Light meters PAR - PUR - PPF - PPFD

[Dxpert]

I was doing some reading / research and came across theses two video's that I beleive some folks will find useful. Have a watch.

https://youtu.be/6hUkufXBb3I
https://youtu.be/Pc_tqLYhITA I found the ~15 minute mark the best. But the whole video is fantastic.