CELEX: 51991SC1047
Language: en
Date: 1991-06-20
Title: PROPOSAL FOR A COUNCIL DIRECTIVE ON THE APPROXIMATION OF THE LAWS OF THE MEMBER STATES RELATING TO UNITS OF MEASUREMENT

17.7.91                                Official Journal of the European Communities                                N o C 185/13
               Proposal for a Council Directive on [the approximation of the laws of the Member States
                                                 relating to] units of measurement
                                                           (91/C 185/06)
                                                         SEC(91) 1047 final
                                        (Submitted by the Commission on 21 June 1991)
 THE COUNCIL OF THE EUROPEAN COMMUNITIES,                              the Member States adhere; whereas the 'International
                                                                       System of Units' (SI) was drawn up as a result of these
                                                                       resolutions;
  Having regard to the Treaty establishing the European
 Economic Community, and in particular Article 100a
                                                                       Whereas it is necessary, in order to avoid serious diffi-
 thereof,                                                              culties, to provide for a transitional period during which
                                                                       units of measurement which are not compatible with the
 Having regard to the proposal from the Commission,                    international system can be phased out; whereas it is
                                                                       nevertheless essential to allow the Member States
                                                                       wishing to do so to bring into force as quickly as
 In cooperation with the European Parliament,                          possible, on their territory, the provisions of Chapter 1
                                                                       of Annex I; whereas it is therefore necessary to limit the
                                                                       duration of this transitional period at Community level
 Having regard to the opinion of the Economic and
                                                                       while, at the same time, leaving the Member States free
 Social Committee,
                                                                       to curtail that period;
 Whereas Council Directive 80/181/EEC of 20                           Whereas, during the transitional period, it is essential,
 December 1979 on the approximation of the laws of the                 particularly in order to protect the consumer, to
 Member States relating to units of measurement and on                 maintain a clear position on the use of units of
 the repeal of Directive 71/354/EEC ('), as last amended              measurement in trade between the Member States;
 by Directive 89/617/EEC (2), has been substantially                  whereas the obligation on the Member States to allow
 amended; whereas for reasons of clarity and rationality              use of supplementary indications on products and
 the said Directive should be consolidated;                           equipment imported from other Member States during
                                                                      this transitional period seems to serve this purpose well;
 Whereas units of measurement are essential in the use of             Whereas the systematic adoption of a solution of this
 all measuring instruments, to express measurements or                kind for all measuring instruments, including medical
 any indication of quantity; whereas units of                         instruments, is however not necessarily desirable;
 measurement are used in most fields of human activity;               whereas the Member States should therefore be able to
 whereas it is necessary to ensure the greatest possible              require that, on their territory, measuring instruments
 clarity in their use; whereas it is therefore necessary to           bear indications of quantity in a single legal unit of
 make rules for their use within the Community for                    measurement;
 economic, public health, public safety or administrative
 purposes;                                                            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
Whereas, however, there exist international conventions
                                                                      use of products and equipment bearing indications of
or agreements in the field of international transport
                                                                      quantity in units of measurement which are no longer
which bind the Community or the Member States;
                                                                      legal units of measurement, when such products and
whereas these conventions or agreements have to be
                                                                      equipment are necessary to supplement or replace
respected;
                                                                      components or parts of such products, equipment and
                                                                      instruments already on the market; whereas it is
Whereas the laws which regulate the use of units of                   therefore necessary for Member States to authorize the
measurement in the Member States differ from one                     placing on the market and the use of such products and
Member State to another and as a result hinder trade;                equipment to complete and replace components, even
whereas, in these circumstances, it is necessary to                  when they bear indications of quantity in units of
harmonize       laws,   regulations    and      administrative       measurement which are no longer legal units of
provisions in order to overcome such obstacles;                      measurement, so that products, equipment or instruments
                                                                     already on the market may continue to be used;
Whereas units of measurement are the subject of interna-
                                                                     Whereas the International Organization for Standardiz-
tional resolutions adopted by the General Conference of
                                                                     ation (ISO) on 15 May 1983 adopted an international
Weights and Measures (CGPM) set up by the Metre
                                                                     standard on the representation of SI and other units for
Convention signed in Paris on 20 May 1875, to which all
                                                                     use in systems with limited sets of characters; whereas it
                                                                     is advisable for the Community to adopt the solutions
(') OJ No L 39, 15. 2. 1980, p. 40.                                  which have already been approved on a wider inter-
O OJ No L 357, 7. 12. 1989, p. 28.                                   national level by ISO Standard 2955 of 15 May 1983;
 ---pagebreak---  N o C 185/14                          Official Journal of the European Communities                                17.7.91
Whereas in a recommendation of 22 May 1981 the                         agreements binding the Community or the Member
World Health Organization requested that the                           States.
 millimetre of mercury be retained in addition to the kilo-
pascal as a unit for the measurement of the pressure of                                    Article 3
blood and other body fluids; whereas it is advisable for
the Community to adopt this solution;                             1.     For the purposes of this Directive supplementary
                                                                  indication means one or more indications of quantity
                                                                 expressed in units of measurement not contained in
Whereas the barn is the unit universally used to measure
                                                                  Chapter 1 of Annex I accompanying an indication of
the effective cross-sectional area on the occasion of
                                                                 quantity expressed in a unit contained in that Chapter.
 nuclear reactions; whereas experience has shown that
this specific unit could not easily be replaced by an SI         2.     The use of supplementary indications shall be auth-
unit; whereas it is therefore necessary to authorize its use     orized until 31 December 1999.
in the nuclear field;
                                                                  3.     However, Member States may require that
                                                                 measuring instruments bear indications of quantity in a
Whereas this Directive must not affect the obligations on
                                                                 single legal unit of measurement.
the Member States arising from Directives 80/181 / E E C ,
 85/1/EECO) and 89/617/EEC,                                      4.     The indication expressed in a unit of measurement
                                                                 listed in Chapter 1 shall predominate. In particular, the
HAS ADOPTED THIS DIRECTIVE:                                      indications expressed in units of measurement not listed
                                                                 in Chapter 1 shall be expressed in characters no larger
                                                                 than those of the corresponding indication in units listed
                           Article 1                             in Chapter 1 of Annex I.
The legal units of measurement within the meaning of
this Directive which must be used for expressing quan-                                     Article 4
tities shall be those contained in Annex I:                      The use of units of measurement which are not or are no
                                                                 longer legal shall be authorized for:
(a) those listed in Chapter 1;
                                                                 — products and equipment already on the market
(b) those listed in Chapter 2 only in those Member                    and/or in service on the date on which this Directive
     States where they were authorized on 21 April 1973               is adopted,
     and until a date to be fixed by those States;
                                                                 — components and parts of products and of equipment
(c) those listed in Chapter 3 only in those Member                    necessary to supplement or replace components or
     States where they were authorized on 21 April 1973               parts of the above products and equipment.
     and until a date to be fixed by those States. This date     However, the use of legal units of measurement may be
     may not be later than 31 December 1994;                     required for the indicators of measuring instruments.
(d) those listed in Chapter 4 only in those Member
                                                                                           Article 5
     States where they were authorized on 21 April 1973
     and until a date to be fixed by those States. This date     International standard ISO 2955 of 15 May 1983 'Infor-
     may not be later than 31 December 1999.                     mation processing — Representations of SI and other
                                                                 units for use in systems with limited character sets' shall
                                                                 apply in the field covered by paragraph 1 thereof.
                          Article 2
(a) The obligations arising pursuant to Article 1 relate to                                Article 6
     measuring instruments used, measurements made and
     indications of quantity expressed in units of               The Directives listed in Annex II are hereby repealed,
     measurement, for economic, public health, public            without prejudice to the obligations of the Member
     safety or administrative purposes.                          States concerning the implementation of the said
                                                                 Directives.
(b) This Directive shall not affect the use in the field of
                                                                 References to the said Directives shall be construed as
     air and sea transport and rail traffic of units, other
                                                                 references to this Directive.
     than those made compulsory by the Directive, which
     have been laid down in international conventions or
                                                                                           Article 7
(') OJ No L 2, 3. 1. 1985, p. 11.                                This Directive is addressed to the Member States.
 ---pagebreak--- 17.7.91                              Official Journal of the European Communities                                   N o C 185/15
                                                            ANNEX I
                                                          CHAPTER 1
                       LEGAL UNITS OF MEASUREMENT REFERRED TO IN ARTICLE 1 (a)
        1. SI UNITS AND THEIR DECIMAL MULTIPLES AND SUBMULTIPLES
           1.1. SI base units
                                                                                             Unit
                                           Quantity
                                                                                    Name                Symbol
                 Length                                                          metre                 m
                 Mass                                                            kilogram              kg
                Time                                                             second                s
                 Electric current                                                ampere                A
                Thermodynamic temperature                                        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 time
                The second is the duration of 9 192 631 770 periods 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 a vacuum, would
                produce between the conductors a force equal to 2 x 10"7 ton per metre of length.
                (CIPM (1946), resolution 2, approved by the ninth CGPM (1948)).
                 Unit of thermodynamic temperature
                The kelvin, unit of thermodynamic temperature, is the fraction 1/273,16 of the thermodynamic
                temperature of the triple point of water.
                (Thirteenth CGPM (1967), resolution 4).
 ---pagebreak--- No C 185/16                            Official Journal of the European Communities                                      17. 7. 91
                   Unit of amount of substance
                  The mole is the amount of substance of a system which contains as many elementary entities as
                  there are atoms in 0,012 kg of carbon 12.
                  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 partides.
                  (Fourteenth CGPM (1971), resolution 3).
                   Unit of luminous intensity
                  The candela is the luminous intensity, in a given direction, of a source which emits monochromatic
                  rays with a frequency of 540 x 10" hertz and whose energy intensity in that direction is 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
                                                                                                Unit
                                                Quantity
                                                                                      Name                Symbol
                          Celsius temperature                                    degree Celsius             °C
          Celsius temperature t is defined as the difference t = T — T 0 between the two thermodynamic
          temperatures T and T 0 where T 0 = 273,15 kelvins. An interval of or difference in temperature may be
          expressed either in kelvins or in degrees Celsius. The unit of 'degree Celsius' is equal to the unit 'kelvin'.
             1.2. Other SI units
                  1.2.1. Supplementary SI units
                                                                                                Units
                                                Quantity
                                                                                      Name                Symbol
                         Plane angle                                             radian               rad
                         Solid angle                                             steradian            sr
                         (Eleventh CGPM, 1960, resolution 12).
                         Definitions of supplementary SI units:
                         Plane angle unit
                         The radian is the plane angle between two radii which, on the circumference of a circle, cut
                         an arc equal in length to the radius.
                         (International standard ISO 31 — I, December 1965).
                         Solid angle unit
                         The steradian is the solid angle which has its apex at the centre of a sphere and which
                         describes on the surface of the sphere an area equal to that of a square having as its side the
                         radius of the sphere.
                         (International standard ISO 31 — I, December 1965).
 ---pagebreak--- 17. 7. 91                             Official Journal of the European Communities                                              N o C 185/17
               1.2.2. Derived SI units
                      Units derived coherently from SI base units and supplementary SI units are given as algebraic
                      expressions in the form of products of powers of the SI base units and/or supplementary SI
                      units with a numerical factor equal to 1.
               1.2.3. Derived SI units having names and symbols
                                                                         Units                            Expression
                                     Quantity                                              In other            In terms of base
                                                                  Name         Symbol      SI units            or supplementary
                                                                                                                    SI units
                      Frequency                                hertz          Hz                          S"1
                      Force                                    newton         N                           m • kg • s -2
                      Pressure, stress                        pascal          Pa         N • m-2          m_1 • kg • s -2
                      Energy, work; quantity of heat          joule           J          N- m             m2 • kg • s"2
                                                                                               1
                                l
                      Power ( ), radiant flux                 watt            W          J-s-             m2 • kg • s_J
                      Quantity of electricity, electric
                      charge                                   coulomb        C                           s • A
                      Electric potential, potential
                      difference, electromotive force         volt            V          W-A-1            m2 • kg • s -5 • A"1
                                                                                                   1
                      Electric resistance                      ohm            Q          V • A"           m2 • kg • s-5 • A-2
                                                                                                 1
                      Conductance                              Siemens        S          A-V-             m-2 • kg"1 • s> • A2
                                                                                                   1      m"2 • kg"1 • s4 • A2
                      Capacitance                              farad          F          c • v-
                      Magnetic flux                           weber           Wb         V- s             m2 • kg • s"2 • A - 1
                      Magnetic flux density                    tesla          T          Wb • m"      2
                                                                                                          kg • s-2 • A"1
                      Inductance                               henry          H          Wb • A"1         m2 • kg • s-2 • A-2
                      Luminous flux                            lumen          lm                          cd • sr
                      Illuminance                              lux            lx         lm • m' 2        m"2 • cd • sr
                      Activity
                       (of a radionuclid)                      becquerel      Bq                          S" 1
                      Absorbed dose, specific energy
                      imported, kerma, absorbed
                      dose index                               gray           Gy         J kg"1           m2 • s-2
                      Dose equivalent                          sievert        Sv         J • kg-          m2 • s"*
                      (') Special names for the units of power: the name volt ampere (symbol "VA') when it is used to express
                          the apparent power of alternaung 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, derived SI units may be expressed by the special names and symbols given in
                      the above tables; for example, the SI unit of dynamic viscosity may be expressed as
                      m'1 • kg • s"1 of N • s • nr 2 of Pa • s.
          1.3. Prefixes and their symbols used to designate certain decimal multiples and submultiples
                     Factor              Prefix            Symbol                 Factor             Prefix              Symbol
               10"                   exa                E                    lO"1               deci                  d
               10 ,s                 peta               P                    io-2               centi                 c
               1012                  tera               T                    io- s              milli                 m
               10'                   giga               G                    io-*               micro                 V-
               104                   mega               M                    io-'               nano                  n
               105                   kilo               k                    io-12              pico                  P
               102                   hecto              h                    io- i i            femto                 f
               101                   deca               da                   io-"               atto                  a
 ---pagebreak--- N o C 185/18                                Official J o u r n a l of the E u r o p e a n Communities                                 17.7.91
                    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 it 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
                                                                                             Unit
                                  Quantity
                                                                Name                  Symbol                       Value
                    Volume                               litre                  1 or L (»)           1 1 = 1 dm3 -        10-3 m5
                    Mass                                 tonne                 t                     1 t = 1 Mg = 103 kg
                    Pressure, stress                     bar                   bar( J )              1 bar = 10s Pa
                    (') The two symbols T and 'L' may be used for the litre unit.
                         (Sixteenth CGPM (1979), resolution 5).
                    (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 W H I C H ARE DEFINED O N T H E BASIS OF SI UNITS BUT ARE N O T DECIMAL
               MULTIPLES OR SUBMULTIPLES T H E R E O F
                                                                                       Unit
                      Quantity
                                                     Name                         Symbol                          Value
               Plane angle               revolution * (') (a)                                     1 revolution = 2 n rad
                                                                                                                n
                                         grade * or gon *                    gon*                 1
                                                                                                  1 gon = —         radA
                                                                                                  10 =
                                         degree                              °
                                                                                                         ifo rad
                                         minute of angle                     '                    1                 rad
                                                                                                     "   10 800
                                         second of angle                     *                    1                   fad
                                                                                                     ~   648 000
               Time                      minute                              min                  1 min = 60 s
                                         hour                                h                    1 h = 3 600 s
                                         day                                 d                    1 d = 86 400 s
               (') The character (") after a unit name or symbol indicates that it does not appear in the lists drawn up by the CGPM,
                   CIPM or 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'.
 ---pagebreak--- 17.7.91                                Official Journal of the European Communities                                             N o C 185/19
        3. UNITS DEFINED INDEPENDENTLY OF THE SEVEN SI BASE UNITS
           The unified atomic mass unit is one-twelfth of the mass of an atom of the nuclide 12C.
           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.
                                                                              Unit
               Quantity
                                             Name                       Symbol                              Value
           Mass                unifed automic mass unit             u                    1 u * 1,660 565 5 x 10"27 kg
           Energy              electronvolt                         eV                   1 eV « 1,602 189 2 x 10"" J
           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
                                                                                        Unit
                         Quantity
                                                         Name                    Symbol                        Value
           Vergency of optical systems             dioptre * (')                                  1 dioptre = 1 m"1
           Mass of precious stones                 metric carat                                   1 metric carat = 2 x 10"4 kg
           Area of farmland and building
           land                                    are                       a                    1 a = 102 m2
           Mass per unit length of textile
           yarns and threads                       tex *                    tex *                 1 tex = 10"' kg-m" 1
           Blood pressure and pressure             Millimetre of
           of other body fluids                    mercury                   mm Hg (*)            1 mm Hg = 133,322 Pa
           Effective cross-sectional area          Barn                     b                     1 b = 10 - ' m2
           (') The character (*) after a unit name or symbol indicates that it does not appear in the lists drawn up by the CGPM,
               CIPM or BIPM. This applies to the whole of this Annex.
           Note: The 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 1 form compound units.
 ---pagebreak--- No C 185/20                              Official Journal of the European Communities                                 17. 7. 91
                                                            CHAPTER 2
           LEGAL UNITS OF MEASUREMENT REFERRED TO IN ARTICLE 1 (b), PERMITTED FOR
                                                       SPECIFIC USES ONLY
                                                                                    Unit
                    Field of application
                                                         Name                 Approximate value           Symbol
           Road traffic signs, distance and         mile             1  mile =     1609 m              mile
           speed measurement                        yard             1  yd =      0,9144 m            yd
                                                    foot             1  ft -      0,3048 m             ft
                                                    inch             1  in -      2,54 x 10"2m         in
           Dispense of draught beer and             pint             lpt    =     0,5683 x 10-3mJ      Pt
           cider;    milk • in       returnable
           containers
           Land registration                        acre             1 ac =       4 047 m2             ac
           Transaction in precious metals           troy ounce       1 oz tr = 31,10 x 10"J kg         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 with those in Chapter 1 to form compound units. '
                                                            CHAPTER 3
                         LEGAL UNITS OF MEASUREMENT REFERRED TO IN ARTICLE 1 (c)
           QUANTITIES, NAMES OF UNITS, SYMBOLS AND APPROXIMATE VALUES
           Length
           inch                                   1 in       = 2,54 x 10-1 m
           foot                                   1 ft       = 0,3048 m
           mile                                   1 mile     = 1 609 m
           yard                                   1 yard     = 0,9144 m
           Area
           square foot                            1 sq ft    = 0,929 x 10"1 m2
                                                                       2
           acre                                   1 ac       = 4 047 m
                                                                         2
           square yard                            1 sq yd    = 0,8361 m
           Volume
           fluid ounce                            1 fl oz    - 28,41 x 10-' m3
           gill                                   1 gill     - 0,1421 x lO"5 mJ
           pint                                   1 pt       = 0,5683 x 10"J m3
           quart                                  1 qt       = 1,137 x lO"3 mJ
           gallon                                 1 gal      = 4,546 x lO"5 m3
           Mass
           ounce (avoirdupois)                    1 oz       = 28,35 x lO"3 kg
           troy ounce                             1 oz tr    « 31,10 x 10-3 kg
           pound                                  1 lb       = 0,4536 kg
           Energy
           therm                                  1 therm    = 105,506 x 10* J
           Until the date to be fixed pursuant to Article 1 (c), the units listed in Chapter 3 may be combined with
           each other or with those in Chapter 1 to form compound units.
 ---pagebreak--- 17.7.91                                Official Journal of the European Communities                                 No C 185/21
                                                            CHAPTER 4
        LEGAL UNITS OF MEASUREMENT REFERRED TO IN ARTICLE I (d), PERMITTED IN
                                                  SPECIALIZED FIELDS ONLY
                                                                                Unit
                  Field of application
                                                         Name             Approximate value                  Symbol
        Marine navigation                           fathom         1 fm =      1,829 m                  fm
        Beer, cider, waters, lemonades              pint           1 pt =      0,5683 x 1 0 - W         Pt
        and fruit juices in returnable              fluid ounce    1 fl oz -   28,41 x lO-'m5           fl oz
        containers
        Spirit drinks                               gill           1 gill =    0,142 x 1 0 - W          gill
        Goods sold loose in bulk                    ounce          1 oz =      28,35 x 10-J kg          oz
                                                    (avoirdupois)
                                                    pound          1 lb =      0,4536 kg                lb
        Gas supply                                  therm          1 therm = 105,506 x 10*J             therm
        Until the date to be fixed pursuant to Article 1 (d), the units listed in this Chapter may be combined with
        each other or with those in Chapter 1 to form compound units.
                                                              ANNEX II
                                            Directive                                   Deadline for implementation
        80/181/EEC (OJ N o L 39, 15. 2. 1980, p. 40)                                   1 July 1981
        85/1/EEC (OJ N o L 2, 3. 1. 1985, p. 11)                                       1 July 1985
        89/617/EEC (OJ No L 357, 7. 12. 1989, p. 28)                                   30 November 1991