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Old 06/08/2005, 06:59 AM
Sanjay Sanjay is offline
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Join Date: Nov 2000
Location: State College, PA
Posts: 1,706
Quote:
Originally posted by KH971
Sanjay, thanks for all of your time and efforts, could you explain what PPFD means ? I am not aware of the meaning?

Thanks Keith

I just recieved my 400 SE XM15k's
love the color but i am awaiting the PAR figures, I doubt they will be good. I also run Icecap elec. ballast.
Keith:

PPFD - Photosynthetic Photon Flux Density
It is basically the count of number of photons falling on a given area (usually 1 meter square) in one second. It is measured in the units of micromoles/m^2/sec. 1 micromole = 10^17 photons.

PAR - photsynthetically available radiation is technically measured as PPFD, hence used interchangeable with PPFD.

sanjay.