UV Suppliment Lighting
- Thread starter DrGreenT420
- Start date
SSGrower
Well-Known Member
Got something against a vacation in CO?
Or_Gro
Well-Known Member
Lol, I don’t need to go on vacation for seeds....they’re expensive enuff over the internet..,,
oldbeancounter
Well-Known Member
ChiefRunningPhist
Well-Known Member
I wish I knew the actual WV range. This excerpt is from the .pdf @Randomblame posted.
12hrs = 43,200 seconds
1kJ = 1000J
Watts = J/s
Total daily dose of 13.4kJ/m2
13,400J ÷ 43,200s
=
0.31J/s per m2;
Or...
0.31W/m2
310mW/m2
31μW/cm2
28.8mW/ft2
Total daily dose of 6.7kJ/m2
6,700J ÷ 43,200s
=
0.155J/s per m2;
Or...
0.155W/m2
155mW/m2
15.5μW/cm2
14.4mW/ft2
If you plan on running UVB for less than 12hrs per day, then your intensity or wattage will increase else the total daily dosage won't be satisfied.
12hrs = 43,200 seconds
1kJ = 1000J
Watts = J/s
Total daily dose of 13.4kJ/m2
13,400J ÷ 43,200s
=
0.31J/s per m2;
Or...
0.31W/m2
310mW/m2
31μW/cm2
28.8mW/ft2
Total daily dose of 6.7kJ/m2
6,700J ÷ 43,200s
=
0.155J/s per m2;
Or...
0.155W/m2
155mW/m2
15.5μW/cm2
14.4mW/ft2
If you plan on running UVB for less than 12hrs per day, then your intensity or wattage will increase else the total daily dosage won't be satisfied.
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Or_Gro
Well-Known Member
I didn’t check your nums...i ran mine for 6 hrs/day for the 13.4 num highlighted in blue...@80uW/cm sq, 22” above tops w 2x54w 4’ t-5 arcadia 14%uvb
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ChiefRunningPhist
Well-Known Member
Haha well we can check numbers a quick way.
According to the math, taking 6hrs to dose 13.4kJ/m2 should be 2× the intensity of emitting 13.4kJ/m2 over a 12hr duration.
12hrs = 31μW/cm2
6hrs = 62μW/cm2
Was 62μW/cm2 close to what you were measuring?
EDIT:
I see where you detailed. Unless I've made some math error, looks like you were closer to 17.2kJ/m2 total daily doseage (~28% more).
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Or_Gro
Well-Known Member
I was measuring closer to 80, but reasonably close @22”
ChiefRunningPhist
Well-Known Member
UV index takes the 'SPD curve' (Sunlight spectrum) and multiplies each nm's intensity (*) by the weighted % (*) at each nm of the 'weighted curve' (erythemal curve). The resulting products (*) of the 2 curves' y-axis values (per nm) creates a new curve (Effective spectrum).
Once the effective spectrum curve has been calculated/created you find the total area under the effective spectrum curve and divide by 25mW/m2 for a final UV index calculation.
In the UV index figure, total UVA radiation is weighted <1% of its true value, UVB is weighted >99% of its true value.
UVA will still effect the UV index value due to solar UVA being 500× more prevalent than UVB, but much less so at <1% weight. I think UV index might give us a good idea in terms of UVB intensity for our plants(?).
These are interesting, I might try one...
https://www.ebay.com/p/Smart-UV-Light-Index-Detector-Ultra-Violet-Meter-Tester-for-iPhone-Android-Phone/1851573534?
^^Curious what it'd read at when your other meter was at 80μW/cm2 @Or_Gro
Once the effective spectrum curve has been calculated/created you find the total area under the effective spectrum curve and divide by 25mW/m2 for a final UV index calculation.
In the UV index figure, total UVA radiation is weighted <1% of its true value, UVB is weighted >99% of its true value.
UVA will still effect the UV index value due to solar UVA being 500× more prevalent than UVB, but much less so at <1% weight. I think UV index might give us a good idea in terms of UVB intensity for our plants(?).
These are interesting, I might try one...
https://www.ebay.com/p/Smart-UV-Light-Index-Detector-Ultra-Violet-Meter-Tester-for-iPhone-Android-Phone/1851573534?
^^Curious what it'd read at when your other meter was at 80μW/cm2 @Or_Gro
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Or_Gro
Well-Known Member
Ok dude, i’ll try it...it’s coming by rowboat from China, so don’t hold your breath...start prayin that it at least gives consistent readings, so it can be calibrated to my uvb meter... the lux/ppfd uv analog.
@Randomblame , whaddaya think?
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ChiefRunningPhist
Well-Known Member
ChiefRunningPhist
Well-Known Member
I've been looking at the UV index pretty much all day long lol and I'm actually starting to morph into possibly using 280nm instead of 305nm - 325nm for my UVB WVs. @SSGrower
Example:
250mW/m2 of only 280nm LED.
280nm erythemal weight % = 100%; 1
The < 295nm range has an erythemal weight of 100%, so the area under the SPD curve below 295nm is multipled by 100%, or 1 to subsequently calculate the portion of the UV index coming from emissions 295nm and below.
If there are no other emissions between 280nm - 400nm besides the sole 250mW/m2 of 280nm supplied by the 280nm LED, then the area under the 280nm SPD curve is the one and only portion to create the entire UV index figure from.
(When you multiply anything by 1 you get what you started with, so the area of the 'effective spectrum' curve from 295nm and below is the exact same as the area of the 'SPD curve' when/if it's below 295nm)
(250mW/m2 of 280nm) × (100%)
=
The weighted portion of the UV index from 295nm and below
=
250mW/m2
There are no other emissions (lets assume) to multiply anything by, so emissions 281nm+ = (0mW/m2) × (Y%), and anything multiplied by 0 is 0, so 0mW/m2 + 250mW/m2 = 250mW/m2, which is the same thing as the value of the integration of the effective spectrum curve from 280nm - 400nm (area under). A 25mW/m2 standard is then used to divide the weighted radiation figure to arrive at a final UV index figure.
(250mW/m2) ÷ (25mW/m2)
=
10.0 UV index
What I'm thinking..
1. Get UV index meter
2. Tune UV index to "Y" value using 305nm - 325nm WVs
3. Tune UV index to "Y" value using 280nm WVs
4. Tune UV index to "Y" value using 50/50 (280nm)/(305nm - 325nm) WVs
5. Note wattage consumption in 2, 3, & 4
6. Note differences to plants in 2, 3, & 4
Idk how translatable UV index will be when applied to a single WV, I'm guessing less power nessecary, but idk and very curious.
Example:
250mW/m2 of only 280nm LED.
280nm erythemal weight % = 100%; 1
The < 295nm range has an erythemal weight of 100%, so the area under the SPD curve below 295nm is multipled by 100%, or 1 to subsequently calculate the portion of the UV index coming from emissions 295nm and below.
If there are no other emissions between 280nm - 400nm besides the sole 250mW/m2 of 280nm supplied by the 280nm LED, then the area under the 280nm SPD curve is the one and only portion to create the entire UV index figure from.
(When you multiply anything by 1 you get what you started with, so the area of the 'effective spectrum' curve from 295nm and below is the exact same as the area of the 'SPD curve' when/if it's below 295nm)
(250mW/m2 of 280nm) × (100%)
=
The weighted portion of the UV index from 295nm and below
=
250mW/m2
There are no other emissions (lets assume) to multiply anything by, so emissions 281nm+ = (0mW/m2) × (Y%), and anything multiplied by 0 is 0, so 0mW/m2 + 250mW/m2 = 250mW/m2, which is the same thing as the value of the integration of the effective spectrum curve from 280nm - 400nm (area under). A 25mW/m2 standard is then used to divide the weighted radiation figure to arrive at a final UV index figure.
(250mW/m2) ÷ (25mW/m2)
=
10.0 UV index
What I'm thinking..
1. Get UV index meter
2. Tune UV index to "Y" value using 305nm - 325nm WVs
3. Tune UV index to "Y" value using 280nm WVs
4. Tune UV index to "Y" value using 50/50 (280nm)/(305nm - 325nm) WVs
5. Note wattage consumption in 2, 3, & 4
6. Note differences to plants in 2, 3, & 4
Idk how translatable UV index will be when applied to a single WV, I'm guessing less power nessecary, but idk and very curious.
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oldbeancounter
Well-Known Member
oddly enough I am getting 10,000 lux
ya that is sign for me not to buy when it starts out misleading like that.
oldbeancounter
Well-Known Member
good find
there are lots of them for sale so there must be some validity to the product ...well I hope anyways,
going to wait and see if it works first for you.
Randomblame
Well-Known Member
Nice little device and it's measuring range(240-380nm) is wide enough. If the software weights the wavelengths in the way the chief has explained it (and I believe him) UV index measuring devices can also be used.
Just multiply the readings by factor 25 and you should have numbers in μW/cm². 5 hours á 75μW/cm² means 375μW/cm² per day and would lead to a daily dose of 13,5kJ/m²(x 0,036) and it means an UV index of 3.0 for 5 hours.
2,5h with UV-index 6.0 or 150μW/cm² would be the same dose...
But 285nm has the strongest effect on the UVR8 receptor and the effect is around 10 times stronger like 295-300nm. When there is typically no UVB below 295nm in sunlight and a plant in 3000m height in columbia usually gets 13,4kj/m² per day from natural sunlight it suggest you only need a 1/10 of that when you use 285nm directly.
280nm would also trigger the UVR8 receptor but probably less effective like 285nm and the light would have probably a more damaging effect too cuz 280nm diodes emit UVC too.
As long as we have no 285nm diodes I would rather go with 290nm than 280. Both are only 5nm away but 290nm would have almost no UVC.
RM3
Well-Known Member
Like every other led made it is equivalent
the 9 watt led in my bathroom is equivalent to 60 watts