LI-COR LI-6400, Manual

Page: 240 / 846

Light Sensor Considerations
6400-02 and -02B Light Sources
8-6 Using the LI-6400
8
6400-02 and -02B Light Sources
Spectral Considerations
The 6400-02 spectral output has one peak centered at about 670 nm, while the
6400-02B has a secondary peak centered at about 465 nm (Figure 8-3). While
the red only LED source provides a very suitable light source for photosyn-
thetic studies (Tennessen, et al, 1994
2
), the addition of the blue LEDs in the
6400-02 enlarges the scope of suitable applications to include stomatal kinet-
ics.
In-chamber light is measured with an unfiltered silicon photodiode that is part
of the LED source. See
Light Source Calibration on page 18-24.
2.
Tennessen D.J., D.L. Singsaas, T.D. Sharkey, 1994. Light-emitting diodes as a
light source for photosynthesis research. Photosynthesis Research 39 : 85-92.
Figure 8-3. Typical output of a 6400-02B LED source at 25¡C. (A 6400-02
source has the same red peak, but no blue peak.)
0
20
40
60
80
100
400 500 600 700 800
Relative Output (%)
Wavelength (nm)