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Revision as of 20:45, 23 January 2022

57 bytes added ,  23 January 2022
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The measure of photons per second produced by a light. Photons are measured in micro (10^-6) [https://en.wikipedia.org/wiki/Mole_(unit) moles] there are a huge amount of photons coming from any light source. One µmol is actually 602 quadrillion photons. Simply put, this metric is the intensity per second from a light.
=== PPFD ===
Photosynthetic Photon Flux Density: its unit is μmol/m^2/s. It is a measure of light[[Light#PAR|PAR]] intensity (light that can be used for photosynthesis) over an area per second. This is important to note when buying a grow light. For example, light A may provide an intensity of 800 μmol/s in a 1m^2 area, while light B provides the same intensity in a 4m^2 area. Light B provides the same intensity but over four times the area, so it can support a larger plant. In this case, light B has a greater PPFD.
 
=== μmol/J ===
The light intensity a horticultural light produces per Joule of power it uses. This is a measure of its efficiency. At the time of writing, the most efficient LED package available is the [https://www.samsung.com/led/lighting/mid-power-leds/3030-leds/lm301h/ LM301H] by Samsung. It achieves 3.10 μmol/J @ 65 mA, 25°C. Note the efficiency will change depending on the temperature and current supplied.
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