Abstract:
An optical
chlorophyll sensor has been developed
by employing its unique light
absorption and fluorescence properties
.
Characteristic absorption peaks of chlorophyll a
and b occur at 430 nm and 453 nm in blue region and at 665 nm and 642 nm in red region
respectively and fluorescence emission peaks
occur
at 680 nm and 750 nm. LEDs with
peak emission wavelength at 405 nm, 435 nm, 525 nm and 680 nm were used as
wavelength selective light sources and Hamamatsu s5972 photodiode together with
optical filters (
5
40AESP short pass and 670AF30 band pass
filters
)
were used as
detectors.
It is found that there is a good
l
inear relationship between
the chlorophyll
concentration
(in arbitrary units)
and the natural logarithm of the
blue and red
absorption
intensities
(
