CI-340 Operation Manual
CID Bio-Science
1554 NE 3
rd
Ave
Camas, WA 98607, USA
Phone: +1 (360) 833-8835
Fax: +1 (360) 833-1914
[email protected]
www.cid-inc.com
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In open systems, ambient air is taken in through the intake on the instrument. The ambient air
is then added into the leaf chamber after having the mole fraction or concentration of CO
2
and H
2
O
measured (Figure 4). The air is measured again after passing over the leaf surface at a known flow rate,
and the photosynthesis rate is calculated according to equation found in the Equations section of the
manual as are the transpiration rate and stomatal conductance.
In a closed system, the air is not renewed during the measurement. The closed system mode
recirculates air within the analyzer environment and leaf chamber, as seen the upper portion of Figure
4. The CO
2
concentration in the chamber is decreased by leaf photosynthetic activity, while the H
2
O
concentration increases. The change in CO
2
and H
2
O concentrations per unit of time are correlated with
net photosynthesis (assimilation) and transpiration, respectively.
The leaf chambers for closed system measurements are specially designed to help calculate the
volume of air inside the chamber (versus the area of leaf surface needed for open system calculations).
Figure 4: The top illustrates a closed system set up, with tubing connecting the intake and exhaust. The bottom
illustrates an open system set up, with a filter attached to the intake and the exhaust remaining free allowing air to be
renewed in the leaf chamber during measurement.
There are several different leaf chambers available for use with leaves and plants, as seen in
Figure 5. Each individual chamber is designed to interchange with the CI-340; however, they serve
different sizes of the plant element. There are five available sizes of leaf chambers to conduct
experiments for the open system method (Table 2). The closed system environment deals with
chambers of variable volume. There are four available sizes of leaf chambers to conduct experiments
for the closed system method (Table 3).
Summary of Contents for CI-340
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