Maintaining Measuring Intensity with the 6400-40 Fluorometer
Researchers are often interested in fluorescence parameters that require measurements on both dark- and light-adapted leaves. One such trait is non-photochemical quenching (qN or NPQ), which is calculated as a function of both Fm (dark-adapted maximum fluorescence) and Fm’ (non-zero actinic steady-state maximum fluorescence). There is often confusion over which settings need to be held constant between dark- and light-adapted measurements in order to accurately calculate these parameters.
The best technique for dark-adapting leaves is to place them in complete…