 This part of IEC 80000 gives names, symbols, and definitions for quantities and units of electromagnetism.

221 Where appropriate, conversion factors are also given.
222 2 Normative references

223 The following documents are referred to in the text in such a way that some or all of their

224 content constitutes requirements of this document. For dated references, only the edition

225 cited applies. For undated references, the latest edition of the referenced document

226 (including any amendments) applies.

227 IEC 60027-1:1992, Letter symbols to be used in electrical technology – Part 1: General

228 IEC 60050-111, International electrotechnical vocabulary – Part 111: Physics and chemistry

229 IEC 60050-121, International electrotechnical vocabulary – Part 121: Electromagnetism

230 IEC 60050-131, International electrotechnical vocabulary – Part 131: Circuit theory

231 ISO 80000-3, Quantities and units – Part 3: Space and time
232 ISO 80000-4:2006, Quantities and units – Part 4: Mechanics
233
234 3 Names, symbols, definitions and units of quantities

235 The names, symbols, and definitions for quantities and units of electromagnetism are given in the

236 tables on the following pages.

237 NOTE In general, these quantities can depend on time even when not explicitly noted.

238 All surfaces are assumed to be oriented surfaces (see IEC 60050-102, item102-04-37)

239 NOTE: The font in the formulas is different from the font of the main text.

240
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241 Table 1 – Quantities and units in electromagnetism
Quantity Unit
Item No. Remarks
Name Symbol Definition Symbol

6-1 electric current I scalar quantity equal to the quotient of the net A Electric current is one of the base

(6-1) quasi-infinitesimal (see IEC 60050-121, item quantities in the International System

121-11-06) electric charge dQ (item 6-2) of Quantities, ISQ, on which the

transferred thorough a surface during a quasi- International System of Units, SI, is

infinitesimal (see IEC 60050-121, item 121-11- based.
06) time interval dt and the duration of that
Electric current I through a surface S
interval;
can also be written as
I = dQ/dt
where endA is vector surface element.
Electric current produces a magnetic
field, see item 6-25.
For a more complete definition, see
item 6-8 and IEC 60050-121,
item 121-11-13.

6-2 electric charge Q additive scalar property of discrete particles C Electric charge can be positive,

(6-2) and their agglomerations exhibiting forces (ISO A s negative or zero. The sign convention

80000-4) by means of electric fields (item 6-10) s A is such that the elementary electric

charge, e, of the proton, is positive.
See IEC 60050-121, item121-11-01.
To denote a point charge q is often
used, and that is done in the present
document.
The coherent SI unit of charge is
coulomb, C. Another frequently used
unit is the ampere-hour Ah mentioned
in IEC 60050-313, item 313-01-16,
widely used for battery
characteristics.
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Quantity Unit
Item No. Remarks
Name Symbol Definition Symbol

6-3 electric charge density, ρ scalar quantity representing the spatial C / m See IEC 60050-121, item 121-11-07.

(6-3) volumic (electric) charge m s A
distribution of electric charge,
where dQ is quasi-infinitesimal 121-11-06]
electric charge (item 6-2) contained in an
quasi-infinitesimal (see IEC 60050-121, item
121-11-06) domain located at position r and dV
is quasi-infinitesimal (see IEC 60050-121, item
121-11-06) volume (ISO 80000-3) of this
domain

6-4 surface density of electric scalar quantity representing the areal 2 See IEC 60050-121, item 121-11-08.

C / m
charge, distribution of electric charge,
(6-4)
m s A
areic (electric) charge
where dQ is quasi-infinitesimal (see IEC 60050-
121, item 121-11-06) electric charge (item 6-2)
contained in an quasi-infinitesimal (see
IEC 60050-121, item 121-11-06) domain
located at position r and dA is quasi-
infinitesimal (see IEC 60050-121, item 121-11-
06) area (ISO 80000-3) of this domain

6-5 linear density of electric charge, τ scalar quantity representing the linear C / m See IEC 60050-121, item121-11-09.

(6-5) distribution of electric charge,
lineic (electric) charge m s A
where dQ is quasi-infinitesimal (see IEC 60050-
121, item 121-11-06) electric charge (item 6-2)
contained in an quasi-infinitesimal (see
IEC 60050-121, item 121-11-06) domain
located at position r and dl is quasi-
infinitesimal (see IEC 60050-121, item 121-11-
06) length (ISO 80000-3) of this domain
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Quantity Unit
Item No. Remarks
Name Symbol Definition Symbol

6-6 electric dipole moment p vector quantity given by C m The electric dipole moment of a

(6-14) substance within a domain is the
p = q(r – r ) m s A
+ –
vector sum of electric dipole moments
and r are the position vectors (ISO
where r+ –
of all electric dipoles contained in the
80000-3) to carriers of electric charges q and –
domain.
q (item 6-2), respectively
See IEC 60050-121, items 121-11-35
and 121-11-36.

6-7 electric polarization P vector quantity representing the spatial 2 See IEC 60050-121, item 121-11-37.

C / m
(6-13) distribution of electric dipole moment,
m s A
where dp is quasi-infinitesimal (see IEC 60050-
121, item 121-11-06) electric dipole moment
(item 6-6) of a substance in an quasi-
infinitesimal (see IEC 60050-121, item 121-11-
06) domain at position r and dV is volume (ISO
80000-3) of this domain

6-8 electric current density J vector quantity given by the volumic density of 2 There can be different charge carriers

A / m

(6-15) charge carriers forming an electric current (item with different velocities.

m A
6-1), given by;
Electric current I (item 6-1) through a
surface S is
where ρ is electric charge density (item 6-3) at
position r and v is velocity (ISO 80000-3) of the
where e dA is vector surface element.
charge carriers there
See IEC 60050-121, item 121-11-11.

6-9 linear electric current density J vector quantity given by the areic density of A / m See IEC 60050-121, item 121-11-12.

(―) electric charge carriers forming an electric
m A
surface current (item 6-1), given by
where σ is surface density of electric charge
(item 6-4) at position r and v is velocity (ISO
80000-3) of the charge carriers there
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Quantity Unit
Item No. Remarks
Name Symbol Definition Symbol

6-10 electric field strength E vector field quantity which exerts on any V m See IEC 60050, item 121-11-18.

‒3 ‒1
(6-5) charged particle located at position r a force F
kg m s A q is the charge of a test particle.
(ISO 80000-4) equal to the product of E and
electric charge q (item 6-2) of the particle, thus:

6-11.1 electric potential V scalar quantity expressed by V The electric potential is not unique,

2 ‒3 ‒1
(6-6.1) since any constant scalar field
kg m s A
–grad V = E +
quantity can be added to it without
changing its gradient.
where E is electric field strength (item 6-10), A
The electric potential, the electric
is magnetic vector potential (item 6-32) and t is
field, and the electric magnetic vector
time (ISO 80000-3)
potential depend on position.
See IEC 60050-121, item 121-11-25.
6-11.2 electric potential difference V scalar quantity given by V
2 ‒3 ‒1
(6-6.2)
kg m s A
V = V – V
ab a b
where Va and Vb are the electric potentials (item
where E is electric field strength (item
6-11.1) at points a and b, respectively
6-10), A is magnetic vector potential
(item 6-32), t is time (ISO 80000-3,
item 3-9), and r is position vector
(ISO 80000-3, item 3-1.10) along a
given curve C, from point a to point b.
See IEC 60050-121, item 121-11-26.

6-11.3 voltage, U on a conductor, scalar quantity given by the V The name “voltage”, commonly used

2 ‒3 ‒1

(6-6.3) electric potential difference V (6-11.2) in the English language, is given in

electric tension U kg m s A
ab,
between two points a and b respectively the IEV but is an exception from the
principle that a quantity name should
not refer to any name of unit.
See IEC 60050-121, item 121-11-27.
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Quantity Unit
Item No. Remarks
Name Symbol Definition Symbol

6-12 electric flux density, D vector quantity given by C / m The electric flux density is related to

(6-7) electric charge density via div D = ρ
electric displacement D =ε E + P
0 m s A
where div denotes divergence.
where ε0 is the electric constant (item 6-14.1),
The electric flux density, the field
E is electric field strength (item 6-10), and P is
strength, and the polarization depend
electric polarization (item 6-7)
on position.
See IEC 60050-121, item 121-11-40.

6-13 capacitance C for a capacitive element quotient of electric F See IEC 60050-131, item 131-12-13.

‒1 ‒2 4 2
(6-9) charge Q (item 6-2) and voltage U (item 6-
kg m s A
11.3);

6-14.1 electric constant, ε scalar quantity given by See IEC 60050-121, item 121-11-03.

0 F / m
‒1 ‒3 4 2
(6-10.2) permittivity of vacuum
kg m s A This quantity is considered to be
constant in time.
where µ is the magnetic constant (item 6-26.1)
and c is the speed of light (item 6-35.2)

6-14.2 permittivity ε proportionality constant between electric flux F / m permittivity ε is a property of a

‒1 ‒3 4 2

(6-10.1) density D (item 6-12) and electric field strength medium. For an inhomogeneous

kg m s A
E (item 6-10); medium, permittivity ε depends on
position.
D = εE
For an isotropic medium, ε is a scalar
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