Dear Ajay,

many instruments are available for measuring chlorophyll fluorescence on light-adapted photosynthesizing organs. Basically, they use a modulated measuring light for chlorophyll excitation and record the photons that are emitted at higher wavelengths with the same modulation. Such instruments are generally very expensive, but MultispeQ (see https://www.photosynq.com/multispeq) represents a cheaper yet technically complete and affordable choice. It measures, among others, the most relevant indexes of operating efficiency of photosynthesis, energy dissipation processes and provides estimations of electron flow and carbon fixation rates, all parameters that describe and quantify the effective operation of the photosynthetic process.

Hope this will help you.

Best wishes,

Carlo

Yes it is common to use light adapted protocol as well. You will have the estimates of PhiPSII and Fv/Fm under light. However, you will not be able to measure non-photochemical quenching.