Choosing the good grow lighter for your adeptness is essential to develop goodly plants and getting a maximum recurrence from your investing . One of the most challenging issues that growers concerned in buy horticultural lights face when researching horticultural kindling is interpreting and understanding the many terms and metrics that are used to measure and describe the brightness level that the horticultural inflammation organization emits .

When researching about light spectrum and plant lighting efficacy you have probably come across PPF , PPFD , PPE , PAR and Lumens . Below is a list and explanation of the most common terms used :

Plants and humans do not perceive light in the same means . The human eye comprehend green brightness level as brightest whereas plant life apply mostly blue and red twinkle . Lumen is a unit of lucent fluxion that relates to the brightness of lighter visible to the human oculus . Luminous fluxion is calculated by weight ( multiplying ) the apparitional distribution of quantity of visible light by economic value representing human centre sensitivity to finicky wavelengths . For this reason , a clear source having a mellow lm value may not always be suitable for growing plants . Lumens are colligate to lux in that one lux is one lumen per square meter .

PAR‍(Photosynthetically Active Radiation ) is a region of the luminosity spectrum ( 400 to 700 nm ) that plants utilize for the procedure of photosynthesis . PAR is not a measuring or metric but delimitate the cooking stove of light needed to support photosynthesis .

Plant and human response to light

PPF(Photosynthetic Photon Flux ) is a measure of the entire amount of igniter within PAR that a light author give out each 2nd . The social unit used to express PPF is micromoles of photons per second ( µmol / s ) .

PPF is an authoritative metric for count how efficient a lamp is at convert electrical energy into photons of PAR . withal , it is of essence to note that PPF does not tell you how much of the measured lighting really arrives at the works canopy . PPF measurements used to describe light sources should be done in specialized calorie-free laboratories using appropriate equipment such as light sensors connect to integrating spheres or goniometers . One recommended means is to practice a light fellowship that uses third - party examination .

PPFD‍(Photosynthetic Photon Flux Density ) assess the amount of light source within PAR that actually falls on a given aerofoil ( the industrial plant canopy surface area ) each second . The unit used to show PPFD is micromoles of photons per straight meter per second ( µmol / m2 / s ) . This mensuration is done using a specialised tool called PAR Light Meter or a properly calibrated spectrometer , which captures , and measures photon pass off by a light root .

It is important for grower using LED grow luminosity to use the right measurement legal instrument as there are some that are not truly compatible with LEDs and could give a false PAR range . This is because some sensor are calibrated to mensurate luminous power or do not beguile the full red in LED light .

PPE‍(Photosynthetic Photon Efficacy ) is the PAR photon output of a light source ( assess in micromoles per bit or µmol / s ) separate by the comment baron ( Watt ) to produce that brightness level .

PPE does not include the photons outside the PAR range . wavelength outside of the PAR range like far - crimson ( FR ) have proven to have a positivist effect on growth and steer morphologic response of plants . The efficacy of light contain FR is low than the efficaciousness of light source let out only blue and cherry light when measured as PAR photons per wall - plug energy consumption , even if they may give expert results in plant biomass yield and healthy growth .

appraise and interpreting the total production of a lamp is a foxy thing . It is important to understand that light follows some mere geometric convention . The PPFD decreases with the distance from a lamp while the footprint increases , so it is important to regard the size of it of the illuminated area ( light footprint ) and how consistent the lite distribution is over this region . You should always quest a scant architectural plan for your grow facility before buy lights .

Many LED luminosity are not outfit with optics design to distribute light uniformly . Measuring the turnout of light at a exclusive decimal point can bring out fictitious information about its actual output . Therefore , it is advisable to measure short chroma at many item of an lit sphere .

Since you are evaluating grow lights and light spectrum on plants , you desire to make certain that the lighting manufacturers you are working with are knowledgeable on horticultural firing and can provide you fair to middling information about light end product , efficacy , spectral lineament and uniformity in units that are relevant for plants . you’re able to find Heliospectra ’s promiscuous characteristics and metrics list on our Cartesian product specification sail .

The metric we have discussed above focus on photon output but not light quality and efficiency of flora production . It is significant that you also regard the light-headed requisite or light pauperization of your specific crop . You desire your lamps to deliver photon that are efficiently engage by your plants and enable them to grow well and achieve your desire timber .