using 1 light meter for 2 different lights

[budsofgeorgia]

what do you guys do if you use a light meter / app and you have 2 different lights that gives a different ppfd readings

 

[LoveGrowingIt]

I'm not sure what you mean. I use a light meter when I move plants so I can set the light in the new tent to about the same level as it was in the old tent. That seems to work okay.

 

[Smokey0418]

what do you guys do if you use a light meter / app and you have 2 different lights that gives a different ppfd readings

Adjust accordingly.

 

[budsofgeorgia]

like i have a viparspectra ks3000 in 1 tent and a spiderfarmer sf4000 in another the ppfd is diff for both so how could i use the same meter or same phone app with out changing anything all the time

 

[Mothman]

like i have a viparspectra ks3000 in 1 tent and a spiderfarmer sf4000 in another the ppfd is diff for both so how could i use the same meter or same phone app with out changing anything all the time

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I’m still unsure of the issue. I use handheld Photone with paper, checking various points across the canopy. I’ve learned that adding 2.5 to my DLI hand measurement gives me the approx reading I’d get with tent flap closed.

I never measure ppfd any more. DLI gives me what I need from veg thru flower. It should do the same for you regardless of tent size or light, right?

 

[budsofgeorgia]

I’m still unsure of the issue. I use handheld Photone with paper, checking various points across the canopy. I’ve learned that adding 2.5 to my DLI hand measurement gives me the approx reading I’d get with tent flap closed.

I never measure ppfd any more. DLI gives me what I need from veg thru flower. It should do the same for you regardless of tent size or light, right?

saying you had both lights at 12 inches the ks3000 would measure 1000 in the center the sf4000 would be 1821 at center both at 12 inches how could you check that using 1 meter or app

 

[budsofgeorgia]

while writing my previous comment i realized i have the photone app calibrated to the sf4000 so maybe if redownload the app and not have it calibrated to a specific light and just use it with how it set from the factory so to speak it would work for both

 

[Smokey0418]

If one were to have a calibrated guage then what difference would it make putting it under any light.

Put it under the light measure and smoke one.

Enjoy

 

[LoveGrowingIt]

like i have a viparspectra ks3000 in 1 tent and a spiderfarmer sf4000 in another the ppfd is diff for both so how could i use the same meter or same phone app with out changing anything all the time

There are two aspects of testing instruments: validity and reliability. Validity means it is accurate, meaning it has been calibrated against a known-good instrument. Reliability means it measures the same every time it's used, which would mean it doesn't lose its calibration between uses.

So, when measuring two different lights, it would be better to use the same light meter if the meter is reliable AND if the purpose is comparison. So, for example, I don't worry if my light meter is valid when my purpose is to move plants and have them under the same light intensity from one light to the next.

 

[LoveGrowingIt]

Does anyone close the tent when checking the light level? I've noticed the reading is quite different when the door is open versus closed.