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1p Kinetic Test Setup Screen
Det Gain
This is detector electronic gain control. It should only be raised if the modulation
intensity can not be raised high enough to prevent a “signal too low” message. Raising
this value lowers the signal to noise ratio, and can produce a noisier trace.
Far red intensity and duration
are set at the default settings of 50% and a duration
of 5 seconds. This feature is only used with optional Kramer lake model and puddle
model protocols. Actinic int.
Actinic intensity
is adjusted from zero to 100% intensity with 5% increments, using
the plus and minus buttons. The value may be measured with the PAR Clip if it is used
for measurements. The actinic intensity is about 1,500 umols at 100% intensity when
using the PAR Clip and about 2500 umols with a dark clip. The scale is almost linear
from 0 to 100%, however, for exact measurements, the PAR Clip or an external PAR
meter should be used to measure the light irradiation on the leaf. Shade leaves will
saturate at much lower levels than sun leaves.
Set up screen #3
Using Default PAR
This allows one to enter a PAR light level into measuring files, when PAR is measured
with a separate instrument, and if the PAR Clip is not used. The PAR CLIP can be used
to measure the PAR (light) intensity before the test or a separate PAR meter can be used.
When making this measurement, it is recommended that the light level be tested just after
the actinic light is turned on, after five minutes, and at twenty minutes. As the actinic
light heats up, the intensity output drops somewhat. The greatest amount of change
occurs in the first five minutes. The change after five minutes is within a just a few
percent of the light intensity. For this reason, one may want to run quenching tests for
twenty-five or thirty minutes to insure steady state photosynthesis at a specific light level.
“Fm’ Measure” - On the third set up screen, the user can
change from standard saturation flashes to multi-flash
saturation pulses. This feature is recommended for high light
levels. It estimates the fluorescence intensity with an
infinitely intense saturation flash.
For detailed information, see the section on Multi-Flash in
chapter 3.
