CHAPTER 12 MEASUREMENTS WITH THE MINI-PAM
Fig. 10:
On the basis of these considerations so-called 'quenching
coefficients' qP and qN were defined, which can be determined by
simple fluorescence measurements (see 12.3.6). For qP- and qN-
determination it is necessary to define the extremes of maximal and
minimal fluorescence yield, which are given in the dark-adapted state
(see 12.3.4). However, quenching analysis is not restricted to qP- and
qN-determination and very relevant information can be also obtained
without previous dark-adaptation of the samples. This is an important
point for field investigations, for which the MINI-PAM was
optimized.
In recent years, evidence from a number of research groups has
shown that the overall quantum yield of photochemical energy
conversion can be assessed by the simple expression:
YIELD = (Fm'-F)/Fm' = ∆F/Fm'
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