Transcript
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Quantity Dimension Alternatives Definition/Notes
A:
Acceleration,
angulars-2 rad.s-2 [AngularVelocity]/[Time]
Abb number 1 Dimensionless Inverse ofrefractive index.
Absorbed radiationdose
m2.s-2 J.kg-1, Gy (gray) [Energy]/[Mass]
Absorbed dose rate m2.s-3 Gy.s-1 [Absorbed dose]/[Time]
Acceleration, linear m.s-2 [Velocity]/[Time]
Action kg.m2.s-1 J.s [Energy]*[Time], [Moment ofmotion]*[Distance]
Activity of
radioactive sources-1 Bq (becquerel) [Events]/[Time]
Admittance,
inductivekg-1.m-2.s3.A2 S (siemens) 1/[Inductive impedance].
Admittance, of acircuit kg-1
.m-2
.s3
.A2
S (siemens)
1/[Circuit impedance].
Angular
acceleration s-2 rad.s-2 [AngularVelocity]/[Time]
Angular moment of
inertiakg.m2 [Mass]*[Distance2]
Angular moment of
motionkg.m2.s-1 J.s [Moment of
motion]*[Distance]. Like[action].
Angular velocity s-1 rad.s-1 [Plane angle]/[Time]
Annealing point K Temperature at which
viscosity drops below 1012Pa.s
Area m2 [Distance]*[Distance]
Attenuation m-1 dB/m [Ratio]/m. Applies topropagation.
B:
Bandwidth s-1 Hz [Frequency]
Baud rate bit.s-1 baud [Information]/[Time]. Also:information flux.
Bulk modulus kg-1.m.s2 Pa-1 [Pressure]/([Volume]/[Volume]). Same ascompressibility.
C:
Capacitance,
electrickg-1.m-2.s4.A2 C.V-1, F (farad) [Charge]/[Potential]
Capacitive
reactancekg.m2.s-3.A-2 (ohm) 1/(i[Angular frequency].
[Capacitance])
Capacitive
susceptancekg-1.m-2.s3.A2 S (siemens) 1/[Capacitive reactance].
Circulation m2.s-1 J.s.kg-1 [Angular moment]/[Mass],[Velocity]*[Loop length]
Characteristicimpedance
kg.m2.s-3.A-2 V.A-1, , ohm ([Mag.Permeability]/[El.Permittivity])
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Charge, electric s.A C (coulomb) [Current]*[Time]
Charge, quantum 1 Dimensionless [Charge]/[Elementary chargequantum]
Charge,
molecular/ionic,
quantum
1 Dimensionless [Charge of a molecule or ion]/[Elementary charge quantum]
Charge density m-3.s.A C.m-3 [Charge]/[Volume]
Charge/mass ratio kg-1.s.A C.kg-1 [Charge]/[Mass]. Same asspecific charge
Charge, molar s.A.mol-1 C.mol-1 [Charge]/[Quantity]
Chemical potential,
molarkg.m2.s-2.mol-1
J.mol-1 [InternalEnergy]/[QuantityOfSubstance]
Circuit admittance kg-1.m-2.s3.A2 S (siemens) 1/[Circuit impedance].
Circuit impedance kg.m2.s-3.A-2 (ohm)
Collision cross
section
m2 [Distance]*[Distance]. Same
as cross section
Compressibility kg-1.m.s2 Pa-1 [Pressure]/([Volume]/[Volume]). Same as bulkmodulus.
Compression kg.m-1.s-2 N.m-2, Pa (pascal) [Force]/[Area]. ... same aspressure
Compression
moduluskg-1.m.s2 Pa-1 [Pressure]/([Volume]/
[Volume]). Same ascompressibility.
Compressive
strengthkg.m-1.s-2 N.m-2, Pa [Force]/[Area]. Same
dimension as pressure.
Concentration,molar
m-3.mol [Quantity]/[Volume]. Same asmolar density.
Concentration, by
mass1 Dimensionless [Mass of substance]/[Total
mass]. Same as massconcentration
Concentration, by
volume1 Dimensionless [Volume of substance]/[Total
volume]. Same as volumeconcentration.
Concentration, by
weight1 Dimensionless [Mass of substance]/[Total
mass]. Same as massconcentration
Conductance,
electrickg-1.m-2.s3.A2 A.V-1, S (siemens) 1/[Resistance].
Conductivity,
electrickg-1.m-3.s3.A2 S.m-1 1/[Resistivity]
Conductivity, molar kg-1.s3.A2.mol-1
S.m2.mol-1 [El.conductivity]/[Concentration]
Conductivity,
thermalkg.m.s-3.K-1 W.m-1.K-1 [Heat flux]/
([Distance]*[Temperature])
Constringence 1 Dimensionless [Transversal striction]/[Londitudinal elongation].
Convergence
m-1
dioptry
in optics, but not only ...
Count of 1 This covers all kinds of
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events/instances enumerations.
Count rate s-1 [Events]/[Time]
Couple kg.m2.s-2 N.m 2*[Force]*[Distance] for twonon-aligned opposing forces.
Critical angle of
repose
rad or degree Steepest angle of a slope
before a slideCross section m2 [Distance]*[Distance]
Cryoscopic constant kg.mol-1.K K/(mol/kg) [Temperature]/[Molality]
Current, electric A A (ampere)
Current density
(electric)m-2.A [Current]/[Area]. Same as
current intensity.
Current intensity
(electric)m-2.A [Current]/[Area]. Same as
current density.
Current noise,
variance nJ2
s.A2 A2/Hz [Current]2/[Bandwidth]
Curvature radius
m
of a line in plane/space orsurface in space
D:
Density of electric
chargem-3.s.A C.m-3 [Charge]/[Volume]
Density of electric
currentm-2.A [Current]/[Area]. Same as
current intensity.
Density of energy kg.m-1.s-2 J.m-3 [Energy]/[Volume].
Density of mass kg.m-3 [Mass]/[Volume]. Same asspecific density.
Density of
substance
m-3.mol [Quantity]/[Volume]. Same asconcentration.
Dielectric constant 1 Dimensionless [Permittivity]/[Permittivity ofvacuum]. Same as relativepermittivity
Dielectric
strength/rigiditykg.m.s-3.A-1 V.m-1 [Potential]/[Distance]. Same
as electric strength
Diffusion coefficient m2.s-1 [Distance2]/[Time].
Diffusivity, thermal m2.s-1 ([Temperatute]/[Time])/[2Temperature].
Dipole moment,
electric
m.s.A C.m [Charge]*[Distance]
Dipole moment,
magneticm2.A J.T-1 [Current]*[Area]
Dispersive power 1 Dimensionless Ratio of differences ofrefractive indices.
Dispersivity
quotientm-1 [Refractive index]/
[Wavelength]
Distance m in all Euclidean n-dimensional spaces.
Dose of absorbed
radiationm2.s-2 J.kg-1, Gy (gray) [Energy]/[Mass].
Dose rate m2.s-3 Gy.s-1 [Absorbed dose]/[Time].Drift speed m.s-1 Steady-state speed of an
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object..Duration s s (second)
Dynamic viscosity kg.m-1.s-1 Pa.s ([Force]/[Area])/[Velocity]
E:
Ebullioscopic
constantkg.mol-1.K K/(mol/kg) [Temperature]/[Molality].
Electric capacitance kg-1.m-2.s4.A2 C.V-1, F (farad) [Charge]/[Potential]
Electric charge s.A C (coulomb) [Current]*[Time]
Electric
conductancekg-1.m-2.s3.A2 A.V-1, S (siemens) [Current]/[Potential].
Inverse ofresistance.
Electric
conductivitykg-1.m-3.s3.A2 S.m-1 1/[Resistivity].
Electric
conductivity, molarkg-1.s3.A2.mol-1
S.m2.mol-1 [El.conductivity]/[Concentration].
Electric current A A (ampere)
Electric dipolemoment m.s.A
C.m
[Charge]*[Distance]
Electric field
strengthkg.m.s-3.A-1 V.m-1 [Potential]/[Distance]. Also
called electric intensity
Electric field
gradientkg.s-3.A-1 V.m-2 [El.field strength]/
[Distance].
Electric flux density m-2.s.A C.m-2 [Charge]/[Area]. Also calledelectric induction
Electric inductance kg.m2.s-2.A-2 V.s.A-1, H (henry) [Potential]/[dCurrent/dt]
Electric induction m-2.s.A C.m-2 [Charge]/[Area]. Moreproperly electric flux density
Electric intensity kg.m.s-3.A-1 V.m-1 [Potential]/[Distance]. Moreproperly electric fieldstrength
Electric
permittivitykg-1.m-3.s4.A2 F.m-1 [El.flux density]/[El.field
strength].
Electric
permittivity,
relative
1 Dimensionless [Permittivity]/[Permittivity ofvacuum]. Same as dielectricconstant
Electric
polarizationm-2.s.A C.m-2 [Charge]/[Area]. Like electric
flux density
Electric potential
kg.m
2
.s
-3
.A
-1
W.A
-1
, J.C
-1
, V(volt) [Power]/[Current], [Energy]/[Charge]
Electric quadrupole
momentm2.s.A C.m2 [Electric dipole]*[Distance],
[Electric charge]*[Distance2]
Electric resistance kg.m2.s-3.A-2 V.A-1, (ohm) [Potential]/[Current]
Electric resistivity kg.m3.s-3.A-2 .m ([Resistance]*[Length])/[Area].
Electric strength kg.m.s-3.A-1 V.m-1 [Potential]/[Distance]. Alsocalled dielectric strength.
Electromagnetic
vector potentialkg.m.s-2.A-1 V.s.m-1, T.m [El.field strength]*[Time] or
[Mag.flux
density]*[Distance]Electromotive force kg.m2.s-3.A-1 V [Potential]
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(emf)
Electrostriction
coefficientkg-2.m-2.s6.A2 m2.V-2 ([Volume]/[Volume])/
[Electric field strength]2.
Energy kg.m2.s-2 N.m, J (joule) [Force]*[Distance],[Power]*[Time].
Energy, molar kg.m2.s-2.mol-1
J.mol-1 [Energy]/[Quantity].
Energy, specific m2.s-2 J.kg-1 [Energy]/[Mass].
Energy density kg.m-1.s-2 J.m-3 [Energy]/[Volume].
Energy flux kg.m2.s-3 J.s-1, W (watt) [Energy]/[Time]. Same aspower.
Enthalpy kg.m2.s-2 J Like energy and heat.
Enthalpy, molar kg.m2.s-2.mol-1
J.mol-1 [Enthalpy]/[Quantity]. Likemolar heat.
Enthalpy, specific m2.s-2 J.kg-1 [Enthalpy]/[Mass]. Like
specific heat.
Entropy kg.m2.s-2.K-1 J.K-1 [Heat]/[Temperature].
Entropy, molar kg.m2.s-2.K-1.mol-1
J.K-1.mol-1 [Entropy]/[Quantity].
Entropy, specific m2.s-2.K-1 J.K-1.kg-1 [Entropy]/[Mass].
Evolution rate on
log-scales-1 d{ln(Q)}/dt = (dQ/dt)/Q. Also
relative evolution rate
Expansion
coefficient, thermalK-1 ([Length]/[Length])/
[Temperature].
Exposure kg-1.s.A C.kg-1 [Charge]/[Mass]. Used forionising radiations.
Extinctioncoefficient
m-1 dB/m Used for propagation ofradiation.
F:
Fire point K Temperature at which ignitedvapour keeps burning
Flash point K Temperature at which vapourcan be kept burning
Force kg.m.s-2 N (newton) [Mass]*[Acceleration].
Force,
thermodynamickg.m.s-2.mol-1
N/mol [Chemical potential]/[Distance].
Free energy
kg.m
2
.s
-2
J
Also Helmholtz function.Like energy.
Free energy, molar kg.m2.s-2.mol-1
J.mol-1 [Free energy]/[Quantity].Also molarHelmholtzfunction
Free energy,
specificm2.s-2 J.kg-1 [Free energy]/[Mass]. Also
specific Helmholtz function
Free enthalpy kg.m2.s-2 J Also Gibbs function. Likeenergy.
Free enthalpy,
molarkg.m2.s-2.mol-1
J.mol-1 [Free enthalpy]/[Quantity].Also molarGibbs function
Free enthalpy,specific
m2.s-2 J.kg-1 [Free enthalpy]/[Mass]. Alsospecific Gibbs function
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Frequency of waves
or eventss-1 Hz (hertz)
Frequency drift
rates-2 Hz.s-1 [Frequency]/[Time].
Friction kg.m.s-2 N (newton) Tangential force between two
moving surfaces.Friction coefficient 1 Dimensionless [Tangential force]/[Normal
force].
Fugacity kg.m-1.s-2 Pa Effective pressure in realgases.
G:
Gain of a device 1 Dimensionless [Output]/[Input], like-quantities ratio. Often in dB.
g-factor of a
particle1 Dimensionless [Magnetic moment]/([Spin].
[Bohr magneton])
Gradient, of electricfield kg.s
-3
.A
-1
V.m
-2
[El.field strength]/[Distance].
Gradient, of
magnetic fieldkg.m-1.s-2.A-1 T.m-1 [Mag.flux density]/
[Distance].
Gradient, thermal K.m-1 [Temperature]/[Distance].Same as temperaturegradient
Gravitational field
intensitym.s-2 [Force]/[Mass],
[Acceleration]. Same asgravity
Gravitational field
potential
m2.s-2 [Energy]/[Mass].
Gravity m.s-2 [Force]/[Mass],[Acceleration]. Same as grav.field intensity
Gyromagnetic ratio kg-1.s.A Hz.T-1 [Mag.moment]/[Angularmoment of motion].
H:
Half life s typically of a radioactivesubstance
Hamiltonian kg.m2.s-2 J [Force]*[Distance],[Power]*[Time]. Like energy
Hardness kg.m-1.s-2 N.m-2 [Force]/[Area]. Same aspressure.
Heat kg.m2.s-2 J Like energy.
Heat, molar kg.m2.s-2.mol-1
J.mol-1 [Heat]/[Quantity].
Heat, specific m2.s-2 J.kg-1 [Heat]/[Mass].
Heat capacity kg.m2.s-2.K-1 J.K-1 [Heat]/[Temperature].
Heat capacity,
molarkg.m2.s-2.K-1.mol-1
J.K-1.mol-1 [Heat capacity]/[Quantity].
Heat capacity,
specific
m2.s-2.K-1 J.K-1.kg-1 [Heat capacity]/[Mass].
Heat | Thermal kg.m.s-3.K-1 W.m-1.K-1 [Heat flux]/
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conductivity ([Distance]*[Temperature]).
Heat flux kg.m2.s-3 J.s, W [Heat]/[Time]. Likepower.
Heat flux density kg.s-3 W.m-2 [Heat flux]/[Area]. Same asirradiance.
I:Illuminance cd.sr.m-2 lm.m-2, lx (lux) [Luminous flux]/[Area].
Impact resistance kg.s-2 J.m-2 [Energy]/[Area]
Impedance,
characteristickg.m2.s-3.A-2 V.A-1, , ohm ([Mag.Permeability]/
[El.Permittivity]).
Impedance,
inductivekg.m2.s-3.A-2 (ohm) i[Angular frequency].
[Inductance]
Impedance, of a
circuitkg.m2.s-3.A-2 (ohm)
Impulse kg.m.s-1 [Moment of motion],
[Force]*[Time],[Mass]*[Velocity].
Inductance kg.m2.s-2.A-2 V.s.A-1, Wb.A-1, H(henry)
[Potential]/[dCurrent/dt],[Mag.flux]/[Current]
Induction, electric m-2.s.A C.m-2 [Charge]/[Area]. Same aselectric flux density
Inductive
admittancekg-1.m-2.s3.A2 S (siemens) 1/[Inductive impedance].
Inductive
impedancekg.m2.s-3.A-2 (ohm) i[Angular frequency].
[Inductance]
Information bit-1 bit One bit is the elementary
information quantum.Information flux bit.s-1 baud [Information]/[Time]. Also
called baud rate.
Intensity of electric
currentm-2.A [Current]/[Area]. Same as
current density.
Internal energy kg.m2.s-2 J Like energy and heat.
Internal energy,
molarkg.m2.s-2.mol-1
J.mol-1 [Internal energy]/[Quantity].Like molar heat.
Internal energy,
specificm2.s-2 J.kg-1 [Internal energy]/[Mass]. Like
specific heat.
Ion mobility kg-1.m-1.s2.A m2.s-1.V-1 [Velocity]/[Electric fieldstrength].
Ionic force
(strength)m-3.mol Sum([Concentration]*[Ionic
quantum charge]2).Ionic quantum
charge1 Dimensionless [Ion charge]/[Elementary
charge quantum]
Ionic strength
(force)m-3.mol Sum([Concentration]*[Ionic
quantum charge]2).Irradiance kg.s-3 W.m-2 [Heat flux]/[Area]. Same as
heat flux density
J:
Joule-Thomsoncoefficient
kg-1.m.s2.K K.Pa-1 [Temperature]/[Pressure].
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K:
Katalytic activity mol.s-1 katal [Quantity]/[Time]. Same asmolar production rate
Kinematic viscosity m2.s-1 [Dynamic viscosity]/[Density]
K-space vector m-1 same as reciprocal spaceposition.
L:
Lagrangian kg.m2.s-2 J [Force]*[Distance],[Power]*[Time]. Like energy
Length m m (meter)
Linear stiffness kg.s-2 N.m-1 [Force]/[Displacement]. ... ofa structure
Logarithmic ratio
logb(A/A')
1 log in any base b Applicable to any ratio of likequantities.
Logarithmic ratioln(A/A') 1
Np (neper)
Uses natural logarithm.
Logarithmic ratio
Log(P/P')/101 dB (decibel) Uses base-10
logarithm.Aplies only topower P.
Logarithmic ratio
Log(X/X')/201 dB (decibel) Aplies to voltages (X=V) and
currents (X=I).
Logarithmic scale
differential1 Dimensionless dQ/Q, d{ln(Q)}, for any
quantity Q. Also relativedifferential
Luminance cd.m-2 [Luminosity]/[Area]
Luminosity cd cd (candle) Same as luminous intensityLuminous
coefficient1 Dimensionless [Luminous efficacy]/[683
lm/W]. Same as luminousefficiency
Luminous efficacy cd.sr.kg-1.m-1.s3
lm/W [Luminous flux]/[Power]
Luminous efficiency 1 Dimensionless [Luminous efficacy]/[683lm/W]. Same as luminouscoefficient
Luminous
emittancecd.sr.m-2 lm.m-2, lx (lux) Same as illuminance, but for
sources
Luminous energy cd.sr.s lm.s [Luminous flux]*[Time].Also known as talbot
Luminous flux cd.sr lm (lumen) [Luminosity]*[Solid angle].Same as luminous power
Luminous intensity cd cd (candle) Same as luminosity
Luminous power cd.sr lm (lumen) [Luminosity]*[Solid angle].Same as luminous flux
M:
Magnetic dipole
momentm2.A J.T-1 [Current]*[Area]. Like
magnetic moment.
Magnetic fieldgradient
kg.m-1
.s-2
.A-1
T.m-1
[Mag.flux density]/[Distance].
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Magnetic field
strengthm-1.A [Current]/[Distance]. Also
called magnetic intensity
Magnetic flux kg.m2.s-2.A-1 V.s, W.s.A-1, Wb(weber)
[Potential]*[Time], [Power]/[dCurrent/dt]
Magnetic flux
density
kg.s-2.A-1 Wb.m-2, T (tesla) [Mag.flux]/[Area]. Also
called magnetic inductionMagnetic induction kg.s-2.A-1 Wb.m-2, T (tesla) [Mag.flux]/[Area]. More
properly magnetic fluxdensity
Magnetic intensity m-1.A [Current]/[Distance]. Moreproperly magnetic fieldstrength
Magnetic moment m2.A J.T-1 [Current]*[Area]
Magnetic
permeabilitykg.m.s-2.A-2 H.m-1 [Mag.flux density]/[Mag.field
strength].
Magneticpermeability,
relative1
Dimensionless
[Permeability]/[Permeabilityof vacuum].
Magnetic
quadrupole
moment
m3.A m.J.T-1 [Mag.dipole]*[Distance]
Magnetic
susceptibility1 Dimensionless [Relative permeability]-1.
Magnetization m-1.A [Mag.moment]/[Volume].Like magnetic field strength
Magnetogyric ratio kg.s-1.A-1 T.Hz-1 [Angular moment of motion]/
[Mag.moment].
Magnetomotive
force (mmf)A [Current]*[Number of turns]
Magnitude of a star 1 Dimensionless m-m'=-100.4(S/S'), where S,S'are the luminous fluxes of twostars
Mass kg kg (kilogram)
Mass density kg.m-3 [Mass]/[Volume]. Same asspecific density.
Mass concentration 1 Dimensionless [Mass of substance]/[Totalmass]. Also concentration byweight
Mass flow kg.s-1 kg [Mass]/[Time]. Same asmass production rate
Mass production
ratekg.s-1 [Mass]/[Time]. Same as
mass flow.
Mass, molar kg.mol-1 [Mass]/[Quantity]
Modulus of
compressionkg-1.m.s2 Pa-1 [Pressure]/([Volume]/
[Volume]). Same ascompressibility3
Modulus of rigidity kg.m.s-2 N, N.rad-1 [Force]/[Angle]. Same as
shear modulus.
Mobility, ionic kg-1.m-1.s2.A m2.s-1.V-1 [Velocity]/[Electric field
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strength].Molality kg-1.mol mol/kg [Quantity]/[Mass]. A way to
specify concentration of asolution.
Molar charge s.A.mol-1 C.mol-1 [Charge]/[Quantity]
Molarconcentration
m-3.mol [Quantity]/[Volume]. Same asconcentration
Molar conductivity,
electrickg-1.m-3.s3.A2.mol-1
S.m-1.mol-1 [El.conductivity]/[Concentration].
Molar density m-3.mol [Quantity]/[Volume]. Same asconcentration.
Molar energy kg.m2.s-2.mol-1
J.mol-1 [Energy]/[Quantity].
Molar enthalpy kg.m2.s-2.mol-1
J.mol-1 [Enthalpy]/[Quantity]. Likemolar heat.
Molar entropy
kg.m
2
.s
-2
.K
-
1.mol-1 J.K
-1
.mol
-1
[Entropy]/[Quantity].
Molar free energy kg.m2.s-2.mol-1
J.mol-1 [Free energy]/[Quantity].Also molarHelmholtzfunction
Molar free enthalpy kg.m2.s-2.mol-1
J.mol-1 [Free enthalpy]/[Quantity].Also molarGibbs function
Molar heat kg.m2.s-2.mol-1
J.mol-1 [Heat]/[Quantity].
Molar heat capacity kg.m2.s-2.K-1.mol-1
J.K-1.mol-1 [Heat capacity]/[Quantity].
Molar internalenergy
kg.m2.s-2.mol-1J.mol-1 [Internal energy]/[Quantity].
Like molar heat.
Molar mass kg.mol-1 [Mass]/[Quantity]
Molar production
ratemol.s-1 katal [Quantity]/[Time]. Like
katalytic activity.
Molar refractivity m3.mol-1 [(r2-1)/(r2+2)]/[Concentration], where r isthe refractive index
Molar relaxivity m3.s-1.mol-1 [Relaxation rate]/[Concentration].
Molar solubility m-3.mol [Quantity]/[Volume]. Same asconcentration
Molar volume m3.mol-1 [Volume]/[Quantity].
Molarity m-3.mol [Quantity]/[Volume]. Same asconcentration ormolardensity
Molecular quantum
charge1 Dimensionless [Charge of a molecule]/
[Elementary charge quantum]
Moment of force kg.m2.s-2 N.m [Force]*[Distance].
Moment of motion kg.m.s-1 [Mass]*[Velocity], [Massflow]*[Distance].
Mutual inductance
kg.m2
.s-2
.A-2
V.s.A-1
, Wb.A-1
, H(henry) [Potential]/[dCurrent/dt],[Mag.flux]/[Current]
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N:
Notch resistance kg.s-2 J.m-2 [Energy]/[Area]
Number density m-3 [Particles]/[Volume].
Number density,
molarmol-1 [Particles]/[Mol]. The
Avogadro constant.
Number ofevents/instances
1 This covers all kinds ofenumerations.
Number of turns 1 Often used in electricengineering.
O:
Osmotic pressure kg.m-1.s-2 Pa
P:
Peltier coefficient kg.m2.s-3.A-1 W.A-1, V [Heat flux]/[Current].
Permeability,
magnetickg.m.s-2.A-2 H.m-1 [Mag.flux density]/[Mag.field
strength].
Permittivity,electric kg
-1
.m-3
.s4
.A2
F.m-1
[El.flux density]/[El.fieldstrength].
Permittivity,
relative1 Dimensionless [Permittivity]/[Permittivity of
vacuum]. Dielectricconstant.
Phase angle 1 rad in exp(i(t+))
Phase drift rate s-1 rad.s-1 [Phase angle]/[Time].
Pi coefficient, molar kg.m-1.s-2.mol-1
J.m-3 [InternalEnergy]/[Volume].
Piezzoelectric
coefficientkg.m.s-3.A-1 V.m-1 [Electric field strength]/
([Length]/[Length]).
Plane angle 1 radPolarization,
electricm-2.s.A C.m-2 [Charge]/[Area]. Like electric
flux density.
Position vector m in all Euclidean n-dimensional spaces.
Potential, electric kg.m2.s-3.A-1 W.A-1, J.C-1, V(volt)
[Power]/[Current], [Energy]/[Charge]
Power kg.m2.s-3 J.s-1, W (watt) [Energy]/[Time].Equivalent to energy flux.
Prandtl number 1 Dimensionless [Kinematic viscosity]/
[Thermal diffusivity].
Propagation loss m-1 dB/m [Ratio]/m. Used for any otherquantity.
Poynting vector kg.s-3 W.m-2 [El.field strength]/[Mag.fieldstrength]. Like irradiance
Pressure kg.m-1.s-2 N.m-2, Pa (pascal) [Force]/[Area].
Probability of an
event1 Real number lying in the
interval [0,1].
Probability density
on ln-scale1 Np-1 [Probability]/[Natural-
logarithmic ratio]
Q:
Quadrupolemoment, electric
m2.s.A C.m2 [Electric dipole]*[Distance],[Electric charge]*[Distance2]
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Quadrupole
moment, magneticm3.A m.J.T-1 [Mag.dipole]*[Distance]
Quantity of
substancemol mol
Quantum charge 1 Dimensionless [Charge]/[Elementary charge
quantum] Quantum charge,
molecular or ionic1 Dimensionless [Molecule/ion charge]/
[Charge quantum]
Quotient of
dispersivitym-1 [Refractive index]/
[Wavelength]
R:
Radiance kg.s-3.sr-1 W.m-2.sr-1 ([Power]/[Area])/[Solidangle].
Radiation dose m2.s-2 J.kg-1, Gy (gray) [Energy]/[Mass].
Radiation dose rate m2.s-3 Gy.s-1 [Absorbed dose]/[Time].
Radioactivity
s-1
Bq (becquerel)
[Events]/[Time].
Radius of curvature m of a line in plane/space orsurface in space
Rotational stiffness kg.m2.s-2.rad-1
N.m.rad-1 [Moment of force]/[Angle]. ...of a structure.
Ratio of like
quantities1 Dimensionless Q1/Q2, with Q1 and Q2
having the same dimension
Reactance,
capacitivekg.m2.s-3.A-2 (ohm) 1/(i[Angular frequency].
[Capacitance])
Reciprocal space
positionm-1 same as k-space vector.
Redox potential kg.m2.s-3.A-1 V (volt) Same as reduction potential.Reduction potential kg.m2.s-3.A-1 V (volt) Same as redox potential.
Refractive index 1 Dimensionless Light speeds ration (in amedium)/(in vacuum).
Refractivity, molar m3.mol-1 [(r2-1)/(r2+2)]/[Concentration]
Refractivity,
specificm3.kg-1 [(r2-1)/(r2+2)]/[Specific
density],
Relative differential 1 Dimensionless dQ/Q, d{ln(Q)}, for anyquantity Q. Also log-scaledifferential
Relative evolutionrate s
-1
d{ln(Q)}/dt = (dQ/dt)/Q. Alsoevolution rate on log-scale
Relative
permeability,
magnetic
1 Dimensionless [Permeability]/[Permeabilityof vacuum].
Relative
permittivity,
electric
1 Dimensionless [Permittivity]/[Permittivity ofvacuum]. Dielectricconstant.
Relative variation 1 Dimensionless Q/Q, for any quantity Q.
Relaxation rate s-1 1/[Relaxation time]. Used inall branches of Science.
Relaxation time s Used in all branches ofScience.
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Relaxivity, molar m3.s-1.mol-1 [Relaxation rate]/[Concentration].
Reluctance,
magnetickg-1.m-1.s2.A2 m.H-1 1/[Permeability].
Resistance, electric kg.m2.s-3.A-2 V.A-1, (ohm) [Potential]/[Current]
Resistance, thermal kg-1.m-2.s3K K/W of a device. [T]/[Power].Resistance to
impactkg.s-2 J.m-2 [Energy]/[Area]. Same
dimension as notchresistance
Resistivity, electric kg.m3.s-3.A-2 .m ([Resistance]*[Length])/[Area].
Reynolds number 1 Dimensionless [Velocity]*[length]/[Kinematic viscosity]
RF attenuation m-1 dB/m [Ratio]/m. Applies topropagation.
S:Seeback coefficient kg.m2.s-3.A-1.K-1
V.K-1 [Potential]/[Temperature].Same as thermoelectricpower
Self-diffusion
coefficientm2.s-1 [Distance2]/[Time].
Settling rate s-1 typically dB/s [Ratio]/[Time].
Shear modulus kg.m.s-2 N, N.rad-1 [Force]/[Angle]. Same asmodulus of rigidity
Softening point K Temperature at whichhardness drops below a level.
Solid angle 1 sr (steradian)Solubility, molar m-3.mol [Quantity]/[Volume]. Same as
concentration
Sonic attenuation m-1 dB/m [Power ratio]/m. Applies topropagation.
Specific charge kg-1.s.A C.kg-1 [Charge]/[Mass].Charge/mass ratio.
Specific density kg.m-3 [Mass]/[Volume]. Same asdensity of mass
Specific energy m2.s-2 J.kg-1 [Energy]/[Mass].
Specific enthalpy m2.s-2 J.kg-1 [Enthalpy]/[Mass]. Likespecific heat.
Specific entropy m2.s-2.K-1 J.K-1.kg-1 [Entropy]/[Mass].
Specific free energy m2.s-2 J.kg-1 [Free energy]/[Mass]. Alsospecific Helmholtz function
Specific free
enthalpym2.s-2 J.kg-1 [Free enthalpy]/[Mass]. Also
specific Gibbs function
Specific heat m2.s-2 J.kg-1 [Heat]/[Mass].
Specific heat
capacitym2.s-2.K-1 J.K-1.kg-1 [Heat capacity]/[Mass].
Specific internal
energy
m2.s-2 J.kg-1 [Internal energy]/[Mass]. Like
specific heat.Specific refractivity m3.kg-1 [(r2-1)/(r2+2)]/[Specific
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density]
Specific volume m3.kg-1 [Volume]/[Mass].
Speed m.s-1 [Distance]/[Time]. Same asvelocity.
Spin 1 Dimensionless of a quantum particle
Star magnitude 1 Dimensionless m-m' = -100.4(S/S'), where S,S'are luminous fluxes of twostars
Stiffness, linear kg.s-2 N.m-1 [Force]/[Displacement]. ... ofa structure.
Stiffness, rotational kg.m2.s-2.rad-1
N.m.rad-1 [Moment of force]/[Angle]. ...of a structure.
Strain point K Temperature at whichviscosity drops below 1013.5
Pa.s
Strength,compressive kg.m
-1
.s
-2
N.m
-2
, Pa [Force]/[Area]. Samedimension as pressure.
Strength, dielectric kg.m.s-3.A-1 V.m-1 [Potential]/[Distance]. Sameas electric strength
Strength, electric
fieldkg.m.s-3.A-1 V.m-1 [Potential]/[Distance]. Also
called electric intensity
Strength, ionic m-3.mol Sum([Concentration]*[Ionicquantum charge]2).
Strength, magnetic
fieldm-1.A [Current]/[Distance]. Also
called magnetic intensity
Strength, tensile kg.m-1.s-2 N.m-2, Pa [Force]/[Area]. Same as
pressure.Surface density of
chargem-2.s.A C.m-2 [Charge]/[Area]
Surface element m2 [Distance]*[Distance]. Sameas area
Surface energy kg.s-2 J/m2 [Energy]/[Area]. Same assurface tension.
Surface tension kg.s-2 N/m [Force]/[Length]. Same assurface energy.
Susceptance,
capacitivekg-1.m-2.s3.A2 S (siemens) 1/[Reactance].
Susceptibility,
magnetic1 Dimensionless [Relative permeability]-1.
Stress kg.m-1.s-2 Pa, N.m-2 [Force]/[Area]. Same aspressure.
T:
Temperature K K(kelvin)
Temperature
gradientK.m-1 [Temperature]/[Distance].
Same as thermal gradient
Tensile strength kg.m-1.s-2 N.m-2, Pa [Force]/[Area]. Same aspressure.
Tension
kg.m-1
.s-2
Pa, N.m-2
[Force]/[Area]. Likepressure.
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Thermal
conductivitykg.m.s-3.K-1 W.m-1.K-1 [Heat flux]/
([Distance]*[Temperature]).Same as heat conductivity
Thermal diffusivity m2.s-1 ([Temperatute]/[Time])/[2Temperature].
Thermal expansioncoefficient
K-1 ([Length]/[Length])/[Temperature].
Thermal gradient K.m-1 [Temperature]/[Distance].Same as temperaturegradient
Thermal resistance kg-1.m-2.s3K K/W of a device. [T]/[Power].Thermodynamic
forcekg.m.s-2.mol-1
N/mol [Chemical potential]/[Distance].
Thermoelectric
power |
Thermopower
kg.m2.s-3.A-1.K-1
V.K-1 [Potential]/[Temperature].Same as Seeback coefficient
Thomson coefficient kg.m2.s-3.A-1.K-1
W.K-1.A-1 [Heat flux]/([Temperature]*[Current]).
Time s s (second)
Torque kg.m2.s-2 N.m [Force]*[Distance]. Same asmoment of force
Traction kg.m.s-2 N (newton) Maximum tangential forcebefore slipping.
Traction coefficient 1 Dimensionless [Traction]/[Weight].
Transmission loss m-1 dB/m [Ratio]/m. Used for any otherquantity.
U:V:
van der Waals
constant: akg.m5.s-2 Pa.m6 a in (p+a/V2)(V-b)=RT.
van der Waals
constant: bm3 b in (p+a/V2)(V-b)=RT.
van der Waals virial
constant: Akg-1.m5.s-2.mol-2
A in p=(n/V)RT+(n/V)2(RTB-A).
van der Waals virial
constant: Bkg-1.m3.mol-1 B in p=(n/V)RT+(n/V)2(RTB-
A).Variance of current
noise nJ2
s.A2 A2/Hz [Current]2/[Bandwidth]
Variance of voltage
noise nV2
kg2.m4.s-5.A-2 V2/Hz [Voltage]2/[Bandwidth]
Vector potential,
electromagnetickg.m.s-2.A-1 V.s.m-1, T.m [El.field strength]*[Time],
[Mag.fluxdensity]*[Distance]
Velocity m.s-1 [Distance]/[Time]. Same asspeed.
Verdet constant kg-1.m-1.s2.A1 rad.m-1.T-1 ([Angle]/[Length])/[Magneticflux density]
Virial coefficient:second kg.m
5
.s-
2.mol-2 Pa.(mol.m-3
)-2
A inp=(n/V)RT+A(n/V)2+B(n/V)3
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+C(n/V)4.Virial coefficient:
thirdkg.m8.s-2.mol-3
Pa.(mol.m-3)-3 B inp=(n/V)RT+A(n/V)2+B(n/V)3
+C(n/V)4.Virial coefficient:
fourth
kg.m11.s-
2.mol-4Pa.(mol.m-3)-4 C in
p=(n/V)RT+A(n/V)2+B(n/V)3+C(n/V)4.
Viscosity, dynamic kg.m-1.s-1 Pa.s ([Force]/[Area])/[Velocity]
Viscosity, kinematic m2.s-1 [Dynamic viscosity]/[Density]
Voltage kg.m2.s-3.A-1 V [Potential], same aselectromotive force
Voltage noise,
variance nV2
kg2.m4.s-5.A-2 V2/Hz [Voltage]2/[Bandwidth]
Volume m3 [Area]*[Distance]
Volumeconcentration 1
Dimensionless
[Volume of substance]/[Totalvolume]
W:
Wavelength m [Wave velocity]/[Frequency].
Wavenumber m-1 [Number of waves]/[Distance].
Work function kg.m2.s-2 J, eV [Energy] needed to remove anelectron.
X:
Y:
Young modulus kg.m-1.s-2 N.m-2, Pa [Stress]/([Length]/[Length]).
Z:
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