Micromole μmol/s (micromole) is the unit in which P.A.R. is expressed. This unit indicates how many micromoles per second a light source emits. μmol/s is one-millionth of a mol (10−6 mol).
Photosynthetic photon flux (PPF)
PPF stands for photosynthetic photon flux. This measures the total amount of P.A.R. produced by a light source per second. The PPF is also expressed in the unit μmol/s (micromole per second).
Photosynthetic photon flux density (PPFD)
PPFD stands for photosynthetic photon flux density which signifies how much PAR ends up on the crop. The closer the light source is to the crop, the higher the PPFD will be. The distance from the light source to the crop determines; homogeneity, light intensity and light pollution. The ideal recipe differs per situation and is tailor-made. We’re happy to help you to realize a suitable plan. PPFD is expressed in the unit μmol / s (micromole per second).
William buys a lamp with an output of 2000 PPF. This means that William’s lamp emits 2000 μmol/s (micromoles per second). The distance from the lamp to the crop is 3 meters. Williamm can measure his PPFD with a PAR sensor. He measures that 100 μmol/s (micromoles per second) is on his crop.