Reality check: 4 T8s=6000 fc?
I just got a light meter today and at six inches under my bank of 4 T8s it gives a reading of 6000fc--or at least I think it does. Is that even remotely possible?
Unless I am missing something (and I do that from time to time), the meter has two levels, one for sun and HID (or just higher levels) and one for fluorescents, (or just lower levels). One takes up where the other leaves off. The fluorescent (lower) gauge is calibrated up to 10 X 100. I put it six inches beneath my bank of lights and the needle springs off the chart--but there is no way to read whether it is 1500 fc, 2000 fc, 2500 fc--just more than 1000 fc. If I flick the switch from fluorescent to sun/HID it reads 1000 x 6, or 6000 fc--an unbelievable reading for a bank of 4 T8s, right? They are on for 16 hrs a day and my phals would be dust by now at those levels, wouldn't they?
So which is more wrong here, me or the meter? The meter is supposed to be accurate with 2%. Is it really possible my 4 T8s really are giving off 6000 fc of light? I might think 2000-2500 max. Or is the meter likely incorrect and I have grounds to return the meter and buy another one. What test can I use?
I notice in the highly recommended Hydrofarm meter you have a similar setup, two scales calibrated for low end and high end light. I suppose I could buy one of those at $25 or so and compare and still not be out a load of money...
I don't know what to do...
Maybe my meter is giving a perfectly good reading (hard to believe as it is), but how can I tell? And if I got the Hydrofarm meter (or any other meter for that matter) and the readings differed, how would I know which one was correct? I guess I'm asking "What is truth?" or at least "Where can I find it?"
Frustrated Charlie
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