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Wazzel
12/17/2014, 06:33 AM
Has anyone taken the time to test how an LED fixtures power relates to par? I think that can be useful information for LED users.

Guess I should step up I have a LED fixture and a Par meter (that I have never used). When my meter gets back from its current rental I will do the AI Hydra52 and post some results.

sirreal63
12/17/2014, 07:28 AM
I have seen people post up par numbers at different percentages of power but I think you should do it, the more information posted the better it is.

Wazzel
12/17/2014, 07:34 AM
I will when I get my meter back.

alton
12/17/2014, 01:06 PM
When you use leds you actually need two meters PAR and Foot Candle/Lux meter. When checking Metal Halide there is about 20 to 25% difference in the two. With some Leds it is very close to metal halide lamps. But I have seen some Led fixtures 2000% difference which is why some leds burn corals, not too much Par but too much intensity. One of my favorite examples is a Marineland reef capable LED. I had it on a 40 gallon breeder and I had a green birds nest six inches away from one of the leds and it fried the coral. So I checked it with both meters; at the top the Par reading was 200 with 100 on the bottom. With my foot candle meter at the top it was 4,000 foot candles which is equal to 400w DE MH.

Wazzel
12/17/2014, 01:47 PM
Well I do not own a Lux meter. Do you recommend a particular one? Does apogee make one?

I think knowing how par and fixture power are related could help people set their lights with out have to have a meter of any kind.

alton
12/17/2014, 03:04 PM
Well I do not own a Lux meter. Do you recommend a particular one? Does apogee make one?

I think knowing how par and fixture power are related could help people set their lights with out have to have a meter of any kind.

I have it at home so I don't remember the brand name but most are $100 or less. I will check tonight, I picked it up at an Electrical Supply house

rishu_pepper
12/17/2014, 03:21 PM
Tagging along, Wazzel's info has been invaluable for my Hydra 52s. Please let us know the results when you have the readings :)

Reefvet
12/17/2014, 03:23 PM
Has anyone taken the time to test how an LED fixtures power relates to par? I think that can be useful information for LED users.

Tuff to do with the PAR meter not reading all LEDs the same.

Apogee instruments offers some correction info here (http://www.apogeeinstruments.com/light-intensity-measurements-for-light-emitting-diodes-leds/).

Wazzel
12/17/2014, 05:47 PM
Yup. Knew about the correction factor need to work out the test procedure.