2.6 Setting of PAM together with Infrared gas analyzer to control CO2 and O2 supply
A special chamber was custom-designed and developed to enable precise control of CO2 and O2 environments. This chamber was tightly mounted on the detector-emitter of the Dual-PAM-100 fluorimeter which was connected through a hole to the Li-COR 6400 portable infrared gas analyzer to control CO2 supplies (390 or 2000 μL L-1) by Li-cor and via another window to an oxygen source equipped with an oxymeter to adjust the flow of oxygen from the source to the chamber. Oxygen sources with different concentrations (e.g. 2 and 21% as used in this study) are supplied by a gases distribution station (GDS). The setting for experiments using different levels of CO2 and O2 was as depicted in Figure 1 and video in supplemental data.