Product Manual
Turf-Tec International Daylight Indicator – Light Meter - Copyright 2013
Page 6 - www.turf-tec.com
Effect of light intensity on plant growth and quality
Relative
Light
Level
Daily Light
Integral (DLI)
molm
-2
d
-1
Light intensity
at Noon
μmolm
-2
s
-1
Generalized Plant
Growth Response
Very Low 2 to 5 100 to 200 Poor quality
Low 5 to 10 200 to 400 Minimum
acceptable quality
Medium 10 to 20 400 to 800 Good quality
High 20 to 30 800 to 1200 Excellent quality
Very High 30 to 60 1200 to 2000 Excellent quality
Table 1. Generalized plant responses to different light levels.
Please note that it is not possible to convert a single light intensity reading to DLI.
Additionally, temperature is an important factor of plant growth and quality (table
adapted from Hamrick, Debbie ed. Ball Red Book. Batavia, IL: Ball Publishing.
2003).
Replacing the Battery
The Daylight Indicator uses three cell batteries A76/LR44/AG13/L1154.
To change the battery:
1. Remove the three screws from the underside of the unit.
2. Lift off and turn over the top of the Daylight Indicator.
3. Remove the batteries.
4. Clean the battery contacts prior to installing batteries.
5. Batteries must be installed in the correct direction and polarity
(see image below).
6. Re-align the top of the Daylight Indicator with the base. Replace and
tighten the screws.