tested it today
Kudos to Mistergreen and O2surplus, and others who have contributed, for all the wonderful work put into making this device!
I finally got some time to test it this weekend on some of my fixtures.
On my 2x24 watt 24" T5HO Nova Extreme with 2 year bulbs, measured in air , I got the following PAR values:
8" from light => 150
15" from light => 50
Tried to measure in water, but notice some water in the diode cup.
Now meter is off line until cup is made air tight.