Measuring Chlorophyll Fluorescence with the CFM
CIRAS-2 Operator's Manual Version 2.04
- 97 -
For New Customers:
The software will already be installed on the User Interface. A back-up copy of the software is also
available on the PCMCIA card also supplied. For remote operation from a PC, you must load the
appropriate software to your PC.
For Existing Customers (Upgrades):
You must first uninstall the software on both the User Interface and the external PC (Add/Remove
Programs) before loading the new software. After successful removal of the previous version software,
proceed to install the new software per the instructions supplied.
Power Requirements
The entire system is powered by the CIRAS-2 internal 12V NiMH batteries through the connection to the
leaf cuvette. The peak current is several amps which is drawn only for short periods (i.e light saturation
pulses). Normally, the CFM draws about 100 mA which will have a minimal impact on the life of the
internal batteries. If desired, the leaf cuvette can be connected to an external battery (or 12V, regulated
power supply in the lab) using the external power supply cable (red & black leads) supplied with the
cuvette as standard.
Warning. For connection to an external battery or power supply, make sure that
you properly connect the red lead to the Positive (+) terminal and the black lead
to Negative (-) terminal.
Leaf Cuvette Window
The leaf cuvette is normally supplied with a window (CALFLEX) that reflects most of the incident IR
radiation to minimize the heat load on the leaf. However, this window will not transmit at the fluorescence
wavelength. Therefore, each CFM is supplied with a plain glass window which must be fitted to the
cuvette in place of the CALFLEX window. If you have received a complete new CIRAS system including
the CFM, the plain glass will already be fitted to the leaf cuvette.
If you have upgraded to the CFM, you
must make sure that you replace the CALFLEX window with the plain glass window if you plan on
making simultaneous gas exchange and fluorescence measurements.
Once the glass window is fitted, it is assumed that the LED light unit will always be used with the leaf
cuvette. This is not a problem as the LED light unit does not output any near IR. However, if a different
light unit (i.e. quartz halogen) is used or gas exchange measurements are made under sunlight
conditions, you must remove the glass window and refit the CALFLEX window to the leaf cuvette.
The table in Appendix 1.,
CIRAS-2 Settings for Leaf Cuvettes and Probes
, illustrates the TRANS factors
used by CIRAS-2 based on the light unit and cuvette window used for converting PAR (µmol
m
-2
s
-1
) to energy (Wm
-2
) absorbed by the leaf. These values are set by default depending on hardware
settings (i.e. leaf cuvette type, light unit, etc.) set up in the
Parameters Editor Dialog
. The default
TRANS value for the LED light unit (with CFM) is 0.14 for both the CALFLEX and plain glass window.
Note, if using our other style light units (i.e. quartz halogen) or sun/sky, please refer to the CIRAS-2
Operation Manual for further information on TRANS factors.
Replacing Cuvette Window
Place the leaf cuvette down on a soft flat surface. Using a No. 1 Posi screwdriver, carefully remove the 4
screws on the window plate. Remove the plate and store it carefully for later use. Next, put a slight smear
of silicone grease around the edge of the replacement window plate, secure it in place and secure it to the
leaf cuvette by uniformly tightening the 4 retaining screws.