That's correct, assuming the lumens scale up and down evenly at different currents, which this strip apparently does. Regarding the other calculations, I thought the wattage was implied in the luminous efficacy number. If I take total luminous flux and multiply it by watts and plug that into a PPF calculator, I'm still getting the same numbers as when I calculate the other way. Guess I'm missing something here.
These PPF values are completely dependent on how far the meter is from the light, and as such they are not very valuable alone. Like you said the Gavita DE 1000 is 2100 PPF. But if I'm trying to replace my DE 1000 am I supposed to take that data and match it to an LED. The only relevant data is how much micromoles / s of photon energy are hitting my plants, all of them not just the ones in the middle. But that information seems to be harder to come by without a meter.
The problem is that the calculator is asking for efficiency in micromoles / joule, and all I have to work with is lumens / watt. It says to take the value for micromoles / j and multiply it by the wattage to get the PPF. If I instead use the number for lm / w and multiply it by watts the number is way too large.
You must be. I think you have to take into account the max current the driver can put out because otherwise you'd have a potentially infinite ppfd based on the number of strips the user chooses to use based on your equation surely?
PPF output of a fixture is constant. When it's on, that's how 'much' light it can generate.
Which strips are you trying to figure out efficacy in μmol/joule for? The 2ft. EB Gen 3 3000k 90 CRI strips?
Well, there's probably a good reason I'm not an electrical engineer. Here's another calculator. Samsung F L09 have a typical luminous flux of 8670. If I input 8600 and choose high cri 3000k led, I get 163.64 umol/s, which is right in the ballpark of the 168 lm/w quoted on the Samsung data sheet. If I multiply umol/s or lm/w by the number of strips and input it into the other calculator, I'm getting reasonable PPFD numbers. I thought this method was sound, but maybe not.
I'm only a beginner myself mate, but it just doesn't make sense that the ppfd goes up infinitely based on the number of strips. I think power has to factor into the equation then see what you get out. Pretty sure that's the bit missing from the calculation.
Can you source those?
1 watt=1 joule/sec umoles/watt is luminous efficacy.
So 168 lm/w x 51.5 watts x 3000? That's a PPF of over 25 million. Maybe I should give up on math and just grow weed.
Okay that makes sense. I should have been multiplying luminous efficacy x watts first. Thank you.
The article doesn't state how to convert lumens/w to umoles/joules.
According to this I would get