Figure 1.

Schematic representation showing the experimental setting of Li-cor 6400 together with Dual-PAM-100, through a chamber holding on the emitter-detector system of the PAM, for controlling CO₂ level (390 or 2,000 μl L^{− 1}) and using an oxygen source equipped with an oxymeter to adjust oxygen flux from the appropriate O2 source (2 or 21%) to the chamber and accordingly be able to monitor the CO₂ and O₂ concentrations in the chamber during measurements. (A) Close chamber; (B) Open chamber and (C) Setting of Li-cor 6400 together with Dual-PAM-100 to control the gas concentration (O₂ and CO₂) in the newly designed chamber. See also video for setting. IRGA and PAM mean infrared gas analyzer and pulse amplitude modulation, respectively.