Technical Regulations for Legal Measurements Units

⚠ ترجمة رسمية — النص العربي الأصلي هو النسخة الملزمة قانونًا.

9 مادة

1. المادة 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.

2. المادة 2

   Scope of Application

   1. 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.

   2. 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.

3. المادة 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.

4. المادة 4

   Legal Measurement Units

   1. 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.

   2. 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.

   3. 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.

   4. 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

   5. 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.

5. المادة 5

   Local Measurement Units

   1. 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.

   2. 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.

6. المادة 6

   General Provisions

   1. 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.

   2. 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.

   3. 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.

7. المادة 7

   Executive Resolutions The Minister, in coordination with the competent authority, shall issue the Resolutions necessary to apply the provisions of this Resolution.

8. المادة 8

   Repeals Any provision that violates or contradicts the provisions of this Resolution shall be repealed.

9. المادة 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: time Quantity: time Unit: The second Unit: The second Symbol: s Symbol: 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 Δν Cs , where Hz = s -1 . It is defined by taking the fixed numerical value of the caesium frequency Δν Cs, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be 9 192 631 770 when expressed in the unit Hz, which is equal to s -1 . This definition implies the following exact relation This definition implies the exact relation Δν Cs, = 9 192 631 770 Hz.

   Δν Cs, = 9 192 631 770 Hz. Inverting this relation gives an expression for the unit second in terms of the defining constant Cs Δν ,

   Inverting this relation gives an expression for the unit second in terms of the defining constant Δν Cs, : 1 Hz = ΔνCs 9 192 631 770

   or Or 1 Hz = 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 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 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. 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.

   Quantity: length Quantity: length Unit: The metre Unit: The metre Symbol: M Symbol: 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 Δν Cs

   It is defined by taking the fixed numerical value of the speed of light in vacuum c to be 299 792 458 when expressed in the unit m s -1 , where the second is defined in terms of Δν Cs

   This definition implies the exact relation This definition implies the exact relation c=299 792 458 m s -1 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 Δν

   CS: Inverting this relation gives an expression for the unit second in terms of the defining constant ΔνCs: 1 m = ( 퐶 299 792 458 ) 푆

   = 9 192 631 770 299 792 458

   퐶 ΔνCs

   ≈30.633 319 퐶 ΔνCs

   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. 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.

   Quantity: Mass Quantity: Mass Unit: The kilogram Unit: The kilogram Symbol: kg Symbol: 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 m s -1 ), where the metre and the second are defined in terms of c and Δν Cs

   It is defined by taking the fixed numerical value of the Planck constant h to be 6.626 070 15 × 10 -34 when expressed in the unit J s, which is equal to kg m s -1 , where the metre and the second are defined in terms of c and Δν Cs

   This definition implies the exact relation This definition implies the exact relation h= 6.626 070 15 × 10 -34 kg m s -1 h= 6.626 070 15 × 10 -34 kg m s -1

   Inverting this relation gives an expression for the unit kilograms in terms of the defining constants h, and ΔνCS and c Inverting this relation gives an exact expression for the kilogram in terms of the three defining constants h, Δν Cs and c 1 Kg = ( 퐻 6.626 070 15 × 10 −34 ) 푚. −2 푠

   Which is equal to Which is equal to 1 Kg = (299 792 458) ( 6.626 070 15 × 10 −34 )( 9 192 631 770 ) ℎ Δν 푐푠 퐶

   ≈1.475 5214×10 ℎ Δν 푐푠 퐶

   The effect of this definition is to define the unit (J s = kg m 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. The effect of this definition is to define the unit kg m s -1 (the unit of both the physical quantities action and angular momentum). 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.

   Quantity: electric current Quantity: electric current Unit: The ampere Unit: The ampere Symbol: A Symbol: 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 Δν Cs

   It is defined by taking the fixed numerical value of the elementary charge e to be 1.602 176 634 × 10 -19 when expressed in the unit C, which is equal to A s, where the second is defined in terms of Δν Cs

   This definition implies the exact relation This definition implies the exact relation

   e=1.602 176 634 x 10 -19 A s 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 Δν CS: Inverting this relation gives an exact expression for the unit ampere in terms of the defining constants e and Δν Cs : 1 퐴= ( 푒 1.602 176 634 ×10 −19 ) 푠 −1

   Which is equal to Which is equal to 1 퐴= ( 9 192 631 770 ) (1.602 176 634 ×10 −19 ) Δν 푐푠 푒

   ≈6.789.687 × 10 훥휈 푐푠 푒

   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. 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.

   Quantity: thermodynamic temperature Quantity: thermodynamic temperature Unit: The kelvin Unit: The kelvin Symbol: K Symbol: 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 m s -2 K -1 , where the It is defined by taking the fixed numerical value of the Boltzmann constant k to be 1.380 649 × 10-23 when expressed in the unit J K -1 , which is equal to kg m s -2 K -1 ,

   kilogram, metre and second are defined in terms of h, c and Δν Cs

   where the kilogram, metre and second are defined in terms of h, c and

   Δν Cs This definition implies the exact relation This definition implies the exact relation k=1.380 649 × 10 -23 kg m s -2 K -1 k=1.380 649 × 10 -23 kg m s -2 K -1

   Inverting this relation gives an expression for the unit kelvin in terms of the defining constants k, h and Δν CS: Inverting this relation gives an exact expression for the kelvin in terms of the defining constants k, h and Δν Cs

   1 퐾= ( 1.380 649 × 10 −23 푘 ) 푘푔 푚 푠 −2

   Which is equal to Which is equal to 1 퐾= 1.380 649 × 10 −23 ( 6.626 070 15 × 10 −34 ) (9 192 631 770) Δν 푐푠 ℎ 푘

   ≈2.266 6653 Δν 푐푠 ℎ 푘

   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

   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

   j.

   Quantity: amount of substance Quantity: amount of substance Unit: The mole Unit: The mole Symbol: mol Symbol: mol

   One mole contains exactly (6.02 214 076 X 10 ) elementary entities, this number is the fixed numerical value of the Avogadro constant, N A , 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. 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. One mole contains exactly 6.02 214 076 × elementary entities. This number is the fixed numerical value of the Avogadro constant, N A , when expressed in the unit mol -1 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 This definition implies the exact relation N A = 6.022 140 76 × 10 mol -1 N A = 6.022 140 76 × 10 mol -1

   Inverting this relation gives an exact expression for the mole in terms of the defining constant N A

   Inverting this relation gives an exact expression for the mole in terms of the defining constant N A :

   1 푚표푙= (6.022 140 76 ×10 ) 푁 퐴

   The effect of this definition is that the mole is the amount of substance of a system that contains (6.02 214 076 X ) elementary entities. The effect of this definition is that the mole is the amount of substance of a system that contains 6.02 214 076 × 10 elementary entities.

   Quantity: luminous intensity Quantity: luminous intensity Unit: The candela Unit: The candela Symbol: cd Symbol: cd It is defined by taking the fixed numerical value of the luminous efficacy (K cd ) of (683 lm W -1 ) for a monochromatic beam with a frequency 540 x 10 Hz, where Im W -1 =cd sr W =cd sr kg m s

   the kilogram, metre and second are defined in terms of -h, c and Δν Cs

   is the SI unit of luminous intensity in a given direction. It is defined by taking the fixed numerical value of the luminous efficacy of monochromatic radiation of frequency 540 × 10 Hz, K cd , to be 683 when expressed in the unit Im W -1 , which is equal to cd sr W -1 , or cd sr kg m s , where the kilogram, metre and second are defined in terms of h, cand Δν Cs

   This definition implies the exact relation This definition implies the exact relation K cd = 683 cd sr kg m s K cd = 683 cd sr kg m s

   for monochromatic radiation of frequency ν = 540 × 10 Hz for monochromatic radiation of frequency ν = 540 × 10 Hz. Inverting this relation gives an exact expression for the candela in

   Inverting this relation gives an exact expression for the candela in terms of the defining constants K cd and h and Δν Cs

   terms of the defining constants K cd hand Δν Cs

   1 푐푑=( 푘 푐푑 )푘푔 푚 푠 −3 푠푟 −1

   Which is equal to Which is equal to 1 푐푑 = ( 6.626 070 15 × 10 −34 ) (9 192 631 770) ( Δν 푐푠 ) ℎ 퐾 푐푑

   ≈2.614 8305 ×10 ( Δν 푐푠 ) ℎ 퐾 푐푑

   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 10 and has a radiant intensity in that direction of (1/683) W sr -1

   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 10 Hz 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 m m Square metre Square metre Area Area m m Cubic metre Cubic meters Volume Volume rad/s rad/s Radian per second Radian per second Angular velocity Angular velocity rad/s rad/s

   Radian per second squared Radian per second squared Angular acceleration Angular acceleration m/s m/s Metre per second Metre per second Velocity Velocity m/s m/s

   meter per second squared Metre per second squared Acceleration Acceleration kg/m kg/m Kilogram per metre Kilogram per metre Lineic mass, linear density Lineic mass, linear density kg/m kg/m

   Kilogram per square metre Kilogram per square metre Areic mass, surface density Areic mass, surface density kg/m kg/m

   Kilogram per cubic metre Kilogram per cubic metre Density (mass density) Density (mass density) m /s m /s Metre squared per second Metre squared per second Kinematic viscosity Kinematic viscosity

   Volume flow rate Volume flow rate Cubic metre per second Cubic metre per second m /s m /s Mass flow rate Mass flow rate Kilogram per second Kilogram per second kg/s kg/s Magnetomotive force Magnetomotive force ampere ampere A A Magnetic field strength Magnetic field strength Ampere per metre Ampere per metre A/m A/m Luminance Luminance Candela per square metre Candela per square metre cd/m Cd/m

   Wave number Wave number 1 per meter 1 per metre 1/m 1/m

   Table (3) Derived Units with Special Names and Symbols 1 Quantity: Plane angle Unit: Radian Unit Symbol: 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 Quantity: Solid angle Unit: Steradian Unit symbol: 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 Quantity: Frequency Unit: hertz Unit symbol: 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 Quantity: Force Unit: Newton Unit Symbol: 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 Quantity: Pressure, stress Unit: Pascal Unit symbol: 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 Quantity: Work, energy, quantity of heat Unit: joule Unit Symbol: 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 Quantity: Energy flow rate, heat flow rate power Unit: watt Unit Symbol: W A Watt is the power that represents the rate at which 1 Joule of energy is produced or consumed per second. 8 Quantity: temperature, interval of temperature Unit: Degree Celsius Unit Symbol: °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: Quantity of electricity, electric charge Unit: coulomb Unit Symbol: C A Coulomb is the quantity of electric charge transferred in 1 second by a constant electric current of 1 Ampere. 10 Quantity: Electric potential, electromotive force Unit: volt Unit Symbol: 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 Quantity: Electric resistance Unit: ohm Unit Symbol:  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 Quantity: Conductance Unit: siemens Unit Symbol: 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 Quantity: Electric capacitance Unit: farad Unit Symbol: 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 Quantity: inductance Unit: Henry Unit Symbol: 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 Quantity: Magnetic flux Unit: weber Unit Symbol: 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 Quantity: Magnetic flux density, magnetic induction Unit: Tesla Unit Symbol: 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 Quantity: Catalytic activity Unit: katal Symbol: 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 Quantity: Luminous flux Unit: lumen Unit Symbol: 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 Quantity: Illuminance Unit: lux Unit Symbol: 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 Quantity: Activity of a radioactive source Unit: Becquerel Unit Symbol: 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 Quantity: Absorbed dose, kerma Unit: gray Unit Symbol: 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 Quantity: Dose equivalent Unit: sievert Unit Symbol: 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 N.m Newton metre Newton metre Moment of force Moment of force -1 Pa.s Pa.s Pascal Second Pascal second Dynamic viscosity Dynamic viscosity -2 J/K J/K Joule per kelvin Joule per kelvin Entropy Entropy -3 l/(kg0K) l/(kg0K) Joule per kilogram kelvin Joule per kilogram kelvin Specific heat capacity Specific heat capacity -4 W/(m.K) W/(m.K) Watt per metre kelvin Watt per metre kelvin Thermal conductivity Thermal conductivity -5 v/m v/m Volt per meter Volt per metre Electric field strength Electric field strength -6 W/sr W/sr Watt per steradian Watt per steradian Radiant intensity Radiant intensity

   c/kg c/kg Coulomb per kilogram Coulomb per kilogram Exposure Exposure -8

   Table (5) Examples of Some Dimensionless Derived Units No. Unit -1 Refractive index Refractive index -2 Relative permeability Relative permeability -3 Friction factor Friction factor -4 Prandtl number 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 Q quetta quetta 10

   1000 000 000 000 000 000 000 000 000 R R ronna ronna 10 1 000 000 000 000 000 000 000 000 000 Y Y Yotta Yotta 10 1 000 000 000 000 000 000 000 000 Z Z Zeta Zeta 10 1 000 000 000 000 000 000 000 E E Exa Exa 10 1000 000 000 000 000 000 P P Peta Peta 10 1000000000 000 000 T T Tera Tera 10 1000000000 000 G G Giga Giga 10 1000000000 M M mega mega 10 1000 000 K K Kilo Kilo 10 H H hecto hecto 10 da da deca deca 10 D D deci deci 10 0.1 c C centi centi 10 -2 0.01 M M milli milli 10 -3 0.001 mc  micro micro 10 -6 0.000 001 n n nano nano 10 -9 0.000 000 001 P p Pico pico 10 -12 0.000 000 000 001 f f femto femto 10 -15 0.000 000 000 000 001 a a atto atto 10 -18 0.000 000 000 000 000 001 z z zepto Zepto 10 -21 0.000 000 000 000 000 000 001

   y y Yocto Yocto 10 -24 0.000 000 000 000 000 000 000 001 r R ronto Ronto 10 -27 0.000 000 000 000 000 000 000 000 001 q Q quecto 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 minute min Min 1 min = 60s hour hour H H 1h = 60 min = 3600 s One day day d d 1d = 24 h Plane Angle Degree Degree ( ) ° ° 1° = (/180) rad Minute minute ‘ ‘ 1’= (1/60)’= (/10 800) rad Second Second ” ” 1” - (1/60)” = (/648 000) rad gon (degree) gon gon 1° = (/200) rad Capacity litre litre ( ) L L,l 1 l = 1 dm = 10 -3 m

   Mass Metric ton ton ( ) Ton t 1t = 10 kg Pressure bar bar bar bar 1 bar = 10 Pa Algorithmic quantity Nipper

   (7) and

   (6) neper Np Np 1Np = ln e = 1

   (8) bel bel B B 1 B = (1/2) In 10 (Np) = lg 10 B

   1. Standard no. 15031 recommends dividing the degree using decimals rather than using minutes and seconds.

   2. This unit and symbol (1) 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.

   3. In some English-speaking countries this unit is called the "metric ton".

   4. Example of algorithmic quantities: power level. power level

   5. When using units of algorithmic quantities, the quantities being measured shall be stated.

   6. Natural logarithms are used to obtain the algebraic value of quantities expressed in nipper.

   7. 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.

   8. 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 m

   Atoms and Nuclear Physics .2 Dynamic viscosity Dynamic viscosity poise poise P 1 P = 0.1 Pa.s 1 cP = 10 -3 Pa.s

   .3 Kinematic viscosity Kinematic viscosity stokes stokes St 1 St = 10 -4 m /s 1 cSt = 10 -6 m /s

   .4 Radioactive source activity curie curie Ci (9) 1 Ci = 37 GBq = 3.7 X 10 Bq

   5. Absorbed dose of radiation rad rad (10) 1 rad = 0.01 Gy = 10 -2

   Gy Radiation

   6. Exposure to radiation Exposure rdntgen 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:

   9. This unit can be used with the prefixes for multiples and parts of units of measurement th CGPM, 1964

   10. This unit can be used with the prefixes for multiples and parts of units of measurement th CGPM, 1964

   11. This unit can be used with the prefixes for multiples and parts of units of measurement th CGPM, 1964

   Low blood pressure measurement Millimetre of mercury

   1 bar =100 kPa = 10 Pa bar (12) bar

   1 r = 2 rad r cycle revolution Plane Angle 8.

   1 diopter = 1 m -1 diopter diopter strength of optical systems strength of optical Systems

   Pearls and precious stones trading 1 carat = 2x10 -4 kg = 200 mg Ct (13) Metric carat Metric carat Mass 10. Sea and air travel 1 nautical mile = 1852 m n mile Nautical mile nautical mile Height 11. Sea and air travel 1 nautical mile per hour - (1852/3600) m/s knot knot knot Velocity 12.

   12. This unit can be used with the prefixes for multiples and parts of units of measurement th CGPM, 1964

   13. 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 1 in = 2.54 cm = 2.54 X 10 -2 m A

   IN angstrom angstrom (15) inch inch length 8.1 Timber trading 1 st = 1 m St Stere Volume 8.2

   1 q = 100 kg = 10 Kg 1 lb= 453.592 g Q Lb quintal pound pound Mass B.3 1 Kgf = 1 Kp = 9.806 65 N Kgf kp Kilogram- force kilopond Force d«

   1 atm = 101.325 kPa = 1.013 25X10 Pa Atm Standard atmospher Pressure 8.5

   1 at = 98.0665 kPa = 0.980.665 X 10 Pa At technical atmospher Medical treatment 1Torr = 101.325/760 Pa Torr Torr

   1 mH2O 9.806.65 kPa = 9.806.656 X 10 Pa mH2o Metre of water 1kgf.m = 1kp.m = 9.806.65 (16) k.gfm Kilogram Force-Meter

   8.6

   14. According to the document of the International Organisation for Legal Metrology OIML D2:1999:

   15. According to reference (10), this unit can still be used.

   1 cal = 4.186.8 kp.m Cal Kilogram force metre Kilopond metre Kilopond metre calorie 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 K cd /m = 10 cd/m sb stilb Luminance 8.8

   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 electronvolt eV 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 X 10 -19

   Mass Unified atomic mass unit Unified atomic mass unit U I. 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 Astronomical unit ua ua It is the average distance between the Earth and the Sun. 1 ua 1.495.978.706.91 x 10 m ± 0.000 000 00030 × 10 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 litre 1 Gallon - 4.546 litre Cubic metre cubic metre 1 Gallon - 4.546 X 10 -3 m

   .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 millilitre 1 TOLA = 11.6638 ml (Liquid)