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CobKits

CobKits

Well-Known Member
now i understand how spheres work (its all in the instruments, a sphere is a sphere and if its reasonably round and has the right coating and baffles, it will work, they all vary and are calibrate-able for absolute measurements).

so im gonna build a 2 meter one (well 6 feet at least)

start with one of these:
http://www.ebay.com/itm/181934445396?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT

-lay up several layers of vinyl ester fiberglass on the outside and reinforce as needed
-build flanges for it (i have a cnc now with 32x64" table so i should be able to do that in 3 sections)
-build hinges
-coat the inside with this : http://pro-lite.co.uk/File/barium_sulphate_coating.php

and ive got all the tools (li-cor par meter, ocean optics spectrometer, ocean optics tungsten calibration lamp) so i should be able to get damn close. when i can do a test and send it out to 2 other labs and get same results it will prove valid

then we can test cobs vs quantums vs arctubes vs heatsinks with different colors, etc etc
 
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CobKits

CobKits

Well-Known Member
BuddyColas said:
You really back your products.
Click to expand...
well im just an efficiency dork like y'all

i select the best products i can so its not really fluff for those but really with the constant barrage of new products its whats necessary to stay on top of it

ive nearly given up on blindly trusting datasheets good for scoping but need field confirmation. according to datasheet vero22C was supposed to be right there with vero29B. i havent put the vero 29 B in the sphere yet but im hoping for a $25 chip it tests higher than the V22 did
upload_2017-4-11_14-11-18.png

upload_2017-4-11_14-13-49.png





CLM was supposed to be right there with CXM22 and looked like a great 36V option. do the above results in my graph look anything like this:

upload_2017-4-11_14-4-51.png

also apart from data within a mfr's stable being bunk theres no parity

vero22C claims 169 lm/W @ 50W, Tc 45, Tj 48
cxm22 claims 162 lm/W @ 50W, Tj 48 (that above chart was 55Tj)
clm22 claims 161 lm/W @ 50W, Tj 48
cree PCT claims 177 lm/W @ 50W, Tj 48:

upload_2017-4-11_14-25-34.png

citi 1818 is about 165 lm/W in that spot

theres just no equivalence at all between manufacturers despite their claims to standardized measurement methods. cxm22 seems to be the most under-spec'd, and CXB3590 seem to be the most over-spec'd consistently
 
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CobKits

CobKits

Well-Known Member
well on an absolute basis... but 0-100 scale is completely arbitrary. 5-7% spread relatively. that said cob tech is really consistent and if you graphed 5 different hps bulbs youd prob see a similar spread (but much lower on the chart lol)
 
Abiqua

Abiqua

Well-Known Member
CobKits said:
i will be shooting all the spectrums i can, but not necessarily doing comparative output tests on all these. Spectrum is absolute, unlike relative output, so i hope to get us a good catalog of SPDs to work with

the only downside is that with the intensity in the sphere it saturates my meter, so ive been shooting them at low wattage (200 mA on 50V chips and 300 mA on 36V chips - those are the points that fall right about on the 10W mark in the graph. i know that spectrum can shift with temperature as well as current, id love to hear some suggestions on if i can improve this @Rahz @Malocan @Abiqua. For now im just trying to keep it somewhat standard and not saturate my meter and get goofy results

particularly as we get into 90 cri chips. how do we reconcile the overall PAR measurement that will be lower by the steeply filtered Li-Cor discarding the wavelengths above 700? is there some correction factor that needs to be derived to get a more accurate QER/YPF?
Click to expand...
i think you may be able to adjust the dwell time of the sensor as well.....
 
frica

frica

Well-Known Member
CobKits said:
well im just an efficiency dork like y'all

i select the best products i can so its not really fluff for those but really with the constant barrage of new products its whats necessary to stay on top of it

ive nearly given up on blindly trusting datasheets good for scoping but need field confirmation. according to datasheet vero22C was supposed to be right there with vero29B. i havent put the vero 29 B in the sphere yet but im hoping for a $25 chip it tests higher than the V22 did
Click to expand...
How much does a sphere measurement cost?
 
sixstring2112

sixstring2112

Well-Known Member
CobKits said:
now i understand how spheres work (its all in the instruments, a sphere is a sphere and if its reasonably round and has the right coating and baffles, it will work, they all vary and are calibrate-able for absolute measurements).

so im gonna build a 2 meter one (well 6 feet at least)

start with one of these:
http://www.ebay.com/itm/181934445396?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT

-lay up several layers of vinyl ester fiberglass on the outside and reinforce as needed
-build flanges for it (i have a cnc now with 32x64" table so i should be able to do that in 3 sections)
-build hinges
-coat the inside with this : http://pro-lite.co.uk/File/barium_sulphate_coating.php

and ive got all the tools (li-cor par meter, ocean optics spectrometer, ocean optics tungsten calibration lamp) so i should be able to get damn close. when i can do a test and send it out to 2 other labs and get same results it will prove valid

then we can test cobs vs quantums vs arctubes vs heatsinks with different colors, etc etc
Click to expand...
So i wasn't too far off when i said you should buy a basketball and paint it white inside and mount the licor in that sucker (:
 
s0p3rsa1yan

s0p3rsa1yan

Active Member
@CobKits maybe you could help me with something..
Want to buy some new leds and drivers. My only leds im using at the moment are the CXA3070.
Because im not in the US, shipping and custom cost for something heavy as heatsinks will cost me quite a bit.
So its best i will by a few leds and run them high. So i will need a few leds(and heatsinks) to cover a certain space.
I was thinking i should buy the CLU058-1825
In what Watt you recommend running them?
And which Driver to go along with that?

I dont want to run them too high and have them as efficient as HPS, but not too low so i would need alot of them.
My space is 1.2X2 meter.
 
frica

frica

Well-Known Member
CobKits said:
You guys are too kind, im just paying forward what i learned here


i have my own but the big light labs charge a few hundred bucks per measurement
Click to expand...
Could you test a Philips bulb once? Or is it too much a pain in the ass to set up things for just a cheap bulb?
Those Philips 2700K 100W equiv ones you can get from homedepot are supposed to deliver 103 lm/w.

I think that should be about 36-38% efficient.(PPF should be around 22)
But I'm really curious how efficient the light will be once the diffuser/bulb part is cut off.
I think it should be at least 40%, but it could be more.(PPF 24-25.)

But am wondering.

It's impossible to compare the total output the normal way with just a light meter in the growbox because of the diffuser.
But with a sphere it should be relatively trivial.


A bulb test could be a really nice thing for the microgrow community.
 
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pop22

pop22

Well-Known Member
Build your own sphere....... now that's hardcore! I love it!

CobKits said:
now i understand how spheres work (its all in the instruments, a sphere is a sphere and if its reasonably round and has the right coating and baffles, it will work, they all vary and are calibrate-able for absolute measurements).

so im gonna build a 2 meter one (well 6 feet at least)

start with one of these:
http://www.ebay.com/itm/181934445396?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT

-lay up several layers of vinyl ester fiberglass on the outside and reinforce as needed
-build flanges for it (i have a cnc now with 32x64" table so i should be able to do that in 3 sections)
-build hinges
-coat the inside with this : http://pro-lite.co.uk/File/barium_sulphate_coating.php

and ive got all the tools (li-cor par meter, ocean optics spectrometer, ocean optics tungsten calibration lamp) so i should be able to get damn close. when i can do a test and send it out to 2 other labs and get same results it will prove valid

then we can test cobs vs quantums vs arctubes vs heatsinks with different colors, etc etc
Click to expand...
 
pop22

pop22

Well-Known Member
I'm not sure why you'd want to use them, other than low cost. Even then the cost of one citi 12 and heatsink with a driver can be had for around $50-$60. Now yes, thats quite a bit more than a bulb but how much more light will you get from the COB? at the same approximate 25 watts, the 1212 is, I guestimate, about 170lm/w..

I've built bulb based light. A waste of time and money in the long run, IMO.

And anyone notice that CFLs are disappearing from store shelves?

frica said:
Could you test a Philips bulb once? Or is it too much a pain in the ass to set up things for just a cheap bulb?
Those Philips 2700K 100W equiv ones you can get from homedepot are supposed to deliver 103 lm/w.

I think that should be about 36-38% efficient.(PPF should be around 22)
But I'm really curious how efficient the light will be once the diffuser/bulb part is cut off.
I think it should be at least 40%, but it could be more.(PPF 24-25.)

But am wondering.

It's impossible to compare the total output the normal way with just a light meter in the growbox because of the diffuser.
But with a sphere it should be relatively trivial.


A bulb test could be a really nice thing for the microgrow community.
Click to expand...
 
frica

frica

Well-Known Member
pop22 said:
I'm not sure why you'd want to use them, other than low cost. Even then the cost of one citi 12 and heatsink with a driver can be had for around $50-$60. Now yes, thats quite a bit more than a bulb but how much more light will you get from the COB? at the same approximate 25 watts, the 1212 is, I guestimate, about 170lm/w..

I've built bulb based light. A waste of time and money in the long run, IMO.

And anyone notice that CFLs are disappearing from store shelves?
Click to expand...
Lumen/w values are closer than you think.

A 2700K 1212 at 35/36W is "only" 146 lm/w , then there are still driver losses.
So it's closer to 130 lm/w. But should be around 140 lm/w around 25W. (system efficiency)


For me it's most important knowing how much light is gained by removing the diffuser as we have a bit more efficient Philips/Osram bulbs in Europe.
Philips 13W is 115 lm/w here, if the diffuser is 90% efficient, it's around 130 lm/w without bulb.
90% is generous, if it's 85% efficient, then it's 135 lm/w without bulb. That's total system efficiency. With driver losses already factored in.

Also assuming Philips isn't lying.

Anyway those bulbs have an easy time going beyond 1g/w.
Price difference is huge, and it's just for small scale grows obviously.
 
CobKits

CobKits

Well-Known Member
frica said:
Could you test a Philips bulb once? Or is it too much a pain in the ass to set up things for just a cheap bulb?
Those Philips 2700K 100W equiv ones you can get from homedepot are supposed to deliver 103 lm/w.
Click to expand...
ive got a bunch of those from last year and yeah they should fit in the sphere. these use all different kinds of midpower diodes ill bet a lot exceed the published specs (EPA minimums) if you want me to test a particular model send it over (pm me)
 
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