1980L0181 — EN — 30.11.1989 — 002.001 — 1
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►B COUNCIL DIRECTIVE
of 20December 1979
on the approximation of the laws of the Member States relating to units of measurement and on the
repeal of Directive 71/354/EEC
(80/181/EEC)
(OJ L 39, 15.2.1980, p. 40)
Amended by:
Official Journal
No page date
►M1Council Directive 85/1/EEC of 18 December 1984 L 2 11 3.1.1985
►M2Council Directive 89/617/EEC of 27 November 1989 L 357 28 7.12.1989
Corrected by:
►C1Corrigendum, OJ L 296, 15.10.1981, p. 52 (80/181/EEC)
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COUNCIL DIRECTIVE
of 20December 1979
on the approximation of the laws of the Member States relating to
units of measurement and on the repeal of Directive 71/354/EEC
(80/181/EEC)
THE COUNCIL OF THE EUROPEAN COMMUNITIES,
Having regard to the Treaty establishing the European Economic
Community, and in particluar Article 100 thereof,
Having regard to Council Directive 71/354/EEC of 18 October 1971 on
the approximation of the laws of the Member States relating to units ofmeasurement(
1), as last amended by Council Directive 76/770/EEC(2),
Having regard to the proposal from the Commission(3),
Having regard to the opinion of the European Parliament(4),
Having regard to the opinion of the Economic and Social Committee(5),
Whereas units of measurement are essential in the use of all measuring
instruments, to express measurements or any indication of quantity;whereas units of measurement are used in most fields of human activity;
whereas it is necessary to ensure the greatest possible clarity in their use;
whereas it is therefore necessary to make rules for their use within theCommunity for economic, public health, public safety or administrativepurposes;
Whereas, however, there exist international conventions or agreements
in the field of international transport which bind the Community or the
Member States; whereas these conventions or agreements have to berespected;
Whereas the laws which regulate the use of units of measurement in the
Member States differ from one Member State to another and as a result
hinder trade; whereas, in these circumstances, it is necessary to
harmonize laws, regulations and administrative provisions in order toovercome such obstacles;
Whereas units of measurement are the subject of international
resolutions adopted by the General Conference of Weights and Measures
(CGPM) set up by the Metre Convention signed in Paris on 20 May
1875, to which all the Member States adhere; whereas the ‘InternationalSystem of Units’(SI) was drawn up as a result of these resolutions;
Whereas the Council on 18 October 1971 adopted Directive 71/354/EEC
on the approximation of the laws of the Member States in order to
eliminate obstacles to trade by adopting the international system of units
at Community level; whereas Directive 71/354/EEC was amended bythe Act of Accession and by Directive 76/770/EEC;
Whereas these Community provisions have not overcome all the
obstacles in this field; whereas Directive 76/770/EEC provides for thereview before 31 December 1979 of the situation regarding units of
measurement, names and symbols listed in Chapter D of the Annex
thereto; whereas it has also proved necessary to review the situationregarding certain other units of measurement;
Whereas it is necessary, in order to avoid serious difficulties, to provide
for a transitional period during which units of measurement which are
not compatible with the international system can be phased out; whereas
it is nevertheless essential to allow the Member States wishing to do soto bring into force as quickly as possible, on their territory, the1980L0181 — EN — 30.11.1989 — 002.001 — 2
(1) OJ No L 243, 29. 10. 1971, p. 29.
(2) OJ No L 262, 27. 9. 1976, p. 204.
(3) OJ No C 81, 28. 3. 1979, p. 6.
(4) OJ No C 127, 21. 5. 1979, p. 80.
(5) Opinion delivered on 24/25 October 1979 (not yet published in the Official
Journal).
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provisions of Chapter I of the Annex; whereas it is therefore necessary
to limit the duration of this transitional period at Community levelwhile, at the same time, leaving the Member States free to curtail that
period;
Whereas, during the transitional period, it is essential, particularly in
order to protect the consumer, to maintain a clear position on the use of
units of measurement in trade between the Member States; whereas theobligation on the Member States to allow use of supplementaryindications on products and equipment imported from other MemberStates during this transitional period seems to serve this purpose well;
Whereas the systematicadoption of a solution of this kind for all
measuring instruments, including medical instruments, is however notnecessarily desirable; whereas the Member States should therefore be
able to require that, on their territory, measuring instruments bear
indications of quantity in a single legal unit of measurement;
Whereas this Directive does not affect the continued manufacture of
products already on the market; whereas it does, however, affect the
placing on the market and use of products and equipment bearingindications of quantity in units of measurement which are no longerlegal units of measurement, when such products and equipment arenecessary to supplement or replace components or parts of such
products, equipment and instruments already on the market; whereas it
is therefore necessary for Member States to authorize the placing on themarket and the use of such products and equipment to complete andreplace components, even when they bear indications of quantity in unitsof measurement which are no longer legal units of measurement, so thatproducts, equipment or instruments already on the market may continue
to be used;
Whereas the International Organization for Standardization (ISO) on 1
March 1974 adopted an international standard on the representation of
SI and other units for use in systems with limited sets of characters;whereas it is advisable for the Community to adopt the solutions whichhave already been approved on a wider international level by ISOStandard 2955 of 1 March 1974;
Whereas Community provisions relating to units of measurement are to
be found in several Community texts; whereas the question of units ofmeasurement is so important that it is essential that reference may be
made to a single Community text; whereas this Directive thereby
consolidates all the Community provisions on the subject and repealsDirective 71/354/EEC,
HAS ADOPTED THIS DIRECTIVE:
Article 1
The legal units of measurement within the meaning of this Directive
which must be used for expressing quantities shall be:
(a) those listed in Chapter I of the Annex;
(b) those listed in Chapter II of the Annex only in those Member States
where they were authorized on 21 April 1973 and until a date to befixed by those States;
(c) those listed in Chapter III of the Annex only in those Member States
where they were authorized on 21 April 1973 and until a date to be
fixed by those States. This date may not be later than 31 December
1994;
(d) those listed in Chapter IV of the Annex only in those Member States
where they were authorized on 21 April 1973 and until a date to befixed by those States. This date may not be later than 31 December1999.1980L0181 — EN — 30.11.1989 — 002.001 — 3
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Article 2
(a) The obligations arising under Article 1 relate to measuring
instruments used, measurements made and indications of quantityexpressed in units of measurement, for economic, public health,
publicsafety or administrative purposes.
(b) This Directive shall not affect the use in the field of air and sea
transport and rail trafficof units, other than those made c ompulsoryby the Directive, which have been laid down in internationalconventions or agreements binding the Community or the MemberStates.
Article 3
1. For the purposes of this Directive ‘supplementary indication’-
means one or more indications of quantity expressed in units ofmeasurement not contained in Chapter I of the Annex accompanying an
indication of quantity expressed in a unit contained in that Chapter.
2. The use of supplementary indications shall be authorized until
►
M231 December 1999 ◄.
3. However, Member States may require that measuring instruments
bear indications of quantity in a single legal unit of measurement.
4. The indication expressed in a unit of measurement listed in
Chapter I shall predominate. In particular, the indications expressed in
units of measurement not listed in Chapter I shall be expressed incharacters no larger than those of the corresponding indication in unitslisted in Chapter I.
Article 4
The use of units of measurement which are not or are no longer legal
shall be authorized for:
— products and equipment already on the market and/or in service on
the date on which this Directive is adopted,
— components and parts of products and of equipment necessary to
supplement or replace components or parts of the above products andequipment.
However, the use of legal units of measurement may be required for the
indicators of measuring instruments.
Article 5
International standard ISO 2955 of ►
M215 May 1983 ◄, ‘Informa-
tion processing — Representations of SI and other units for use insystems with limited character sets’ shall apply in the field covered byparagraph 1 thereof.
Article 6
Directive 71/354/EEC shall be repealed on 1 October 1981.
Article 7
(a) Member States shall adopt and publish before 1 July 1981 the laws,
regulations and administrative provisions necessary to comply with
this Directive and shall inform the Commission thereof.
They shall apply these provisions from 1 October 1981.
(b) As from the date of notification of this Directive, Member States
shall also ensure that the Commission is informed, in sufficient timeto enable it to submit its comments, of any draft laws, regulations or1980L0181 — EN — 30.11.1989 — 002.001 — 4
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administrative provisions which they intend to adopt in the field
covered by this Directive.
Article 8
This Directive is addressed to the Member States.1980L0181 — EN — 30.11.1989 — 002.001 — 5
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ANNEX
CHAPTER I
LEGAL UNITS OF MEASUREMENT REFERRED TO IN ARTICLE 1 (a)
1. SI UNITS AND THEIR DECIMAL MULTIPLES AND SUBMULTIPLES
1.1.SI base units
QuantityUnit
Name Symbol
Length metre m
Mass kilogram kgTime second s
Electric current ampere A
Thermodynamictemperature kelvin K
Amount of substance mole mol
Luminous intensity candela cd
Definitions of SI base units:
Unit of length
A metre is the length of the path travelled in a vacuum by light during
1/299 792 458 seconds.
(Seventeenth CGPM (1983), Resolution 1).
Unit of mass
The kilogram is the unit of mass; it is equal to the mass of the
international prototype of the kilogram.
(Third CGPM (1901), page 70 of the conference report).Unit of timeThe second is the duration of 9 192 631 770periods of the radiation
corresponding to the transition between the two hyperfine levels of the
ground state of the caesium-133 atom.
(Thirteenth CGPM (1967), resolution 1).
Unit of electric current
The ampere is that constant current, which if maintained in two straight
parallel conductors of infinite length, of negligible circular cross-
section, and placed one metre apart in vacuum, would produce between
those conductors a force equal to 2 × 10
−7newton per metre of length.
(CIPM (1946), resolution 2, approved by the ninth CGPM (1948)).Unit of thermodynamic temperatureThe kelvin, unit of thermodynamictemperature, is the frac tion 1/273·16
of the thermodynamictemperature of the triple point of water.
(Thirteenth CGPM (1967), resolution 4).Unit of amount of substance(1) The mole is the amount of substance of a system which contains as
many elementary entities as there are atoms in 0·012 kilogram of
carbon 12.
(2) When the mole is used, the elementary entities must be specified
and may be atoms, molecules, ions, electrons, other particles, or
specified groups of such particles.
(Fourteenth CGPM (1971), resolution 3).
Unit of luminous intensityThe candela is the luminous intensity, in a given direction, of a source
that emits monochromatic radiation of frequency of 540 × 10
12hertz1980L0181 — EN — 30.11.1989 — 002.001 — 6
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and that has a radiant intensity in that direction of (1/683) watt per
steradian.
(Sixteenth CGPM (1979), resolution 3).
1.1.1.Special name and symbol of the SI unit of temperature for
expressing Celsius temperature
QuantityUnit
Name Symbol
Celsius temperature degree Celsius ºC
Celsius temperature t is defined as the difference t = T — T0between
the two thermodynamictemperatures T and T0where T0= 273·15
kelvins. An interval of or difference in temperature may be expressed
either in kelvins or in degrees Celsius. The unit ‘degree Celsius’ is
equal to the unit ‘kelvin’.
1.2.Other SI units
1.2.1.SI supplementary units
QuantityUnit
Name Symbol
Plane angle radian rad
Solid angle steradian sr
(Eleventh CGPM, 1960, resolution 12).
Definitions of SI supplementary units:Unit of plane angleThe radian is the plane angle between two radii of a circle
which cut off on the circumference an arc equal in length to
the radius.
(International standard ISO 31-I, December 1965).Unit of solid angle
The steradian is the solid angle which, having its vertex at
the centre of a sphere, cuts off an area on the surface of the
sphere equal to that of a square with sides of length equal to
the radius of the sphere.
(International standard ISO 31-I, December 1965).
1.2.2.SI derived units
Units derived coherently from SI base units and SI
supplementary units are given as algebraicexpressions in
the form of products of powers of the SI base units and/or
SI supplementary units with a numerical factor equal to 1.
1.2.3.SI derived units having names and symbols
QuantityUnit Expression
Name SymbolIn other SI
unitsIn terms of SI base
or supplementary
units
Frequency hertz Hz s−1
Force newton N m · kg · s−2
Pressure, stress pascal Pa N · m−2m−1·k g·s−2
Energy, work; quantity
of heat joule J N · m m2·k g·s−21980L0181 — EN — 30.11.1989 — 002.001 — 7
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QuantityUnit Expression
Name SymbolIn other SI
unitsIn terms of SI base
or supplementary
units
Power (1), radiant flux watt W J · s−1m2·k g·s−3
Quantity of electricity,
electric charge coulomb C s · A
Electric potential,
potential difference,
electromotive force volt V W · A−1m2·k g·s−3·A−1
Electric resistance ohm Ω V·A−1m2·k g·s−3·A−2
Conductance siemens S A · V−1m−2·k g−1·s3·A2
Capacitance farad F C · V−1m−2·k g−1·s4·A2
Magneticflux weber Wb V · s m2·k g·s−2·A−1
Magneticflux densitytesla TWb · m−
2 kg · s−2·A−1
Inductance henry H Wb · A−1m2·k g·s−2·A−2
Luminous flux lumen lm cd · sr
Illuminance lux lx lm · m−2m−2·cd·s r
Activity (of a radio-
nuclide)becquer-
el Bq s−1
Absorbed dose,specific energy
imparted, kerma,
absorbed dose index gray Gy J · kg
−1m2·s−2
Dose equivalent sievert Sv J · kg−1m2·s−2
(1) Special names for the unit of power: the name volt−ampere (symbol ‘VA’) when it is
used to express the apparent power of alternating electric current, and var (symbol ‘var’)when it is used to express reactive electric power. The ‘var’ is not included in CGPM
resolutions.
Units derived from SI base units or supplementary units
may be expressed in terms of the units listed in Chapter 1.
In particular, SI derived units may be expressed by the
special names and symbols given in the above table; for
example, the SI unit of dynamicvisc osity may be expressed
as m−1·k g·s−1or N · s · m−2or Pa · s.
1.3.Prefixes and their symbols used to designate certain decimal
multiples and submultiples
Factor Prefix Symbol
1018exa E
1015peta P
1012tera T
109giga G
106mega M
103kilo k
102hecto h
101deca da
10−1deci d
10−2centi c
10−3milli m
10−6micro µ
10−9nano n
10−12pico p1980L0181 — EN — 30.11.1989 — 002.001 — 8
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Factor Prefix Symbol
10−15femto f
10−18atto a
The names and symbols of the decimal multiples and submultiples
of the unit of mass are formed by attaching prefixes to the word
‘gram’ and their symbols to the symbol ‘g’.
Where a derived unit is expressed as a fraction, its decimal
multiples and submultiples may be designated by attaching a
prefix to units in the numerator or the denominator, or in both
these parts.
Compound prefixes, that is to say prefixes formed by the
juxtaposition of several of the above prefixes, may not be used.
1.4.Special authorized names and symbols of decimal multiples
and submultiples of SI units
QuantityUnit
Name Symbol Value
Volume litre 1 or L (1)1 l = 1 d m3=1 0−3m3
Mass tonne t 1t = 1 Mg = 103kg
Pressure, stress bar bar (2) 1 bar = 105Pa
(1) The two symbols ‘I’and ‘L’ may be used for the litre unit.
(Sixteenth CGPM (1979), resolution 6).
(2) Unit listed in the International Bureau of Weights and Measures booklet as among the units to be
permitted temporarily.
Note:The prefixes and their symbols listed in 1.3 may be used in
conjunction with the units and symbols contained in Table
1.4.
2. UNITS WHICH ARE DEFINED ON THE BASIS OF SI UNITS BUT
ARE NOT DECIMAL MULTIPLES OR SUBMULTIPLES THEREOF
QuantityUnit
Name Symbol Value
Plane angle revolution* (1)(a) 1 revolution = 2 πrad
grade* or gon* gon* 1 gon ¼π
200rad
degree º 1º ¼π
180rad
minute of angle ′ 100¼π
10800rad
second of angle ′ 100¼π
648000rad
Time minute min 1min = 60 s
hour h 1 h = 3 600 s
day d 1 d = 86 400 s
(1) The character (*) after a unit name or symbol indicates that it does not appear in the lists drawn up by
the CGPM, CIPM o BIPM. This applies to the whole of this Annex.
(a) No international symbol exists.
Note:The prefixes listed in 1.3 may only be used in conjunction with
the names ‘grade’ or ‘gon’ and the symbol ‘gon’.1980L0181 — EN — 30.11.1989 — 002.001 — 9
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3. UNITS DEFINED INDEPENDENTLY OF THE SEVEN SI BASE
UNITS
The unified atomicmass unit is one-twelfth of the mass of an atom of
the nuclide12C.
The electronvolt is the kinetic energy acquired by an electron passing in
a vacuum from one point to another whose potential is one volt higher.
QuantityUnit
Name Symbol Value
Mass unifed atomicmass unit u 1u ≈1 660 565 5 × 10−27kg
Energy electronvolt eV 1eV ≈1 602 189 2 × 10−19J
The value of these units, expressed in SI units, is not known exactly.
The above values are taken from CODATA Bulletin No 11 of
December 1973 of the International Council of Scientific Unions.
Note:The prefixes and their symbols listed in 1.3 may be used in
conjunction with these two units and with their symbols.
4. UNITS AND NAMES OF UNITS PERMITTED IN SPECIALIZED
FIELDS ONLY
QuantityUnit
Name Symbol Value
Vergency of optical
systems dioptre* 1 dioptre = 1 m−1
Mass of precious stones metric carat 1 metric carat = 2 × 10−4kg
Area of farmland and
building land are a 1 a = 102m2
Mass per unit length oftextile yarns and threads tex* tex* 1 tex = 10
−6kg · m−1
Blood pressure and pres-
sure of other body fluidsMillimetre of
mercury mm Hg(*) 1 mm Hg = 133,322 Pa
Effective cross-sectional
area Barn b 1 b = 10−28m2
Note:►M1The prefixes and their symbols listed in 1.3 may be used
in conjunction with the above units and symbols, with the
exception of the millimetre of mercury and its symbol. The
multiple of 102a is, however, called a ‘hectare’. ◄
5. COMPOUND UNITS
Combinations of the units listed in Chapter I form compound units.1980L0181 — EN — 30.11.1989 — 002.001 — 10
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CHAPTER II
LEGAL UNITS OF MEASUREMENT REFERRED TO IN ARTICLE 1 (b),
PERMITTED FOR SPECIFIC USES ONLY
Field of applicationUnit
Name Approximate value Symbol
Road trafficsigns, distanc e and
speed measurementmile 1 mile = 1 609 m mile
yard 1 yd = 0,9144 m yd
foot 1 ft = 0,3048 m ft
inch 1 in = 2,54 × 10−2mi n
Dispense of draught beer and
cider; milk in returnable
containerspint 1 pt = 0,5683 × 10−3m3pt
Land registration acre 1 ac = 4 047 m2ac
Transaction in precious metals troy ounce 1 oz tr = 31,10 × 10−3kg oz tr
Until the date to be fixed under Article 1 (b), the units listed in this Chapter may
be combined with each other or whith those in Chapter I to form compound units.
CHAPTER III
LEGAL UNITS OF MEASUREMENT REFERRED TO IN ARTICLE 1 (c)
QUANTITIES, NAMES OF UNITS, SYMBOLS AND APPROXIMATE
VALUES
Length
inch 1 in = 2·54 × 10−2m
foot 1 ft = 0·3048 m
mile 1 mile =1 609myard 1 yard = 0·9144 m
Area
square foot 1 sq ft = 0·929 × 10
-1m2
acre 1 ac =4 047m2
square yard 1 sq yd = 0·8361 m2
Volumefluid ounce 1 fl oz = 28·41 × 10
−6m3
gill 1 gill = 0·1421 × 10−3m3
pint 1 pt = 0·5683 × 10−3m3
quart 1 qt = 1·137 × 10−3m3
gallon 1 gal = 4·546 × 10−3m3
Mass
ounce (avoirdupois) 1 oz = 28·35 × 10−3kg
troy ounce 1 oz tr = 31·10 × 10−3kg
pound 1 lb = 0·4536 kg
Energy
therm 1 therm = 105·506 × 106J1980L0181 — EN — 30.11.1989 — 002.001 — 11
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Until the date to be fixed under Article 1 (c), the units listed in Chapter III may be
combined with each other or with those in Chapter I to form compound units.
CHAPTER IV
LEGAL UNITS OF MEASUREMENT REFERRED TO IN ARTICLE I (d),
PERMITTED IN SPECIALIZED FIELDS ONLY
Field of applicationUnit
Name Approximate value Symbol
Marine navigation fathom 1 fm = 1,829 m fm
Beer, cider, waters, lemonades
and fruit juices in returnable
containerspint 1 pt = 0,5683 × 10−3m3pt
fluid ounce 1 fl oz = 28,41 × 10−6m3fl. oz
Spirit drinks gill 1 gill = 0,142 × 10−3m3gill
Goods sold loose in bulk ounce
(avoir dupois)1 oz = 28,35 × 10−3kg oz
pound 1 lb = 0,4536 kg lb
Gas supply therm 1 therm = 105,506 × 106J therm
Until the date to be fixed under Article 1 (d), the units listed in this Chapter may
be combined with each other or with those in Chapter I to form compound units.1980L0181 — EN — 30.11.1989 — 002.001 — 12
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