New USB PAR sensor from Apogee

stardustsailor

stardustsailor

Well-Known Member
_MrBelvedere_

_MrBelvedere_

Well-Known Member
stardustsailor said:
Since we're on " tools " ...


NDVI / NRG Plant Health -Photosynthesis Action Camera :
https://www.adafruit.com/products/1722#technical-details-anchor
http://publiclab.org/wiki/near-infrared-camera
http://publiclab.org/wiki/infragram
Thermal Camera for 300 Euros / $ 400 !
http://www.soselectronic.com/?str=1637&article=flir-flir-tg165-for-only-299eur-it-is-a-bargain
http://www.testequipmentdepot.com/flir/thermal-imagers/spot-thermal-cameras/spot-thermal-camera-tg165.htm

Cheers.
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the infragram camera looks really cool, thx
 
dionysus4

dionysus4

Well-Known Member
alesh said:
Yeah and once you have more than one color temp it's about as useful as a $10 luxmeter.
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im super interested to hear you elaborate on that

I was looking on the reef forums where guys were hacking a lux meter by adding filter lenses/better diode etc
i thought this could be a viable option

are you referring to the soft ware not being compatable with the leds?
 
alesh

alesh

Well-Known Member
Since there's a different response for each wavelength, you need to know the SPD of the light you're measuring (or a correction factor derived from SPD) to get meaningful results. And once you're applying a correction factor you can get meaningful results from anything that has at least some response in the desired range. And if don't know the SPD (such as with multiple sources), your results are going to be off anyway.
 
dionysus4

dionysus4

Well-Known Member
alesh said:
Since there's a different response for each wavelength, you need to know the SPD of the light you're measuring (or a correction factor derived from SPD) to get meaningful results. And once you're applying a correction factor you can get meaningful results from anything that has at least some response in the desired range. And if don't know the SPD (such as with multiple sources), your results are going to be off anyway.
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so this is for all par sensors not just this usb sensor kit?

if any one knows the SPD of the cobs it would be you, so I assume we have no practical way of measuring light output from these DIY COB builds?
 
alesh

alesh

Well-Known Member
dionysus4 said:
so this is for all par sensors not just this usb sensor kit?

if any one knows the SPD of the cobs it would be you, so I assume we have no practical way of measuring light output from these DIY COB builds?
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Output - no.
Density at some point - yes, with the limitation described above. No SPD = no correction factor = very large margin of error caused by non linear response of sensors.
 
Greengenes707

Greengenes707

Well-Known Member
alesh said:
Output - no.
Density at some point - yes, with the limitation described above. No SPD = no correction factor = very large margin of error caused by non linear response of sensors.
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Unless your publishing a data sheet...in which a par meter is the wrong tool anyways...Even cheap ass meters are very useful and with in accuracy for all intents and purposes. That lack of response per wavelength is a part of the whole response, and so with "most lights" actually has just very small discrepancies. A pure blue or 680nm diode light could pose issues. But even illumitex was with in margin pre correction factor.

Real world and on paper.
 
alesh

alesh

Well-Known Member
Greengenes707 said:
Unless your publishing a data sheet...in which a par meter is the wrong tool anyways...Even cheap ass meters are very useful and with in accuracy for all intents and purposes. That lack of response per wavelength is a part of the whole response, and so with "most lights" actually has just very small discrepancies. A pure blue or 680nm diode light could pose issues. But even illumitex was with in margin pre correction factor.

Real world and on paper.
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I'm not saying that it's not useful. All I'm saying is that I don't see the $140 (is that right?) difference between Apogee and cheapo luxmeter.

BTW I'm guesstimating 15% error between typical 70CRI 3000K and 90CRI 3000K LED for the Apogee sensor.
 
Greengenes707

Greengenes707

Well-Known Member
Theory is great. Gets us to use things in the real world. Real world applications and implementation are what prove or disprove theory and make a product stay in use.

For some one on a budgetgo for a lux...but better convert it to talk about it in plant terms. But 140$ is nothing truthfully for what we do, maybe the one plant closet grower has an excuse.
 
alesh

alesh

Well-Known Member
Greengenes707 said:
Theory is great. Gets us to use things in the real world. Real world applications and implementation are what prove or disprove theory and make a product stay in use.

For some one on a budgetgo for a lux...but better convert it to talk about it in plant terms. But 140$ is nothing truthfully for what we do, maybe the one plant closet grower has an excuse.
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Well it's quite a lot of money for me. Yeah the dried product I got is worth a lot more in a way...but completely priceless on the other hand as I can't/won't sell it. I am not saying that the sensor is a bad product but it has it's limitations and I, personally, wouldn't buy it.
 
Greengenes707

Greengenes707

Well-Known Member
I feel ya. Opportunity cost of growing is what small time growers still need to think about.
You need weed, and if you're not growing it, someone is and you'll have to get it from them at a cost...opportunity cost.
 
Stephenj37826

Stephenj37826

Well-Known Member
alesh said:
Since there's a different response for each wavelength, you need to know the SPD of the light you're measuring (or a correction factor derived from SPD) to get meaningful results. And once you're applying a correction factor you can get meaningful results from anything that has at least some response in the desired range. And if don't know the SPD (such as with multiple sources), your results are going to be off anyway.
Click to expand...

How hard would doing a correction factor be for all our favorite cobs?
 
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