it gives the µmole/s but no distance. So that measurement is probably at the surface of the bulb
Gavitas can be made to run vert...you just have to rig it yourself which is never as good as factory shit(most of the time).
I have emailed with gavita pretty indepth.
Starts at post 214 if this link doesn't go straight there.
https://www.rollitup.org/led-other-lighting/676858-tags-high-efficiency-lighting-garden-22.html
Gavita shows
PPF(photosynthetic photon flux)...which is all the light put out by the lamp...this is measure in an integral sphere, where the bulb hangs in the middle about 24" from the walls of the sphere, but this distance really isn't too important...as long as the source isn't too big compared to the sphere's area(there is a rule they use to determine what size sphere for what size light source.). The whole inside is the meter basically. This will tell you how much light is available...but because sit is measure from every direction, it will not exactly show what will be hitting your canopy. Things like reflectors, glass/noglass, hanging height are all factors to how all that PPF horse power will get to the wheels(your canopy).
The readings that hyroot is talking about are
PPFD(photosynthetic photon flux DENSITY) readings...meaning they are reading the µmol density for that point in space where the meter is. These takes into account any reflection or other rings outside just the bulbs stats. This will tell you how well the light is actually getting to your canopy.
Both numbers are important and good to look at. PPFD is what we are trying to maximize in the end...but all over the canopy not just center. PPF will show you that there is no way that a light can cover what they say it will if it is wasting all it's possible light(ppf) in the center to make one high PPFD reading(what many led's have done for years).
A lot of PPF spread over the whole area(many good PPFD readings all over canopy)=great light
