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CIRAS-3 Operation Manual V. 1.09
138
Operations
To use the Multi-Pulse function, make sure that you have the required software and firmware as follows:
CIRAS-3
•
Console software Version 1.08 or above.
•
Firmware Version 3.05 or above.
PLC3
•
Firmware Version 3.04 or above.
To set the Multi-Pulse settings:
1. On the home screen, go to
Settings
>
CFM Settings
2. In the “
initial fluorescence measurement
” field, there will be an option for “
PhiPSII-MP
”.
Choose this if you wanted to skip the dark adaptation period and use Multi-Pulse to measure
PhiPSII right away under light adapted state.
3. In the “
repeating fluorescence measurement
” field, choose “
PhiPSII-MP
” for Multi-Pulse.
4. On the lower half of the panel are text fields for putting in “
duration
” and “
intensity
” of each
step. The Multi-Pulse function allows up to 5 steps and requires at least 3 steps; you can
leave the 4
th
and the 5
th
field blank. The default setting of Multi-Pulse is 0.3 sec per step, with
an intensity of 5000, 4000, 3000, 2000, 1000
μmol m
-2
s
-1
.
5. Press
Accept
to accept the CFM Settings, and then
Accept
again to return to the main
menu.
6. Start a measurement operation as described in previous sections of the manual.
Our testing of CIRAS-3 CFM Multi-Pulse function on light-adapted, fully expanded tobacco leaves
suggest that 5 saturating pulses at widely-spaced Q’ intensities (for example, 5000, 4000, 3000, 2000,
1000 μmol m
-2
s
-1
) of 0.3 seconds each produced improved Fm’ measurement vs. Fm’ measured by a
single pulse, especially when actinic light is above 1000. While level of saturating intensities (Q’) are user
definable, for best results, we recommend that at least one step set to be higher than 3000 μmol m
-2
s
-1
(the high point), and at least one step set to be lower than 1500 μmol m
-2
s
-1
(the low point), and generate
the intermediate light intensities by evenly distribute numbers in between.
One advantage of using Multi-Pulse is that lower light intensities can be used compared to single pulse.
This decreases the voltage draw on the instrument and lessens the likelihood of inaccurate readings at
very low battery levels.