Photon Systems Instruments AquaPen-C AP 110-C, Instruction Manual

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Default setting of light color and intensities in AquaPen firmware. These may be changed according to user requirements and algal
growth conditions:
Measuring color – 455 (470, respectively) nm
Flash pulse 30% = Measuring flash pulse
Super pulse 70% = Saturating pulse
Actinic pulse 300 µmol.m -2 .s -1 (30 %) = Actinic light
Please note that those parameters are recommended by manufacturer and can be change according to user
needs.
Setting of optimal intensities of pulses:
Flash pulse setting
The optimum value of Flash pulse can be identified during QY measurement as shown in Fig. 5 below. Before performing QY measurement
it is recommended to set the pulse color according to culture used (blue for algae and red for cyanobacteria) and intensity of Super pulse
to 70 %.
Please note that QY measurement should be performed with dark adapted suspension. following the first exposure to flash pulse (during
QY measurement) the sample may be inhibited and it is recommended to use a new dark-adapted sample for future measurements or
allow sufficient time to re-adapt the sample in the dark.
F
0
increases linearly with growing intensity of the Flash pulse.
The Flash pulse setting recommended by manufacturer is 30%. This intensity of Flash pulse may be increased if the culture is very dilute.
Please note that high intensities of Flash pulse can cause undesirable “actinic effect” as a result of initiated photochemist ry. These effects
may lower F
0
and the QY values.
The optimal Flash pulse intensity is that at which the highest value of QY is reached. This can be determined by measuring QY at different
flash pulse intensities using fresh dark-adapted suspensions of the same culture (Fig. 5). In this example the optimal flash pulse setting is
30%.
Fig. 5 QY measurement performed with different intensities of Flash pulse. Optimal setting is highlighted in red rectangle.