AquaPen-C & AquaPen-P
is a lightweight hand-held PAM fluorometer that is convenient for quick, reliable and easily repeatable measurements of photosynthetic parameters in both algal and cyanobacterial suspensions. The AquaPen-C is equipped with blue and red LEDs, optically filtered, and precisely focused, to deliver light intensities of up to 3,000 µmol.m-2.s-1 to suspensions. Blue excitation light is used for chlorophyll excitation in algal cultures. Red-orange excitation light is used for excitation through phycobilins, and is more suitable for use with cyanobacterial cultures. The AquaPen-P is equipped with a single blue LED emitter (optionally red or white).