Cabinet Resolution Concerning the Technical Regulations for Legal Measurements Units
The Cabinet,
- Having reviewed the Constitution; and
- Based on the proposal submitted by the Minister of Industry and Advanced Technology, and the Cabinet's approval,
Has resolved as follows:
Article (1) — Definitions
In application of the provisions of this Resolution, the words and expressions set forth herein shall bear the meanings ascribed to them, unless the context otherwise requires:
- Ministry: Ministry of Industry and Advanced Technology.
- Minister: Minister of Industry and Advanced Technology.
- Competent Authority: The federal and local government authority in the State that falls within its jurisdiction to implement any of the provisions of this Resolution.
- Legal Measurement Units: Units of measurement that shall be used exclusively in the specific fields according to the legislation in force in the state.
- Prefix: A letter or group of letters before a word that partly indicates meaning (such as Milli, kilo, mega).
- Legal Measurement Instrument: A measuring instrument used in trading, or which, in some form or other, affects the health and safety of individuals or the environment as a result of not being given correct indicators.
- General Conference on Weights and Measures: An intergovernmental organisation established in 1875 under the terms of the Metre Convention, through which member states work together on matters relating to metrology and measurement standards. It consists of delegates from the governments of member states and observers from affiliated countries.
- International System of Units (SI): An interconnected system of units based on the International System of Quantities, the names, symbols, and prefixes of its units, as well as rules for use thereof, have been approved by the General Conference on Weights and Measures.
- Base Units: The legal measurement units approved by the General Conference on Weights and Measures, as units that are dimensionally independent of each other.
- Derived Units: Legal measurement units established as products of powers of base units, in accordance with the algebraic relationships governing the associated quantities.
Article (2) — Scope of Application
-
The provisions of this resolution shall apply to legal units of measurement, symbols and prefixes thereof used in the following areas: a. Legal Measurement Instruments. b. Pre-packaged packages. c. Trading. d. Legal inspections and measurements. e. Health, Safety and Environment Fields. f. Advertisements, publications, books, magazines, and all advertising and media means. g. Contracts and official documents issued by public and private official entities.
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The following areas shall be exempted from the use of legal measurement units, symbols and prefixes thereof: a. Conversion tables between different measurement units. b. Special uses related to military and security fields. c. Documents, contracts and properties in which international treaties and agreements binding on the State require the use of other measurement units. d. Goods and services related to export or documents and publications intended for use in other countries use different measurement units. e. Areas of scientific research. f. Any measurement units referred to for historical purposes. g. Special uses that require the use of non-legal measurement units (such as tire pressure gauges in psi and aviation inch length gauges) provided that they shall be determined with the legal equivalents thereof.
Article (3) — Responsibilities
The Ministry shall bear responsibility for implementing and supervising the requirements of this resolution in collaboration with the authorities authorised to carry out metrological control within the State, as well as with the competent authorities, scientific institutes, and universities. For this purpose, it may take the necessary decisions and procedures to ensure implementation thereof.
Article (4) — Legal Measurement Units
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The legal measurement units adopted by the state and prefixes thereof consist of the following: a. The base units shown in Table (1) attached hereto. b. Derived units, divided into the following groups: 1. Derived measurement units based on the use of only the base units shown in Table (2) attached hereto. 2. The measurement units with special names and symbols shown in Table (3) attached hereto. 3. Derived measurement units whose names and symbols contain derived units with special names and symbols shown in Table (4) attached hereto. 4. The non-dimensional derived measurement units shown in Table (5) attached hereto. 5. Prefixes of measurement units shown in Table (6) attached hereto.
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The legal measurement units accepted for use outside the International System of Units are as follows: a. The measurement units accepted due to the frequent use thereof, shown in Table (7) attached hereto. b. Acceptable measurement units, which are not permitted to be used outside the topics specified therefor, as shown in Table (8) attached hereto. c. The currently accepted units of measurement outside the SI within specific topics, the values of which have been determined by practical experience, and which shall be discontinued in the event of international adoption of alternative units for the fields included and shown in Table (9) attached hereto.
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The measurement units listed in Table (10) attached hereto shall be discontinued, and any person who uses them shall be subject to the penalties prescribed in Article (6) of this resolution.
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The use and notation of prefixes, symbols, quantities, units, and measurement results shall conform to the recommendations of the General Conference on Weights and Measures, as well as the mandatory technical regulations issued in this regard. They shall be presented in the correct form, size, and location, ensuring accuracy and preventing any errors or misleading representations.
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In educational contexts, reference may be made to certain measurement units outside the SI, whether historical or currently in use, for the purpose of understanding the evolution of the science of measurement.
Article (5) — Local Measurement Units
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These are measurement units not recognised internationally, whose use is restricted to within the State for resolving local disputes, if they arise. Use thereof shall be exclusively verbal, and such units may possess different values and symbols outside the State.
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It is prohibited to use the local units of measurement specified in Table (11) attached hereto. The units of measurement referred to shall be replaced according to the conversion factors mentioned in the same table.
Article (6) — General Provisions
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To safeguard the public interest, the Ministry may take such actions as it deems appropriate in cases that cannot be addressed under the provisions of this Resolution, or in the event of a dispute regarding its interpretation or application. The Ministry may rely on prevailing international practices in this domain as a basis for the resolutions thereof.
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The Minister shall have the authority to add or cancel any legal measurement units or to amend any of the tables attached hereto in response to scientific or technical developments, whether global or local, as required by the public interest.
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In the event of a violation of the provisions of this resolution, the administrative penalties stipulated in Cabinet Resolution No. (64) of 2022 regarding the National Measurement System shall be applied.
Article (7) — Executive Resolutions
The Minister, in coordination with the competent authority, shall issue the Resolutions necessary to apply the provisions of this Resolution.
Article (8) — Repeals
Any provision that violates or contradicts the provisions of this Resolution shall be repealed.
Article (9) — Publication and Entry into Force
This Resolution shall be published in the Official Gazette and shall be enforced after (30) thirty days as of the date of its publication.
Mohammed Bin Rashid Al Maktoum Prime Minister
Issued by Us: Date: 02 Muharram 1445 A.H. Corresponding to: 20 July 2023 AD
Schedule (1) — SI Base Units
| Quantity | Unit | Symbol | Definition and Implication |
|---|---|---|---|
| time | The second | s |
The second is defined by taking a fixed numerical value of 9 192 631 770 Hz. The unperturbed ground-state hyperfine transition frequency of the caesium 133 atom ΔVcs, where Hz = s¯¹.
This definition implies the following exact relation: Δνcs = 9 192 631 770 Hz. Inverting this relation gives an expression for the unit second in terms of the defining constant CsΔv: 1 s = 1 / (9 192 631 770 Δνcs) The effect of this definition is that the second is equal to the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the unperturbed ground state of the 133 Cs atom. The reference to an unperturbed atom is intended to make it clear that the definition of the SI second is based on an isolated caesium atom that is unperturbed by any external field, such as ambient black-body radiation. |
| length | The metre | M |
It is defined by taking the fixed numerical value of the speed of light in vacuum c to be 299 792 458 (299 792 458 m s¯¹) where the second is defined in terms of ΔvCs.
This definition implies the exact relation: c = 299 792 458 m s¯¹ Inverting this relation gives an expression for the unit metre in terms of the defining constants c and ΔvCs: 1 m = (299 792 458) s / c 1 m ≈ 30.633 319 C / ΔvCs The effect of this definition is that one metre is the length of the path travelled by light in vacuum during a time interval with duration of 1/299 792 458 of a second. |
| Mass | The kilogram | kg |
It is defined by taking the fixed numerical value of the Planck constant h to be (6.626 070 15 × 10⁻³⁴), where (J s = kg m² s⁻¹), where the metre and the second are defined in terms of c and ΔvCs.
This definition implies the exact relation: h = 6.626 070 15 × 10⁻³⁴ kg m² s⁻¹ Inverting this relation gives an expression for the unit kilograms in terms of the defining constants h, and ΔVCS and c: 1 Kg = (H / (6.626 070 15 × 10⁻³⁴)) m.⁻² s Which is equal to: 1 Kg = ( (299 792 458)² / (6.626 070 15 × 10⁻³⁴)(9 192 631 770) ) * (h Δvcs / C²) 1 Kg ≈ 1.475 5214 × 10⁴⁰ (h Δvcs / C²) The effect of this definition is to define the unit (J s = kg m² s⁻¹) (The unit of physical quantities and angular momentum), which, together with the definitions of the second and the metre this leads to a definition of the unit of mass expressed in terms of the Planck constant h. |
| electric current | The ampere | A |
It is defined by taking the fixed numerical value of the elementary charge e to be (1.602 176 634 × 10⁻¹⁹) c, where C=A S, where the second is defined in terms of ΔvCs.
This definition implies the exact relation: e = 1.602 176 634 x 10⁻¹⁹ A s Inverting this relation gives an expression for the unit ampere in terms of the defining constants e and ΔvCS: 1 A = e / ( (1.602 176 634 × 10⁻¹⁹) s⁻¹ ) Which is equal to: 1 A = 1 / ( (9 192 631 770)(1.602 176 634 × 10⁻¹⁹) Δvcs e ) 1 A ≈ 6.789.687 × 10⁸ Δvcs e The effect of this definition is that one ampere is the electric current corresponding to the flow of 1/(1.602 176 634 × 10⁻¹⁹) elementary charges per second. |
| thermodynamic temperature | The kelvin | K |
It is defined by taking the fixed numerical value of the Boltzmann constant k to be 1.380 649 × 10⁻²³, where J K⁻¹ = Kg m² s⁻² K⁻¹, where the kilogram, metre and second are defined in terms of h, c and ΔVcs.
This definition implies the exact relation: k = 1.380 649 × 10⁻²³ kg m² s⁻² K⁻¹ Inverting this relation gives an expression for the unit kelvin in terms of the defining constants k, h and ΔVCS: 1 K = (1.380 649 × 10⁻²³) / k kg m²s⁻² Which is equal to: 1 K = (1.380 649 × 10⁻²³) / ( (6.626 070 15 × 10⁻³⁴)(9 192 631 770) ) * (Δvcs h / k) 1 K ≈ 2.266 6653 (Δvcs h / k) The effect of this definition is that one kelvin is equal to the change of thermodynamic temperature that results in a change of thermal energy kt by 1.380 649 × 10⁻²³. |
| amount of substance | The mole | mol |
One mole contains exactly (6.02 214 076 X 10²³) elementary entities, this number is the fixed numerical value of the Avogadro constant, NA, when expressed in the unit mol⁻¹ (the inverse of the mole), and is called the Avogadro number. The amount of substance, symbol n, of a system is a measure of the number of specified elementary entities. An elementary entity may be an atom, a molecule, an ion, an electron, any other particle or specified group of particles.
This definition implies the exact relation: NA = 6.022 140 76 × 10²³ mol⁻¹ Inverting this relation gives an exact expression for the mole in terms of the defining constant NA: 1 mol = (6.022 140 76 × 10²³) / NA The effect of this definition is that the mole is the amount of substance of a system that contains (6.02 214 076 X 10²³) elementary entities. |
| luminous intensity | The candela | cd |
It is defined by taking the fixed numerical value of the luminous efficacy (Kcd) of (683 lm W⁻¹) for a monochromatic beam with a frequency 540 x 10¹² Hz, where lm W⁻¹ = cd sr W⁻¹ = cd sr kg⁻¹m⁻²s³
the kilogram, metre and second are defined in terms of -h, c and ΔvCs. This definition implies the exact relation: Kcd = 683 cd sr kg⁻¹m⁻²s³ for monochromatic radiation of frequency: v = 540 × 10¹² Hz Inverting this relation gives an exact expression for the candela in terms of the defining constants Kcd and h and ΔvCs: 1 cd = (Kcd / 683) kg m²s⁻³sr⁻¹ Which is equal to: 1 cd = 1 / ( (6.626 070 15 × 10⁻³⁴)(9 192 631 770)² 683 ) * (Δvcs)²h Kcd 1 cd ≈ 2.614 8305 × 10¹⁰ (Δvcs)²h Kcd The effect of this definition is that one candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540 X 10¹² and has a radiant intensity in that direction of (1/683) W sr⁻¹. |
Table (2) — Examples of Some Derived Units Based on the Use of Base Units Only
| Symbol | Unit | Quantity |
|---|---|---|
| m² | Square metre | Area |
| m³ | Cubic metre | Volume |
| rad/s | Radian per second | Angular velocity |
| rad/s² | Radian per second squared | Angular acceleration |
| m/s | Metre per second | Velocity |
| m/s² | Metre per second squared | Acceleration |
| kg/m | Kilogram per metre | Lineic mass, linear density |
| kg/m² | Kilogram per square metre | Areic mass, surface density |
| kg/m³ | Kilogram per cubic metre | Density (mass density) |
| m²/s | Metre squared per second | Kinematic viscosity |
| m³/s | Cubic metre per second | Volume flow rate |
| kg/s | Kilogram per second | Mass flow rate |
| A | ampere | Magnetomotive force |
| A/m | Ampere per metre | Magnetic field strength |
| Cd/m² | Candela per square metre | Luminance |
| 1/m | 1 per metre | Wave number |
Table (3) — Derived Units with Special Names and Symbols
| No. | Quantity | Unit | Unit Symbol | Definition |
|---|---|---|---|---|
| 1 | Plane angle | Radian | rad | A radian is the unit of plane angle, defined as the angle between two radii of a circle that intersect an arc whose length is equal to the radius of the circle. |
| 2 | Solid angle | Steradian | sr | A steradian is the unit of solid angle, defined as the angle with its vertex at the centre of a sphere that intercepts an area on the surface of the sphere equal to that of a square whose side length is equal to the sphere radius. |
| 3 | Frequency | hertz | Hz | Hertz is a unit of frequency, defined as the number of cycles of a periodic phenomenon occurring per second. Frequency is the number of cycles of a periodic phenomenon occurring in one second. |
| 4 | Force | Newton | N | A Newton is the force that, when applied to a stationary mass of 1 kilogram, causes it to accelerate at a rate of 1 metre per second squared. |
| 5 | Pressure, stress | Pascal | Pa | A Pascal is a unit of pressure defined as the amount of uniform pressure that, when applied to a flat surface of 1 square meter, exerts a total force of 1 Newton perpendicular to that surface. It is also the uniform stress that, when applied to a flat surface with an area of 1 square meter, results in a total force of 1 Newton acting on that surface. |
| 6 | Work, energy, quantity of heat | joule | J (1) | A Joule is the work done when a force of 1 Newton moves an object a distance of 1 meter in the direction of the force. |
| 7 | Energy flow rate, heat flow rate power | watt | W | A Watt is the power that represents the rate at which 1 Joule of energy is produced or consumed per second. |
| 8 | Temperature, interval of temperature | Degree Celsius | °C (°) | In addition to the thermodynamic temperature (K) expressed in Kelvin, the Celsius temperature (D) is also used, which is defined by the equation: D = KH - 273.15. The unit "degree Celsius" is numerically equivalent to the unit "kelvin"; however, "degree Celsius" is a specific name used instead of "kelvin." Temperature differences or ranges can be expressed either in degrees Celsius or in kelvins. |
| 9 | Quantity of electricity, electric charge | coulomb | C | A Coulomb is the quantity of electric charge transferred in 1 second by a constant electric current of 1 Ampere. |
| 10 | Electric potential, electromotive force | volt | V | A Volt is the electrical potential difference between two points in a conducting wire carrying a constant current of 1 Ampere, where the power consumed between these points is 1 Watt. |
| 11 | Electric resistance | ohm | Ω | An Ohm is the electrical resistance between two points of a conductor when a constant current of 1 Ampere flows through it, and the electrical potential difference between these points is 1 Volt, provided that the conductor is not connected to any source of electromotive force. |
| 12 | Conductance | siemens | S | A Siemens is the unit of electrical conductivity of a conductor that has an electrical resistance of 1 Ohm. (Electrical conductivity is the inverse of electrical resistance.) |
| 13 | Electric capacitance | farad | F | A Farad is the capacitance of an electrical capacitor that, when charged with an electric charge of 1 Coulomb, exhibits an electrical potential difference of 1 Volt between its plates. |
| 14 | Inductance | Henry | H | A Henry is the unit of electrical inductance of a closed circuit that generates an electromotive force of 1 Volt when the electric current flowing through it changes at a constant rate of 1 Ampere per second. |
| 15 | Magnetic flux | weber | Wb | A Weber is the unit of magnetic flux that, when passing through a single-turn electric circuit, generates an electromotive force of 1 volt as the flux decreases to zero at a constant rate over one second. |
| 16 | Magnetic flux density, magnetic induction | Tesla | T (1) | A Tesla is the unit of magnetic flux density/effect produced in an area of 1 square metre by a uniform magnetic flux of 1 Weber perpendicular to the area. |
| 17 | Catalytic activity | katal | kat | 1. It is the catalytic activity that causes a reaction rate change of mole of reactant per second. 2. When using the katal unit, it is recommended that the measured quantity be specified by linking it to the measurement method used to determine the reagent reaction. Note: According to Resolution No. 12 of the XXI General Conference on Weights and Measures in 1999, this derived unit can be used particularly in the fields of biochemistry and medical sciences. |
| 18 | Luminous flux | lumen | lm | A lumen is a measurement unit for luminous flux, defined as the amount of light emitted through a solid angle of 1 steradian from a light source with a uniform and precise radiation intensity of 1 candela. |
| 19 | Illuminance | lux | lx | Lux is a measurement unit for the illuminance of a surface, defined as the amount of luminous flux of 1 lumen uniformly distributed over an area of 1 square metre. |
| 20 | Activity of a radioactive source | Becquerel | Bq | A becquerel is a measurement unit for the activity of a radioactive source, representing one spontaneous nuclear transformation, disintegration, or change in the number of radionuclides in a given energy state per second. The activity of a radioactive source is measured by the number of spontaneous nuclear transformations or decays, or the change in the number of radionuclides in a given energy state, occurring within one second. |
| 21 | Absorbed dose, kerma | gray | Gy | A Gray is a unit of measurement for the absorbed dose of ionising radiation, defined as the amount of energy of 1 Joule deposited in a substance with a mass of 1 kilogram. |
| 22 | Dose equivalent | sievert | Sv | A Sievert is a unit of measurement for the dose equivalent in biological tissue with a mass of 1 kilogram, which receives an energy of 1 Joule from ionising radiation with a radiation impact factor of 1, under constant radiation flux. In other words, a Sievert quantifies the biological damage caused to tissue due to exposure to ionising radiation and is equivalent to one Joule per kilogram. Note: The dose equivalent is defined as the product of the absorbed dose at a specific point in biological tissue and the radiation effect factor at that point. |
Table (4) — Examples of Derived Units Whose Names and Symbols Contain Derived Units with Special Names and Symbols
| Symbol | Unit | Quantity | No. |
|---|---|---|---|
| N.m | Newton metre | Moment of force | -1 |
| Pa.s | Pascal Second | Dynamic viscosity | -2 |
| J/K | Joule per kelvin | Entropy | -3 |
| 1/(kg.K) | Joule per kilogram kelvin | Specific heat capacity | -4 |
| W/(m.K) | Watt per metre kelvin | Thermal conductivity | -5 |
| v/m | Volt per metre | Electric field strength | -6 |
| W/sr | Watt per steradian | Radiant intensity | |
| c/kg | Coulomb per kilogram | Exposure | -8 |
Table (5) — Examples of Some Dimensionless Derived Units
| No. | Unit |
|---|---|
| -1 | Refractive index |
| -2 | Relative permeability |
| -3 | Friction factor |
| -4 | Prandtl number |
Since the unit of dimensionless derived quantities is simply 1, it is not expressed explicitly. However, some of these dimensionless units have special names and symbols to avoid confusion with other derived units. Examples include the radian (rad), the steradian (sr), and the neper (Np).
Table (6) — SI Prefixes
| Prefix Symbol | Prefix Name | Multiplication Factor | Value |
|---|---|---|---|
| Q | quetta | 10³⁰ | 1 000 000 000 000 000 000 000 000 000 |
| R | ronna | 10²⁷ | 1 000 000 000 000 000 000 000 000 000 |
| Y | Yotta | 10²⁴ | 1 000 000 000 000 000 000 000 000 |
| Z | Zeta | 10²¹ | 1 000 000 000 000 000 000 000 |
| E | Exa | 10¹⁸ | 1000 000 000 000 000 000 |
| P | Peta | 10¹⁵ | 1000000000 000 000 |
| T | Tera | 10¹² | 1000000000 000 |
| G | Giga | 10⁹ | 1000000000 |
| M | mega | 10⁶ | 1000 000 |
| K | Kilo | 10³ | 1000 |
| H | hecto | 10² | 100 |
| da | deca | 10¹ | 10 |
| D | deci | 10⁻¹ | 0.1 |
| C | centi | 10⁻² | 0.01 |
| M | milli | 10⁻³ | 0.001 |
| μ | micro | 10⁻⁶ | 0.000 001 |
| n | nano | 10⁻⁹ | 0.000 000 001 |
| P | pico | 10⁻¹² | 0.000 000 000 001 |
| f | femto | 10⁻¹⁵ | 0.000 000 000 000 001 |
| a | atto | 10⁻¹⁸ | 0.000 000 000 000 000 001 |
| z | zepto | 10⁻²¹ | 0.000 000 000 000 000 000 001 |
| y | yocto | 10⁻²⁴ | 0.000 000 000 000 000 000 000 001 |
| r | ronto | 10⁻²⁷ | 0.000 000 000 000 000 000 000 000 001 |
| q | quecto | 10⁻³⁰ | 0.000 000 000 000 000 000 000 000 000 |
Table (7) — Acceptable Measurement Units Due to their Frequent Use
| Quantity | Unit | Symbol | Value in international units |
|---|---|---|---|
| Time | minute | min | 1 min = 60s |
| hour | H | 1h = 60 min = 3600 s | |
| One day | d | 1d = 24 h | |
| Plane Angle | Degree | ° | 1° = (π/180) rad |
| Minute | ' | 1'= (1/60)'= (π/10 800) rad | |
| Second | " | 1" - (1/60)" = (π/648 000) rad | |
| gon | gon | 1° = (π/200) rad | |
| Capacity | litre | L,l | 1l = 1 dm³ = 10⁻³ m³ |
| Mass | Metric ton | t | 1t = 10³ kg |
| Pressure | bar | bar | 1 bar = 10⁵ Pa |
| Algorithmic quantity | Nipper | Np | 1Np = ln e = 1 |
| bel | B | 1 B = (1/2) ln 10 (Np) = lg 10 B |
- Standard no. 15031 recommends dividing the degree using decimals rather than using minutes and seconds.
- This unit and symbol (l) were adopted by the CIPM in 1879. The alternative symbol (L) was adopted by the 16th General Conference on Weights and Measures in 1979, to remove confusion between the letter l and the number 1.
- In some English-speaking countries this unit is called the "metric ton".
- Example of algorithmic quantities: power level. power level
- When using units of algorithmic quantities, the quantities being measured shall be stated.
- Natural logarithms are used to obtain the algebraic value of quantities expressed in nipper.
- The Niper unit is considered to be compatible with the SI but has not yet been adopted by the General Conference on Weights and Measures.
- Decimal logarithm (logarithm to the base 10) is used to obtain the algebraic value of quantities expressed in Bel. The sub-multiple fraction decibel and the symbol (dB) are usually used.
Table (8) — Measurement Units Acceptable Outside the SI, which Shall Not be Used Outside the Topics for Which They are Specified
| No. | Measured Quantity | Unit | Symbol | Value in international units | Special use |
|---|---|---|---|---|---|
| 1. | Area | barn | B | 1 b = 10⁻²⁸ m² | Atoms and Nuclear Physics |
| .2 | Dynamic viscosity | poise | P | 1 P = 0.1 Pa.s | |
| Dynamic viscosity | poise | 1 cP = 10⁻³ Pa.s | |||
| .3 | Kinematic viscosity | stokes | St | 1 St = 10⁻⁴ m²/s | |
| Kinematic viscosity | stokes | 1 cSt = 10⁻⁶ m²/s | |||
| .4 | Radioactive source activity | curie | Ci (9) | 1 Ci = 37 GBq = 3.7 X 10¹⁰ Bq | |
| 5. | Absorbed dose of radiation | rad | rad (10) | 1 rad = 0.01 Gy = 10⁻² Gy | Radiation |
| 6. | Exposure to radiation | rontgen | R (11) | 1 R = 0.258 mC/Kg = 2.58 X 10⁻⁴ C/Kg | |
| 7. | Pressure | Millimetre of mercury | mmHg | 1 mmHg = 133.322 Pa | Only in specialised areas, such as: Low blood pressure measurement |
| bar | bar | 1 bar = 100 kPa = 10⁵ Pa | |||
| cycle revolution | r | 1 r = 2π rad | Plane Angle | ||
| diopter | diopter | 1 diopter = 1 m⁻¹ | strength of optical systems | ||
| Pearls and precious stones trading | carat | Ct (13) | 1 carat = 2x10⁻⁴ kg = 200 mg | Metric carat Mass | |
| Sea and air travel | nautical mile | n mile | 1 nautical mile = 1852 m | Nautical mile Height | |
| Sea and air travel | knot | knot | 1 nautical mile per hour = (1852/3600) m/s | Velocity |
- This unit can be used with the prefixes for multiples and parts of units of measurement 12th CGPM, 1964
- This unit can be used with the prefixes for multiples and parts of units of measurement 12th CGPM, 1964
- This unit can be used with the prefixes for multiples and parts of units of measurement 12th CGPM, 1964
- This unit can be used with the prefixes for multiples and parts of units of measurement 12th CGPM, 1964
- The symbol ct has not been adopted by either the General Conference on Weights and Measures or ISO but is widely used.
Table (9) — Currently Accepted Units of Measurement Outside the International System of Units which Shall Be Discontinued
| Special-use | Value in international units | Symbol | Unit | Measured Quantity | No., Item (14) |
|---|---|---|---|---|---|
| Magnetic wavelength | 1 A = 0.1 nm = 10⁻¹⁰ m | A | angstrom | length | 8.1 |
| 1 in = 2.54 cm = 2.54 X 10⁻² m | IN | inch | |||
| Timber trading | 1 st = 1 m³ | St | Stere | Volume | 8.2 |
| 1 q = 100 kg = 10² Kg | Q | quintal | Mass | 8.3 | |
| 1 lb = 453.592 g | Lb | pound | |||
| 1 Kgf = 1 Kp = 9.806 65 N | Kgf kp | Kilogram-force kilopond | Force | d« | |
| 1 atm = 101.325 kPa = 1.013 25×10⁵ Pa | Atm | Standard atmospher | Pressure | 8.5 | |
| 1 at = 98.0665 kPa = 0.980.665 X 10⁵ Pa | At | technical atmospher | |||
| Medical treatment | 1 Torr = 101.325/760 Pa | Torr | Torr | ||
| 1 mH2O 9.806.65 kPa = 9.806.656 X 10³ Pa | mH2o | Metre of water | |||
| 1kgf.m = 1kp.m = 9.806.65 (16) | k.gfm | Kilogram Force-Meter | 8.6 | ||
| 1 cal = 4.186.8 | Cal | calorie | Work, energy and heat | ||
| 1 metric horsepower = 0.735.498.75 KW = 735.498.75 W | watt | metric horsepower (cheval-vapeur) | Power | 8.7 | |
| 1 sb = 10 Kcd/m² = 10⁴ cd/m² | sb | stilb | Luminance | 8.8 |
- According to the document of the International Organisation for Legal Metrology OIML D2:1999:
- According to reference (10), this unit can still be used.
- This unit can be used with the prefixes for multiples and parts of units of measurement 12th CGPM, 1964
Table (10) — Units of Measurement Accepted in Specific Subjects and their Values Determined by Practical Experience
| Quantity | Unit | Symbol | Definition | Value in international units |
|---|---|---|---|---|
| Energy | electronvolt | eV | It is the kinetic energy that an electron loses when it travels through a vacuum and is subjected to an electrical potential difference of 1 Volt. | 1 eV = 1.602.177.33 X 10⁻¹⁹ ±0.000 000 49 × 10⁻¹⁹ |
| Mass | Unified atomic mass unit | U | It is a mass equal to 1/12 of the mass of the free carbon atom in the reference state. | 1 u = 1.660.540.2 × 10⁻²⁷ kg ±0.000 001 0 × 10⁻²⁷ kg |
| Height | Astronomical unit | ua | It is the average distance between the Earth and the Sun. | 1 ua 1.495.978.706.91 x 10¹¹ m ± 0.000 000 00030 × 10¹¹ m |
Table (11) — Table of Conversion Factors for Some Measurement Units that have been Cancelled
| No. | Prohibited unit | Measurement Field | Alternative measure unit | Conversion Factor |
|---|---|---|---|---|
| .1 | gallon | All fields | litre | 1 Gallon = 4.546 litre |
| Cubic metre | 1 Gallon = 4.546 X 10⁻³ m³ | |||
| .2 | Foot | All fields | Metre metre | 1 Foot = 0.304800 m |
| .3 | war/yard | All fields | Metre metre | 1 War (Yard) = 0.9144 m |
| .4 | Tola | All fields | Gram gram | 1 TOLA = 11.6638 g (Solid) |
| millilitre | 1 TOLA = 11.6638 ml (Liquid) |