Fluorescence Measurement Techniques

Chlorophyll fluorometers are constructed such that the immediate outcomes of the measurements provide information on quantum yields (Y) of electrons passing through photosystem II (PSII). If the photosynthetically active radiation (PAR) absorbed by PSII (PARa) is known, then photosynthetic rates can be calculated as electron transport rates (ETR). If only the incident irradiance (PARi) is known (which often is the case), then relative ETRs (rETR) can be calculated as the product of Y and PARi. There are sometimes easy ways to at least estimate PARa, and they will be described in this chapter, as will other practical means to measure photosynthetic parameters using fluorometry.