tolerance range)
– Most frequent colour temperature at
Zumtobel: 3000 4000 K
– readjustment the course the LED’s
service life
– Temperature-based readjustment keep
the colour temperature constant
– Constant colour temperature during
dimming
Technology used Zumtobel’s LED modules
700
0.1
0.2
0.7
0.7 0.2
0.3
0.1 0.3 0.6
0.0 0.0
y
x
0.4
0.4
0.0 0.2 0.6 0. This means that different colour
coordinates can have the same CCT.4 0.1
0.6
0.76
The Lighting Handbook
Colour temperature and CCT
Colour temperature (CT)
– Colour temperature, well light colour,
in warm, neutral and daylight white
– Corresponds colour tines white,
quoted the Correlated Colour
Temperature (CCT) Kelvin (K)
– Colour coordinates the Planckian radiator
(Planckian curve)
– Real light sources often deviate from this:
correlated colour temperature (CCT)
– Judd straight lines: all points these lines
have the same correlated colour tempera-
ture.7
0.5
0.
stableWhite
Invariable colour temperature
– Specific initial colour temperature
(incl.7 0.5 0.8
∞
10000
6000
4000 3000 2500
2000 1500
TC(°K)
520
540
560
580
600
620
500
490
480
460
470
380
LED technology
.8
0.9
0.8
0.5 0.6 0.8
∞
10000
6000
4000 3000 2500
2000 1500
TC(°K)
520
540
560
580
600
620
500
490
480
460
470
380
700
0.3
0.2 0.3 0.0
y
x
0.5
0.4 0.9
0.1 0
