Lux meter reads sun at 130k lux midday. Is it broken?

[kreikrei]

Hey guys.
Just for "fun" wanted too see how bright is the sun, so midday I took my cheap lux meter ( uni-t ut383 - abut 25 usd) to my balcony to check it.

It showed 130k lux, but google says sun maxes out at 100k.

I am assuming my meter is broken or there is something I am missing?

Thanks

 

[HydroKid239]

Check the bottom of the sun.. see if it says “Made in China”

 

[hotrodharley]

Hey guys.
Just for "fun" wanted too see how bright is the sun, so midday I took my cheap lux meter ( uni-t ut383 - abut 25 usd) to my balcony to check it.

It showed 130k lux, but google says sun maxes out at 100k.

I am assuming my meter is broken or there is something I am missing?

Thanks

Well it’s definitely questionable. At best. What type grow light would you be using this on?

 

[kreikrei]

Well it’s definitely questionable. At best. What type grow light would you be using this on?

mars hydro ts 1000, and kingbrite 240with cree leds
I know that because of red diodes, the results would be innacurate

But with the help of this - https://www.waveformlighting.com/horticulture/convert-lux-to-ppfd-online-calculator, you can get a more accurate result
My end goal would be a PAR meter, but that is in the future.

Hmmm... I cant think of any other reasn fr the 130k measurmentother than a broken meter.
Sun isnt broken lol

130k should be 100k (midday, no clouds) -I think its a decent calibration method lol

 

[hotrodharley]

mars hydro ts 1000, and kingbrite 240with cree leds
I know that because of red diodes, the results would be innacurate

But with the help of this - https://www.waveformlighting.com/horticulture/convert-lux-to-ppfd-online-calculator, you can get a more accurate result
My end goal would be a PAR meter, but that is in the future.

Hmmm... I cant think of any other reasn fr the 130k measurmentother than a broken meter.
Sun isnt broken lol

130k should be 100k (midday, no clouds) -I think its a decent calibration method lol

PAR meter should be now. Speaking from experience. Immediately dial in the proper light level. Immediately. No screwing around. Less than $200 and you’re good to go.

 

[kreikrei]

PAR meter should be now. Speaking from experience. Immediately dial in the proper light level. Immediately. No screwing around. Less than $200 and you’re good to go.

I agree, but I do not have spare 200 usd

I broke my phone a month ago, and couldnt post pics, since I ran into deficiencieson my first grow (started May 1st).
Due to not being able te resolve them, I think my plants will go down sadly and I will start a new round in 3 weeks.

So I need to buy a phone first in order to post pics when I screw up next time

 

[hotrodharley]

I agree, but I do not have spare 200 usd

I broke my phone a month ago, and couldnt post pics, since I ran into deficiencieson my first grow (started May 1st).
Due to not being able te resolve them, I think my plants will go down sadly and I will start a new round in 3 weeks.

So I need to buy a phone first in order to post pics when I screw up next time

Vegging plants don’t need that much light. Start low power. If they start stretching then turn it up. Maybe by flip you can get a meter. I use mine all the time. All the time. The PPFD at any given spot can vary enough that it’s worth arranging plants so everything is getting fairly equal coverage.

I set my stuff up and it doesn’t stretch, bleach or burn.

 

[kreikrei]

Vegging plants don’t need that much light. Start low power. If they start stretching then turn it up. Maybe by flip you can get a meter. I use mine all the time. All the time. The PPFD at any given spot can vary enough that it’s worth arranging plants so everything is getting fairly equal coverage.

I set my stuff up and it doesn’t stretch, bleach or burn.

Weird thing about the start of my first grow was that all 3 of my plants stretched, despite me giving them about 15-20k lux after they popped from the ground.

I have read the recomendation is about 5-15k lux, and I thought I was overdoing it, but they still stretched.
Maybe it was the strain (2 sativas), but 1 indica dominant hybrid also stretched, go figure...

 

[Star Dog]

Vegging plants don’t need that much light. Start low power. If they start stretching then turn it up. Maybe by flip you can get a meter. I use mine all the time. All the time. The PPFD at any given spot can vary enough that it’s worth arranging plants so everything is getting fairly equal coverage.

I set my stuff up and it doesn’t stretch, bleach or burn.

Do you alter the intensity throughout flowering?

 

[hotrodharley]

Do you alter the intensity throughout flowering?

Oh yeah. Everything but 100% and only run about 95% in a weak attempt to lengthen service life. I’d run it at 100% if I could afford to replace it easily.

But again it’s important to me to measure so distance is set for max penetration without burn or bleaching.

 

[Lenin1917]

Nowhere does it say the sun maxes out at 100,000 lux. It probably says something like “typical lux” x- 100,000. That at noon (when the sun is at its peak) on an elevated platform(balcony) it measured higher should be of no surprise to anyone.

 

[Star Dog]

Yes the sun's intensity is relevant to the time of day, time of the year and the latitude.

 

[kreikrei]

Nowhere does it say the sun maxes out at 100,000 lux. It probably says something like “typical lux” x- 100,000. That at noon (when the sun is at its peak) on an elevated platform(balcony) it measured higher should be of no surprise to anyone.

Yup, did more reading and you are right.
However, do you think that being on balcony ( a few feet above ground) effects the readings vs ground level? We are talking MASSIVE distances here. What would a few feet change when the light has to travel tens of kilometers through many layers of atmosphere?

I could see how on top if Mount Everest vs ground level could provide a noticeable differenc.

Hey, I am just spitballing here, I am in no way educated about this topic.

 

[Kassiopeija]

Also the amount of reflection od sunlight to the measuring spot