CIRAS-3 Operation Manual V. 1.09
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CFM-3 Control
J Parameters
Factors used for calculation of electron transport rate.
Leaf abs. factor
α.
Default value set to 0.84 but can be determined by use of
an integrating sphere.
PSII abs. factor
β.
Default value set to 0.5 but a known range of values exist
for different plant types.
Modulating Light
Gain.
Used to adjust the resolution of the fluorescence signal. We
recommend that the gain be set to a % that achieves a steady F
o
value
between 400-700.
Modulation Level.
Modulation Level (1-4) determines the frequency of
sample fluorescence counts. Higher levels have better signal to noise, while
lower levels have poor signal to noise but have no actinic effect. For example,
greater noise due to a lower modulating frequency can have a large effect on
measuring the lowest two values used to arrive at an average of Fo’ under far-
red light..
The dark adaptation period can be manually terminated before the elapsed time in Settings is reached by
pressing
End Dark A (F3)
. This will cause the modulating lights to switch on for a fixed period of 1.5
seconds, followed by the saturating pulse pre-defined in CFM Settings or CFM Control.
Mod Lt Off (F6)
and
Mod Lt On (F7)
toggle the modulating lights off or on. After making changes press
Back (F1)
to
return to the Controls dialog and
Accept (F2)
to finalize the modifications.
F1
F3
F2
F4
F6
F5
F7
F8
