TARGAS-1 Operation Manual V. 1.02 89 support@ppsystems.com
• the leaf is exposed on both upper and lower leaf surfaces
• the upper and lower boundary layer resistances are similar
• stomata are evenly distributed on both upper and lower leaf surfaces.
Definition of Symbols and Physical Constants Used in Equations
Measured Parameters
Flow rate of dry air into cuvette at STP
Boundary layer resistance to water vapor
Photon flux density incident on cuvette
Calculated Parameters
Mass flow of air per unit leaf area into cuvette
Partial pressure of water vapor of air entering cuvette = H
2
Partial pressure of water vapor of stirred cuvette air = H
2
Saturated vapor pressure (inside the leaf) at leaf temperature
Temperature difference between the air and the leaf
Radiation absorbed by the leaf
Stomatal resistance to water vapor
Stomatal conductance to water vapor
2
concentration of air entering cuvette = CO
2
2
concentration of air inside and exiting the cuvette = CO
2
2
Assimilation rate (net photosynthesis)
2
2
2
concentration of sub-stomatal cavity