Par readings

Manfromthenorth

Well-Known Member
I was once told I could break an anvil with a rubber hammer lol I'm trying to shy away from that though. Yeah for sure man I think she is gonna put out enough x12 of them auta grow some reefer. :weed:
 

Manfromthenorth

Well-Known Member
Hey did you guys know that you can use a multi meter to find a bad chip or a backwards chip in a searies circuit? Some how it lights the cobs up but there real dim and if you got one in backwards it won't light the circuit. If you can't understand what I'm talking about I can make a short vid.
 

Goerilla

Member
Hey did you guys know that you can use a multi meter to find a bad chip or a backwards chip in a searies circuit? Some how it lights the cobs up but there real dim and if you got one in backwards it won't light the circuit. If you can't understand what I'm talking about I can make a short vid.
You don´t need a multimeter for that, a piece of wire will do the trick.

Rilla.
 

CobKits

Well-Known Member
How much umols gives 1212 3000K 80CRI at 1.05A? At 30 or 40 cm.
@CobKits
heres a test from last year, at 12" from gen5 3000k 80 1212 cob, no reflector, on mecha 111x80 heatsink at steady state. numbers which by themselves are basically useless imo but have at it

upload_2017-4-26_17-57-31.png
 

KonopCh

Well-Known Member
heres a test from last year, at 12" from gen5 3000k 80 1212 cob, no reflector, on mecha 111x80 heatsink at steady state. numbers which by themselves are basically useless imo but have at it

View attachment 3931763
Why useless?
I don't have PAR meter, so this is some approximation I guess.
I have 6x1212 at 1.05A and 1x CXB3590 at 1.8A in 80x80 tent. PPFD is around 800-1000 but...distance, distance...
 

CobKits

Well-Known Member
Why useless?
because that is the equivalent of a light in a black hole with no reflector, no reflective surfaces around it, and no other additive light sources from adjacent fixtures. it doesnt at all represent what you would measure in a room, it was a test done in an open space for comparative purposes only. with adjacent lights at 12"/30cm spacing in a good reflective tent or closet and you could expect double that reading or more.

.distance, distance...
get yourself a tent and you'll never worry about distance again, the higher the better in most cases, and if not, you dont have enough wattage to begin with IMO
 

KonopCh

Well-Known Member
because that is the equivalent of a light in a black hole with no reflector, no reflective surfaces around it, and no other additive light sources from adjacent fixtures. it doesnt at all represent what you would measure in a room, it was a test done in an open space for comparative purposes only. with adjacent lights at 12"/30cm spacing in a good reflective tent or closet and you could expect double that reading or more.


get yourself a tent and you'll never worry about distance again, the higher the better in most cases, and if not, you dont have enough wattage to begin with IMO
I have reflective walls in my tent. Also 280W COBs in 80x80cm tent I think is more than enough. This gives me more than 800 PPFD.
I just don't understand... light gets "lost" when traveling to the sides of the tent and then bouncing back to plants. So direct measurment under COB is better, but you said it is not.

Higher the better? Then only top of plants get 800-1000 PPFD, 100cm lower on plant ... well, popcorn?
 

CobKits

Well-Known Member
I just don't understand... light gets "lost" when traveling to the sides of the tent and then bouncing back to plants.
only a portion of it, like 10%

Higher the better? Then only top of plants get 800-1000 PPFD, 100cm lower on plant ... well, popcorn?

its actually the opposite. if you have say 280W and your cobs are at 12" and you are reading 800 ppfd at the top of canopy it wont be very deep.

if you have say 400W and you have to raise your cobs be at 24" to reduce the canopy ppfd to 800, youre going to have a lot better penetration at lower canopy as the ratio of the distance from lightsource to top of canopy to distance from lightsource to bottom of canopy is less
 

CobKits

Well-Known Member
my current 3x3 tent has an ELG240-48A running 9 cobs at 27W each. i think im going to swap it for an hlg 320-48A and bump them up to 43W/cob

50% more light and only 5% less efficient. a little too much light but the heatsinks can handle it and i can always dim
 

KonopCh

Well-Known Member
only a portion of it, like 10%




its actually the opposite. if you have say 280W and your cobs are at 12" and you are reading 800 ppfd at the top of canopy it wont be very deep.

if you have say 400W and you have to raise your cobs be at 24" to reduce the canopy ppfd to 800, youre going to have a lot better penetration at lower canopy as the ratio of the distance from lightsource to top of canopy to distance from lightsource to bottom of canopy is less
I don't understand this.
If 280W COBs are 30-40cm from canopy and gives 800-900 umoles... or 480W COBs are 60cm from canopy and gives 800-900 umoles... Is the same? First option is closer to canopy if they're driven softer than option 2.... ?
 

CobKits

Well-Known Member
I don't understand this.
If 280W COBs are 30-40cm from canopy and gives 800-900 umoles... or 480W COBs are 60cm from canopy and gives 800-900 umoles... Is the same? First option is closer to canopy if they're driven softer than option 2.... ?
second will deliver a lot more light to lower canopy
 
Top