Quantity |
Level
Cat. |
Use
Id. |
Name |
Convesion factors to SI units (1 unit equals)
|
Represen.
Symbol |
Cross
ref. |
|
| Light and Related Electromagnetic
Radiations |
|
frequency
|
1
|
|
hertz
|
|
Hz
|
507
|
|
circular frequence
|
1
|
|
reciprocal second
|
|
s-¹
|
508
|
| |
1
|
|
radian per second
|
|
rad/s
|
509
|
|
wavelength
|
1
|
|
metre
|
|
m |
510
|
| |
1
|
|
|
10-10 m (exactly)
|
Å
|
511
|
|
wavenumber, repetency
|
1
|
|
reciprocal metre
|
|
m-¹
|
512
|
|
angular wave number, angular repetency
|
1
|
|
radian per metre
|
|
rad/m |
513
|
|
velocity (speed) on propagation
of electromagnetic waves in vacuo
|
1
|
|
metre per second
|
|
m/s
|
514
|
|
radiant energy
|
1
|
|
joule
|
|
J
|
515
|
|
radiant energy density
|
1
|
|
joule per cubic metre
|
|
J/m³
|
516
|
| |
1M
|
|
megajoule per cubic metre
|
|
MJ/m³
|
517
|
|
spectral concentration of
radiant energy density (in terms of wavelength), spectral radiant energy
density (in terms of wave lenght)
|
1
|
|
joule per metre to the fourth
power
|
|
J/m4
|
518
|
|
radiant power, (radiant energy
flux)
|
1
|
|
watt
|
|
W
|
519
|
|
radiant energy fluence
|
1
|
|
joule per metre squared
|
|
J/m²
|
520
|
|
radiance exposure
|
|
|
|
|
|
|
|
photon flux
|
1
|
|
reciprocal second
|
|
s-¹
|
522
|
|
photon intensity
|
1
|
|
reciprocal second per steradian
|
|
s-¹/sr
|
523
|
|
photon luminance, photon
radiance
|
1
|
|
reciprocal second per steradian
metre squared
|
|
s-¹/(sr.m²)
|
524
|
|
photon exitance, irradiance
|
1
|
|
reciprocal second per metre
squared
|
|
s-¹/m²
|
525
|
|
photon exposure
|
1
|
|
reciprocal metre squared
|
|
m-²
|
526
|
|
radiant energy, fluence rate
|
1
|
|
watt per square metre
|
|
W/m²
|
527
|
|
radiant exitance
|
|
|
|
|
|
|
|
irradiance
|
|
|
|
|
|
|
|
first radiation constant
|
|
|
|
|
|
|
|
radiant intensity
|
1
|
|
watt per steradian
|
|
W/sr
|
531
|
|
radiance
|
1
|
|
watt per steradian square metre
|
|
W/(sr.m²)
|
532
|
|
Stefan - Boltzmann constant
|
1
|
|
watt per square metre kelvin to
the fourth power
|
|
W/(m².K4)
|
533
|
|
second radiation constant
|
1
|
|
metre kelvin
|
|
m.K
|
534
|
|
emissivity
|
1
|
|
one
|
|
1
|
535
|
|
spectral emissivity
|
|
|
|
|
|
|
|
emissivity at a specified
wavelength
|
|
|
|
|
|
|
|
directional spectral emissivity
|
|
|
|
1
|
|
|
luminous intensity
|
1
|
|
candela
|
|
cd
|
539
|
|
luminous flux
|
1
|
|
lumen
|
|
lm
|
540
|
|
quantity of light
|
1
|
|
lumen second
|
|
lm.s
|
541
|
| |
1S
|
|
lumen hour
|
|
lm.h
|
542
|
|
luminance
|
1
|
|
candela per square metre
|
|
cd/m²
|
543
|
|
luminous exitance
|
1
|
|
lumen per square metre
|
|
lm/m²
|
544
|
|
illuminance
|
1
|
|
lux
|
|
lx
|
545
|
|
light exposure
|
1
|
|
lux second
|
|
lx.s
|
546
|
| |
1S
|
|
lux hour
|
3 600 lx.s
|
lx.h
|
547
|
|
luminious efficacy
|
1
|
|
lumen per watt
|
|
lm/W
|
548
|
spectral luminous efficacy,
luminous efficacy at a specified wavelength,
maximum spectral luminous efficacy
|
|
|
|
|
|
|
|
luminous efficiency
|
1
|
|
one
|
|
1
|
550
|
|
spectral luminous efficiency,
luminous efficiency at a specified wavelength
|
|
|
|
|
|
|
|
CIE colorimetric functions
|
1
|
|
one
|
|
1
|
552
|
|
coordinates trichromatic
|
1
|
|
one
|
|
1
|
553
|
|
spectral absorption factor,
spectral absorptance
|
1
|
|
one
|
|
1
|
554
|
|
spectral reflection factor,
spectral reflectance
|
|
|
|
|
|
|
|
spectral transmission factor,
spectral transmittance
|
|
|
|
|
|
|
|
spectral radiance factor
|
|
|
|
|
|
|
|
optical density
|
1
|
|
one
|
|
1
|
558
|
|
refractive index
|
1
|
|
one
|
|
1
|
559
|
|
linear attenuation coefficient,
linear extinction coefficient
|
1
|
|
reciprocal metre
|
|
m-¹
|
560
|
|
linear absorption coefficient
|
|
|
|
|
|
|
|
molar absorption coefficient
|
1
|
|
square metre per mole
|
|
m²/mol
|
562
|
|
object distance
|
|
|
|
|
|
|
|
image distance
|
1
|
|
metre
|
|
m |
564
|
|
focal distance
|
|
|
|
|
|
|
|
vergence, lens power
|
1
|
|
reciprocal metre
|
|
m-¹
|
566
|
| Acoustics
|
|
|
|
|
|
|
|
period,
|
1
|
|
second
|
|
s
|
567
|
|
periodic time
|
|
|
|
|
|
|
|
frequency
|
1
|
|
hertz
|
|
Hz
|
569
|
|
frequency interval
|
1
|
|
octave
|
|
|
570
|
|
angular frequency, pulsatance
|
1
|
|
reciprocal second
|
|
s-¹
|
571
|
| |
1
|
|
radian per second
|
|
rad/s
|
572
|
|
wavelength
|
1
|
|
metre
|
|
m
|
573
|
|
repetency, wavenumber
|
1
|
|
reciprocal metre
|
|
m-¹
|
574
|
|
angular repetency, angular
wavenumber
|
1
|
|
radian per metre
|
|
rad/m
|
575
|
|
volumic mass, density, mass density
|
1
|
|
kilogram per cubic metre
|
|
kg/m³
|
576
|
|
static pressure,
|
1
|
|
pascal
|
|
Pa
|
577
|
|
(instantaneous) sound pressure
|
1
|
|
bar
|
105 Pa (exactly)
|
bar |
578
|
| |
2
|
X
|
dyne per square centimetre
|
10-¹ Pa (exactly)
|
dyn/cm²
|
579
|
|
(instantaneous) sound particle
displacement
|
1
|
|
metre
|
|
m
|
580
|
|
(instantaneous) sound particle velocity
|
1
|
|
metre per second
|
|
m/s
|
581
|
|
(instantaneous) sound particle acceleration
|
1
|
|
metre per second squared
|
|
m/s²
|
582
|
|
(instantaneous) volume flow
rate,
|
1
|
|
cubic metre per second
|
|
m³/s
|
583
|
|
velocity of sound (phase
velocity)
|
1
|
|
metre per second
|
|
m/s
|
584
|
|
group velocity
|
|
|
|
|
|
|
|
sound energy density, volumic
sound energy
|
1
|
|
joule per cubic metre
|
|
J/m³
|
586
|
| |
2
|
X
|
erg per cubic centimetre
|
10-1 J/m³ (exactly)
|
erg/cm³
|
587
|
|
sound power
|
1
|
|
watt
|
|
W
|
588
|
| |
2
|
X
|
erg per second
|
10-7 W (exactly)
|
erg/s
|
589
|
|
sound intensity
|
1
|
|
watt per square metre
|
|
W/m²
|
590
|
| |
1S
|
|
milliwatt per square metre
|
|
mW/m² |
591
|
| |
1S
|
|
microwatt per square metre
|
|
µW/m² |
592
|
| |
1S
|
|
picowatt per square metre
|
|
pW/m² |
593
|
| |
2
|
X
|
erg per second square centimetre
|
10-3 W/m² (exactly)
|
erg/(s.m²)
|
594
|
|
characteristic impedence of a
medium
|
1
|
|
pascal second per metre
|
|
Pa. s/m
|
595
|
|
surface density of mechanical
impedance
|
2
|
X
|
dyn second per cubic centimetre
|
10 Pa. s/m (exactly)
|
dyn.s/cm³
|
596
|
|
acoustic impedance
|
1
|
|
pascal second per cubic metre
|
|
Pa.s/m³
|
597
|
| |
2
|
X
|
dyne second per centimetre to
the fifth
|
105 Pa. s/m³ (exactly)
|
dyn. s/cm5
|
598
|
|
mechanical impedence
|
1
|
|
newton second per metre
|
|
N.s/m
|
599
|
| |
2
|
X
|
dyne second per centimetre
|
10-³ N.s/m
|
dyn.s/cm
|
600
|
sound pressure level
sound power level
|
1
|
|
decibel
|
|
dB
|
601
|
|
damping coefficient
|
1
|
|
reciprocal second
|
|
s-¹
|
602
|
| |
|
|
neper per second
|
|
Np/s
|
603
|
time constant,
relaxation time
|
1
|
|
second
|
|
s
|
604
|
|
logarithmic decrement
|
1
|
|
neper
|
|
Np
|
605
|
attenuation coefficient
phase coefficient
propogation coefficient
|
1
|
|
reciprocal metre
|
|
m-¹
|
606
|
|
dissipation factor, dissipance
|
1
|
|
one
|
|
1
|
607
|
|
reflection factor, reflectance
|
|
|
|
|
|
|
|
transmission factor,
transmittance
|
|
|
|
|
|
|
|
absorption factor, absorbance
|
|
|
|
|
1
|
|
|
sound reduction index
|
1
|
|
decibel
|
|
dB
|
611
|
|
equivalent absorption area of a
surface or object
|
1
|
|
square metre
|
|
m²
|
612
|
|
reverberation time
|
1
|
|
second
|
|
s
|
613
|
|
loudness level
|
1
|
|
phon
|
|
|
614
|
|
loudness
|
1
|
|
sone
|
|
|
615
|