The Units of Measurement Regulations 2009

S.I. 2009/3046 · Made 16 November 2009

Weights And Measures

Made 16th November 2009

Laid before Parliament 19th November 2009

Coming into force 1st January 2010

The Secretary of State, being a Minister designated^f1 for the purposes of section 2(2) of the European Communities Act 1972^f2 in relation to units of measurement to be used for economic, health, safety, or administrative purposes, in exercise of the powers conferred by that subsection, makes the following Regulations:

Annotations to the whole text

Footnotes

f1: S.I.1976/897, to which there are amendments not relevant to these Regulations.
f2: 1972 c.68; section 2(2) was amended by the Legislative and Regulatory Reform Act 2006 c.51, section 27(1).

1Citation and commencement
2Interpretation
3Removal of time limit on use of supplementary indications
4Further amendments of the 1986 Regulations
5Consequential amendments of the Units of Measurement Regulations 2001
Signature
Schedule Substituted paragraph 2(3) for Schedule 1 to the Units of Measurement Regulations 1986
Explanatory note

1Citation and commencement

These Regulations may be cited as the Units of Measurement Regulations 2009 and come into force on 1st January 2010.

2Interpretation

In these Regulations, “the 1986 Regulations” means the Units of Measurement Regulations 1986^f1.

3Removal of time limit on use of supplementary indications

(1)

In section 8(5A) of the Weights and Measures Act 1985^f1 (which allows the use for trade of supplementary indications up to and including 31 December 2009), omit “up to and including 31 December 2009,”.

(2)

In regulation 7 of the 1986 Regulations (which relates to supplementary indications), omit “up to and including 31 December 2009”.

4Further amendments of the 1986 Regulations

(1)

The 1986 Regulations are further amended as follows.

(2)

In Schedule 1—

(a)

in paragraph 1—

(i)

at the end of the entry beginning “The kelvin” insert “This definition refers to water having the isotopic composition defined by the following amount-of-substance ratios: 0.00015576 mole of ²H per mole of ¹H, 0.0003799 mole of ¹⁷O per mole of ¹⁶O and 0.0020052 mole of ¹⁸O per mole of ¹⁶O.”; and

(ii)

in the italic heading “Special name and symbol of the SI unit of temperature for expressing Celsius temperature”, for “SI unit” substitute “SI derived unit”;

(b)

in paragraph 2—

(i)

for the italic heading “Other SI units” substitute “SI derived units”;

(ii)

omit sub-paragraph (1);

(iii)

for sub-paragraph (2) substitute—

“(2)
General rule for SI derived units

Units derived coherently from SI base units are given as algebraic expressions in the form of products of powers of the SI base units with a numerical factor equal to 1.”;and

(iv)

for sub-paragraph (3) substitute the table and the notes set out in the Schedule.

5Consequential amendments of the Units of Measurement Regulations 2001

(1)

The Units of Measurement Regulations 2001^f1 are amended as follows.

(2)

In regulation 2 omit—

“—

“the Act” means the Weights and Measures Act 1985, and”.

(3)

Omit regulations 3 and 4(2).

Signature

Drayson

Minister of State for Science and Innovation,

Department for Business, Innovation and Skills

16th November 2009

Substituted paragraph 2(3) for Schedule 1 to the Units of Measurement Regulations 1986

“(3)
SI derived units with special names and symbols

Quantity Unit Name Unit Symbol Expression in terms of other SI units Expression in terms of SI base units

Plane angle radian rad m.m^-1
Solid angle steradian sr m².m^-2
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
Power*, radiant flux Watt W J.s^-1 m².kg.s^-3
Electric charge, quantity of electricity coulomb C s.A
Electric potential, potential difference, electromotive force Volt V W.A^-1 m².kg.s^-3.A^-1
Electric resistance Ohm $Ω$ V.A^-1 m².kg.s^-3.A^-2
Conductance siemens S A.V^-1 m^-2.kg^-1.s³.A²
Capacitance Farad F C.V^-1 m^-2.kg^-1.s⁴.A²
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 cd
Illuminance Lux lx lm.m^-2 m^-2.cd
Activity (of a radionuclide) becquerel Bq s^-1
Absorbed dose, specific energy imparted, kerma, absorbed dose index Gray Gy J.kg^-1 m².s^-2
Dose equivalent, dose equivalent index sievert Sv J.kg^-1 m^2.s^-2
Catalytic activity Katal kat mol.s^-1

Notes

Units derived from SI base units may be expressed in terms of the units listed in this Schedule.

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 dynamic viscosity may be expressed as m^-1. kg.s^-1 or N.s.m^-2 or Pa.s.

*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.”

Quantity	Unit Name	Unit Symbol	Expression in terms of other SI units	Expression in terms of SI base units
Plane angle	radian	rad		m.m^-1
Solid angle	steradian	sr		m².m^-2
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
Power*, radiant flux	Watt	W	J.s^-1	m².kg.s^-3
Electric charge, quantity of electricity	coulomb	C		s.A
Electric potential, potential difference, electromotive force	Volt	V	W.A^-1	m².kg.s^-3.A^-1
Electric resistance	Ohm	$Ω$	V.A^-1	m².kg.s^-3.A^-2
Conductance	siemens	S	A.V^-1	m^-2.kg^-1.s³.A²
Capacitance	Farad	F	C.V^-1	m^-2.kg^-1.s⁴.A²
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	cd
Illuminance	Lux	lx	lm.m^-2	m^-2.cd
Activity (of a radionuclide)	becquerel	Bq		s^-1
Absorbed dose, specific energy imparted, kerma, absorbed dose index	Gray	Gy	J.kg^-1	m².s^-2
Dose equivalent, dose equivalent index	sievert	Sv	J.kg^-1	m^2.s^-2
Catalytic activity	Katal	kat		mol.s^-1

Explanatory note

(This note is not part of the Regulations)

These Regulations implement in part the amendments made by Directive 2009/3/EC of the European Parliament and the Council (OJ L114, 7.5.2009, p 10) to Council Directive 80/181/EEC (OJ L39, 15.2.1980, p 40) which relates to the use of units of measurement.

Regulation 3 removes the time limit (specified in the Weights and Measures Act 1985 and the Units of Measurement Regulations 1986 (“the 1986 Regulations”)) on the use of supplementary indications of quantity expressed in imperial units of measurement (31 December 2009). The use of such supplementary indications is, therefore, permitted indefinitely. Regulation 5 makes consequential amendments to the Units of Measurement Regulations 2001, which inserted the time limit in question.

Regulation 4 makes a number of amendments to the 1986 Regulations, in order to implement technical measures adopted by the General Conference on Weights and Measures. For example, a new unit of measurement, the “katal” is included within the International System of Units as the unit of measurement of catalytic activity, so as to ensure a uniform indication of units of measurement in the fields of medicine and biochemistry.

A full impact assessment has not been produced for this instrument as no impact on the private or voluntary sectors is foreseen.

The Units of Measurement Regulations 2009

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Footnotes

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