Reading PAR

[bebecillo]

I've read lots of info talking about par but can't find any details other than conversion factors and technical jargon. My 80W LED reports 10.000 lux and now that i put my plant closer it reports about 30k, altough it oscillates, probably due to electrical noise and led refresh rate.

(Feel free to drop on my grow, link's at my signature)

Anyway, I'm getting my light meassurements using a xiaomi flora and cannabis is hidden under another name so I don't think it's safe to trust its safety zone (specially since lots of you have multiple 600w leds), but the daily report gives me a mmol reading (umol) and that should translate to par, right

Anyway. My point is i need help translating the device readings and guesstimate the conversion factor considering this is calibrated for sunlight and not led light. Can anyone help me please?

Some links I used

Conversion - PPFD to Lux

 

[Scientific]

I would imagine that that Xiaomi Flora is calibrated for white light (their info says "sunlight") and it is thus worthless for blurple LED light.

 

[bebecillo]

I know, but assuming it read 1600 mmol and it's calibrated to sunlight that would be about 86.000 lux which is close to full daylight. I doubt my 90W LED can give such great output 10-15cm away from the light, altough the xiaomi flora reports 38.000 lux most of the time. Maybe someone measured his/her LED lights to have an idea?

 

[NaturalSpirit]

I've read lots of info talking about par but can't find any details other than conversion factors and technical jargon. My 80W LED reports 10.000 lux and now that i put my plant closer it reports about 30k, altough it oscillates, probably due to electrical noise and led refresh rate.

(Feel free to drop on my grow, link's at my signature)

Anyway, I'm getting my light meassurements using a xiaomi flora and cannabis is hidden under another name so I don't think it's safe to trust its safety zone (specially since lots of you have multiple 600w leds), but the daily report gives me a mmol reading (umol) and that should translate to par, right

Anyway. My point is i need help translating the device readings and guesstimate the conversion factor considering this is calibrated for sunlight and not led light. Can anyone help me please?

Some links I used

Conversion - PPFD to Lux

This is interesting stuff! I am quite new to This so Subbed for Sure! If you like to hand out Some tips on my journal... link is in the bio..

What doet of app do you use? It looks great!

 

[Scientific]

assuming it read 1600 mmol and it's calibrated to sunlight that would be about 86.000 lux

Sorry, but no, I really think that the readings you are getting are just worthless. Your device is just not set up to deal with LED light.

 

[CrazyDutch]

Hi peeps I will post here my reading's and yes you can use the sensor of your smartphone ( light sensor) to measure lx lm and Kelvin , who can afford it can buy better stuff but those who have just a smartphone you still can measure stuff and with help from apps or sites you can get almost all numbers from your grow

 

[Scientific]

you can use the sensor of your smartphone ( light sensor) to measure lx lm and Kelvin

You can use your phone to measure white light. Measurements of blurple LED light will be meaningless.

 

[Scientific]

those who have just a smartphone you still can measure stuff and with help from apps or sites you can get almost all numbers from your grow

Here are side-by-side measurements with a dedicated lux meter and a smart phone app. You can see that they differ by over 3X. Which are your going to trust?

The lux meter has the advantage of having an integrating dome (the white hemisphere) to average the light levels for more accurate readings, and it is of course designed and calibrated just for measuring light (but not blurple LED light--it's useless for that).

7,000 lux? Or 24,000 lux?

 

[CrazyDutch]

I don't use only apps for measuring, I'm not lazy and calculate also myself or use other methods

 

[CrazyDutch]

Here are side-by-side measurements with a dedicated lux meter and a smart phone app. You can see that they differ by over 3X. Which are your going to trust?

The lux meter has the advantage of having an integrating dome (the white hemisphere) to average the light levels for more accurate readings, and it is of course designed and calibrated just for measuring light (but not blurple LED light--it's useless for that).

7,000 lux? Or 24,000 lux?

and look at that years ago taken picture, I believe the sensors on mobiles changed with years plus that's a Apple without a sensor measuring with camera instead

 

[CrazyDutch]

and I didn't say at the beginning that a sensor from mobile is better, I was writing if you can't afford one use mobile

 

[Scientific]

and I didn't say at the beginning that a sensor from mobile is better, I was writing if you can't afford one use mobile

Understood, but I'm saying that it looks as if the results from the phone app are not worth much...

 

[Scientific]

I don't use only apps for measuring, I'm not lazy and calculate also myself or use other methods

Very impressive calculations, but you do have to measure something eventually, do you not?

For all the effort and money we put into our grows, spending $20 on a lux meter seems like a small expenditure.

 

[CrazyDutch]

I know for most that's small money but for me 1 week food and on the light bulbs or specs you can find numbers for using in your calculations

 

[CrazyDutch]

I use those apps more to look if I have a bit even lit canopy because I have to use different light bulbs

 

[CrazyDutch]

and another thing is that the plants themselves say more than any technic can say as long as you can understand them a bit

 

[Scientific]

and another thing is that the plants themselves say more than any technic can say as long as you can understand them a bit

Yes, along with all the science and engineering it's important to just carefully observe the plants and learn how they are growing and how they respond. No argument there!

 

[Stillalive420]

I don't use meters or smartphones, I use dyna gro protekt and I set the king plus 1000 watt 10 inches above the tops of my plants, and 1 300watt led on the left side and 1 300watt led on the right side, I think your safe with that 85 watts lol

 

[Scientific]

I don't use meters or smartphones, I use dyna gro protekt and I set the king plus 1000 watt 10 inches above the tops of my plants, and 1 300watt led on the left side and 1 300watt led on the right side, I think your safe with that 85 watts lol

And what, pray tell, is "dyna gro protekt"?

 

[Stillalive420]

It's a silica supplement, also fights heat stress, pathogens few other things, point being I don't worry about led burning my plants.