| Label | Symbol | Quantity | Concept definition | EQ label | Code | Reference | Supplemental references |
|---|---|---|---|---|---|---|---|
| METRE | m | Bohr radius | (4π ε0h2)/(mee2 where ε0 is the electric constant IEC 80000-6:2008, item 6-14.1, h is the reduced Planck constant IEC 80000-6:2008, item 10-6.2, me is the rest mass of an electron ISO 80000-10:2009, item 10-2, and e is the elementary charge ISO 80000-10:2009, item 10-5.1; 0,529 177 208 5936 x 10-10 metre. | LENGTH | 142 | ISO 80000-10:2009, item 10-7.a | |
| Burgers vector | The vector characterizing a dislocation, i.e. the closing vector in a Burgers circuit encircling a dislocation line. | ISO 80000-12:2009, item 12-7.a | |||||
| coherence length | The distance ISO 80000-3:2006, item 3-1.9 in a superconductor over which the effect of a perturbation is appreciable. | ISO 80000-12:2009, item 12-39.a and item 12-39.2 | |||||
| Compton wavelength | h/mc0, where h is the Planck constant ISO 80000-10:2009, item 10-6.1, m is the rest mass ISO 80000-10:2009, item 10-2 of a particle and c0 is the speed of light in vacuum ISO 80000-7:2008, item 7-4.1. | ISO 80000-10:2009, item 10-22.a | |||||
| diffusion length | The square root of L2, where L2 is the diffusion area ISO 80000-10:2009, item 10-74.2. | ISO 80000-10:2009, item 10-75.a and item 10-75.2 | |||||
| diffusion length | The square root of D τ, where D is the diffusion coefficient ISO 80000-9:2009, item 9-45 and τ is lifetime ISO 80000-3:2006, item 3-7. | ISO 80000-12:2009, item 12-34.a | |||||
| electron radius | -e2/(4π ε0mec02) where e is the elementary charge ISO 80000-10:2009, item 10-5.1, ε0 is the electric constant IEC 80000-6:2008, item 6-14.1, me is the rest mass of an electron ISO 80000-10:2009, item 10-2, and c0 is the speed of light in vacuum ISO 80000-7:2008, item 7-4.1. | ISO 80000-10:2009, item 10-21.a | |||||
| fundamental lattice vectors | The fundamental translation vectors for the crystal lattice. | ISO 80000-12:2009, item 12-1.a and item 12-1.2 | |||||
| half-value thickness | The thickness ISO 80000-3:2006, item 3-1.4 of the attenuating layer that reduces the quantity of interest of a unidirectional beam to half of its initial value. | ISO 80000-10:2009, item 10-54.a | |||||
| image distance | For a centred optical system, distance ISO 80000-3:2006, item 3-1.9 from an image of the given object to the closest surface of the centred optical system. | ISO 80000-7:2008, item 7-59.a and item 7-59.2 | |||||
| image focal distance | For a centred optical system, distance ISO 80000-3:2006, item 3-1.9 from the focal point at the image side to the closest surface of the centred optical system. | ISO 80000-7:2008, item 7-59.a and item 7-59.4 | |||||
| lattice plane spacing | The distance between successive lattice planes. | ISO 80000-12:2009, item 12-3.a | |||||
| lattice vector | The translation vector that maps the crystal lattice on itself. | ISO 80000-12:2009, item 12-1.a and item 12-1.1 | |||||
| length | The length of the path travelled by light in vacuum during a time interval of 1 / 299 792 458 of a second. SI base unit. |
ISO 80000-3:2006, 3-1.a | ISO 80000-1:2009, Table 1, "length" | ||||
| mean free path | The average distance ISO 80000-3:2006, item 3-1.9 that particles travel between two successive specified reactions or processes. | ISO 80000-10:2009, item 10-73.a | |||||
| mean free path | For a particle, the average distance between two successive collisions with other molecules. | ISO 80000-9:2009, item 9-44.a | |||||
| mean free path of electrons | The mean free path ISO 80000-10:2009, item 10-73 of electrons. | ISO 80000-12:2009, item 12-16.a and item 12-16.2 | |||||
| mean free path of phonons | The mean free path ISO 80000-10:2009, item 10-73 of phonons. | ISO 80000-12:2009, item 12-16.a and item 12-16.1 | |||||
| mean linear range | The mean total rectified path length ISO 80000-3:2006, item 3-1.1 travelled by a particle in the course of slowing down to rest (or to some suitable cut-off energy) in a given substance under specified conditions averaged over a group of particles having the same initial energy ISO 80000-5:2007, item 5-20.1. | ISO 80000-10:2009, item 10-58.a | |||||
| migration length | The square root of M2, where M2 is the migration area ISO 80000-10:2009, item 10-74.3. | ISO 80000-10:2009, item 10-75.a and item 10-75.3 | |||||
| nuclear radius | The conventional radius of the sphere in which the nuclear matter is included. | ISO 80000-10:2009, item 10-19.a | |||||
| object distance | For a centred optical system, distance ISO 80000-3:2006, item 3-1.9 from a given object to the closest surface of the centred optical system. | ISO 80000-7:2008, item 7-59.a and item 7-59.1 | |||||
| object focal distance | For a centred optical system, distance ISO 80000-3:2006, item 3-1.9 from the focal point at the object side to the closest surface of the centred optical system. | ISO 80000-7:2008, item 7-59.a and item 7-59.3 | |||||
| slowing-down length | The square root of L2, where L2 is the slowing-down area ISO 80000-10:2009, item 10-74.1. | ISO 80000-10:2009, item 10-75.a and item 10-75.1 | |||||
| sound particle displacement | Instantaneous displacement of a particle in a medium from what would be its position in the absence of sound waves. | ISO 80000-8:2007, item 8-10.a | |||||
| wavelength | The distance in the direction of propagation of a sinusoidal wave between two successive points where at a given instant in time the phase differs by 2π (see ISO 80000-3:2006, item 3-25, Remarks). | ISO 80000-3:2006, item 3-17.a | ISO 80000-7:2008, item 7-3.a and item 7-3.2; ISO 80000-8:2007, item 8-5.a | ||||
| METRE_FOURTH_POWER | m4 | second moment of area (second axial moment of area) | The integral of rQ2 over A, where rQ is the radial distance ISO 80000-3:2006, item 3-1.6 from a Q-axis in the plane of the surface considered and A is area ISO 80000-3:2006, item 3-3. | SECOND_MOMENT_AREA | 143 | ISO 80000-4:2006, item 4-20.a and item 4-20.1 | |
| METRE_KELVIN | m · K | second radiation constant | The constant c2 in the expression for the spectral radiant exitance ISO 80000-7:2008, item 7-18 of a blackbody at the thermodynamic temperature T ISO 80000-5:2007, item 5-1, thus Mλ(λ) = c1 f(λ, T) = c1 (λ-5/(exp(c2 λ-1 T-1) - 1). | SECOND_RADIATION- _CONSTANT |
144 | ISO 80000-7:2008, item 7-58.a | |
| METRE_PER_HOUR | m/h | velocity | dr/dt, where r is position vector ISO 80000-3:2006, item 3-1.11 and t is time ISO 80000-3:2006, item 3-7. 1 m/h = 1 / 3,6 x 10-3 m/s (exactly). |
SPEED | 145 | ISO 80000-3:2006, item 3-8.a and item 3-8.1 | ISO 80000-1:2009, 6.5.4 |
| METRE_PER_SEC | m/s | group velocity (group speed) | dω/dk, where ω is angular frequency ISO 80000-3:2006, item 3-16 and k is angular wavenumber ISO 80000-3:2006, item 3-19. | SPEED | 146 | ISO 80000-3:2006, item 3-20.a and item 3-20.2 | |
| phase velocity (phase speed) | ω/k, where ω is angular frequency ISO 80000-3:2006, item 3-16 and k is angular wavenumber ISO 80000-3:2006, item 3-19. | ISO 80000-3:2006, item 3-20.a and item 3-20.1 | |||||
| sound particle velocity | δδ/δt, where δ is sound particle displacement ISO 80000-8:2007, item 8.10 and t is time. | ISO 80000-8:2007, item 8-11.a | |||||
| velocity | dr/dt, where r is position vector ISO 80000-3:2006, item 3-1.11 and t is time ISO 80000-3:2006, item 3-7. | ISO 80000-3:2006, item 3-8.a and item 3-8.1 | |||||
| METRE_PER_SEC_SQD | m/s2 | acceleration | dv/dt, where v is velocity ISO 80000-3:2006, item 3-8.1 and t is time ISO 80000-3:2006, item 3-7. | ACCELERATION | 147 | ISO 80000-3:2006, item 3-9.a | |
| sound particle acceleration | dv/dt, where v is sound particle velocity ISO 80000-8:2007, item 8.11 and t is time. | ISO 80000-8:2007, item 8-12.a | |||||
| MINUTE | min | time (duration) | 1 min = 60 s (exactly). | TIME | 150 | ISO 80000-3:2006, item 3-7.b | ISO 80000-1:2009, Table 5, "time" |
| MINUTE_ARC | ' | angle (plane angle) | s/r, where s is the length of the included arc of a circle between two radii of the circle ISO 80000-3:2006, item 3-1.8 and r is the radius of the circle ISO 80000-3:2006, item 3-1.5. 1' = (1 / 60)° = (π / 10 800) rad (exactly). |
PLANE_ANGLE | 151 | ISO 80000-3:2006, item 3-5.c | ISO 80000-1:2009, Table 5, "plane angle" |
| MINUTE_PER_CUBIC_METRE | min/m3 | volumic number of molecules or other elementary entities (number density of molecules or other elementary entities) | N/V, where N is the number of particles in the 3D domain with the volume V 1 min/3 = 60 s/m3 (exactly). |
VOLUMIC_DOSE | 152 | ISO 80000-9:2009, item 9-10.a and item 9-10.1 | ISO 80000-1:2009, 6.5.3 (derived), ISO 80000-10:2009, item 10-64.a and item 10-64.1 |
| MOLE | mol | amount of substance | The amount of substance of a system which contains as many elementary entities as there are atoms in 0,012 kilogram of carbon 12. When the mole is used, the elementary entities shall be specified, and may be atoms, molecules, ions, electrons, other entities, or specified groups of them. The definition applies to unbound atoms of carbon 12, at rest and in their ground state. The mole is also used for entities such as holes and other quasi-particles, double bonds, etc. SI base unit. |
AMOUNT_SUBSTANCE | 153 | ISO 80000-9:2009, item 9-1.a | ISO 80000-1:2009, Table 1, "amount of substance" |
| MOLE_PER_CUBIC_M | mol/m3 | amount-of-substance concentration (concentration) | nB/V where nB is the amount of substance ISO 80000-9:2009, item 9-1 of B and V is the volume ISO 80000-3:2006, item 3-4 of the solution. | CONCENTRATION | 154 | ISO 80000-9:2009, item 9-13.a | |
| MOLE_PER_KG | mol/kg | ionic strength | (1/2)Σzi2bi, where the summation is carried out over all ions with charge number zi ISO 80000-9:2009, item 9-50 and molality mi ISO 80000-9:2009, item 9-16. | MOLALITY_SOLUTE | 155 | ISO 80000-9:2009, item 9-52.a | |
| molality of solute B | nB/mA, where nB is the amount of substance ISO 80000-9:2009, item 9-1.of solute B and mA is the mass ISO 80000-4:2006, item 4-1 of the solvent substance A. | ISO 80000-9:2009, item 9-16.a | |||||
| MOLE_PER_LITRE | mol/l, mol/L | amount-of-substance concentration (concentration) | nB/V where nB is the amount of substance ISO 80000-9:2009, item 9-1 of B and V is the volume ISO 80000-3:2006, item 3-4 of the solution. 1 mol/l = 103 mol/m3 (exactly). |
CONCENTRATION | 156 | ISO 80000-9:2009, item 9-13.b | |
| MOLE_PER_MOLE | mol/mol | amount-of-substance fraction of B (mole fraction of substance B) | nB/n, where nB is the amount of substance ISO 80000-9:2009, item 9-1 of B and n is the total amount of substance ISO 80000-9:2009, item 9-1 in the mixture. 1 mol/mol = 1. |
MOLE_FRACTION | 157 | ISO 80000-9:2009, item 9-14.a | ISO 80000-1:2009, 6.5.5 |
| NEPER | Np | level difference of two field quantities | The difference between two levels of field quantities with the same reference F0. The level of a field quantity is LF = ln (F/F0), where F and F0 represent two field quantities of the same kind, F0 being a reference quantity. 1 Np is the level of a field quantity when ln (F/F0) = 1, i.e. F/F0 = e. |
FIELD_OR_POWER- _LEVEL_DIFF |
159 | ISO 80000-3:2006, item 3-21.a | |
| level difference of two power quantities | The difference between two levels of power quantities with the same reference P0. The level of a power quantity is LP = (1/2) ln (P/P0), where P and P0 represent two power quantities of the same kind, P0 being a reference quantity. | ISO 80000-3:2006, item 3-22.a | |||||
| logarithmic decrement | δT, where δ is damping coefficient ISO 80000-3:2006, item 3-23 and T is period ISO 80000-3:2006, item 3-12. | ISO 80000-3:2006, item 3-24.b | |||||
| NEPER_PER_SECOND | Np/s | damping coefficient | 1/τ, where τ is the time constant of an exponentially varying quantity ISO 80000-3:2006, item 3-13. | DAMPING_COEFFICIENT | 160 | ISO 80000-3:2006, item 3-23.b | |
| NEWTON | N | force | dp/dt where p is momentum ISO 80000-4:2006, item 4-8 and t is time ISO 80000-3:2006, item 3-7. | FORCE | 161 | ISO 80000-4:2006, item 4-9.a and item 4-9.1 | ISO 80000-1:2009, Table 2, "force" |
| NEWTON_M_SQD_PER_KG_SQD | (N · m2)/kg2 | gravitational force between two particles | G m1m2/r2 where G is the gravitational constant, m1 and m2 are the masses of the two particles ISO 80000-4:2006, item 4-1 and r is the distance between the two particles ISO 80000-3:2006, item 3-1.9. 1 N · m2/kg2 = 1 m3/(kg · s2). |
GRAVITATIONAL_FORCE | 162 | ISO 80000-4:2006, item 4-10.a | |
| NEWTON_METRE | N · m | moment of force | The cross product r x F where r is the position vector ISO 80000-3:2006, item 3-1.11 and F is force ISO 80000-4:2006, item 4-9.1. 1 N · m = 1 (m2 · kg2)/s2. |
MOMENT_FORCE | 163 | ISO 80000-4:2006, item 4-13.a and item 4-13.1 | |
| NEWTON_METRE_SECOND | N · m · s | angular impulse | The integral of moment of force ISO 80000-4:2006, item 4-13.1 over time ISO 80000-3:2006, item 3-7. 1 N · m · s = 1 (m2 · kg2)/s. |
ANGULAR_IMPULSE | 164 | ISO 80000-4:2006, item 4-14.a | |
| NEWTON_PER_METRE | N/m | surface tension | dF/dl, where F ISO 80000-4:2006, item 4-9.1 is the force component perpendicular to a line element in a surface and l is the length ISO 80000-3:2006, item 3-1.1 of the line element. 1 N/m = 1 kg/s2. |
SURFACE_TENSION | 165 | ISO 80000-4:2006, item 4-25.a | |
| NEWTON_PER_SQ_M | N/m2 | fugacity of substance B in a gaseous mixture | pB, where for a gaseous mixture pB is proportional to the absolute activity, λB ISO 80000-9:2009, item 9-18, the proportionality factor, which is a function of temperature only, being determined by the condition that, at constant temperature and composition, pB/pB tends to 1 for an indefinitely dilute gas. | PRESSURE | 166 | ISO 80000-9:2009, item 9-20.a | |
| modulus of elasticity | σ/ε where σ is normal stress ISO 80000-4:2006, item 4-15.2 and ε is linear strain ISO 80000-4:2006, item 4-16.1. 1 N/m2 = 1 Pa = 1 kg/(m · s2). |
ISO 80000-4:2006, item 4-18.a and item 4-18.1 | ISO 80000-4:2006, item 4-15.a (Definition) | ||||
| osmotic pressure | The excess pressure required to maintain osmotic equilibrium between a solution and the pure solvent separated by a membrane permeable to the solvent only. 1 N/m2 = 1 Pa = 1 kg/(m · s2). |
ISO 80000-9:2009, item 9-30.a | ISO 80000-4:2006, item 4-15.a (Definition) | ||||
| partial pressure of substance B | For a gaseous mixture, pB = xB·p, where xB is the amount-of-substance fraction of substance B ISO 80000-9:2009, item 9-14 and p is the total pressure ISO 80000-4:2006, item 4-15.1. | ISO 80000-9:2009, item 9-19.a | |||||
| pressure | dF/dA, where dF is the force ISO 80000-4:2006, item 4-9.1 component perpendicular to the surface element of area dA ISO 80000-3:2006, item 3-3. 1 N/m2 = 1 Pa = 1 kg/(m · s2). |
ISO 80000-4:2006, item 4-15.a (Definition) and item 4-15.1 | ISO 80000-1:2009, Table 2, "pressure, stress" | ||||
| sound pressure | The difference between the instantaneous total pressure and the static pressure. | ISO 80000-8:2007, item 8-9.a and item 8-9.2 | |||||
| static pressure | The pressure that would exist in the absence of sound waves. | ISO 80000-8:2007, item 8-9.a and item 8-9.1 | |||||
| NEWTON_SECOND | N · s | impulse | The integral of force ISO 80000-4:2006, item 4-9.1 over time ISO 80000-3:2006, item 3-7. 1 N · s = 1 (m · kg)/s. |
IMPULSE | 167 | ISO 80000-4:2006, item 4-11.a | |
| NEWTON_SECOND_PER_METRE | (N · s)/m | mechanical surface impedance | At a surface, the complex quotient of the total force on the surface by the component of the average sound particle velocity ISO 80000-8:2007, item 8-11 at the surface in the direction of the force. 1 (N · s)/m = 1 kg/s. |
MECHANICAL_IMPEDANCE | 168 | ISO 80000-8:2007, item 8-21.a | |
| OCTAVE | none | logarithmic frequency integer | lb(f2/f1), where f1 and f2 >= f1 are frequencies ISO 80000-8:2007, item 8-2 of two tones. | FREQUENCY_INTERVAL | 169 | ISO 80000-8:2007, item 8-3.a | |
| OHM | Ω | impedance (complex impedance) | U/I, where U is the voltage phasor IEC 80000-6:2008, item 6-50 and I is the electric current phasor IEC 80000-6:2008, item 6-49. | RESISTANCE | 170 | IEC 80000-6:2008, item 6-51.a and item 6-51.1 | |
| modulus of impedance | |Z|, where Z is impedance IEC 80000-6:2008, item 6-51.1. | IEC 80000-6:2008, item 6-51.a and item 6-51.4 | |||||
| reactance | Im Z, where Z is impedance IEC 80000-6:2008, item 6-51.1 and Im denotes the imaginary part. | IEC 80000-6:2008, item 6-51.a and item 6-51.3 | |||||
| resistance | For resistive component, u/i, where u is instantaneous voltage IEC 80000-6:2008, item 6-11.3 is i is instantaneous electric current IEC 80000-6:2008, item 6-1. 1 Ω = 1 V/A = 1 (m2 · kg)/(s3 · A2). |
IEC 80000-6:2008, item 6-46.a | ISO 80000-1:2009, Table 2, "electrical resistance" | ||||
| resistance (to alternating current) | Re Z, where Z is impedance IEC 80000-6:2008, item 6-51.1 and Re denotes the real part. | IEC 80000-6:2008, item 6-51.a and item 6-51.2 | |||||
| OHM_METRE | Ω · m | residual resistivity | For metals, the resistivity IEC 80000-6:2008, item 6-44 extrapolated to zero thermodynamic temperature ISO 80000-5:2007, item 5-1. | RESISTIVITY | 171 | ISO 80000-12:2009, item 12-18.a | |
| resistivity | 1/σ, if it exists, where σ is conductivity IEC 80000-6:2008, item 6-43. 1 Ω · m = 1 (m3 · kg)/(s3 · A2). |
IEC 80000-6:2008, item 6-44.a | |||||
| PASCAL | Pa | fugacity of substance B in a gaseous mixture | pB, where for a gaseous mixture pB is proportional to the absolute activity, λB ISO 80000-9:2009, item 9-18, the proportionality factor, which is a function of temperature only, being determined by the condition that, at constant temperature and composition, pB/pB tends to 1 for an indefinitely dilute gas. | PRESSURE | 173 | ISO 80000-9:2009, item 9-20.a | |
| modulus of elasticity | σ/ε where σ is normal stress ISO 80000-4:2006, item 4-15.2 and ε is linear strain ISO 80000-4:2006, item 4-16.1. | ISO 80000-4:2006, item 4-18.a and item 4-18.1 | |||||
| osmotic pressure | The excess pressure required to maintain osmotic equilibrium between a solution and the pure solvent separated by a membrane permeable to the solvent only. | ISO 80000-9:2009, item 9-30.a | |||||
| partial pressure of substance B | For a gaseous mixture, pB = xB·p, where xB is the amount-of-substance fraction of substance B ISO 80000-9:2009, item 9-14 and p is the total pressure ISO 80000-4:2006, item 4-15.1. | ISO 80000-9:2009, item 9-19.a | |||||
| pressure | dF/dA, where dF is the force ISO 80000-4:2006, item 4-9.1 component perpendicular to the surface element of area dA ISO 80000-3:2006, item 3-3. | ISO 80000-4:2006, item 4-15.a and item 4-15.1 | ISO 80000-1:2009, Table 2, "pressure, stress" | ||||
| sound pressure | The difference between the instantaneous total pressure and the static pressure. | ISO 80000-8:2007, item 8-9.a and item 8-9.2 | |||||
| static pressure | The pressure that would exist in the absence of sound waves. | ISO 80000-8:2007, item 8-9.a and item 8-9.1 | |||||
| PASCAL_PER_KELVIN | Pa/K | pressure coefficient | (δp/δT)V, where p is pressure ISO 80000-4:2006, item 4-15.1, T is thermodynamic temperature ISO 80000-5:2007, item 5-1, and V is volume ISO 80000-3:2006, item 3-4. 1 Pa/K = 1 kg/(m · s2 · K). |
PRESSURE_COEFFICIENT | 174 | ISO 80000-5:2007, item 5-4.a | |
| PASCAL_PER_SEC | Pa/s | pressure change rate | The rate of change in force is exerted per unit area. 1 Pa/s = 1 kg/(m · s3). |
PRESSURE_CHANGE_RATE | 175 | ISO 80000-1:2009, 6.5.3 (derived) | |
| PASCAL_SEC | Pa · s | dynamic viscosity (viscosity) | τzz/(dvz/dz), where τzz is shear stress ISO 80000-4:2006, item 4-15.3 in a fluid moving with a velocity ISO 80000-3:2006, item 3-8.1 gradient dvz/dz perpendicular to the plane of shear. This definition applies to a laminar flow for which vz = 0. 1 Pa · s = 1 kg/(m · s). |
DYNAMIC_VISCOSITY | 176 | ISO 80000-4:2006, item 4-23.a | |
| PASCAL_SEC_PER_CUBIC_METRE | (Pa · s)/m3 | acoustic impedance | At a surface, the complex quotient of the average sound pressure ISO 80000-8:2007, item 8-9.2 over that surface by the sound volume flow rate ISO 80000-8:2007, item 8-13 through that surface. 1 (Pa · s)/m3 = 1 kg/(m4 · s). |
ACOUSTIC_IMPEDANCE | 177 | ISO 80000-8:2007, item 8-20.a | |
| PASCAL_SEC_PER_METRE | (Pa · s)/m | characteristic impedance of a medium | At a point in a non-dissipative medium and for a plane progressive wave, the quotient of the sound pressure ISO 80000-8:2007, item 8-9.2 by the component of the sound particle velocity ISO 80000-8:2007, item 8-11 in the direction of the wave propagation. 1 (Pa · s)/m = 1 kg/(m2 · s). |
SURFACE_DENSITY- _MECH_IMPED |
178 | ISO 80000-8:2007, item 8-19.a | |
| PERCENT | % | special (pure number) | 1% = 0,01 x 1 (often omitted). | PURE_NUMBER | 179 | ISO 80000-1:2009, 6.5.5 | |
| PHON | none | loudness level | ln(peff/p0)1 kiloHz = ln 10 · lg(peff/p0)1 kHz, where peff is the root-mean-square value of the sound pressure of a pure tone of 1 kilohertz, which is judged by a normal observer under standardized listening conditions as being as loud as the sound under investigation, and where p0 = 20 μPa. 1 phon is the loudness level when 2 lg (peff/p0)1 kHz = 0,1. |
LOUDNESS_LEVEL | 180 | ISO 31-7:1992, 7-31.a | |
| PPB_MASS_FRACTION | none | mass fraction of substance B | The mass ISO 80000-4:2006, item 4-1 of B divided by the total mass of the mixture. 1 x 10-9 kg/kg (exactly). |
MASS_FRACTION | 181 | ISO 80000-1:2009, 6.5.5 | ISO 80000-9:2009, item 9-12.a |
| PPM_MASS_FRACTION | none | mass fraction of substance B | mB/m, where mB is the mass ISO 80000-4:2006, item 4-1 of substance B and m is the total mass of the mixture. 1 x 10-6 kg/kg (exactly). |
MASS_FRACTION | 182 | ISO 80000-1:2009, 6.5.5 | ISO 80000-9:2009, item 9-12.a |
| PPT_MASS_FRACTION | none | mass fraction of substance B | mB/m, where mB is the mass ISO 80000-4:2006, item 4-1 of substance B and m is the total mass of the mixture. 1 x 10-12 kg/kg (exactly). |
MASS_FRACTION | 183 | ISO 80000-1:2009, 6.5.5 | ISO 80000-9:2009, item 9-12.a |
| PPTH_MASS_FRACTION | none | mass fraction of substance B | mB/m, where mB is the mass ISO 80000-4:2006, item 4-1 of substance B and m is the total mass of the mixture. 1 x 10-3 kg/kg (exactly). |
MASS_FRACTION | 184 | ISO 80000-1:2009, 6.5.5 | ISO 80000-9:2009, item 9-12.a |
| RADIAN | rad | angle (plane angle) | s/r, where s is the length of the included arc of a circle between two radii of the circle ISO 80000-3:2006, item 3-1.8 and r is the radius of the circle ISO 80000-3:2006, item 3-1.5. 1 rad = 1 m/m = 1 A complete angle (full circle) is 2π rad. |
PLANE_ANGLE | 186 | ISO 80000-3:2006, item 3-5.a | ISO 80000-1:2009, Table 2, "plane angle" |
| angle of optical rotation | Angle through which plane-polarized light is rotated clockwise, as seen when facing the light source, in passing through an optically active medium. | ISO 80000-9:2009, item 9-57.a | |||||
| phase difference | φu - φi, where φu is the initial phase of the voltage IEC 80000-6:2008, item 6-11.3 and φi is the initial phase of the electric current IEC 80000-6:2008, item 6-1. | IEC 80000-6:2008, item 6-48.a | |||||
| RADIAN_PER_METRE | rad/m | angular repetency (angular wavenumber) | ω/c = 2π/λ, where ω is angular frequency ISO 80000-8:2007, item 8-4, c is phase speed of sound ISO 80000-8:2007, item 14.1, 2π is the phase difference, and λ is wavelength ISO 80000-8:2007, item 8-5. | ANGULAR_REPETENCY | 187 | ISO 80000-8:2007, item 8-7.a | |
| angular repetency (angular wavenumber) | 2π σ, where σ is wavenumber ISO 80000-3:2006, item 3-18. | ISO 80000-3:2006, item 3-19.a | ISO 80000-12:2009, item 12-10.a | ||||
| RADIAN_PER_SEC | rad/s | angular frequency | 2π f, where f is frequency ISO 80000-3:2006, item 3-15.1. | ANGULAR_VELOCITY | 188 | ISO 80000-3:2006, item 3-16.a | ISO 80000-8:2007, item 8-4.a |
| angular velocity | ω = dφ/dt, where φ is plane angle ISO 80000-3:2006, item 3-5 and t is time ISO 80000-3:2006, item 3-7. The vector ω is directed along the axis of rotation in the direction for which the rotation is clockwise. | ISO 80000-3:2006, item 3-10.a | |||||
| cyclotron angular frequency | (|q|/m) B, where q is electric charge IEC 80000-6:2008, item 6-2 of the particle, m is its mass ISO 80000-4:2006, item 4-1, and B is magnetic flux density IEC 80000-6:2008, item 6-21. | ISO 80000-10:2009, item 10-17.a | |||||
| Debye angular frequency | The cut-off angular frequency ISO 80000-3:2006, item 3-16 in the Debye model of the vibrational spectrum of a solid. | ISO 80000-12:2009, item 12-11.a | |||||
| Larmor angular frequency | (e/2me) B, where e is the elementary charge ISO 80000-10:2009, item 10-5.1, me is the rest mass of electron ISO 80000-10:2009, item 10-2 and B is magnetic flux density IEC 80000-6:2008, item 6-21. | ISO 80000-10:2009, item 10-16.a and item 10-16.1 | |||||
| nuclear precession angular frequency | γB, where γ is the gyromagnetic coefficient ISO 80000-10:2009, item 10-13.2 and B is magnetic flux density IEC 80000-6:2008, item 6-21. | ISO 80000-10:2009, item 10-16.a and item 10-16.2 | |||||
| RADIAN_PER_SEC_SQD | rad/s2 | angular acceleration | dω/dt, where ω is angular velocity ISO 80000-3:2006, item 3-10 and t is time ISO 80000-3:2006, item 3-7. | ANGULAR_ACCELERATION | 189 | ISO 80000-3:2006, item 3-11.a | |
| SECOND | s | carrier lifetime | The time constant ISO 80000-3:2006, item 3-13 for recombination or trapping of minority charge carriers in semiconductors. | TIME | 192 | ISO 80000-12:2009, item 12-33.a and item 12-33.2 | |
| half-life | The average duration ISO 80000-3:2006, item 3-7 required for the decay of one half of the atoms or nuclei. | ISO 80000-10:2009, item 10-33.a | |||||
| mean lifetime (mean life) | 1/λ, where λ is the decay constant ISO 80000-10:2009, item 10-26. | ISO 80000-10:2009, item 10-27.a | |||||
| period duration (period) | The duration of one cycle. | ISO 80000-3:2006, item 3-12.a | ISO 80000-8:2007, item 8-1.a | ||||
| reactor time constant | The duration ISO 80000-3:2006, item 3-7 required for the neutron fluence rate ISO 80000-10:2009, item 10-45 in a reactor to change by the factor e when the fluence rate is rising or falling exponentially. | ISO 80000-10:2009, item 10-82.a | |||||
| relaxation time | The time constant ISO 80000-3:2006, item 3-13 for exponential decay towards equilibrium. | ISO 80000-12:2009, item 12-33.a and item 12-33.1 | |||||
| reverberation time | The duration required for the space-averaged sound energy density in an enclosure to decrease to 10-n/10 of its initial value (i.e., by n dB) after the source emission has stopped. | ISO 80000-8:2007, item 8-29.a | |||||
| time (duration) | The duration of 9 192 631 770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of the caesium-133 atom. SI base unit. |
ISO 80000-3:2006, item 3-7.a | ISO 80000-1:2009, Table 1 | ||||
| time constant (of an exponentially varying quantity) | If a quantity is a function of time given by F(t) = A + Be-t/τ, where t is time ISO 80000-3:2006, item 3-7 and A and B are two constants, then τ is the time constant. | ISO 80000-3:2006, item 3-13.a | |||||
| SECOND_ARC | " | angle (plane angle) | s/r, where s is the length of the included arc of a circle between two radii of the circle ISO 80000-3:2006, item 3-1.8 and r is the radius of the circle ISO 80000-3:2006, item 3-1.5. 1" = (1 / 3 600)° = (π / 648 000) rad (exactly). |
PLANE_ANGLE | 193 | ISO 80000-3:2006, item 3-5.d | ISO 80000-1:2009, Table 5, "plane angle" |
| SECOND_PER_CUBIC_M_RADIAN | s/(m3 · rad) | density of states (in terms of angular frequency) | The number of vibrational modes in an infinitesimal interval of angular frequency ISO 80000-3:2006, item 3-16, divided by the range of that interval and by volume ISO 80000-3:2006, item 3-4. 1 s/(m3 · rad) = 1 s/m3 (exactly). |
SPECTRAL_CONC- _VIBRAT_MODES |
194 | ISO 80000-12:2009, item 12-13.a | |
| SECOND_PER_CUBIC_METRE | s/m3 | volumic number of molecules or other elementary entities (number density of molecules or other elementary entities) | N/V, where N is the number of particles in the 3D domain with the volume V. | VOLUMIC_DOSE | 195 | ISO 80000-9:2009, item 9-10.a and item 9-10.1 | ISO 80000-1:2009, 6.5.3 (derived), ISO 80000-10:2009, item 10-64.a and item 10-64.1 |
| SIEMENS | S | admittance (complex admittance) | 1/Z, where Z is impedance IEC 80000-6:2008, item 6-51.1. | ELECTRIC_CONDUCTANCE | 196 | IEC 80000-6:2008, item 6-52.a and item 6-52.1 | |
| conductance | For resistive component, 1/R, where R is resistance IEC 80000-6:2008, item 6-46. 1 S = 1 Ω-1 = 1 (s3 · A2)/(m2 · kg). |
IEC 80000-6:2008, item 6-47.a | ISO 80000-1:2009, Table 2, "electrical conductance" | ||||
| SIEMENS_M_SQD_PER_MOLE | (S · m2)/mol | molar conductivity | χ/cB, where χ is the electrolytic conductivity ISO 80000-9:2009, item 9-54 and cB is the amount-of-substance concentration ISO 80000-9:2009, item 9-13. 1 (S · m2)/mol = 1 (s3 · A2)/(kg · mol). |
MOLAR_CONDUCTIVITY | 197 | ISO 80000-9:2009, item 9-55.a | |
| SIEMENS_PER_METRE | S/m | conductivity | ui, where u is instantaneous voltage IEC 80000-6:2008, item 6-11.3 and i is instantaneous electric current IEC 80000-6:2008, item 6-1. 1 S/m = 1 (s3 · A2)/(m3 · kg). |
ELECTRIC- _CONDUCTIVITY |
198 | IEC 80000-6:2008, item 6-43.a | |
| electrolytic conductivity | J/E, where J is the electrolytic current density IEC 80000-6:2008, item 6-8 and E is the current field strength IEC 80000-6:2008, item 6-10. | ISO 80000-9:2009, item 9-54.a | |||||
| SIEVERT | Sv | dose equivalent (of ionizing radiation) | At the point of interest in tissue, D Q where D is the absorbed dose ISO 80000-10:2009, item 10-84.1 and Q is the quality factor ISO 80000-10:2009, item 10-85 at that point. 1 Sv = 1 J/kg = 1 m2/s2. |
DOSE_EQUIVALENT | 199 | ISO 80000-10:2009, item 10-86.a | ISO 80000-1:2009, Table 3, "dose equivalent" |
| SONE | none | loudness | A normal observer's auditory estimate of the ratio between the strength of the sound considered and that of a reference sound having a loudness level of 40 phons. | LOUDNESS | 200 | ISO 31-7:1992, 7-32.a | |
| SQ_METRE | m2 | area | The double integral over x and y, where x and y are cartesian coordinates ISO 80000-3:2006, item 3-1.10. | AREA | 201 | ISO 80000-3:2006, item 3-3.a | ISO 80000-8:2007, item 8-28.a; ISO 80000-10:2009, item 10-18.a; ISO 80000-10:2009, item 10-39.a and items 10-39.1 and 10-39.2; ISO 80000-10:2009, item 10-53.a; ISO 80000-10:2009, item 10-74.a and items 10-74.1, 10-74.2, 10-74.3 |
| SQ_METRE_AMP_PER_JOULE_SEC | (m2 · A)/(J · s) | gyromagnetic ratio (magnetogyric ratio, gyromagnetic coefficient) | μ/J where μ is the magnetic dipole moment ISO 80000-10:2009, item 10-10.1 and J is the total angular momentum ISO 80000-10:2009, item 10-12. 1 (m2 · A)/(J · s) = 1 (s · A)/kg. |
GYROMAGNETIC- _COEFFICIENT |
202 | ISO 80000-10:2009, item 10-13.a and item 10-13.2 | |
| SQ_METRE_AMPERE | m2 · A | magnetic dipole moment | For a particle or nucleus, the vector quantity μ causing an increment ΔW = -μ · B to its energy W ISO 80000-5:2007, item 5-20.1 in an external magnetic field with magnetic flux densit B IEC 80000-6:2008, item 6-21. | MAGNETIC_MOMENT | 203 | ISO 80000-10:2009, item 10-10.a and item 10-10.1 | |
| magnetic moment (magnetic area moment) | I en A, where I is electric current IEC 80000-6:2008, item 6-1 in a small closed loop, en is a unit vector perpendicular to the loop, and A is the area ISO 80000-3:2006, item 3-3 of the loop. | IEC 80000-6:2008, item 6-23.a | |||||
| SQ_METRE_KELVIN_PER_WATT | (m2 · K)/W | thermal insulance (coefficient of thermal insulance) | 1/K where K is coefficient of heat transfer ISO 80000-5:2007, item 5-10.1. 1 (m2 · K)/W = 1 (s3 · K)/kg. |
THERMAL_INSULANCE | 204 | ISO 80000-5:2007, item 5-11.a | |
| SQ_METRE_PER_JOULE | m2/J | spectral cross-section | Cross-section ISO 80000-10:2009, item 10-39.1 for a process for ejecting or scattering a particle into an elementary cone with energy E ISO 80000-5:2007, item 5-20.1 in an energy interval, divided by the solid angle dΩ ISO 80000-3:2006, item 3-6 of that cone and the range dE of that interval. 1 (m2/J = 1 s2/kg. |
SPECTRAL_CROSS- _SECTION |
205 | ISO 80000-10:2009, item 10-41.a | |
| SQ_METRE_PER_JOULE_SR | m2/(J · sr) | spectral angular cross-section | Cross-section ISO 80000-10:2009, item 10-39.1 for ejecting or scattering a particle into an elementary cone with energy E ISO 80000-5:2007, item 5-20.1 in an energy interval, divided by the solid angle dΩ ISO 80000-3:2006, item 3-6 of that cone and the range dE of that interval. 1 (m2/(J · sr) = 1 s2/(kg · sr). |
SPECTRAL_ANGULAR- _CROSS_SECT |
206 | ISO 80000-10:2009, item 10-42.a | |
| SQ_METRE_PER_KG | m2/kg | mass attenuation coefficient | μ/ρ where μ is the linear attenuation coefficient ISO 80000-10:2009, item 10-50 and ρ is the mass density ISO 80000-4:2006, item 4-2 of the medium. | MASS_ATTENUATION- _COEFF |
207 | ISO 80000-10:2009, item 10-51.a | |
| SQ_METRE_PER_MOLE | m2/mol | molar absorption coefficient | aVm, where a is the linear absorption coefficient ISO 80000-7:2008, item 7-25.2 and Vm is the molar volume ISO 80000-9:2009, item 9-6. | MOLAR_ABSORPTION- _COEFF |
208 | ISO 80000-7:2008, item 7-27.a | |
| molar attenuation coefficient | μ/c where μ is the linear attenuation coefficient ISO 80000-10:2009, item 10-50 and c is the amount-of-substance concentration ISO 80000-9:2009, item 9-13 of the medium. | ISO 80000-10:2009, item 10-52.a | |||||
| SQ_METRE_PER_SECOND | m2/s | diffusion coefficient | D, where CB(vB) = -D grad CB, where CB is the local molecular concentration of substance B ISO 80000-9:2009, item 9-10.2 in the mixture and (vB) is the local average velocity ISO 80000-3:2006, item 3-8.1 of the molecules of B. | KINEMATIC_VISCOSITY | 209 | ISO 80000-9:2009, item 9-45.a | ISO 80000-10:2009, item 10-66.a |
| kinematic viscosity | ν/ρ, where ν is dynamic viscosity ISO 80000-4:2006, item 4-24 and ρ is mass density ISO 80000-4:2006, item 4-2. | ISO 80000-4:2006, item 4-24.a | |||||
| thermal diffusivity | λ/ρcp, where λ is thermal conductivity ISO 80000-5:2007, item 5-9, ρ is mass density ISO 80000-4:2006, item 4-2, and cp is specific heat capacity at constant pressure ISO 80000-5:2007, item 5-16.2. | ISO 80000-5:2007, item 5-14.a | |||||
| SQ_METRE_PER_STERADIAN | m2/sr | angular cross-section | The cross-section for ejecting or scattering a particle into an elementary cone, divided by the solid angle dΩ ISO 80000-3:2006, item 3-6 of that cone. | ANGULAR_CROSS- _SECTION |
210 | ISO 80000-10:2009, item 10-40.a | |
| SQ_METRE_PER_VOLT_SECOND | m2/(V · s) | mobility | The average drift speed ISO 80000-3:2006, item 3-8.1 imparted to a charged particle in a medium by an electric field, divided by the electric field strength IEC 80000-6:2008, item 6-10. 1 (m2/(V · s) = 1 (s2 · A)/kg. |
MOBILITY | 211 | ISO 80000-10:2009, item 10-63.a | |
| SQ_METRE_RADIAN_PER_KG | (m2 · rad)/kg | specific optical rotatory power | αA/m, where α is the angle of optical rotation ISO 80000-9:2009, 9-57 and m is the mass ISO 80000-4:2006, item 4-1 of the optically active component in the path of a linearly polarized light beam of cross-sectional area ISO 80000-3:2006, item 3-3 A. | MASSIC_OPTICAL_ROT- _POWER |
212 | ISO 80000-9:2009, item 9-59.a | |
| SQ_METRE_RADIAN_PER_MOLE | (m2 · rad)/mol | molar optical rotatory power | αA/m, where α is the angle of optical rotation ISO 80000-9:2009, 9-57 and n is the amount of substance ISO 80000-9:2009, item 9-1 of the optically active component in the path of a linearly polarized light beam of cross-sectional area ISO 80000-3:2006, item 3-3 A. | MOLAR_OPTICAL_ROT- _POWER |
213 | ISO 80000-9:2009, item 9-58.a | |
| STERADIAN | sr | solid angle | A/r2, where A is the area of the included surface of a sphere in a cone with its apex at the centre of the sphere ISO 80000-3:2006, item 3-3 and r is the radius of the sphere ISO 80000-3:2006, item 3-1.5. 1 sr = 1 (m2/(m2 = 1 A complete angle over all space (full sphere) is 4π sr. |
SOLID_ANGLE | 214 | ISO 80000-3:2006, item 3-6.a | ISO 80000-1:2009, Table 2, "solid angle" |
| TEC | none | electron fluence | At a given point in space, the number dN of electrons incident on a small spherical domain, divided by the cross-sectional area dA ISO 80000-3:2006, item 3-3 of that domain, thus dN/dA. 1 TEC = 1016 1/m2 (exactly). |
AREAL_ENTITY_DENSITY | 215 | ISO 80000-10:2009, item 10-44.a | |
| TESLA | T | magnetic flux density | B, where F = qv x B, F is force ISO 80000-4:2006, item 4-9.1 and v is velocity ISO 80000-3:2006, item 3-8.1 of any test particle with electric charge q IEC 80000-6:2008, item 6-2. 1 T = 1 Wb/m2 = 1 kg/(s2 · A). |
MAGNETIC_FLUX- _DENSITY |
216 | IEC 80000-6:2008, item 6-21.a | ISO 80000-1:2009, Table 2, "magnetic flux density" |
| thermodynamic critical magnetic flux density | B2c, where Gn - Gs = (1/2) (B2c V/μ0), Gn and Gs are the Gibbs energies ISO 80000-5:2007, item 5-20.5 at zero magnetic flux density IEC 80000-6:2008, item 6-21 in a normal conductor and superconductor, respectively, μ0 is the magnetic constant IEC 80000-6:2008, item 6-26.1 and V is volume ISO 80000-3:2006, item 3-4. | ISO 80000-12:2009, item 12-37.a and item 12-37.1 | |||||
| TONNE | t | mass | 1 t = 1 000 kg (exactly). | MASS | 218 | ISO 80000-4:2006, item 4-1.b | ISO 80000-1:2009, Table 5, "mass" |
| TONNE_PER_CUBIC_METRE | t/m3 | mass density (density) | The mass ISO 80000-4:2006, item 4-1 divided by the volume ISO 80000-3:2006, item 3-4. 1 t/m3 = 103 kg/m3 (exactly). |
VOLUMIC_MASS | 219 | ISO 80000-4:2006, item 4-2.b | |
| UNITLESS | 1 (often omitted) | special (pure number) | 1. | PURE_NUMBER | 221 | ISO 80000-1:2009, 6.5.5 | |
| VOLT | V | electric potential | V, where -grad V = E + δA/δt, where E is electric field strength IEC 80000-6:2008, item 6-10, A is magnetic vector potential ISO 80000-3:2006, item 3-7. 1 V = 1 W/A = 1 (m2 · kg)/(s3 · A). |
ELECTRIC_POTENTIAL | 222 | IEC 80000-6:2008, item 6-11.a and item 6-11.1 | ISO 80000-1:2009, Table 2, "electric potential difference" |
| Peltier coefficient | The Peltier heat power developed at a junction, divided by the electric current IEC 80000-6:2008, item 6-1 flowing from substance a to substance b. | ISO 80000-12:2009, item 12-23.a | |||||
| source voltage (source tension) | The voltage IEC 80000-6:2008, item 6-11.3 between the two terminals of a voltage source when there is no electric current IEC 80000-6:2008, item 6-1 through the source. 1 V = 1 W/A = 1 (m2 · kg)/(s3 · A). |
IEC 80000-6:2008, item 6-36.a | ISO 80000-1:2009, Table 2, "electric potential difference" | ||||
| VOLT_AMP | V · A | apparent power | UI, where U is rms value of voltage IEC 80000-6:2008, item 6-11.3 and I is rms value of electric current IEC 80000-6:2008, item 6-1. 1 V · A = 1 (m2 · kg)/(s3 · A). |
APPARENT_POWER | 223 | IEC 80000-6:2008, item 6-57.a | ISO 1000:1992, Annex A, 5-49 |
| VOLT_PER_KELVIN | V/K | Seebeck coefficient | dEab/dT, where dEab is the thermosource voltage between substances a and b ISO 80000-12:2009, item 12-21 and T is the thermodynamic temperature ISO 80000-5:2007, item 5-1 of the hot junction. 1 V/K = 1 (m2 · kg)/(s3 · A · K). |
SEEBECK_COEFFICIENT | 224 | ISO 80000-12:2009, item 12-22.a | |
| Thomson coefficient | The Thomson heat power developed divided by the electric current IEC 80000-6:2008, item 6-1 and the temperature ISO 80000-5:2007, item 5-1 difference. | ISO 80000-12:2009, item 12-24.a | |||||
| VOLT_PER_METRE | V/m | electric field strength | F/q, where F is force ISO 80000-4:2006, item 4-9.1 and q is electric charge IEC 80000-6:2008, item 6-2. 1 V/m = 1 N/C = 1 (m · kg)/(s3 · A). |
ELECTRIC_FIELD- _STRENGTH |
225 | IEC 80000-6:2008, item 6-10.a | |
| VOLT_SQD_PER_KELVIN_SQD | V2/K2 | Lorenz coefficient | λ/(σT), where λ is thermal conductivity ISO 80000-5:2007, item 5-9, σ is electrical conductivity IEC 80000-6:2008, item 6-43, and T is thermodynamic temperature ISO 80000-5:2007, item 5-1. 1 V2/K2 = 1 (m4 · kg2)/(s6 · A2 · K2). |
LORENZ_COEFFICIENT | 226 | ISO 80000-12:2009, item 12-19.a | |
| WATT | W | heat flow rate | The rate at which heat ISO 80000-5:2007, item 5-6 crosses a given surface. | POWER | 227 | ISO 80000-5:2007, item 5-7.a | |
| power | For a particle, F ·v, where F is force ISO 80000-4:2006, item 4-9.1 and v is velocity ISO 80000-3:2006, item 3-8.1. 1 W = 1 J/s = 1 (m2 · kg)/s3. |
ISO 80000-4:2006, item 4-26.a | ISO 80000-1:2009, Table 2, "power" | ||||
| power (instantaneous power) | u/i, where u is instantaneous voltage IEC 80000-6:2008, item 6-11.3 and i is instantaneous electric current IEC 80000-6:2008, item 6-1. 1 W = 1 J/s = 1 (m2 · kg)/s3. |
IEC 80000-6:2008, item 6-45.a | ISO 80000-1:2009, Table 2, "power" | ||||
| radiant flux (radiant power) | dQ/dt, where dQ is the radiant energy ISO 80000-7:2008, item 7-6 emitted, transferred, or received during a time interval of the duration dt ISO 80000-3:2006, item 3-7. | ISO 80000-7:2008, item 7-13.a | |||||
| sound power | Through a surface, product of the sound pressure, p ISO 80000-8:2007, item 8-9.2, and the component of the particle velocity, un ISO 80000-8:2007, item 8-11, at a point on the surface in the direction normal to the surface, integrated over that surface ISO 80000-8:2007, item 8-16.2. | ISO 80000-8:2007, item 8-16.a | |||||
| WATT_HOUR | W · h | active energy | The integral over time of p, where p is instantaneous power IEC 80000-6:2008, item 6-45, and the integral interval is the the interval from t1 to t2. 1 W · h = 3 600 J (exactly). |
ENERGY | 228 | IEC 80000-6:2008, item 6-62.b | |
| WATT_PER_KELVIN | W/K | thermal conductance | 1/R where R is thermal resistance ISO 80000-5:2007, item 5-12. 1 W/K = 1 (m2 · kg)/(s3 · K). |
THERMAL_CONDUCTANCE | 229 | ISO 80000-5:2007, item 5-13.a | |
| WATT_PER_METRE_K | W/(m · K) | thermal conductivity | The areic heat flow rate ISO 80000-5:2007, item 5-8 divided by temperature ISO 80000-5:2007, item 5-1 gradient. 1 W/(m · K) = 1 (m · kg)/(s3 · K). |
THERMAL_CONDUCTIVITY | 230 | ISO 80000-5:2007, item 5-9.a | |
| WATT_PER_SQ_CM_SEC | W/(cm2 · s) | radiant exitance rate | At a point on a surface, the radiant energy flux leaving the element of the surface over an interval of time, divided by the area of that element and that time. 1 W/(cm2 · s) = 10-4 W/(m2 · s) (exactly). |
RADIANT_EXITANCE- _RATE |
231 | ISO 80000-1:2009, 6.5.4 (derived) | |
| WATT_PER_SQ_M_HZ | W/(m2 · Hz) | flux density (frequency dependent) | The amount of a given type of radiation that crosses a specified area within a specified period. 1 W/(m2 · Hz) = 1 kg/s2. |
FLUX_DENSITY | 232 | ISO 80000-1:2009, 6.4 and 6.5.3 (derived) | |
| WATT_PER_SQ_M_K_FOURTH_PWR | W/(m2 · K4) | Stefan-Boltzmann constant | Constant σ in the expression for the radiant exitance M ISO 80000-7:2008, item 7-18 of a blackbody at thermodynamic temperature T ISO 80000-5:2007, item 5-1, thus M = σ T4. 1 W/(m2 · K4) = 1 kg/(s3 · K4). |
STEFAN_BOLTZMAN- _CONSTANT |
233 | ISO 80000-7:2008, item 7-56.a | |
| WATT_PER_SQ_METRE | W/m2 | areic heat flow rate (density of heat flow rate) | Φ/A, where Φ is heat flow rate ISO 80000-5:2007, item 5-7 and A is area ISO 80000-3:2006, item 3-3. 1 W/m2 = 1 kg/s3. |
IRRADIANCE | 234 | ISO 80000-5:2007, item 5-8.a | |
| energy fluence rate | dΨ/dt, where dΨ is the increment of the energy fluence ISO 80000-10:2009, item 10-47 during an infinitesimal time interval with duration dt ISO 80000-3:2006, item 3-7. | ISO 80000-10:2009, item 10-48.a | |||||
| irradiance | At a point on a surface, dΦ/dA, where dΦ is the radiant flux ISO 80000-7:2008, item 7-19 incident on an element of the surface with area dA ISO 80000-3:2006, item 3-6. | ISO 80000-7:2008, item 7-19.a | |||||
| Poynting vector | The cross product E x H, where E is electric field strength IEC 80000-6:2008, item 6-10 and H is magnetic field strength IEC 80000-6:2008, item 6-25. | IEC 80000-6:2008, item 6-34.a | |||||
| radiant exitance | At a point on a surface, dΦ/dA, where dΦ is the radiant flux ISO 80000-7:2008, item 7-13 leaving an element of the surface with area dA ISO 80000-3:2006, item 3-3. | ISO 80000-7:2008, item 7-18.a | |||||
| sound intensity | p ·v, where p is sound pressure ISO 80000-5:2007, item 8-9.2 and v is sound particle velocity ISO 80000-5:2007, item 8-11. | ISO 80000-8:2007, item 8-17.a and item 8-17.1 | |||||
| spherical irradiance (radiant fluence rate) | At a given point in space, the integral over Ω of L where dΩ is the solid angle ISO 80000-3:2006, item 3-6 of each elementary beam passing through the given point and L its radiance ISO 80000-7:2008, item 7-15 at that point in the direction of the beam. | ISO 80000-7:2008, item 7-16.a | |||||
| WATT_PER_SQ_METRE_K | W/(m2 · K) | coefficient of heat transfer | The areic heat flow rate ISO 80000-5:2007, item 5-8 divided by thermodynamic temperature ISO 80000-5:2007, item 5-1 difference. 1 W/(m2 · K) = 1 kg/(s3 · K). |
COEFFICIENT_HEAT- _TRANSFER |
235 | ISO 80000-5:2007, item 5-10.a and item 5-10.1 | |
| WATT_PER_SQ_METRE_MICRON | W/(m2 · μm) | integrated spectral radiance | At a point on a surface and integrated over all directions, the radiant intensity of an element of the surface, divided by the area of the orthogonal projection of this element on a plane perpendicular to the given direction, as a function of radiant wavelength. 1 W/(m2 · μm) = 1 kg/(s3 · μm). |
SPECTRAL_RADIANCE- _INTEGRATED |
236 | ISO 80000-1:2009, 6.5.3 (derived) | |
| WATT_PER_SQ_METRE_SEC | W/(m2 · s) | radiant exitance rate | At a point on a surface, the radiant energy flux leaving the element of the surface over an interval of time, divided by the area of that element and that time. 1 W/(m2 · s) = 1 kg/s4. |
RADIANT_EXITANCE- _RATE |
237 | ISO 80000-1:2009, 6.5.3 (derived) | |
| WATT_PER_SQ_METRE_SR | W/(m2 · sr) | radiance | At a point on a surface and in a given direction, (dI/dA) (1/cos α), where dI is the radiant intensity ISO 80000-7:2008, item 7-14 emitted from an element of the surface with area dA ISO 80000-3:2006, item 3-3 and angle α is the angle between the normal to the surface and the given direction. 1 W/(m2 · sr) = 1 kg/(s3 · sr). |
RADIANCE | 238 | ISO 80000-7:2008, item 7-15.a | |
| WATT_PER_SQ_METRE_SR_MICRON | W/(m2 · sr · μm) | spectral radiance | At a point on a surface and in a given direction, the radiant intensity of an element of the surface, divided by the area of the orthogonal projection of this element on a plane perpendicular to the given direction, as a function of radiant wavelength. 1 W/(m2 · sr · μm) = 1 kg/(s3 · sr · μm). |
SPECTRAL_RADIANCE | 239 | ISO 80000-1:2009, 6.5.3 (derived) | |
| WATT_PER_STERADIAN | W/sr | radiant intensity | In a given direction from a source, dΦ/dΩ, where dΦ is the radiant flux ISO 80000-7:2008, item 7-13 leaving the source in an elementary cone containing the given direction with the solid angle dΩ ISO 80000-3:2006, item 3-6. 1 W/sr = 1 (m2 · kg)/(s3 · sr). |
RADIANT_INTENSITY | 240 | ISO 80000-7:2008, item 7-14.a | |
| WATT_SECOND | W · s | electrical active energy | The practical unit of energy in electrical systems. 1 W · s = 1 J (exactly). |
ENERGY | 241 | ISO 80000-1:2009, Table 2, "energy" | ISO 80000-1:2009, 6.5.3 (derived) |
| WATT_SQ_METRE | W · m2 | first radiation constant | The constant c1 in the expression for the spectral radiant exitance ISO 80000-7:2008, item 7-18 of a blackbody at the thermodynamic temperature T ISO 80000-5:2007, item 5-1, thus Mλ(λ) = c1 f(λ, T) = c1 (λ-5/(exp(c2 λ-1 T-1) - 1) 1 W · m2 = 1 (m4 · kg)/s3. |
FIRST_RADIATION- _CONSTANT |
242 | ISO 80000-7:2008, item 7-57.a | |
| WEBER | Wb | magnetic flux | The integral of the dot product B · endA over a surface S, where B is magnetic flux density IEC 80000-6:2008, item 6-21 and endA is vector surface element ISO 80000-3:2006, item 3-3. 1 Wb = 1 V · s = 1 (m2 · kg)/(s2 · A). |
MAGNETIC_FLUX | 243 | IEC 80000-6:2008, item 6-22.a and item 6-22.1 | ISO 80000-1:2009, Table 2, "magnetic flux" |
| WEBER_PER_METRE | Wb/m | magnetic vector potential | A, where B = rot A and B is magnetic flux density IEC 80000-6:2008, item 6-21. 1 Wb/m = 1 (m · kg)/(s2 · A). |
MAGNETIC_VECTOR- _POTENTIAL |
244 | IEC 80000-6:2008, item 6-32.a |
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