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
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Cabinet Resolution of 2023 Concerning the Technical Regulations for Legal Measurements Units 7
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 ΔνCs, where
Hz = s-1.
It is defined by taking the fixed numerical
value of the caesium frequency ΔνCs, 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
ΔνCs,= 9 192 631 770 Hz. ΔνCs,= 9 192 631 770 Hz.
Inverting this relation gives an
expression for the unit second in
terms of the defining constant CsΔν,
Inverting this relation gives an expression
for the unit second in terms of the defining
constant ΔνCs,:
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 133Cs
atom.
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Cabinet Resolution of 2023 Concerning the Technical Regulations for Legal Measurements Units 8
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 andΔν CS:
Inverting this relation gives an expression
for the unit second in terms of the defining
constant ΔνCs:
1 m = ( 𝐶
299 792 458)𝑆
= 9 192 631 770
299 792 458
𝐶
ΔνCs
≈ 30.633 319 𝐶
ΔνCs
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Cabinet Resolution of 2023 Concerning the Technical Regulations for Legal Measurements Units 9
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 m2 s-1),
where the metre and the second are
defined in terms of c and ΔνCs
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 m2 s-1, where the
metre and the second are defined in terms
of c and ΔνCs
This definition implies the exact
relation
This definition implies the exact relation
h= 6.626 070 15 × 10-34 kg m2 s-1 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
ΔνCS and c
Inverting this relation gives an exact
expression for the kilogram in terms of the
three defining constants h, ΔνCs and c
1 Kg = ( 𝐻
6.626 070 15 × 10−34) 𝑚.−2 𝑠
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Cabinet Resolution of 2023 Concerning the Technical Regulations for Legal Measurements Units 10
Which is equal to Which is equal to
1 Kg = (299 792 458)2
(6.626 070 15 × 10−34)(9 192 631 770)
ℎ Δν𝑐𝑠
𝐶2
≈ 1.475 5214 × 1040 ℎ Δν𝑐𝑠
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.
The effect of this definition is to define the
unit kg m2 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 ΔνCs
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 ΔνCs
This definition implies the exact
relation
This definition implies the exact relation
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Cabinet Resolution of 2023 Concerning the Technical Regulations for Legal Measurements Units 11
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
andΔνCS:
Inverting this relation gives an exact
expression for the unit ampere in terms of
the defining constants e and ΔνCs:
1 𝐴 = ( 𝑒
1.602 176 634 × 10−19) 𝑠−1
Which is equal to Which is equal to
1 𝐴 = 1
(9 192 631 770)(1.602 176 634 × 10−19) Δν𝑐𝑠𝑒
≈ 6.789.687 × 108𝛥𝜈𝑐𝑠𝑒
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 m2 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 m2 s-2 K-1,
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Cabinet Resolution of 2023 Concerning the Technical Regulations for Legal Measurements Units 12
kilogram, metre and second are
defined in terms of h, c and ΔνCs
where the kilogram, metre and second are
defined in terms of h, c and ΔνCs
This definition implies the exact
relation
This definition implies the exact relation
k=1.380 649 × 10-23 kg m2 s-2 K-1 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
ΔνCS:
Inverting this relation gives an exact
expression for the kelvin in terms of the
defining constants k, h and ΔνCs
1 𝐾 = (1.380 649 × 10−23
𝑘 ) 𝑘𝑔 𝑚2𝑠−2
Which is equal to Which is equal to
1 𝐾 = 1.380 649 × 10−23
(6.626 070 15 × 10−34)(9 192 631 770)
Δν𝑐𝑠ℎ
𝑘
≈ 2.266 6653 Δν𝑐𝑠ℎ
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
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.
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Cabinet Resolution of 2023 Concerning the Technical Regulations for Legal Measurements Units 13
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 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. 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 ×
1023 elementary entities. This number is
the fixed numerical value of the Avogadro
constant, NA, 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
NA = 6.022 140 76 × 1023 mol-1 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
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
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Cabinet Resolution of 2023 Concerning the Technical Regulations for Legal Measurements Units 14
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.
The effect of this definition is that the mole
is the amount of substance of a system that
contains 6.02 214 076 × 1023 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 (Kcd) of (683 lm W-1) for a
monochromatic beam with a
frequency 540 x 1012 Hz, where
Im W-1 =cd sr W1=cd sr kg 1m 2s3
the kilogram, metre and second are
defined in terms of -h, c and ΔνCs
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 × 1012 Hz, Kcd, to be 683
when expressed in the unit Im W-1, which
is equal to cd sr W-1, or cd sr kg 1m 2s3,
where the kilogram, metre and second are
defined in terms of h, cand ΔνCs
This definition implies the exact
relation
This definition implies the exact relation
Kcd = 683 cd sr kg 1m 2s3 Kcd = 683 cd sr kg 1m 2s3
for monochromatic radiation of
frequency
ν = 540 × 1012 Hz
for monochromatic radiation of frequency
ν = 540 × 1012 Hz. Inverting this relation
gives an exact expression for the candela in
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Cabinet Resolution of 2023 Concerning the Technical Regulations for Legal Measurements Units 15
Inverting this relation gives an exact
expression for the candela in terms of
the defining constants Kcd and h and
ΔνCs
terms of the defining constants Kcd hand
ΔνCs
1 𝑐𝑑 = ( 𝑘𝑐𝑑
683) 𝑘𝑔 𝑚2𝑠−3𝑠𝑟−1
Which is equal to Which is equal to
1 𝑐𝑑
= 1
(6.626 070 15 × 10−34)(9 192 631 770)2 683 (Δν𝑐𝑠)2ℎ 𝐾𝑐𝑑
≈ 2.614 8305 × 1010(Δν𝑐𝑠)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
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 Hz and has a radiant intensity in
that direction of (1/683) W sr-1.
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Cabinet Resolution of 2023 Concerning the Technical Regulations for Legal Measurements Units 16
Table (2)
Examples of Some Derived Units Based on the Use of Base Units Only
Symbol Unit Quantity
m2 m2 Square metre Square metre Area Area
m3 m3 Cubic metre Cubic meters Volume Volume
rad/s rad/s Radian per
second
Radian per
second
Angular
velocity
Angular
velocity
rad/s2 rad/s2
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/s2 m/s2
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/m2 kg/m2 Kilogram per
square metre
Kilogram per
square metre
Areic mass,
surface density
Areic mass,
surface
density
kg/m3 kg/m3 Kilogram per
cubic metre
Kilogram per
cubic metre
Density (mass
density)
Density (mass
density)
m2/s m2/s
Metre
squared per
second
Metre squared
per second
Kinematic
viscosity
Kinematic
viscosity
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Cabinet Resolution of 2023 Concerning the Technical Regulations for Legal Measurements Units 17
Volume flow
rate
Volume flow
rate
Cubic metre
per second
Cubic metre
per second
m3/s m3/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/m2 Cd/m2
Wave number Wave number 1 per meter 1 per metre 1/m 1/m
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Cabinet Resolution of 2023 Concerning the Technical Regulations for Legal Measurements Units 18
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.
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Cabinet Resolution of 2023 Concerning the Technical Regulations for Legal Measurements Units 19
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 Symbo
