6.1 General Attributes
45
Abbreviation
Duv
UV distance between CIE1960 plane coordinate(s) and Planck’s blackbody
radiation with the same color temperature. A value close to 0 indicates the
color temperature and color are closer to that of the blackbody radiation. A
positive value indicates it is above the blackbody radiation, while a negative
value indicates it is below the blackbody radiation.
Δx
X difference between CIE1931 plane coordinates and Planck’s blackbody
radiation with the same color temperature.
Δy
Y difference between CIE1931 plane coordinates and Planck’s blackbody
radiation with the same color temperature.
Δu'
U' difference between CIE1976 plane coordinates and Planck’s blackbody
radiation with the same color temperature.
Δv'
V’ difference between CIE1976 plane coordinates and Planck’s blackbody
radiation with the same color temperature.
fc
Non-SI unit of illuminance defined as lumens per square foot (lm/ft
2
).
Purity
Percent of the dominant wavelength in the standard illuminant. The closer
the color purity is to 100%, the closer it is to the dominant wavelength.
IRR
Flux of radiant energy per unit area within the range of a specified
wavelength.
PPFD
Number of photons per unit area per unit of time for photosynthetically-active
radiation (400~700nm wavelength range).
PPFD-R
PFD in the 600~700 nm wavelength range.
PPFD-G
PFD in the 500~600 nm wavelength range.
Full Name
CIE1960 UV Color Coordinate Difference
CIE1931 Color Coordinate Difference
CIE1931 Color Coordinate Difference
CIE1976 Color Coordinate Difference
CIE1976 color coordinate difference
Foot-candle
Color Purity
Irradiance
Photosynthetic Photon Flux Density
PFD in Red Field
PFD in Green Field
Unit
fc
%
W/m
2
µmol/(m
2
*s)
µmol/(m
2
*s)
µmol/(m
2
*s)
46
6.1 General Attributes
Abbreviation
PPFD-B
PFD in the 400~500 nm wavelength range.
PFD
Number of photons in range of 380~780nm subjected by unit area in unit
time.
PFD-UV
PFD in range of 380~400nm
PFD-FR
PFD in range of 700~780nm
PFD-B: G ratio
PPFD ratios within the 400~500nm range and 500~600nm range.
PFD-R: FR ratio
PPFD ratios within the 600~700nm range and 700~800nm range.
Chlorophyll A
Chlorophyll is a photosynthetic pigment that exists in plants, algae and
cyanobacteria. Chlorophyll A is the pigment that mainly undergoes
photoreaction, and that’s why it is also called the primary pigment.
Chlorophyll B
Chlorophyll is a photosynthetic pigment that exists in plants, algae and
cyanobacteria. Chlorophyll B can absorb light energy and sends it to
Chlorophyll A for photoreaction; it is also called the accessory pigment.
Beta-carotene
β-carotene is one of the carotenoids; it is widely found in the leaves, flowers
and roots of plants.
Phytochrome A red
Phytochrome A red is a pigment in plants; it is a protein. When it absorbs red
light, it will change into a pigment that absorbs far-red light, Pfr. Plants mainly
receive external light signals through phytochrome to adjust their own
growths, developments and flowerings.
Phytochrome A far red
Phytochrome A far red is a pigment in plants; it is a protein. When it absorbs
far-red light, it will drive the pigment back into the form of absorbing red light,
Pr. Plants mainly receive external light signals through phytochrome to
adjust their own growths, developments and flowerings.
Full Name
PFD in Blue Field
Photosynthetic Photon Flux Density
PFD in UV field
PFD in FR field
PPFD ratio between the blue and green fields
PPFD ratio between the red and far-red fields
β-carotene
Phytochrome – Protein red
Phytochrome – Proteinfar-red
Unit
µmol/(m
2
*s)
µmol/(m
2
*s)
µmol/(m
2
*s)
µmol/(m
2
*s)